Patent Publication Number: US-2019167467-A1

Title: Methods and apparatuses for performing remote titration of mandibular protrusion

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 14/407,194, filed on Dec. 11, 2014, which is a national stage application filed under 35 U.S.C. § 371 of PCT/US2013/045644, filed on Jun. 13, 2013, which claims the benefit of U.S. Provisional Patent Application No. 61/659,231, filed on Jun. 13, 2012, titled “Methods and Apparatuses for Performing Remote Titration of Mandibular Protrusion,” the disclosures of which are expressly incorporated herein by reference in their entireties. 
    
    
     BACKGROUND 
     Obstructive sleep apnea (OSA) is a common disease that carries significant risks for cardiovascular disease, mortality, and economic costs. Almost thirty years ago, initial population studies found the prevalence of OSA to be five to nine percent of the adult population. Excess body weight is a risk factor for the development of OSA, and the recent rise in prevalence of obesity has led to revised estimates of OSA prevalence, now at seventeen percent of the adult population. OSA is poorly recognized clinically; currently 85% of apneics remain undiagnosed and untreated. 
     OSA derives fundamentally from structural abnormalities of the pharynx that cause pharyngeal narrowing or closure during sleep and produce recurrent apneas and hyponeas. During wakefulness, compensatory neuro-muscular reflexes protect the pharynx from collapse. These reflexes are lost during sleep, leaving the collapsible human pharynx susceptible to narrowing or closure. Nasal continuous positive airway pressure (CPAP), comprised of an air generator and nose mask, is the standard therapy for OSA. CPAP delivers positive pressure to the pharyngeal lumen, thereby dilating it and eliminating obstruction. While CPAP therapy is highly efficacious, it is cumbersome and its effectiveness is compromised by a relatively low adherence rate. Adherence depends on the methods used to initiate therapy and on the severity of OSA, being higher in subjects with more severe hypoxemia and excessive daytime sleepiness. In current practice, CPAP therapy adherence rate appears to approximate fifty percent. 
     The only currently available alternative to CPAP is oral appliance (OA) therapy. Oral appliances maintain patency of the airway during sleep by stabilizing and protruding the mandible and/or the tongue. The most commonly used type of OA is a custom-made mandibular repositioner (MR) which protrudes the mandible. Mandibular protrusion in paralyzed subjects dilates both the velopharynx and the oropharynx. In clinical practice, a specialist dentist fabricates a custom-fitted OA covering upper and lower teeth. The appliance is then empirically adjusted to progressively protrude the mandible until a therapeutic end-point is reached. MR therapy is better accepted by the OSA subject than nasal CPAP therapy, and self-reported adherence rates are high. Unfortunately, MR therapy is not uniformly effective in OSA. Reported effectiveness ranges from 50 to 65 percent, and a recent study found 50 percent success rate. 
     Because of the uncertainties regarding use of MR therapy for treating OSA, current practices focus primarily on the use of nasal CPAP therapy. Virtually all subjects found to have OSA receive a trial of nasal CPAP. If the subjects prove non-adherent with CPAP therapy, the subjects may then be offered MR therapy. The American Academy of Sleep Medicine recommends MR therapy as a CPAP therapy alternative in subjects with OSA of mild to moderate severity. However, lacking a valid test for clinically selecting subjects with OSA who will have a favorable response to MR therapy, reimbursement for MR therapy is usually provided only for apneics who fail CPAP therapy. 
     SUMMARY 
     Methods and apparatus for performing system validation and providing predictive criteria during remote titration of mandibular protrusion are disclosed herein. The effectiveness of MR therapy can possibly be improved by screening OSA subjects to prospectively identify those suitable for MR therapy and providing a target therapeutic protrusive distance. Development of a set of criteria that can be consistently applied and that require the minimum amount of data can possibly increase the effectiveness and efficiencies of the test. Moreover, even if a subject were known to be a favorable candidate, the dentist currently has no way to determine the target therapeutic protrusive position. Studies of the passive pharynx indicate that the response of the pharynx to mandibular protrusion is ‘dose dependent.’ For example, incremental mandibular protrusion produces corresponding pharyngeal enlargement. However, clinical experience shows that excessive mandibular protrusion is undesirable, producing side effects, such as, pain and tooth movement that lead to discontinuation of therapy. Current practice is for the dentist to progressively protrude the mandible until a symptomatic response occurs, and then reassess the subject to determine if OSA has resolved. Thus, prospective identification of suitable candidates and target protrusive positions would facilitate treatment of OSA with MR therapy. Additionally, in contrast to titration systems that are manually adjusted (i.e., where the scale can be read directly from the titration device), an unattended titration (i.e., remote titration systems) requires that a control system is accurately reading the physical position of the device. Thus, methods for validating operation of the titration system are disclosed herein. 
     A device that can be used to identify favorable candidates for MR therapy and predict the therapeutic protrusive distances is disclosed herein. The device, called a remotely controlled mandibular protruder (RCMP), includes upper and lower dental trays which are inserted into the mouth and connected to a small extra-oral motor which moves the mandibular tray relative to the maxillary tray and, thereby, protrudes the mandible. This device is also discussed in detail in U.S. Patent Application Pub. No. 2010/0316973, titled “APPARATUSES AND METHODS FOR MANDIBULAR PROTRUSION,” to Remmers et al., filed Jun. 4, 2010, which is incorporated herein in its entirety by reference. The device is applied during polysomnography, where sleep and cardio-respiratory variables are continuously recorded while the subject sleeps overnight in a sleep laboratory, and the position is controlled remotely by a sleep technologist in an adjacent room. The protrusive distance applied to the teeth are displayed on the polysomnographic monitor and the technologist moves the mandible, step-wise, while monitoring the changes in cardio-respiratory variables. The goal of the test is to determine: (1) whether or not mandibular protrusion reduces evidence of pharyngeal obstruction, and (2) the minimum protrusive distance required to eliminate obstruction. 
     An example method for identifying a candidate for oral appliance therapy can include: receiving data from a patient while the patient was sleeping with a dental appliance; identifying at least a portion of the data associated with a period of REM sleep; identifying a number of respiratory disturbances in the portion of the data associated with the period of REM sleep; and determining whether the patient is a favorable candidate for oral appliance therapy based on the number of respiratory disturbances in the portion of the data associated with the period of REM sleep. The patient data can be associated with one or more periods of rapid eye movement (REM) sleep and non-REM sleep. Optionally, the method can prioritize the use of data collected during REM sleep stages over data collected during one or more non-REM sleep stages, for example, by using only patient data collected during REM sleep stages. The patient data can be collected from a polysomnography equipment, portable sleep recorders (either Level II or III) or another method of collecting physiololgic data while the patient is sleeping. 
     Optionally, a frequency of respiratory disturbances in the portion of the data associated with the period of REM sleep can be less than or equal to a fixed frequency. For example, the fixed frequency can be 1 respiratory disturbance per 5 minute period. Additionally, the patient can be considered a favorable candidate for oral appliance therapy when the frequency of respiratory disturbances in the portion of the data associated with the period of REM sleep is less than or equal to the fixed frequency. 
     In some implementations, the period of REM sleep can be equal to or greater than 5 minutes. In addition, the period of REM sleep can include a continuous, uninterrupted period of REM sleep. Alternatively, the period of REM sleep can include a plurality of fragmented periods of REM sleep. 
     In another implementation, the data can also be associated with one or more periods of sleep in a supine position and a lateral position. The method can further include: identifying a portion of data associated with a period of REM sleep in the supine position; identifying a number of respiratory disturbances in the portion of the data associated with the period of REM sleep in the supine position; and determining whether the patient is a favorable candidate for oral appliance therapy based on the number of respiratory disturbances in the portion of the data associated with the period of REM sleep in the supine position. 
     Similarly to above, a frequency of respiratory disturbances in the portion of the data associated with the period of REM sleep in the supine position can be less than or equal to a fixed frequency. For example, the fixed frequency can be 1 respiratory disturbance per 5 minute period. Additionally, the patient can be considered a favorable candidate for oral appliance therapy when the frequency of respiratory disturbances in the portion of the data associated with the period of REM sleep in the supine position is less than or equal to the fixed frequency. 
     In some implementations, the period of REM sleep in the supine position can be equal to or greater than 5 minutes. In addition, the period of REM sleep in the supine position can include a continuous, uninterrupted period of REM sleep. Alternatively, the period of REM sleep in the supine position can include a plurality of fragmented periods of REM sleep. 
     In another implementation, the period of REM sleep in the supine position can be less than 5 minutes. In this implementation, the method can further include: identifying a portion of data associated with a period of REM sleep in the lateral position; identifying a number of respiratory disturbances in the portion of the data associated with the period of REM sleep in the lateral position; and determining whether the patient is a favorable candidate for oral appliance therapy based on the number of respiratory disturbances in the portion of the data associated with the period of REM sleep in the lateral position. 
     Similarly to above, a frequency of respiratory disturbances in the portion of the data associated with the period of REM sleep in the lateral position can be less than or equal to a fixed frequency. For example, the fixed frequency can be 1 respiratory disturbance per 5 minute period. Additionally, the patient can be considered a favorable candidate for oral appliance therapy when the frequency of respiratory disturbances in the portion of the data associated with the period of REM sleep in the lateral position is less than or equal to the fixed frequency. 
     In some implementations, the period of REM sleep in the lateral position can be equal to or greater than 5 minutes. In addition, the period of REM sleep in the lateral position can include a continuous, uninterrupted period of REM sleep. Alternatively, the period of REM sleep in the lateral position can include a plurality of fragmented periods of REM sleep. 
     In yet another implementation, the period of REM sleep in the lateral position can be less than 5 minutes. In this case, the method can further include determining that the data is inconclusive. 
     In some implementations, the dental appliance can be a remote-control mandibular protruder, and the data can be collected during an oral appliance titration study of the patient while the patient was sleeping with the remote-control mandibular protruder. 
     Optionally, the period of REM sleep in the supine position (or alternatively the lateral position) can be greater than or equal to 5 minutes and a frequency of respiratory disturbances in the portion of the data associated with the period of REM sleep in the supine position (or alternatively the lateral position) can be greater than a fixed frequency. In this implementation, the method can further include: identifying whether the data includes data collected for a predetermined titration range; and in the event that the data includes data collected during the predetermined titration range, determining that the patient is not a favorable candidate for oral appliance therapy. Optionally, the predetermined range can include a maximum protrusion of the remote-control mandibular protruder or other titration appliance. Optionally, the maximum protrusion can be approximately the maximum protrusion of the remote-controlled mandibular protruder, for example, within 1 mm of the maximum protrusion or within a certain percentage of the maximum protrusion (e.g., 10% of the protrusive range). Alternatively, the predetermined range can include the range provided by a dentist, the maximum voluntary protrusion of the patient, or some other maximum protrusion range. 
     Alternatively or additionally, the method can further include, in the event that the data does not include data collected during the predetermined titration range, determining that the data is inconclusive. 
     In another implementation, a method for identifying a patient having mild to moderate sleep apnea as a candidate for oral appliance therapy can include: receiving data from a patient while the patient was sleeping with a dental appliance; identifying at least a portion of the data associated with a period of REM sleep in the supine position or the lateral position; identifying a number of respiratory disturbances in the portion of the data associated with the period of REM sleep in the supine position or the lateral position; and determining whether the patient is a favorable candidate for oral appliance therapy based on the number of respiratory disturbances in the portion of the data associated with the period of REM sleep in the supine position or the lateral position. Additionally, the data can be associated with one or more periods of rapid eye movement (REM) sleep and non-REM sleep and one or more periods of sleep in a supine position or a lateral position. Optionally, a patient with mild to moderate sleep apnea has a respiratory disturbance index (RDI) less than 30. 
     Similarly to above, a frequency of respiratory disturbances in the portion of the data associated with the period of REM sleep in the supine position or the lateral position can be less than or equal to a fixed frequency. For example, the fixed frequency can be 1 respiratory disturbance per 5 minute period. Additionally, the patient can be considered a favorable candidate for oral appliance therapy when the frequency of respiratory disturbances in the portion of the data associated with the period of REM sleep in the supine position or the lateral position is less than or equal to the fixed frequency. 
     In some implementations, the period of REM sleep in the supine position or the lateral position can be equal to or greater than 5 minutes. In addition, the period of REM sleep in the supine position or the lateral position can include a continuous, uninterrupted period of REM sleep. Alternatively, the period of REM sleep in the supine position or the lateral position can include a plurality of fragmented periods of REM sleep. 
     In yet another implementation, the method can further include determining an effective protrusion distance. For example, the effective protrusion distance can be a minimum protrusion distance corresponding to a portion of data associated with a period of REM sleep in the supine position and/or the lateral position, where the frequency of respiratory disturbances in the portion of the data is less than or equal to the fixed frequency. 
     A method for displaying results of a titration study of an obstructive sleep apnea therapy of a patient according to an implementation can include: receiving data associated with the titration study; and displaying the data for a plurality of steps of the titration study such that an amount of mandibular protrusion is displayed in relation to at least one of a sleep stage, a count of respiratory events, a sleep position and an oximetry level at each step of the titration study. The data can include at least two of sleep stages, counts of respiratory events, sleep positions, oximetry levels and amounts of mandibular protrusion. 
     Optionally, the sleep stages can include rapid eye movement (REM) and one or more stages of non-REM sleep. In this implementation, the method can further include displaying only portions of the data associated with the REM sleep for a plurality of steps of the titration study such that an amount of mandibular protrusion is displayed in relation to at least one of a sleep stage, a count of respiratory events, a frequency of respiratory events in REM, a sleep position and an oximetry level at each step of the titration study. 
     Additionally, the method can optionally include displaying a chart, where a plurality of rows or columns are arranged by time at each step of the titration study, and an amount of mandibular protrusion is displayed in a same row or column as at least one of a sleep stage, a count of respiratory events, a sleep position and an oximetry level at each step of the titration study. 
     Alternatively, the method can optionally include displaying a graphical hypnogram, where amounts of mandibular protrusion are displayed in temporal relation to at least one of sleep stages, counts of respiratory events, sleep positions and oximetry levels for each step of the titration study. 
     Optionally, the method can further include highlighting a portion of the chart or the hypnogram including data associated with REM sleep. For example, the portion of the chart or the hypnogram can include a segment of REM sleep exceeding a predetermined period of time and a corresponding count of respiratory events. 
     A method for validating operation of an oral appliance titration system including a mandibular protruder having a drive motor can include: receiving calibration data for the drive motor; commanding the mandibular protruder to a plurality of positions; receiving an actual physical position of the mandibular protruder at each of the plurality of commanded positions; comparing the actual position to an expected position of the mandibular protruder at each of the plurality of commanded positions; and detecting whether the titration system is validly operating based on the comparison. 
     In some implementations, the calibration data can define a response of the drive motor within a predetermined tolerance. For example, the response of the drive motor can be linear. Additionally, the calibration data can be an n-character string defining the linear response of the drive motor. 
     Optionally, the method can include comparing the actual physical position to an expected position of the mandibular protruder by calculating a deviation between the actual physical position and a detected feedback position of the mandibular protruder for each of the plurality of commanded positions. The detected feedback position can be related to the calibration data. Additionally, the method can include determining whether the titration system is operating validly based on the calculated deviation for each of the plurality of commanded positions. 
     In some implementations, the titration system is validly operating when the deviation at each of the plurality of commanded positions is within the predetermined tolerance. For example, the predetermined tolerance can be +/−0.5 mm. 
     Optionally, the actual physical position of the mandibular protruder can be determined using a scale on the mandibular protruder. Additionally, the detected feedback position can be related to a detected voltage and the calibration data. 
     In other implementations, the method can include commanding the mandibular protruder to the plurality of commanded positions by commanding the mandibular protruder to at least three positions. For example, the at least three positions can be a fully retruded position of the mandibular protruder, a fully protruded position of the mandibular protruder and a position between the fully retruded and fully protruded positions. 
     In another implementation, the deviation at one or more of the plurality of commanded positions is not within the predetermined tolerance. In this implementation, the method can include: calculating a suggested adjustment for the mandibular protruder; determining whether the suggested adjustment is within a predetermined range; and in response to determining that the suggested adjustment is within the predetermined range, adjusting an initial position of the mandibular protruder based on the suggested adjustment. 
     Optionally, the suggested adjustment can be an average of the deviations for the plurality of commanded positions. Additionally, the predetermined range can be within +/−2.0 mm. 
     In yet another implementation, the method can include: re-commanding the mandibular protruder to the plurality of commanded positions; receiving an updated actual physical position of the mandibular protruder at each of the plurality of commanded positions; calculating an updated deviation between the updated actual physical position and an updated detected feedback position of the mandibular protruder for each of the plurality of commanded positions; and determining whether the titration system is validly operating based on the calculated updated deviation for each of the plurality of commanded positions. 
     Additionally, the titration system is validly operating when the updated deviation at each of the plurality of commanded positions is within the predetermined tolerance. 
     In some implementations, the method can include, in response to determining that the suggested adjustment is not within the predetermined range, recommending replacing the mandibular protruder. 
     In some implementations, the deviation at one or more of the plurality of commanded positions is not within the predetermined tolerance. In this case, the method can further include: calculating a suggested adjustment for the mandibular protruder; calculating a difference between the deviation at each of the plurality of commanded positions and the suggested adjustment; determining whether the difference is within a drive motor tolerance range; and in response to determining that the difference is not within the drive motor tolerance range, recommending replacing the drive motor. 
     In yet another implementation, the titration system also includes a polysomnogram or other sleep data collection system. Additionally, the method can further include calibrating a channel of the polysomnogram. The method for calibrating the channel of the polysomnogram can include: receiving an upper limit and a lower limit for the mandibular protruder; commanding the mandibular protruder to the upper limit and the lower limit; receiving an actual physical position of the mandibular protruder at each of the upper limit and the lower limit; calculating a deviation between the actual physical position and a detected feedback position of the mandibular protruder for each of the upper limit and the lower limit; and determining whether the channel of the polysomnogram is calibrated based on the calculated deviation for each of the upper limit and the lower limit. 
     Optionally, the channel of the polysomnogram is calibrated when the deviation at each of the upper limit and the lower limit is within the predetermined tolerance. For example, the predetermined tolerance can be +/−0.5 mm. Additionally, the upper limit and the lower limit can be patient-specific limits. In particular, the upper limit and the lower limit can be related to a fully protruded and a fully retruded position of a patient&#39;s jaw. 
     Alternatively or additionally, the method can also include: determining whether the actual physical position of the mandibular protruder is greater than the upper limit or less than the lower limit; and upon determining that the actual physical position of the mandibular protruder is greater than the upper limit or less than the lower limit, providing a warning. 
     It should be understood that the above-described subject matter may also be implemented as a computer-controlled apparatus, a computer process, a computing system, or an article of manufacture, such as a computer-readable storage medium. 
     Other systems, methods, features and/or advantages will be or may become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features and/or advantages be included within this description and be protected by the accompanying claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The components in the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding parts throughout the several views. 
         FIGS. 1A-1C  are side elevation views of one of the present mandibular protruders. In  FIG. 1A , upper and lower dental trays of the protruder are in a fully retracted position, in  FIG. 1B  the upper dental tray is extended and the lower dental tray is in the fully retracted position, and in  FIG. 1C  the upper dental tray is retracted and the lower dental tray is at least partially extended from the retracted position of  FIG. 1A . 
         FIG. 2  is a side elevation view of the mandibular protruder of  FIG. 1A  with the dental trays retracted to the zero point on the scale. 
         FIG. 2A  is a perspective view of a mandibular positioning device suitable for use in the mandibular protruder of  FIG. 1A . 
         FIGS. 3A and 3B  are perspective views of the upper and lower dental trays suitable for use in the mandibular protruder of  FIG. 1A . 
         FIG. 4  is a perspective view of the rail system of the mandibular protruder of  FIG. 1A . 
         FIG. 5  is a further perspective view of the rail system of a mandibular protruder of  FIG. 1A  shown without a portion of the mandibular positioning device. 
         FIGS. 6A and 6B  are partially cutaway, side elevation views of the mandibular protruder of  FIG. 1A  showing the lower dental tray in fully retracted and offset positions, respectively. 
         FIG. 7  is a top plan view of a relative position indicator of the mandibular protruder of  FIG. 1A , that includes a displacement scale. 
         FIG. 8  is a perspective view of another embodiment of a relative position indicator that incorporates a ribbed displacement scale, and that is suitable for use in embodiments of the present mandibular protruders. 
         FIG. 9  is a perspective view of another embodiment of a relative position indicator that incorporates a reference window for a displacement scale, and that is suitable for use in embodiments of the present mandibular protruders. 
         FIG. 10  is a perspective view of one of the present mandibular protruders shown with bite material, shaped to fit a user&#39;s teeth, fitted in the upper and lower dental trays. 
         FIG. 11  is a schematic illustrating an exemplary system for carrying out a sleep titration on a patient with a mandibular protruder. 
         FIG. 12  is a flow diagram of one of the present methods of displacing a patient&#39;s mandible relative to the patient&#39;s maxilla. 
         FIG. 13  depicts an embodiment of the present polymeric bags suitable for use with some embodiments of the present devices. 
         FIGS. 14A-14B  are perspective views of another embodiment of the present mandibular protruders. 
         FIGS. 14C-14D  are enlarged perspective and side views, respectively, of an upper mounting bracket and lower mounting bracket of the protruder of  FIGS. 14A-14B . 
         FIG. 14E  is a top perspective view of the lower mounting bracket of the protruder of  FIGS. 14A-14B . 
         FIG. 14F  is a top perspective view of the upper mounting bracket of the protruder of  FIGS. 14A-14B . 
         FIG. 14G  is a cross-section of a housing of the protruder of  FIGS. 14A-14B . 
         FIG. 14H  is a cross-sectional view of a seal suitable for use in some embodiments of the present mandibular protruders. 
         FIGS. 15A-15D  are various views of an adjustment-mechanism connector or rod suitable for use in embodiments of the present protruders. 
         FIGS. 16A-16B  are cutaway-perspective and side cross-sectional views, respectively, of another embodiment of the present positioning devices. 
         FIG. 16C  is a cross-sectional view of a portion of a housing of the positioning device of  FIGS. 16A-16B . 
         FIG. 17A  is a cutaway perspective view of another embodiment of the present positioning devices. 
         FIG. 17B  is a side view of another embodiment of the present protruders that includes the positioning device of  FIG. 17A . 
         FIGS. 18A-18C  are a flow diagrams of example operations for validating operation of an oral appliance titration system. 
         FIGS. 19A-19C  are flow diagrams of example operations for identifying a patient as a candidate for oral appliance therapy. 
         FIG. 20  is an example chart for displaying results of an obstructive sleep apnea therapy titration study. 
         FIG. 21  is an example hypnogram for displaying results of an obstructive sleep apnea therapy titration study. 
         FIG. 22  is a block diagram of an example computing device. 
     
    
    
     DETAILED DESCRIPTION 
     Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present disclosure. While implementations will be described for performing system validation and providing predictive criteria during remote titration of mandibular protrusion, it will become evident to those skilled in the art that the implementations are not limited thereto, but are applicable for performing system validation and/or providing predictive criteria during other types of obstructive sleep apnea therapy studies. Other types of obstructive sleep apnea therapy include, but are not limited to, PAP therapy, vacuum therapy, nasal vents (nasal EPAP), nasal valve dilation, etc. 
     The term “coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically; two items that are “coupled” may be integral with each other. The terms “a” and “an” are defined as one or more unless this disclosure explicitly requires otherwise. The terms “substantially,” “approximately,” and “about” are defined as largely but not necessarily wholly what is specified, as understood by a person of ordinary skill in the art. 
     The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a method that “comprises,” “has,” “includes” or “contains” one or more steps possesses those one or more steps, but is not limited to possessing only those one or more steps. For example, in a method that comprises adjusting the initial relative position of a lower dental appliance and an upper dental appliance, and relatively displacing the lower dental appliance and the upper dental appliance: the method includes the specified steps but is not limited to having only those steps. For example, such a method could also include determining an optimal mandibular displacement for a patient. Likewise, an apparatus that “comprises,” “has,” “includes” or “contains” one or more elements possesses those one or more elements, but is not limited to possessing only those elements. For example, in a mandibular protruder that comprises an upper dental appliance and a lower dental appliance, the mandibular protruder includes the specified elements but is not limited to having only those elements (e.g., such a protruder could also have a drive motor). 
     Further, a device or structure that is configured in a certain way is configured in at least that way, but it can also be configured in other ways than those specifically described. 
     Referring to  FIGS. 1-6B and 7 , one embodiment is shown of the present mandibular protruders  10  that comprises an upper mounting bracket  12 , and a lower mounting bracket  14 . Upper mounting bracket  12  may incorporate an upper dental appliance  18 , and lower mounting bracket  12  may incorporate a lower dental appliance  20 . For example, in the embodiment shown upper mounting bracket  12  has an upper dental appliance  18  that includes a dental tray, and lower mounting bracket  14  has a lower dental appliance  20  that includes a lower dental tray. In the embodiment shown, upper mounting bracket  12  includes an elongated planar portion that extends from a first end coupled to upper dental appliance  18  to a second end that is configured to be coupled to (and is shown coupled) to device  19  (e.g., via connector  46 ); and lower mounting bracket  14  has an elongated planar portion that extends from a first end coupled to lower dental appliance  20  to a second end that is configured to be coupled to (and is shown coupled) to device  19  (e.g., via connector  50 ). 
     As shown, for example, in  FIGS. 3A-3B , lower mounting bracket  14  may be secured to upper mounting bracket  12  by a connection system that allows at least relative motion of lower mounting bracket  14  and upper mounting bracket  12  in an anterior-posterior direction  27 . Anterior-posterior direction generally refers to the direction that extends between a user&#39;s anterior (e.g., chin) and a user&#39;s posterior (e.g., spine). In some embodiments, lower mounting bracket  14  may be connected to upper mounting bracket  12  for relative linear movement. For example, brackets  12  and  14  may be secured and/or coupled to one another by a connection system  22 , (e.g., in the embodiment shown, a rail system  22 ) that is configured to couple upper mounting bracket  12  to lower mounting bracket  14 . In some embodiments, rail system  22  is configured to couple upper mounting bracket  12  to lower mounting bracket  14  such that relative motion of lower mounting bracket  14  and upper mounting bracket  12  is substantially prevented in a lateral direction (e.g., by sides  24  and  26 ). In the embodiment shown, rail system  22  is configured to constrain relative motion of lower mounting bracket  14  and upper mounting bracket  12  to linear motion in the anterior-posterior direction (indicated by arrows  27  in  FIG. 1A ). For example, in the embodiment shown, protruder  10  comprises a rail system  22  that is configured to couple upper mounting bracket  12  to lower mounting bracket  14  such that relative motion of the lower mounting bracket and the upper mounting bracket is constrained to linear motion in anterior-posterior direction  27 . 
     In the embodiment shown, rail system  22  comprises portions of one or both of upper and lower mounting brackets  12  and  14 , respectively, and/or may otherwise be configured act as a slide guidance mechanism (e.g., to allows accurate anterior/posterior (A-P) positioning of the upper dental appliance  18  with respect to the lower dental appliance  20 ). In the embodiment shown, rail system  22  is configured such that if upper mounting bracket  12  is coupled to lower mounting bracket  14 , relative motion of upper mounting bracket  12  and lower mounting bracket  14  is constrained to linear motion in the A-P direction (e.g., such that rail system  22  prevents vertical and lateral relative movement of the mounts  12  and  14  and thereby appliances  18  and  20 ). In some embodiments, rail system  22  can be configured to provide or permit telescopic movement. Rail system  22  may comprise a portion of one of lower mounting bracket  14  and the upper mounting bracket  12  configured to wrap and/or wrapping at least partially around a portion of the other of lower mounting bracket  14  and upper mounting bracket  12  if upper mounting bracket  12  is coupled to lower mounting bracket  14 , as shown in  FIGS. 3A-3B . For example, in the embodiment shown, a portion of lower mounting bracket  14  is configured to wrap around a portion of upper mounting bracket  12  (e.g., such that the portion of lower mounting bracket  14  that is configured to wrap around the portion of upper mounting bracket  12  is coupled in fixed relation to lower mounting bracket  14 , and is configured to slidably engage upper mounting bracket  14 ). 
     For example, in the embodiment shown in  FIGS. 3A and 3B , lower mounting bracket  14  includes wrap-around edges  24  and  26  along a subsection of the length of lower mounting bracket  14  that are configured to wrap around upper mounting bracket  12  such that upper mounting bracket  12  can slide relative to lower mounting bracket  14  between edges  24  and  26 , if lower mounting bracket  14  is coupled to upper mounting bracket  12 . For example, in the embodiment shown, edges  24  and  26  are configured to provide a channel in which upper mounting bracket  12  can slide relative to lower mounting bracket  14 . Edges  24  and  26  may include and/or be partially defined by guides  23  (e.g., a plurality of guides that extend from sides  24  and  26  over the top of upper mounting bracket  12  when upper and lower mounting brackets  12  and  14  are coupled or assembled), which may, for example, be extensions of the respective bracket  12  or  14 . In the embodiment shown, a plurality of guides  23  extend from each of sides  24  and  26 . For example, at least two guides  23  on at least one of (e.g., both of) sides  24  and  26  are spaced apart to discourage (e.g., independently of a drive motor or adjustment mechanism) vertical rotation of upper mounting bracket  12  relative to lower mounting bracket  14 . Similarly, sides  24  and  26  each extends between two spaced-apart points (e.g., has a length) to discourage (e.g., independently of a drive motor or adjustment mechanism) horizontal rotation of upper mounting bracket  12  relative to lower mounting bracket  14 . As illustrated, for example, in FIGS.  1 A,  3 B, and  7 , rail system  22  is configured to act as a captive enclosure that aligns upper and lower mounting brackets  12  and  14  (and thereby dental appliances  18  and  20 ), and prevents relative movement of the brackets in a coronal dimension (indicated by arrows  28  in  FIG. 1A ), and, in the embodiment shown, prevents relative movement of the brackets in a lateral dimension (indicated by arrows  30  in  FIG. 7 ), thereby allowing relative motion of the mounting brackets  12 ,  14  only in the A-P dimension or direction  27 . 
     A-P dimension or direction  27  generally refers to a dimension or direction that extends from the incisors posteriorly in the occlusal plane (e.g., when protruder is coupled to a patient for use, as described below). A-P direction is not absolute, and instead corresponds to the longitudinal axis of upper mounting bracket  12  and/or the longitudinal axis of lower mounting bracket  14  (which are parallel in the embodiment shown). Lateral dimension or direction  30  generally refers to an axis perpendicular (at a right angle to) A-P dimension  27  and that is also in the occlusal plane. The vertical (or Coronal) dimension or direction  28  refers to an axis that is at right angles to the A-P and lateral directions, in the cranial-caudal direction and parallel to the separation between the occlusal planes. (and may be typically conceived of as passing through the incisors). The dimensions or directions  27 ,  28 , and  30  correlate to when mandibular protruder  10  is positioned in a user&#39;s mouth (not shown) and, as noted above, can be related to the longitudinal axes of upper and lower mounting brackets  12  and  14 , respectively, for the embodiment shown of protruder  10 . 
     Rail system  22  may, in some embodiments, be configured to completely restrict lateral motion by reducing the tolerance between brackets  12  and  14  (e.g., configuring brackets  12  and  14  to fit together more or very closely, such as, for example, via rail system  22 ). In other embodiments, rail system  22  can be configured to allow some lateral relative motion of or between upper mounting bracket  12  and lower mounting bracket  14  by increasing the tolerance between brackets  12  and  14  (e.g., configuring brackets  12  and  14  to fit together more or very closely, such as, for example, via rail system  22 ). In some embodiments, increased lateral motion may also be afforded by pairing upper mounting bracket  12  and/or lower mounting bracket  14  (e.g., rail system  22 ) with a connector (not shown) that is configured to permit some rotation around coronal dimension or direction  28 . In the embodiment shown, the upper side of lower mounting bracket  14  faces and the lower side of upper mounting bracket  12  such that that they can slide in relation to each other in the anterior-posterior (A-P) dimension  27 . 
     In some embodiments, at least one of brackets  12  and  14  may be flexible to accommodate assembly of rail system  22 . For example, upper mounting bracket  12  may be configured to be flexible such that upper mounting bracket  12  can be compressed perpendicular to A-P direction  27  to reduce its width in direction  30  such that upper mounting bracket  12  can be placed between sides  24  and  26  of lower mounting bracket  14 , and the compression released such that upper mounting bracket  12  returns to its original shape and extends under guides  23  of lower mounting bracket  14 . Alternatively, upper and lower mounting brackets  12  and  14  can be coupled or assembled by sliding upper mounting bracket  12  from anterior to posterior in A-P direction  27  such that upper mounting bracket  14  extends between sides  24  and  26  and under guides  23 . In some embodiments, increased vertical relative motion can be permitted between upper mounting bracket  12  and lower mounting bracket  14 , such as, for example, by increasing the tolerances therebetween (e.g., between guides  23  and upper mounting bracket  12 ), omitting guides  23  such that the rail system includes sides  24  and  26  to restrict or constrain lateral movement but does not include guides  23  to restrict or constrain vertical relative movement, and/or the like. In some embodiments, the rail system can comprise, for example, a single rail (e.g., a single vertical member similar to side  24  or  26 ) extends from the middle of lower mounting bracket  14 , through a slot in upper mounting bracket  12 , and/or having a guide (e.g.,  23 ) extending laterally to one or both sides of the slot, such that the rail system is configured to constrain lateral and/or vertical relative motion of upper mounting bracket  12  and lower mounting bracket  14 . 
     In some embodiments, protruder  10  comprises a relative position indicator, such as scale  32  and pointer  34 , for indicating (configured to indicate) relative position of upper mounting bracket  12  and lower mounting bracket  14  (and/or lower dental appliance  20  and upper dental appliance  18 ) if lower mounting bracket  14  is coupled to upper mounting bracket  12 . As used in this disclosure, relative motion and relative position of upper mounting bracket  12  (and upper dental appliance  18 ) and lower mounting bracket  14  (and lower dental appliance  20 ) generally refers to motion or position of lower mounting bracket  14  relative to upper mounting bracket  12  (and/or vice versa). In the embodiment shown, at least a portion of the relative position indicator is integral with rail system  22  (e.g., pointers  34  are integral with sides  24  and  26  and configured to function similarly to guides  23 ). More particularly, in the embodiment shown in  FIG. 7 , the relative position indicator comprises: scale  32  coupled to upper mounting bracket; and at least one pointer  34  (e.g., two pointers  34 ) coupled to lower mounting bracket  12 . In this embodiment, the relative position indicator (e.g., pointer  34  and scale  32 ) is configured such that if upper mounting bracket  12  is coupled to lower mounting bracket  14  such that pointer  34  is within a range of scale  32 , pointer  34  will indicate a position of lower dental appliance  14  relative to upper dental appliance  12  (e.g., a relative position therebetween). In some embodiments, scale  32  is integral with upper mounting bracket  12 . In some embodiments, scale  32  comprises a GEORGE GAUGE scale. 
     The relative position indicator may be at least partially formed of parts, such as pointer  34 , of the rail system  22 . The relative position indicator may comprise quantitative elements, such as the markings that make up (are included in) scale  32 . The relative position indicator allows the relative displacement between appliances  18  and  20  to be accurately measured by measuring the relative displacement between upper and lower mounting brackets  12  and  14 . Pointer  34  may be an arrow-shaped guide, as shown in  FIG. 7 . 
     In the embodiment illustrated, mounting brackets  12  and  14  cooperate to display a graduated measuring system, located for example on the struts (elongated portions) of brackets  12  and  14 , that allows a physician or other user to measure the relative position of appliances  18  and  20  (for or unique to a patient) during a fitting or other procedure for the patient. Scale  32  may provide a reference value of retrusion of the lower jaw, for example indicative of a point where the appliances  18  and  20  are positioned with the patient&#39;s upper and lower incisors vertically aligned. Scale  32  may be designed to measure relative movement of the appliances  18  and  20  with respect to each other in the A-P dimension on either side of the reference value. In one embodiment, a protrusive position of the mandible relative to zero corresponds to a positive number and a retrusive position of the mandible relative to zero corresponds to a negative number. The exact location of the reference value for a given patient may, in some embodiments, be experimentally determined, and may or not be indicated by the zero numeral on scale  32 . However, in some embodiments, the zero numeral may be configured to indicate the vertical alignment of appliances  18  and  20  (that appliances  18  and  20  are aligned, as shown in  FIG. 2 ). In other embodiments, scale  32  may vary. For example, the reference position may be indicated by the numeral 10, retrusive values may occupy or be indicated by numerical values in the range 0-10, and protrusive values occupy or be indicated by numerical range 10-20. 
       FIGS. 8 and 9  depict alternate embodiments of relative position indicators. In the embodiment of  FIG. 8 , lower bracket  14  comprises a scale  32  comprising ribbed elements  36 , and upper mounting bracket  12  comprises a pointer  34  defined on a guide  23 . Ribbed elements  36  may allow taking measurements to be more user-friendly, such as when reference pointer  34  is spaced vertically from a scale surface  38 , as shown. For example, in the embodiment shown, ribbed elements  36  extend upward from scale surface  38  such that the tops of ribbed elements  36  are closer to pointers  34 . In this embodiment, scale surface  38  is inserted in between wrap-around edges  39  and  40  of lower mounting bracket  14  and/or between pointer(s)  34  of upper bracket  12 . Scale surface  38  may be elongated and/or flattened to improve visibility. 
     In the embodiment of  FIG. 9 , the relative position indicator comprises: a scale  32  coupled to upper mounting bracket  12 ; and a window  41  extending through lower mounting bracket  14 . More particularly, in this embodiment, upper mounting bracket  12  comprises a reference window  41  for viewing only a portion of a scale  32 . In this embodiment, scale  32  is coupled to (e.g., integral with) an upper surface  42  of lower mounting bracket  14 . In the embodiment shown, the relative position indicator is thus configured such that if upper mounting bracket  12  is coupled to lower mounting bracket  14  such that window  41  is within a range of scale  32  (such that a portion of scale  32  is viewable through window  41 ), scale  32  is viewable through window  41  to indicate a position of lower dental appliance  14  relative to upper dental appliance  12 . In the embodiment shown, the relative position indicator further comprises a reference pointer  34  that is illustrated by markings  44  and/or includes slits  44  on one or both sides of window  41  such that if scale  32  is viewable through window  41 , pointer  34  will indicate a position of lower dental appliance  20  relative to upper dental appliance  18 . In other embodiments, pointer  34  may also or alternatively be digital, such as, for example a sensor and readout, a barcode reader-type electronic detection device. Other embodiments of reference pointer  34  may include a physical indicator that extends from rail (side  24  or edge surface  39 ) to rail (side  26  or edge surface  40 ) as a bar, or a pointer that comes up from the lower appliance  20  through a slot in the upper appliance  18 . 
     Referring again to  FIGS. 1-7 , in the embodiment shown, protruder  10  comprises a drive motor  16  configured to effect or for effecting relative displacement of lower mounting bracket  14  and upper mounting bracket  12 . More than one motor  16  may be used to effect such displacement. For example, in some embodiments (not shown), the present mandibular protruders can comprises a separate motor for each of brackets  12  and  14 . In the embodiment shown, motor  16  comprises a linear actuator  17  configured to effect relative displacement of lower mounting bracket  14  and upper mounting bracket  12 . In some embodiments, motor  16  is coupled more directly to one of upper mounting bracket  12  and lower mounting bracket  14  than to the other of upper mounting bracket  12  and lower mounting bracket  14 . For example, in the embodiment shown, motor  16  is coupled more directly to upper mounting bracket  12  than the lower mounting bracket  14  (e.g., as a result of motor  16  being actuated, upper mounting bracket  12  and upper dental appliance  18  move relative to motor  16 , while lower dental appliance  20  and lower mounting bracket  14  are not moved relative to motor  16 ). In other embodiments, motor  16  can be coupled more directly to lower mounting bracket  14 . 
     In some embodiments motor  16  can be coupled to one of brackets  12  and  14  by a connector (or shaft or rod)  46 , such as an actuator arm or rod of motor  16 . The other of brackets  12  and  14  may be coupled or mounted directly or indirectly to motor  16  (e.g., to the body of motor  16  instead of linearly actuated connector  46 ), such that if the more-directly coupled bracket  12  or  14  is extended or retracted by motor  16 , relative displacement is effected between appliances  18  and  20 . For example, an indirect coupling may include coupling lower mounting bracket  14  to a housing of motor  16  instead of to connector  46 ). In the embodiment shown, connector  46  is coupled in contact with upper mounting bracket  12 . In some embodiments, linear actuator  17  is configured to allow smooth and/or quiet movement bi-directionally in a single axis (horizontal in dimension or direction  27 ), which may be more comfortable to a patient than a stepping motor (e.g., may be less likely to wake a patient during use of protruder  10  in sleep titration study). However, in some embodiments, motor  16  may comprise a stepping motor or may be configured to be actuated or operated in a step-wise fashion. In some embodiments, linear actuator  17  may be limited to a maximum displacement, such as 20 mm, and/or may be configured to move in smooth minimum fine increments, such as, for example, 0.2 mm increments. Linear actuator  17  may comprise, for example, a Firgelli PQ12-63-6-P motor (available from Firgelli Technologies Inc., Vancouver, B.C., CANADA) that is lightweight and has an appropriate small footprint and box form factor for the protruder  10 . Motor  16  may, for example, comprise a brushless and/or direct current (DC) motor. In other embodiments, motor  16  may comprise other suitable motors or actuators, such as, for example, a hydraulic piston. 
     In the embodiment shown, a mandibular positioning device  19  comprises and/or houses drive motor  16 . Device  19  and brackets  12  and  14  are configured such that brackets  12  and  14  can be coupled to device  19 , such as, for example, with or through connectors (or shafts or rods)  46  and  52 , respectively. In the embodiment shown, upper mounting bracket  12  is configured to be coupled to connector  46  (e.g., drive-motor connector  46 ), and lower mounting bracket  14  is configured to be coupled to connector  52  (e.g., adjustment-mechanism connector  52 , as discussed in more detail below). In the embodiment shown, connector  46  is configured to couple upper mounting bracket  12  (e.g., directly) to drive motor  16 , and connector  52  is configured to couple lower mounting bracket  14  to device  19  such that if drive motor  16  extends and/or retracts bracket  12 , bracket  14  remains stationary relative to device  19  and the housing of motor  16 . In the embodiment shown, connector  52  is parallel to connector  46 . 
     The one of the upper and lower mounting brackets  12 ,  14  that is coupled to be driven by motor  16  (in the embodiment shown, upper mounting bracket  12  and upper dental appliance  18 ), may be coupled to the motor  16  along the anterior-posterior axis  27  such that motor  16  can be actuated or activated to displace appliance  18  along the A-P direction  27 . In this way, appliances  18  and  20  can be precisely and repeatably positioned relative to one another, and thus can precisely and repeatably protrude a patient&#39;s mandible relative to the patient&#39;s maxilla. During adjustment, drive motor  16  may effect relative displacement by extending or retracting connector  46  relative to device  19  such that device  19  is configured to push or pull a patient&#39;s mandible relative to the patient&#39;s maxilla. In the embodiment shown, extending connector  46  pushes the upper bracket  12  away from device  19  and causes drive motor  16  to move away from the patient. Due to a relatively static connection between drive motor  16  and lower mounting bracket  14  (e.g., via connector  52 ), lower mounting bracket  14  is simultaneously pulled, thereby pulling the patient&#39;s mandible (moving the patient&#39;s lower jaw with lower mounting bracket  14 ). The net effect is that a patient&#39;s lower jaw may be protruded forward (in an anterior direction) by exerting a backward force (in a posterior direction) on the upper jaw. 
     In the embodiment shown, mandibular positioning device  19  comprises a housing  48 , such as a casing  48 . Drive motor  16  and related components may be enclosed in casing  48 , such as, for example, to protect drive motor  16  and patient from cross infection and bacteria. In some embodiments, casing  48  may be sealed and/or may be openable or removable (e.g., through an access door, such as shown on the back of housing  48 , which may be attached and/or removable via screws, clips, tabs, or the like). For example,  FIGS. 14C and 17C  depict alternate embodiments of housings suitable for use with embodiments of the present devices  19 . In some embodiments, casing  48  may be applied as a protective spray coating. In the embodiment shown (e.g.,  FIG. 2A ), casing  48  houses or contains drive motor  16  and permits connectors  46  and  52  to extend out of casing  48 . In the embodiment shown, connector  46  of motor  16  is configured to be coupled to a mounting bracket of a first dental appliance (e.g., upper mounting bracket  12  having upper dental appliance  18 ); and connector  52  is configured to be coupled to a mounting bracket of a second dental appliance (e.g., lower mounting bracket  14  having lower dental appliance  20 ). 
     In some embodiments, protruder  10  (e.g., device  19 ) comprises an initial position adjustment mechanism  50 . In embodiments in which drive motor  16  is coupled more directly to one of brackets  12  and  14  (bracket  12  in the embodiment shown), the other of brackets  12  and  14  (bracket  14  in the embodiment shown) may be coupled to adjustment mechanism  50  (e.g., through connector  52 ). Initial position adjustment mechanism  50  is configured to be actuated to adjust the relative position of lower mounting bracket  14  and upper mounting bracket  12  (e.g., independently of drive motor  16 ). More particularly, in the embodiment shown, housing  48  is coupled to drive motor  16  and initial position adjustment mechanism  50 ; drive motor  16  is coupled between housing  48  and upper mounting bracket  12 , and/or configured to adjust the relative position of lower mounting bracket  14  and upper mounting bracket  12  by adjusting the position of upper mounting bracket  12  relative to housing  48 ; and/or initial position adjustment mechanism  50  is coupled between housing  48  and lower mounting bracket  14 , and/or configured to be actuated to adjust the relative position of lower mounting bracket  14  and upper mounting bracket  12  by adjusting the position of lower mounting bracket  14  relative to housing  48 . 
     In this embodiments, protruder  10  is configured such that the position of upper dental appliance  18  with respect to (relative to) lower dental appliance  20  can be adjusted to a reference point (e.g., as a starting point from which a study of or for a patient can commence). This pre-adjustable reference point may be configured at a calibration time or step (e.g., before beginning a study), and/or then fixed in place before the study for the duration of the study. This reference point may be used to effectively zero or calibrate the device to a patient-specific reference retruded position. In some embodiments, the relative position indicator may be adjustable to point to zero on scale  32  when the protruder  10  is in the reference position. For example, in some embodiments, lower mounting bracket  14  can comprise an adjustable pointer  34  that can be adjusted or slid relative to lower mounting bracket  14  (e.g., relative to side  24  or  26 ) and/or upper mounting bracket  14  can comprise scale  32  that can be adjusted or slid relative to upper mounting bracket  12 . Adjustable attachment of lower mounting bracket  14  to the housing of motor  16  can be accomplished by a variety of methods and/or with a variety of structures or configurations. 
     For example, in the embodiment shown (e.g.,  FIGS. 6A and 6B ), initial position adjustment mechanism  50  comprises a manually operable element, such as, for example, a screw  54  and/or a knob  56  coupled to screw  54  such that knob  56  can be rotated outside housing or casing  48  to rotate screw  54  inside housing  48 . In this way, adjustment mechanism  50  is configured such that turning a rotational external fixture, such as knob  56 , rotates screw  54  to mechanically adjust the position of connector  54  (and thereby lower dental appliance  20 ) along the anterior-posterior axis  27  ( FIG. 1A ). This allows the start or initial relative position of the appliances  18 ,  20  to be accurately and reproducibly achieved before initiating a study of a patient. Screw  54  (and thereby knob  56 ) can be coupled to an end  53  of connector  54 . For example, end  53  of connector can be provided with female or internal threads corresponding to male or external threads of screw  54 , and screw  54  can be rotatably coupled to housing  48  such that screw  54  is linearly fixed relative to housing  48 , such that rotation of screw  54  will translate into linear displacement of connector  52 . As shown in  FIGS. 1A and 1B , the depicted initial position adjustment mechanism  50  is configured to allow positioning of lower appliance  20  to a retruded position in which upper appliance  18  is retracted relative to housing  48  (e.g., in which lower mounting bracket  14  is as close to housing  48  as permitted). As shown in  FIG. 1C , when upper appliance  18  fully retracted and lower appliance  20  fully is extended, the full stroke of the drive motor  16  ( FIG. 6A ) is available for protruding a patient&#39;s mandible from the fully retruded position.  FIG. 1A  shows both of appliances  18  and  20  fully retracted, while  FIG. 1B  shows the protruder  10  in a maximally protruded position or configuration in which appliance  18  is fully extended and appliance  20  is fully retracted relative to device  19  (housing  48 ). 
     In some embodiments, connector  52  and/or housing  48  are configured to resist rotation of connector  52  relative to housing  48 . For example, in the embodiment shown, connector  52  comprises longitudinal protrusions  55  that are aligned with the longitudinal axis of connector  52 , and housing or casing  48  comprises grooves  57  configured to receive protrusions  55  such that connector  52  can move linearly relative to housing  48  but is constrained to linear motion (e.g., such that protrusions  55  and grooves  57  cooperate to prevent connector  52  from rotating relative to housing  48 ). In other embodiments, other initial position adjustment mechanisms may be used, such as, for example, motorized mechanisms. In the embodiment shown, adjustment mechanism  50  further comprises a locking nut  67  configured to prevent screw  54  from moving in the A-P direction relative to housing  48 . For example, in some embodiments, the threads of nut  67  are provided or coated with an adhesive or the like such that screw  54  can be threaded into nut  67  to assemble adjustment mechanism  50  and/or device  19 , but then becomes fixed relative to nut  67  to maintain the linear position of screw  54  relative to housing  48  while still permitting rotation of screw  54  relative to housing  48 . 
     Additionally, in the embodiment shown, housing  48  has a sidewall with at least a first opening (corresponding to connector  46 ) and a second opening (corresponding to connector  52 ). In this embodiment, housing  48  is coupled to drive motor  16  and adjustment mechanism  50  such that housing  48  encloses at least a portion of each of drive motor  16  and adjustment mechanism  50 , and such that drive-motor connector  46  extends out of housing  48  through the first opening, and adjustment-mechanism connector  52  extends out of housing  48  through the second opening. In the embodiment shown, adjustment mechanism  50  is configured to linearly adjust the position of adjustment-mechanism connector  52 ; and drive motor  16  is configured to linearly move drive-motor connector  46  in a direction substantially parallel to the direction in which adjustment mechanism  50  can adjust adjustment-mechanism connector  52 . 
     As shown  FIG. 3A , and as noted above, upper dental appliance  18  may comprise an upper dental tray  58 , and lower dental appliance  20  may comprise a lower dental tray  60 . Appliances  18  and  20  may include upper and lower arches, respectively, that fit into a patient&#39;s mouth and/or receive a patient&#39;s teeth (e.g., a portion of a patient&#39;s teeth) to hold or couple to the patient&#39;s jaws. Mounting brackets  12  and  14  extend out from with appliances  18  and  20 , respectively. In some embodiments of the present mandibular protruders, upper dental appliance  18  is integral with, for example molded as a part of, upper mounting bracket  12 . Similarly, in some embodiments, lower dental appliance  20  is integral with, for example molded as a part of, lower mounting bracket  14 . In other embodiments, appliances  18  and  20 , and their respective mounting brackets  12  and  14  may be coupled together as separate parts. Appliances  18  and  20  may be U-shaped disposable or non disposable appliances for a patient&#39;s upper and lower jaws, respectively. In some embodiments (e.g.,  FIG. 10 ), appliances  18  and  20  may comprise at least a partial mould of a patient&#39;s teeth. For example, appliances  18  and  20  may be filled with a quick-set material, such as boil-and-bite insert  62 , which may be used to take fast custom impressions. For example, materials such as a silastic impression material (e.g., PolyFil™ TransBite available from SciCan™ Medtech AG, Cham, Switzerland) and/or a thermoplastic impression material may be used. In some embodiments (e.g., embodiments in which appliances  18  and/or  20  (e.g., trays  58  and/or  60 ) are intended to be disposable, the present kits can comprise a positioning device  19  and a plurality of appliances  18  and/or  20  (e.g., trays  58  and/or  60 ). 
     As discussed below, some embodiments comprise: dental impression material configured to be coupled to at least one of the upper dental appliance and the lower dental appliance, the dental impression material configured to be imprinted with and maintain an impression of a patient&#39;s teeth. A patient may be fitted with appliances  18  and  20  in his or her natural resting or normal bite position, in order to establish the reference position in some cases. The position of appliances  18  and  20  may be secured together, such as by clipping together, to preserve this relative position, such as the natural resting or normal bite position of upper and lower appliances  18  and  20 . Optionally, the position of the appliances  18  and  20  may be secured together, such as by clipping together, to preserve the position determined to be an optimal mandibular displacement (e.g., a target therapeutic distance) determined in a titration study. In the embodiment shown, tray walls  63  and  65  of appliances  18  and  20 , respectively, include slits  64  throughout to import greater flexibility and/or to permit dental impression material to extrude or extend through slits  64  to improve stability of the dental impression material (e.g., insert  62 ) relative to appliances  18  and  20 . Walls  63  and  65  may also provide improved retention of insert  62 . Appliances  18  and  20  may also be configured to maximize fit and comfort, and minimize encroachment on lingual space. Front portions  66  and  68  of appliances  18 ,  20  may be narrower than respective back or lateral portions  70  and  72  (e.g., to fit the natural size of the teeth). In the embodiment shown, appliances  18  and  20  are each configured to permit lateral portions (e.g.,  70 ,  72 ) to flex relative to the front portions  66  and  68  (e.g., via slits between the front portions and the lateral portions. Inner tray walls  63 A and  65 A may be half the height of outer tray walls  63 B and  65 B of appliances  18  and  20 , respectively, (e.g., to provide a better fit and comfort and/or provide greater stability for upper appliance  18  during movement (e.g., upon activation of motor  16 ). In some embodiments, appliances  18  and  20  may be designed and/or configured to such that the molar arms (lateral portions) of the trays spring laterally (are biased in a lateral, outward direction) so the inner wall of the trays are applied firmly (tend to press against) to the lingual surface of the molars and thereby minimize encroachment into the lingual space. In some embodiments, appliances  18  and  20  are flexible and/or smaller in size than existing dental trays (e.g., to improve comfort or fit for a patient). As illustrated (e.g., in  FIGS. 1A-1C and 6A-6B ), upper mounting bracket  12  may include a planar portion extending anteriorly along a plane defined by inferior (lower) surface or aspect  70  of upper dental appliance  18  and/or lower mounting bracket  14  may include a planar portion extending anteriorly along a plane defined by superior (upper) aspect or surface  72  of lower dental appliance  20 , as shown. 
     In the embodiment shown, and as noted above, appliances  18  and  20  are coupled to mandibular positioning device  19  through brackets  12  and  14 , respectively. In the embodiment shown, upper mounting bracket  12 , lower mounting bracket  14 , and rail system  22  are configured to be removably coupled to drive motor  16  (and/or positioning device  19 ). More particularly, in the embodiment shown, drive-motor connector  46  has a longitudinal axis that is substantially parallel to the direction of actuation (e.g., A-P direction  27 ) of drive motor  16 , and one of upper mounting bracket  12  and lower mounting bracket  14  (as shown, upper mounting bracket  12 ) is configured to be coupled to drive-motor connector  46  such that the longitudinal axis of the one of upper mounting bracket  12  and lower mounting bracket  14  (as shown, upper mounting bracket  12 ) is substantially parallel to (and, in some embodiments, co-linear with) the longitudinal axis of drive-motor connector  46 . As shown in  FIGS. 3A and 3B , in some embodiments, such as the embodiment shown, mandibular protruder  10  may include an upper release mechanism (e.g., a nut  74  and bolt  76  arrangement for passing through bracket  12  and connector  46 ), for release of upper dental appliance  18  from device  19  (shown in  FIG. 4 ). Similarly, mandibular protruder  10  may incorporate a lower release mechanism (e.g., a nut  78  and bolt  80  arrangement for passing through bracket  14  and connector  52 ), for release of lower dental appliance  20  from mandibular positioning device  19 . In other embodiments, nuts  74  and/or  78 , and/or bolts  76  and/or  80 , may include and/or may instead comprise any suitable fastener, such as, for example, a wing-nut or wing-bolt that can be tightened or loosened by hand (without additional tools), a pin and/or a cotter pin, and/or the like. In some embodiments, upper mounting bracket  12  and/or lower mounting bracket  14  may be threaded on at least one side of connector  46  or  52 , such that no nuts are needed to tighten or hold bolts  76 . In some embodiments, bolts  76  and/or  80  comprise screws (not shown) such that the nuts are omitted. 
     In some embodiments, upper mounting bracket  12  is configured to be coupled to a connector (e.g.,  46  or  52 ) of an initial adjustment mechanism  50  or a drive motor  16 , and lower mounting bracket  14  is configured to be coupled to a connector (e.g.,  46  or  52 ) of an initial adjustment mechanism  50  or a drive motor  16 . For example, in the embodiment shown, upper mounting bracket is configured to be coupled to connector  46 , and lower mounting bracket  14  is configured to be coupled to connector  52 . More particularly, in the embodiment shown, adjustment-mechanism connector  46  includes a longitudinal axis, a proximal portion  82 A having a first cross-section, and a distal portion  82 B having a second cross-section that is different than the first cross-section; and drive-motor connector  52  includes a longitudinal axis, a proximal portion  84 A having a first cross-section, and a distal portion  84 B having a second cross-section that is different than the first cross-section. More particularly, in the embodiment shown, first cross-sections of proximal portions  82 A and  84 A are circular, and second cross-sections of distal portions  84 A and  84 B have parallel sides (e.g., are similar to rectangles with curved upper and lower perimeters). In some embodiments, connectors  46  and  52  are configured with different sizes and/or cross-sectional shapes so that at least one of connectors  46  and  52  will only couple to one of upper mounting bracket  12  and lower mounting bracket  14 . For example, in some embodiments, distal portion  82 B of connector  46  is wider than distal portion  84 B of connector  52 . In the embodiment shown, adjustment-mechanism connector  52  includes a hole  81  extending through distal portion  84 B transverse to the longitudinal axis of adjustment-mechanism connector  52 ; and drive-motor connector  46  includes a hole  77  extending through distal portion  82 B transverse to the longitudinal axis of drive-motor connector  46 . In this embodiment, connectors  46  and  52  are configured to be coupled to brackets  12  and  14  having respective recesses that correspond to the shape of connectors  46  and  52  (e.g., to improve the strength of connection to between brackets  12  and  14 , and connectors  46  and  52 , respectively. 
     Similarly, as illustrated, for example, in  FIGS. 3A and 3B , upper mounting bracket  12  has a longitudinal axis and a recess  73  configured to receive a portion of connector  46 . Recess  73  has an outer portion with a first cross-section (corresponding to first cross-section of proximal portion  82 A), an inner portion having a second cross-section (corresponding to second cross-section of distal portion  82 B) that is different than the first cross-section, and a hole  75  extending transverse to the longitudinal axis of upper mounting bracket  12 , and through upper mounting bracket  12  across the inner portion of recess  73 . Similarly, lower mounting bracket  14  has a longitudinal axis and a recess  83  configured to receive a portion of connector  52 . Recess  75  has an outer portion with a first cross-section (corresponding to first cross-section of proximal portion  84 A), an inner portion having a second cross-section (corresponding to second cross-section of distal portion  84 B) that is different than the first cross-section, and a hole  79  extending transverse to the longitudinal axis of lower mounting bracket  14 , and through lower mounting bracket  14  across the inner portion of recess  75 . 
     To couple dental appliance  18  to connector  46 , connector  46  may be slid into recess  73 , which may be molded as part of bracket  12 . Bolt  76  may then be passed through hole  75  of bracket  12 , and hole  77  of connector  46 . Nut  74  may then be used to secure bolt  76  in place. Similarly, to couple appliance  20  to connector  52 , connector  52  may first be slid into recess  83 , which may be molded as part of bracket  14 . Bolt  80  may then be passed through hole  79  of bracket  14 , and hole  81  of connector  52 . Nut  78  is then used to secure bolt  80  in place. In the embodiment shown, holes  77  and  81  pass through the width of connectors  46  and  52 , respectively, and align with holes  75  and  79  in recesses  73  and  83 , respectively. Nut  74  can be tightened sufficiently to prevent vertical tilting of upper tray  18 , or can be tightened to a degree that permits some vertical tilting of tray  18  (e.g., within the tolerances of rail system  22 ). Bolt  76  and  80  sizing may be chosen to ensure a tight fit with respective holes  75  and  79  to ensure that little or no movement is possible between device  19  and appliances  18  and  20  (e.g., to rigidly fixed the components of protruder  10  together). Tilting may also be restricted by rail system  22  (e.g., portions of mounting brackets  12  and  14 , and/or appliances  18  and  20 , may be flush and planar to each other). The encapsulation of connectors  46  and  52 , by recesses  73 ,  83 , respectively, provide structures that are configured to prevent rotation about coronal axis  28 . In these and other embodiments, appliances  18  and  20  and brackets  12  and  14  are disposable. Other releasable connection points may be used, such that at least appliances  18  and  20  may be disposable. In some embodiments, protruder  10  itself is fully or partially disposable. Various components of protruder  10  (e.g., brackets  12  and  14 , connectors  46  and  52 , and/or housing  48 ) can comprise acetal-based plastics, such as, for example, Polyoxymethylene (POM). 
     The general operation of the mandibular protruder  10  may be illustrated with reference to  FIGS. 1A-C . Beginning at the retruded position shown in  FIG. 1A , a protrusion of the mandible is achieved by extending connector  46 , thereby exerting an inward force on upper dental appliance  18 . A comparable and opposite protruding force is thus exerted on lower dental appliance  20 . As shown in  FIG. 1B , these forces cause protrusion of the mandible with respect to the maxilla and the rest of the skull (e.g., through protrusion of lower dental appliance  20  relative to upper dental appliance  18 ). As shown in  FIG. 1C , for retrusion of the mandible, the reverse occurs: connector  46  retracts, and thereby exerts an outward or pulling force on upper appliance  18  and an opposite pushing or retruding force on lower appliance  20 . As described above, this will, for most patient&#39;s, cause a retrusion of the mandible. 
     An oral appliance titration study includes patient physiologic data collected from either a portable monitor or a polysomnogram (PSG) and position data collected from the titration device (e.g., the mandibular protruder  10  discussed above). This data is collected, scored and interpreted to provide the test results (e.g., prediction of success and amount of protrusion). In some implementations, the mandibular protruder can be a remote-control mandibular protruder (RCMP). Relative displacement of the RCMP during use is actuated or controlled by a motor or other actuator instead of by physical actuation of the oral appliances or mounting brackets by a user. Remote control of the RCMP is discussed in further detail below. In contrast to titration systems that are manually adjusted (i.e., where the scale can be read directly from the titration device), an unattended titration (such as the RCMP, for example) requires that a control system (e.g., a workstation  92  or controller  94  discussed below, for example) is accurately reading the physical position of the device. To accomplish this, a motor function test and calibration procedure can be executed at the start of each oral appliance titration study. 
     Referring now to  FIG. 18A , example operations for validating operation of an oral appliance titration system are shown. In some embodiments, the oral appliance titration system includes the RCMP discussed above. For example, as discussed above, the mandibular protruder  10  can be a mandibular protruder as shown in any of  FIGS. 1A-1C, 2, 6A-6B, 10 and 14A-14B . In particular, the mandibular protruder  10  can include the upper mounting bracket  12  having the upper dental appliance  18  and the lower mounting bracket  14  having the lower dental appliance  20 . Additionally, the mandibular protruder  10  can include the drive motor  16  that is configured to effect relative displacement between the upper and lower mounting brackets  12 ,  14 . In some implementations, the drive motor  16  includes the linear actuator  17  that can effect relative displacement. At  1802 , calibration data for the drive motor  16  is received. The drive motor  16  can be provided with calibration data by the manufacturer. For example, the drive motor  16  can be calibrated to achieve a high degree of accuracy (e.g., +/−0.5 mm) during the manufacturing process. In some implementations, the calibration data can be a code defining the response of the drive motor  16 . For example, the code can define the response of the drive motor  16  within a predetermined tolerance. Optionally, the response of the drive motor can be linear. In some implementations, extension of the linear actuator  17  within the drive motor  16  can be measured by a voltage drop across a variable resistor. The code can be the linearity of the linear actuator  17  defined by X=a*V+b, where a and b are provided as a n-character string such as a 6-character string, for example. Optionally, to reduce the risk of an invalid code, the n-character string can include a check sum. Accordingly, at the beginning of an oral appliance titration study, the calibration data (i.e., the code) is received by the control system. For example, the code can be manually entered and/or loaded into the control system for a new drive motor. Alternatively or additionally, the control system can store the code for previously used drive motors. A check can then be performed to ensure that the mandibular protruder  10  is adequately described by the calibration data. 
     At  1804 , the mandibular protruder  10  can be commanded to a plurality of positions. Optionally, before commanding the mandibular protruder  10  to the plurality of positions, an initial position of the mandibular protruder  10  can be set. For example, the initial position adjustment mechanism  50  can be set to a fixed position such as its fully extended position, for example. In some implementations, the mandibular protruder  10  can be commanded to a plurality of predetermined positions. For example, the mandibular protruder  10  can be commanded to at least three positions such as a fully retruded position, a fully protruded position and a position between the fully retruded and fully protruded position. It should be understood that other known and fixed positions can also be used. By commanding the mandibular protruder  10  to the plurality of positions, the control system drives the actuator (e.g., the drive motor  16 ) to each of the plurality of positions. 
     At  1806 , an actual physical position of the mandibular protruder  10  is received at each of the plurality of positions. For example, an operator can read the actual physical position of the mandibular protruder  10  from a relative position indicator such as the scale  32  and the pointer  34  of the mandibular protruder  10 , for example. The operator can then enter the actual physical position of the mandibular protruder  10  at each of the plurality of positions into the control system. At  1808 , the actual physical position mandibular protruder  10  can be compared to an expected position of the mandibular protruder  10 . In some implementations, the expected position of the mandibular protruder  10  can be a detected feedback position. For example, as discussed above, extension of the linear actuator  17  within the drive motor  16  can be measured by a voltage drop across a variable resistor. Accordingly, the expected position of the mandibular protruder  10  can be determined based on the measured voltage and the calibration data. At  1810 , it is possible to detect whether the mandibular protruder  10  is validly operating based on the results of the comparison. 
     Referring now to  FIG. 18B , example operations for validating operation of an oral appliance titration system according to another implementation are shown. Similarly to  FIG. 18A , calibration data for the drive motor  16  is received at  1812 , the mandibular protruder  10  is commanded to a plurality of positions at  1814  and the actual physical position of the mandibular protruder at each of the plurality of positions is received at  1816 . Because these operations are identical to steps  1802 - 1806  discussed with regard to  FIG. 18A , these operations are not discussed in further detail below. At  1818 , a deviation between the actual position mandibular protruder  10  and an expected position of the mandibular protruder  10  is calculated for each of the plurality of positions. The expected position of the mandibular protruder  10  is determined similarly as discussed with regard to  FIG. 18A . For example, the expected position of the mandibular protruder  10  can be a detected feedback position. In some implementations, the deviations can be expressed as Eqn. (1) below. 
       dev i =( F   i −5)−( P   i −4)  (1)
 
     where dev i  is a deviation at one of the plurality of positions, F i  is the detected feedback position (i.e., the expected position of the mandibular protruder  10 ) at one of the plurality of positions, P i  is the actual physical position of the mandibular protruder  10  at one of the plurality of positions and “5” and “4” are constants. The constants can reflect the linear actuator extension and scale reading when the upper mounting bracket  12  is flush and the initial position adjustment mechanism  50  is fully extended, for example. It should be understood that the constants can have values other than “5” and “4” depending on the linear actuator extension and scale reading. 
     At  1820 , a determination can be made as to whether the deviation for each of the plurality of positions is within a predetermined tolerance. In some implementations, the predetermined tolerance can be equal to the expected accuracy of the drive motor  16  (e.g., +/−0.5 mm, for example). If the deviation of each of the plurality of positions is within the predetermined tolerance, the system is valid. This is shown at  1830  in  FIG. 18B . In this case, the operator can proceed to calibrating a PSG channel without further adjustment, which is discussed in detail below with regard to  FIG. 18C . If, however, the deviation of at least one of the plurality of positions is not within the predetermined tolerance, a suggested adjustment can be calculated for the mandibular protruder  10 . In some implementations, the suggested adjustment can be an average of the deviations for the plurality of positions. For example, the suggested adjustment can be expressed as Eqn. (2) below. 
         SA =(dev A +dev B +dev C )/3,  (2)
 
     where SA is the suggested adjustment, dev A  is the deviation at the first position, dev B  is the deviation at the second position and dev C  is the deviation at the third position. 
     At  1824 , a determination is made as to whether the suggested adjustment is within a predetermined range. The suggested adjustment can compensate for small variations in the linear actuator  16  and/or scale  32 . The predetermined range can be +/−2.0 mm, for example. If the suggested adjustment is within the predetermined range, then the initial position of the mandibular protruder  10  can be adjusted by the suggested adjustment at  1826 . For example, the initial position can be adjusted with the initial position adjustment mechanism  50 . Then, the operation proceeds to step  1814 , where the mandibular protruder  10  is re-commanded to the plurality of positions. Then, the validation check is re-performed after making the suggested adjustment. If, however, the suggested adjustment is not within the predetermined range, a recommendation is made to replace the mandibular protruder  10  at  1828 . In some implementations, the titration system may provide a warning and/or may prevent the operator from using the mandibular protruder if the suggested adjustment is not made. 
     Alternatively or additionally, a check can be performed to determine if the drive motor  16  is sufficiently linear. For example, a difference between the deviation for each of the plurality of positions and the suggested adjustment can be calculated. The difference between the deviation for each of the plurality of positions and the suggested adjustment can be expressed by Eqn. (3) below. 
         D =dev i   −SA   (3)
 
     where D is the difference, SA is the suggested adjustment, dev i  is the deviation at one of the plurality of positions. If the difference between the deviation and the suggested adjustment for any one of the plurality of positions is greater than the predetermined tolerance, which can be equal to the expected accuracy of the drive motor  16  (e.g., +/−0.5 mm, for example), then the drive motor  16  is considered to be non-linear. In other words, the linearity of the drive motor  16  has degraded. Accordingly, a recommendation is made to replace the drive motor  16 . In some implementations, the titration system may provide a warning and/or may prevent the operator from using the mandibular protruder if the drive motor  16  is not replaced. 
     Referring now to  FIG. 18C , example operations for validating operation of an oral appliance titration system according to yet another implementation are shown. According to this implementation, the titration system can also include a polysomnogram (PSG), and the example operations can further include calibrating a channel of the PSG. Optionally, the channel of the PSG can be calibrated after confirming that the titration system is validly operating as discussed above. At  1842 , upper and lower limits for the mandibular protruder  10  are received. In some implementations, the upper and lower limits are patient-specific. For example, the upper and lower limits can be within an expected range of 20 mm. In some implementations, the upper limit can be approximately the fully protruded position of a patient&#39;s jaw, and the lower limit can be range from approximately the fully retruded position of the patient&#39;s jaw to the neutral position (i.e., habitual bite). Additionally, the lower limit can be the neutral position minus a predetermined offset such as 1 mm, for example. In this implementations, the titration study is performed between the neutral position minus the offset to approximately the fully protruded position because results from approximately the fully retruded position to the neutral position can be less relevant. The upper and lower limits can be provided to the patient before performing the titration study by a dentist, for example. Additionally, the upper and lower limits can be received by the control system. 
     At  1844 , the mandibular protruder  10  is commanded to the upper and lower limits. Then, at  1846 , an actual physical position of the mandibular protruder at each of the upper and lower limits is received. Because these operations are similar to steps  1802 - 1804  discussed with regard to  FIG. 18A , these operations are not discussed in further detail below. At  1848 , a deviation between the actual physical position and an expected position for the mandibular protruder  10  at each of the upper and lower limits is calculated. The expected position of the mandibular protruder  10  can be a detected feedback position, for example. Because this operation is similar to step  1818  discussed with regard to  FIG. 18B , this operation is not discussed in further detail below. At  1850 , a determination is made as to whether the channel of the PSG is calibrated. For example, if the deviation at each of the upper and lower limits are within a predetermined tolerance such as +/−0.5 mm, for example, the channel of the PSG is calibrated. If, however, the deviation at each of the upper and lower limits are not within the predetermined tolerance such as +/−0.5 mm, for example, the channel of the PSG is not calibrated. 
     Alternatively or additionally, a safety check can be performed. As discussed above, upper and lower limits, which are patient-specific, are received. The upper and lower limits can define maximum amounts of protrusion or retrusion of a patient&#39;s jaw. Exceeding either the upper limit or lower limit can cause pain and/or injury to the patient. Accordingly, a determination can be made as to whether the actual physical position of the mandibular protruder is greater than the upper limit or less than the lower limit. In the event that the actual physical position is greater than the upper limit or less than the lower limit, the titration system may provide a warning and/or may prevent the operator from using the mandibular protruder. 
     Referring to  FIGS. 11 and 12 ,  FIG. 11  depicts a schematic of one embodiment of the present systems for carrying out a sleep titration on a patient with a mandibular protruder  10 , and  FIG. 12  depicts a flowchart of one method of displacing a patient&#39;s mandible  88  relative to the patient&#39;s maxilla  90 . In a stage or step  100 , the position of one of brackets  12  and  14 , in this case lower bracket  14 , is relatively adjusted to an initial position. This may be done with the initial position adjustment mechanism  50 , as discussed above. Stage or step  100  may be performed or carried out before or after protruder  10  is in place in the patient&#39;s mouth. As discussed, the initial position may comprise a rest position where the mandible is protruded somewhat relative to a fully retruded position. In some embodiments, the initial position may be a comfortable neutral position for the patient. For example, in some embodiments, step  100  can comprise adjusting the relative position of one of an upper mounting bracket  12  having an upper dental appliance  18 , and a lower mounting bracket  14  having a lower dental appliance  20 . For example, in the embodiment shown above, the relative position of lower mounting bracket  14  can be adjusted (independently of motor  16 ) by rotating screw  54  (e.g., via knob  56 ). 
     In a stage or step  102  (shown in  FIG. 12 ), the other of brackets  12  and  14 , in this case bracket  12 , is relatively displaced with drive motor  16  (e.g., as in  FIG. 6A ) to cause relative displacement between appliances  18  and  20 , and to displace (e.g., protrude or retrude), the patient&#39;s mandible  88 . Step  102  may be accomplished as part of a sleep titration carried out to determine a mandibular protrusion effective in treating obstructive sleep apnea. The effective mandibular protrusion may be determined from a relative position indicator of appliances  18 ,  20 , as discussed above. In a further stage or step, a mandibular protrusion oral appliance, such as a retainer (not shown), may be constructed, adjusted, and/or calibrated for the patient based on the results of the sleep titration. For example, in some embodiments, step  102  can comprise relatively displacing with a drive motor  16  the other of upper mounting bracket  12  and lower mounting bracket  12  when a patient&#39;s upper teeth are disposed in (or otherwise coupled to) upper dental appliance  18  and patient&#39;s lower teeth are disposed in (or otherwise coupled to) lower dental appliance  20  to cause relative displacement of upper dental appliance  12  and lower dental appliance  14  and displace the patient&#39;s mandible relative to the patient&#39;s maxilla. For example, in the embodiment shown, motor  16  can be activated to displace upper mounting bracket  12  relative to housing  48  such that lower mounting bracket  14  and lower dental appliance  20 , and a patient&#39;s mandible, are displaced relative to the patient&#39;s maxilla. For example, relatively displacing the other of upper mounting bracket  12  and lower mounting bracket  14  can protrude the patient&#39;s mandible relative to the patient&#39;s maxilla. 
     In some embodiments, relatively displacing is repeated while the patient&#39;s breathing is monitored and/or may be performed responsive to detection of an interruption in the patient&#39;s breathing. As also described in more detail below, some embodiments of the present methods further comprise: determining an optimal mandibular displacement for the patient at which the patient experiences less than a predetermined maximum number of respiratory disturbances in a period of time. For example, in some embodiments, the maximum number of respiratory disturbances corresponds to a respiratory disturbance index (RDI) (e.g., the predetermined maximum number of respiratory disturbances can correspond to an RDI of 10 per hour and/or an RDI that is less than a baseline RDI for the patient) or apnea-hypopnea index (AHI) (e.g., the predetermined maximum number of apneas and hypopneas can correspond to an AHI of 10 per hour and/or an AHI that is less than a baseline AHI for the patient). In some embodiments, the period of time is 10 minutes. In some embodiments, the predetermined number of respiratory disturbances corresponds to no snoring and/or no inspiratory flow limitation (e.g., during rapid eye movement (REM) sleep) and/or is measured when the patient is supine). In some embodiments, the optimal mandibular protrusion is determined from a relative position indicator that indicates relative position of lower dental appliance  14  and upper dental appliance  12 . The protruder  10  may be used by a physician or other user to determine an optimal mandibular displacement (e.g., from the patient&#39;s natural or resting mandibular position), such that some embodiments of the present methods comprise: communicating the optimal mandibular displacement for the patient to an entity (e.g., a dentist) for construction of a mandibular protrusion oral appliance for the patient. 
     Some embodiments of the present methods comprise: providing a mandibular protruder  10  (e.g., any of the present embodiments of protruder  10 , such as one comprising: an upper mounting bracket  12  having an upper dental appliance  18 ; a lower mounting bracket  14  having a lower dental appliance  20 ; a rail system  22  coupling upper mounting bracket  12  to lower mounting bracket  14  such that relative displacement of lower mounting bracket  14  and upper mounting bracket  12  is constrained to linear motion in an anterior-posterior direction; a drive motor  16  configured to effect relative displacement of lower mounting bracket  12  and upper mounting bracket  14 ; and an initial position adjustment mechanism  50  configured to be actuated to adjust the relative position of lower mounting bracket  14  and upper mounting bracket  12  independently of drive motor  16 ); actuating initial position adjustment mechanism  50  to adjust the relative position of upper mounting bracket  12  and lower mounting bracket  14 ; and relatively displacing with drive motor  16  upper mounting bracket  12  and lower mounting bracket  14  when a patient&#39;s upper teeth are coupled to (e.g., disposed in) upper dental appliance  18  and patient&#39;s lower teeth are coupled to (e.g., disposed in) lower dental appliance  20  to cause relative displacement between upper dental appliance  12  and lower dental appliance  20  and displace the patient&#39;s mandible relative to the patient&#39;s maxilla. 
     For example, an overview of an exemplary use of the present protruders (e.g.,  10 ) and/or systems (e.g., as shown in  FIG. 11 ) may go as follows. A dentist or physician may register numerical values, for example on scale  32 , corresponding to the fully retruded and fully protruded position of the mandible of a patient. The most convenient zero value of the scale may occur when the upper and lower incisors are positioned opposite each other, i.e. “end-to-end” position of the mandible  88  relative to the maxilla  90 . With appliances  18  and  20  positioned on the teeth and secured by for example impression material, the dentist may record the reading on scale  32  at the fully retruded position and fully protruded position. These values and appliances  18 ,  20  may be given to a technologist who then enters the values into a controlling computer (workstation  92 ). Workstation  92  has a software component that allows for the technician to regulate the device. The software in the computer is configured to accept the fully retruded, fully protruded, and “rest” scale readings, and to calculate the position of mandible  88  with these values. Appliances  18  and  20  are then attached to device  19 , and adjustment mechanism  52  of device  19  can be adjusted to the determined rest position or a nominal rest position for comfort (for example fully retruded plus a fixed number of millimeters, e.g., 1, 2, 3, 4, etc. mm). A study (e.g., sleep titration) can be performed (e.g., by a technician) to determine an optimal mandibular displacement for the patient (e.g., a mandibular displacement in which the patient experiences the fewest number of respiratory disturbances) by inputting a command at workstation  92  each time the technician decides or desires to relatively displace (e.g., by an incremental displacement) the patient&#39;s mandible relative to the patient&#39;s maxilla with drive motor  16  (e.g., while the patient is monitored via PSG device  96 ). The optimal mandibular displacement (e.g., the target therapeutic distance) such as, for example, relative to zero, can be noted by the technologist at the end of the study and transmitted with appliances  18  and  20  back to the dentist. Optionally, the appliances  18  and  20  can be clipped together following the completion of the study in the position of the optimal mandibular displacement and provided directly to the patient for nightly therapeutic use. 
     In a further example, the patient first visits the dentist or other healthcare professional to obtain disposable trays  58  and  60 . Some embodiments of the present methods comprise fitting the patient with small, medium, or large trays. Some embodiments comprise filling trays  58  and  60  with Blue-Mousse (Parkell Dental, U.S.A.), boil-and-bite inserts  62 , hardening agent, thermoplastic impression material, and/or the like; inserting top tray  58  into the patient&#39;s mouth, and/or inserting bottom tray  60  into the patient&#39;s mouth (e.g., while rail system  22  is engaged or coupled upper mounting bracket  12  to lower mounting bracket  14 ). The patient can be asked to bite down, such as to imprint the material and/or permit the material to harden or quick set. The patient can be asked to move the jaw to a fully retruded position of the patient&#39;s mandible. Some embodiments comprise reading scale  32  (shown in  FIG. 7 ) on top of upper bracket  12  to determine and/or registering (e.g., recording) a relative position value corresponding to the fully retruded position. The patient can be asked to move the jaw to a fully protruded position. Some embodiments comprise reading scale  32  to determine and/or registering a relative position value corresponding to the fully protruded position of the patient mandible. The patient can be asked to move the jaw to a rest position. Some embodiments comprise reading scale  32  to determine and/or registering a relative position value corresponding to the rest position of the patient&#39;s mandible. Some embodiments comprise removing tray  58  and/or  60 . For example, if trays  58  and  60  are individually removed, bottom tray  60  may be removed first. Some embodiments comprise communicating or transferring the scale readings (e.g., retruded, protruded, rest) and/or trays  58  and  60  to another entity (e.g., sleep technician). In some embodiments (e.g., embodiments for prolonged therapeutic use), the dental impression material is configured to be durable such that the dental impression material will substantially hold its shape for use up to 1, 2, 3, 6, and/or 12 months. In such embodiments, the dental impression material may be molded to a user&#39;s teeth, removed from the patient, and cured or otherwise hardened (e.g., with heat, ultraviolet light, etc.) 
     Some embodiments of the present methods comprise receiving (e.g., from a dentist) trays  58  and  60  for a patient. Some embodiments comprise coupling (e.g., via rail system  22 ) upper tray  58  and lower tray  60 ; coupling upper tray  58  to device  19  (e.g., to motor  16 ) via connector  46  (e.g., in a fully retraced position flush to housing  48  of device  19 ); and/or coupling lower tray  60  to device  19  (e.g., to adjustment mechanism  50 ) via connector  52 . Some embodiments comprise adjusting connector  52  (e.g., via adjustment mechanism  50 ) to ensure that pointer  34  reads at the reference position of scale  32 . In some embodiments, the reference position is the fully retruded position. In other embodiments, the reference position is fully retruded plus a fixed and repeatable nominal amount, such as, for example, equal to, less than, or between, any of: 1, 2, 3, 4, or 5 mm. The additional adjustment may be chosen to provide patient comfort as the patient may not be comfortable in the fully retruded position. Some embodiments comprise storing the retruded, protruded, and rest scale readings for the patient in the computer workstation  92  (e.g. in a storage device of workstation  92 ). 
     Some embodiments comprise inserting trays  58  and  60  into the patient&#39;s mouth (e.g., together). Some embodiments comprise performing a sleep titration test on the patient. In the embodiment shown, controller  94  may be controlled by workstation  92  to provide control of protruder  10  (e.g., to control relative position of upper mounting bracket  12  and lower mounting bracket  14 ). For example, in some embodiments, controller  94  is configured to transmit signals to the drive motor to cause the drive motor to effect relative displacement of the lower mounting bracket and the upper mounting bracket (e.g., to activate the drive motor to displace the upper bracket relative to the housing such that the lower mounting bracket and the patient&#39;s mandible are displaced relative to the patient&#39;s maxilla). In some embodiments controller  94  is also configured to sense the relative position of the lower mounting bracket and the upper mounting bracket, and to transmit (e.g., to workstation) and/or record one or more signals indicative of the position of the lower mounting bracket relative to the upper mounting bracket. In other embodiments, controller  94  comprises a user-input device to permit a user to adjust the relative displacement of upper dental appliance  18  and lower dental appliance  20  by inputting a command directly to controller  92 . 
     In some embodiments, controller  94  is integral with workstation  92 , and/or workstation  92  is configured to control protruder  10  directly. In some embodiments, controller  94  is configured to power protruder  10  (e.g., controller  94  can include a power source such as one or more batteries and/or a medical-grade alternating current (AC) power source). Additionally, controller  94  and/or workstation  92  may be coupled to a polysomnogram  96  (PSG), and/or may be configured to provide or send input signals to track protruder  10  status (e.g., relative position of upper and lower mounting brackets  12  and  14  or dental appliances  18  and  20 ). 
     In the present embodiments, protruder  10  may be referred to as a remote-control mandibular protruder (RCMP) in which the relative displacement during use (e.g., displacement that is effected by the drive motor, as opposed initial adjustments effected by the initial position adjustment mechanism) is actuated or controlled by a motor or other actuator instead of by physical actuation of the dental appliances or mounting brackets by a user. For example, in the embodiments shown, the motor is activated or controlled by a control signal or by application of a voltage to the motor. In some embodiments, the RCMP (protruder  10 ) may allow for a level 1 sleep titration with an oral appliance where the patient will not be disturbed or awakened. Some embodiments comprise: remotely adjusting protruder  10  while monitoring and/or responsive to the PSG, such as, for example, to determine optimal settings for the protruder (e.g., similar in some respects to a level 1 CPAP). This may therefore allow a sleep physician to diagnose and/or recommend oral appliances, such as, for example, for patients who do not respond to or do not use a CPAP (e.g., upon CPAP non-compliance). 
     Referring now to  FIG. 19A , example operations for identifying a candidate for oral appliance therapy according to one implementation are shown. Patients can be labeled as favorable candidates for oral appliance therapy if the majority of respiratory disturbances such as apneas, hyponeas, oxygen desaturations, etc., for example, are eliminated. At  1902 A, data from a patient sleeping with a dental appliance is received. For example, the data is collected during an OSA titration study such as an oral appliance titration study. The collected data optionally includes data from the patient in all sleeping positions (e.g., supine, lateral, etc.) and all stages of sleep (e.g., REM stages and one or more non-REM stages). In some implementations, the dental appliance can be the mandibular protruder  10  or the remote-control mandibular protruder discussed above. Predictive criteria for determining whether a patient is a favorable candidate for oral appliance therapy can optionally prioritize the use of data collected during REM sleep stages over data collected during one or more non-REM sleep stages. Optionally, the predictive criteria can use only data collected during REM sleep stages. In this implementation, data is collected during REM sleep stages and one or more non-REM sleep stages but only data collected during REM sleep stages is used for the predictive criteria. Thus, at  1904 A, at least a portion of the data associated with a period of REM sleep is identified. 
     Additionally, in some embodiments, the predictive criteria can use a portion of data associated with a period of REM sleep, where the period of REM sleep is greater than or equal to a predetermined length of time. For example, the predictive criteria can use a portion of data associated with a period of REM sleep having a minimum length of 5 minutes, for example. In some implementations, the period of REM sleep can be a continuous, uninterrupted period of REM sleep. Alternatively, the period of REM sleep can be a plurality of fragmented periods of REM sleep that, in the aggregate, are greater than or equal to the predetermined length of time. At  1906 A, a number of respiratory disturbances in the portion of data associated with REM sleep are identified. The respiratory disturbances can include, but are not limited to, apneas, hyponeas, oxygen desaturations, etc. The predictive criteria can use a fixed frequency of respiratory disturbances to determine whether the patient is a favorable candidate for oral appliance therapy. For example, if during the portion of data associated with REM sleep, the patient experiences respiratory disturbances at a frequency (e.g., respiratory disturbances per unit time) less than a fixed frequency, then the patient is determined to be a favorable candidate. If, however, during the portion of data associated with REM sleep, the patient experiences respiratory disturbances at a frequency greater than the fixed frequency, then the patient is determined to be an unfavorable candidate. For example, the fixed frequency can optionally be 1 respiratory disturbance per 5 minute period of REM sleep. Accordingly, at  1908 A, a determination can be made as to whether the patient is a favorable candidate for oral appliance therapy. 
     Referring now to  FIG. 19C , example operations for identifying a candidate for oral appliance therapy according to another implementation are shown. Similarly to above, at  1912 , data from a patient sleeping with a dental appliance is received. For example, the data is collected during an OSA titration study such as an oral appliance titration study. The collected data optionally includes data from the patient in all sleeping positions (e.g., supine, lateral, etc.) and all stages of sleep (e.g., REM stages and one or more non-REM stages). In some implementations, the dental appliance can be the mandibular protruder  10  or the remote-control mandibular protruder discussed above. Predictive criteria for determining whether a patient is a favorable candidate for oral appliance therapy can optionally prioritize the use of data collected during REM sleep stages over data collected during one or more non-REM sleep stages. Optionally, the predictive criteria can use only data collected during REM sleep stages. Additionally, the predictive criteria can prioritize the use of data associated with REM sleep in a supine position over data collected during REM sleep in a lateral decubitus position. For example, at  1914 , at least a portion of the data associated with a period of REM sleep in the supine position is identified. 
     The predictive criteria can also use a portion of data associated with a period of REM sleep in the supine position, where the period of REM sleep in the supine position is greater than or equal to a predetermined length of time. For example, the predictive criteria can use a portion of data associated with a period of REM sleep in the supine position having a minimum length of 5 minutes, for example. In some implementations, the period of REM sleep in the supine position can be a continuous, uninterrupted period of REM sleep. Alternatively, the period of REM sleep in the supine position can be a plurality of fragmented periods of REM sleep in the supine position that, in the aggregate, are greater than or equal to the predetermined length of time. At  1916 , a number of respiratory disturbances in the portion of data associated with a period of REM sleep in the supine position are identified. The respiratory disturbances can include, but are not limited to, apneas, hyponeas, oxygen desaturations, etc. The predictive criteria can use a fixed frequency of respiratory disturbances to determine whether the patient is a favorable candidate for oral appliance therapy. For example, if during the portion of data associated with a period of REM sleep in the supine position, the patient experiences respiratory disturbances at a frequency (e.g., respiratory disturbances per unit time) less than a fixed frequency, then the patient is determined to be a favorable candidate at  1918 . For example, the fixed frequency can optionally be 1 respiratory disturbance per 5 minute period of REM sleep. Thus, at  1920 , the predictive criteria reveal a predicted success when the frequency of respiratory disturbances is less than or equal to the fixed frequency. 
     If, however, during the portion of data associated with REM sleep in the supine position, the patient experiences respiratory disturbances at a frequency greater than the fixed frequency at  1918 , a determination is made as to whether there is additional data associated with REM sleep in the supine position is available at  1922 . According to some implementations, when there are a plurality of portions of data associated with REM sleep in the supine position, the portions of data associated with periods of REM sleep in the supine position corresponding to smaller amounts of mandibular protrusion are identified and analyzed before the portions of data associated with periods of REM sleep in the supine position corresponding to greater amounts of mandibular protrusion. Thus, if additional data associated with a period of REM sleep in the supine position is available (e.g., data associated with a period of REM sleep in the supine position having a length greater than a predetermined period of time such as 5 minutes, for example), then steps  1914 - 1918  are repeated for each subsequent portion of data. 
     If, however, additional data associated with a period of REM sleep in the supine position is not available at  1922 , a determination is made as to whether the patient is a side sleeper at  1924 . As discussed above, the predictive criteria can prioritize the use of data associated with a period of REM sleep in the supine position over data associated with a period of REM sleep in the lateral decubitus position. Evidence that the patient is a side sleeper can be obtained from a patient questionnaire, behavior during the sleep study or from a previous sleep study. In some embodiments, evidence of side sleeping is obtained from an previous sleep study that was conducted in the patient&#39;s home or similar environment. To be considered a side sleeper according to implementations discussed herein, the patient should sleep a substantial portion of the night in the lateral position. For example, the patient should sleep the majority of the night (i.e., at least 50%) in the lateral decubitus position. In some implementations, data associated with a period of REM sleep in the lateral position can be used if data associated with a period of REM sleep in the supine position is not available when the patient is a side sleeper. For example, data associated with a period of REM sleep in the lateral position can optionally be used if data associated with a period of REM sleep in the supine position is not available when the patient is a side sleeper, where the period of REM sleep is at least 5 minutes of either continuous, uninterrupted or fragmented REM sleep. 
     At  1932 , if the patient is a side sleeper, at least a portion of the data associated with a period of REM sleep in the lateral position is identified. The predictive criteria can use a portion of data associated with a period of REM sleep in the lateral position, where the period of REM sleep in the lateral position is greater than or equal to a predetermined length of time. For example, the predictive criteria can use a portion of data associated with a period of REM sleep in the lateral position having a minimum length of 5 minutes, for example. In some implementations, the period of REM sleep in the lateral position can be a continuous, uninterrupted period of REM sleep. Alternatively, the period of REM sleep in the lateral position can be a plurality of fragmented periods of REM sleep in the lateral position that, in the aggregate, are greater than or equal to the predetermined length of time. At  1934 , a number of respiratory disturbances in the portion of data associated with a period of REM sleep in the lateral position are identified. The respiratory disturbances can include, but are not limited to, apneas, hyponeas, oxygen desaturations, etc. The predictive criteria can use a fixed frequency of respiratory disturbances to determine whether the patient is a favorable candidate for oral appliance therapy. For example, if during the portion of data associated with a period of REM sleep in the lateral position, the patient experiences respiratory disturbances at a frequency (e.g., respiratory disturbances per unit time) less than a fixed frequency, then the patient is determined to be a favorable candidate at  1936 . For example, the fixed frequency can optionally be 1 respiratory disturbance per 5 minute period of REM sleep. Thus, at  1920 , the predictive criteria reveal a predicted success when the frequency of respiratory disturbances is less than or equal to the fixed frequency. 
     If, however, during the portion of data associated with REM sleep in the lateral position, the patient experiences respiratory disturbances at a frequency greater than the fixed frequency at  1936 , a determination is made as to whether there is additional data associated with REM sleep in the lateral position is available at  1938 . According to some implementations, when there are a plurality of portions of data associated with REM sleep in the lateral position, the portions of data associated with periods of REM sleep in the lateral position corresponding to smaller amounts of mandibular protrusion are identified and analyzed before the portions of data associated with periods of REM sleep in the lateral position corresponding to greater amounts of mandibular protrusion. Thus, if additional data associated with a period of REM sleep in the lateral position is available (e.g., data associated with a period of REM sleep in the lateral position having a length greater than a predetermined period of time such as 5 minutes, for example), then steps  1932 - 1936  are repeated for each subsequent portion of data. 
     If the patient is not determined to be a side sleeper at  1924  or additional data associated with a period of REM sleep in the lateral position is not available at  1938 , a determination is made as to whether data includes data collected for a predetermined titration range at  1926 . In some implementations, the predetermined titration range includes a maximum protrusion of the mandibular protruder or other titration appliance. Alternatively or additionally, the predetermined titration range includes a range previously specified (i.e., a range specified by the dentist), a maximum voluntary protrusion range of a patient or some other maximum limit. The predetermined titration range can optionally include a maximum protrusion +/−1.0 mm or +/− a percentage, such as +/−10%. Optionally, the percentage can be a percentage of the protrusive range. In these implementations, the determination requires that the data be collected at the maximum protrusion. If the data includes data collected for the predetermined titration range, the patient is considered an unfavorable candidate for oral appliance therapy. Thus, at  1928 , the predictive criteria reveal a predicted failure. If the data does not include data collected for the predetermined titration range, the data is considered inconclusive at  1930 . 
     Optionally, if the predictive criteria reveal a predicted success at  1920 , an effective protrusion distance for oral appliance therapy can be determined. As discussed above, when there are a plurality of portions of data associated with REM sleep in the supine position, the portions of data associated with periods of REM sleep in the supine position corresponding to smaller amounts of mandibular protrusion are identified and analyzed before the portions of data associated with periods of REM sleep in the supine position corresponding to greater amounts of mandibular protrusion. The minimum effective amount of mandibular protrusion, therefore, is an amount of mandibular protrusion corresponding to the portion of data associated with the period of REM sleep in the supine position with the smallest amount of mandibular protrusion. This minimum effective amount of mandibular protrusion can optionally be provided as a recommended setting for the oral appliance for oral appliance therapy. In the event that a plurality of portions of data associated with REM sleep in the lateral position are used by the predictive criteria, the portions of data associated with periods of REM sleep in the lateral position corresponding to smaller amounts of mandibular protrusion are identified and analyzed before the portions of data associated with periods of REM sleep in the lateral position corresponding to greater amounts of mandibular protrusion. The effective amount of mandibular protrusion, therefore, is an amount of mandibular protrusion corresponding to the portion of data associated with the period of REM sleep in the lateral position with the smallest amount of mandibular protrusion. This smallest amount of mandibular protrusion can optionally be provided as a recommended setting for the oral appliance for oral appliance therapy. 
     Referring now to  FIG. 19B , example operations for identifying a candidate for oral appliance therapy according to yet another implementation are shown. In this implementation, example operations for identifying a patient having mild to moderate sleep apnea as a candidate for oral appliance therapy are shown. In some implementations, a patient with mild to moderate sleep apnea can have a respiratory disturbance index less than or equal to 30, for example. Unlike the operations discussed with regard to  FIG. 19C , the predictive criteria can use data associated with periods of REM sleep in either the supine or the lateral position regardless of whether the patient is a side sleeper. For example, at  1902 B, data from a patient sleeping with a dental appliance is received. For example, the data is collected during an OSA titration study such as an oral appliance titration study. The collected data optionally includes data from the patient in all sleeping positions (e.g., supine, lateral, etc.) and all stages of sleep (e.g., REM stages and one or more non-REM stages). In some implementations, the dental appliance can be the mandibular protruder  10  or the remote-control mandibular protruder discussed above. Predictive criteria for determining whether a patient is a favorable candidate for oral appliance therapy can optionally prioritize the use of data collected during REM sleep stages over data collected during one or more non-REM sleep stages. Optionally, the predictive criteria can use only data collected during REM sleep stages. Thus, at  1904 B, at least a portion of the data associated with a period of REM sleep in the supine or the lateral position is identified. 
     Additionally, in some embodiments, the predictive criteria can use a portion of data associated with a period of REM sleep in the supine or the lateral position, where the period of REM sleep in the supine or the lateral position is greater than or equal to a predetermined length of time. For example, the predictive criteria can use a portion of data associated with a period of REM sleep in the supine or the lateral position having a minimum length of 5 minutes, for example. In some implementations, the period of REM sleep can be a continuous, uninterrupted period of REM sleep. Alternatively, the period of REM sleep can be a plurality of fragmented periods of REM sleep that, in the aggregate, are greater than or equal to the predetermined length of time. At  1906 B, a number of respiratory disturbances in the portion of data associated with REM sleep in the supine or the lateral position are identified. The respiratory disturbances can include, but are not limited to, apneas, hyponeas, oxygen desaturations, etc. The predictive criteria can use a fixed frequency of respiratory disturbances to determine whether the patient is a favorable candidate for oral appliance therapy. For example, if during the portion of data associated with REM sleep in the supine or the lateral position, the patient experiences respiratory disturbances at a frequency (e.g., respiratory disturbances per unit time) less than a fixed frequency, then the patient is determined to be a favorable candidate. If, however, during the portion of data associated with REM sleep in the supine or the lateral position, the patient experiences respiratory disturbances at a frequency greater than the fixed frequency, then the patient is determined to be an unfavorable candidate. For example, the fixed frequency can optionally be 1 respiratory disturbance per 5 minute period of REM sleep in the supine or the lateral position. Accordingly, at  1908 B, a determination can be made as to whether the patient is a favorable candidate for oral appliance therapy. 
     In addition to providing predictive criteria to determine whether a patient is a favorable candidate for an oral appliance, and optionally providing the effective protrusion distance (e.g., a target therapeutic distance), it is also possible to provide a graphical display of the results of an obstructive sleep apnea titration study. For example, the graphical display can be a report summarizing the physiologic signals collected from the polysomnogram (PSG) and the protrusion data collected from the titration system. In some implementations, the data included in the graphical display can include sleep stages (e.g., REM and one or more non-REM sleep stages), counts of respiratory events (e.g., apneas, hyponeas, oxygen desaturations, etc.), sleep positions (e.g., supine, lateral, etc.), oximetry levels and amounts of mandibular protrusion. Optionally, the data included in the graphical display can include only information used in the predictive criteria discussed above (i.e., data associated with REM sleep). The data included in the graphical display can also include at least two of sleep stages, counts of respiratory events, sleep positions, oximetry levels and amounts of mandibular protrusion. Alternatively or additionally, the graphical display can include data for a plurality of steps of the titration study such that an amount of mandibular protrusion is displayed in relation to at least one of a sleep stage, a count of respiratory events, a sleep position and an oximetry level at each step of the titration study. The amount of mandibular protrusion at each step of the titration study can be created automatically by the PSG and/or titration system, manually by the operator, or a combination of both. In some implementations, the graphical display can be a chart displaying the results of the titration study. Alternatively, in other implementations, the graphical display can be a hypnogram displaying the results of the titration study. 
     In some implementations, an amount of mandibular protrusion at each step of the titration study can be displayed in relation to one or more of the time at each step of the titration study, sleep stage, sleep position, count of respiratory events, oximetry levels, etc. Referring now to  FIG. 20 , an example chart for displaying results of an obstructive sleep apnea titration study is shown. As shown in  FIG. 20 , the amount of mandibular protrusion (i.e., Treatment Level) at each step in the titration study occupies a column of the chart. Additionally, other data associated with each step of the titration study occupies additional columns in the chart such that the data associated with each step of the titration study occupies a row in the chart. For example, the chart includes data for the time in REM sleep (TIME REM), the time in REM sleep in the supine position (TIME REM Supine), the time in REM sleep in the lateral position (TIME REM lateral), total respiratory events during REM sleep in the supine position (Events Supine), total respiratory events during REM sleep in the lateral position (Events Lateral) and respiratory event data (e.g., obstructive apnea count, central apnea count, hyponea count, total apnea and hyponea count (A+H Total), apnea-hyponea index (AHI), respiratory effort related arousal (RERA), total respiratory event count and respiratory disturbance index (RDI). It should be understood that the amount of mandibular protrusion and other data associated with each step of the titration study can alternatively occupy rows in a chart such that the data associated with each step of the titration study occupies a column in the chart. 
     Optionally, a portion of the graphical display can be highlighted. For example, a portion of the chart including data associated with a period of REM sleep can be highlighted. As discussed above, the predictive criteria can use data associated with a period of REM sleep in the supine position (or in some cases the lateral position) greater than or equal to a predetermined length of time (e.g., 5 minutes). In some implementations, one or more portions of the chart including data associated with periods of REM sleep greater than or equal to the predetermined length of time can be highlighted. Alternatively or additionally, one or more portions of the chart including data associated with periods of REM sleep greater than or equal to the predetermined length of time, as well as having a frequency of respiratory events less than or equal to a fixed frequency (e.g., 1 event/5 minute period), can be highlighted. For example, as shown in  FIG. 20 , portions of the chart  2001  are highlighted. The portions of the chart  2001  are segments of REM sleep in the supine position greater than 5 minutes along with corresponding counts of respiratory events. In particular, the portions of the chart  2001  are segments at 14.2 mm of mandibular protrusion with 0 respiratory events and 14.4 mm of protrusion with 4 respiratory events. Although  FIG. 20  illustrates highlighting the amount of mandibular protrusion and the count of respiratory events, it should be understood that any data associated with the amount of mandibular protrusion can optionally be highlighted. 
     Referring now to  FIG. 21 , an example hypnogram for displaying results of an obstructive sleep apnea titration study is shown. The hypnogram graphically displays the amount of mandibular position in temporal relation to sleep stages (e.g., REM and one or more non-REM stages), respiratory events (e.g., apneas, hyponeas, oxygen desaturations, etc.), body positions (e.g., supine, lateral, etc.) and oximetry levels. Similarly to the chart in  FIG. 20 , a portion of the graphical display can optionally be highlighted. For example, a portion of the hypnogram including data associated with a period of REM sleep can be highlighted. As discussed above, the predictive criteria can use data associated with a period of REM sleep in the supine position (or in some cases the lateral position) greater than or equal to a predetermined length of time (e.g., 5 minutes). In some implementations, one or more portions of the hypnogram including data associated with periods of REM sleep greater than or equal to the predetermined length of time can be highlighted. Alternatively or additionally, one or more portions of the hypnogram including data associated with periods of REM sleep greater than or equal to the predetermined length of time, as well as having a frequency of respiratory events less than or equal to a fixed frequency (e.g., 1 event/5 minute period), can be highlighted. For example, as shown in  FIG. 21 , portions of the hypnogram  2101  are highlighted. The portions of the hypnogram  2101  are segments of REM sleep in the supine position greater than 5 minutes along with corresponding counts of respiratory events, sleep stages, oximetry levels and sleep positions. 
     It should be appreciated that the logical operations described herein with respect to the various figures may be implemented (1) as a sequence of computer implemented acts or program modules (i.e., software such as (a) an automated titration study scoring software, (b) the polysomnogram software, (c) the titration system software, (d) a third party software, or (e) any other software) running on a computing device, (2) as interconnected machine logic circuits or circuit modules (i.e., hardware) within the computing device and/or (3) a combination of software and hardware of the computing device. Thus, the logical operations discussed herein are not limited to any specific combination of hardware and software. The implementation is a matter of choice dependent on the performance and other requirements of the computing device. Accordingly, the logical operations described herein are referred to variously as operations, structural devices, acts, or modules. These operations, structural devices, acts and modules may be implemented in software, in firmware, in special purpose digital logic, and any combination thereof. It should also be appreciated that more or fewer operations may be performed than shown in the figures and described herein. These operations may also be performed in a different order than those described herein. 
     When the logical operations described herein are implemented in software, the process may execute on any type of computing architecture or platform. For example, referring to  FIG. 22 , an example computing device upon which embodiments of the invention may be implemented is illustrated. In particular, the controller  94 , the PSG device  96  and/or the workstation  92  discussed above include a computing device, such as computing device  2200  shown in  FIG. 22 . The computing device  2200  may include a bus or other communication mechanism for communicating information among various components of the computing device  2200 . In its most basic configuration, computing device  2200  typically includes at least one processing unit  2206  and system memory  2204 . Depending on the exact configuration and type of computing device, system memory  2204  may be volatile (such as random access memory (RAM)), non-volatile (such as read-only memory (ROM), flash memory, etc.), or some combination of the two. This most basic configuration is illustrated in  FIG. 22  by dashed line  2202 . The processing unit  2206  may be a standard programmable processor that performs arithmetic and logic operations necessary for operation of the computing device  2200 . 
     Computing device  2200  may have additional features/functionality. For example, computing device  2200  may include additional storage such as removable storage  2208  and non-removable storage  2210  including, but not limited to, magnetic or optical disks or tapes. Computing device  2200  may also contain network connection(s)  2216  that allow the device to communicate with other devices. Computing device  2200  may also have input device(s)  2214  such as a keyboard, mouse, touch screen, etc. Output device(s)  2212  such as a display, speakers, printer, etc. may also be included. The additional devices may be connected to the bus in order to facilitate communication of data among the components of the computing device  2200 . All these devices are well known in the art and need not be discussed at length here. 
     The processing unit  2206  may be configured to execute program code encoded in tangible, computer-readable media (or non-transitory computer-readable media). Computer-readable media refers to any media that is capable of providing data that causes the computing device  2200  (i.e., a machine) to operate in a particular fashion. Various computer-readable media may be utilized to provide instructions to the processing unit  2206  for execution. Common forms of computer-readable media include, for example, magnetic media, optical media, physical media, memory chips or cartridges, a carrier wave, or any other medium from which a computer can read. Example tangible, computer-readable media may include, but is not limited to, volatile media, non-volatile media and transmission media. Volatile and non-volatile media may be implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data and common forms are discussed in detail below. Transmission media may include coaxial cables, copper wires and/or fiber optic cables, as well as acoustic or light waves, such as those generated during radio-wave and infra-red data communication. 
     In an example implementation, the processing unit  2206  may execute program code stored in the system memory  2204 . For example, the bus may carry data to the system memory  2204 , from which the processing unit  2206  receives and executes instructions. The data received by the system memory  2204  may optionally be stored on the removable storage  2208  or the non-removable storage  2210  before or after execution by the processing unit  2206 . 
     Computing device  2200  typically includes a variety of computer-readable media. Computer-readable media can be any available media that can be accessed by device  2200  and includes both volatile and non-volatile media, removable and non-removable media. Computer storage media include volatile and non-volatile, and removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. System memory  2204 , removable storage  2208 , and non-removable storage  2210  are all examples of computer storage media. Computer storage media include, but are not limited to, RAM, ROM, electrically erasable program read-only memory (EEPROM), flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by computing device  2200 . Any such computer storage media may be part of computing device  2200 . 
     It should be understood that the various techniques described herein may be implemented in connection with hardware or software or, where appropriate, with a combination thereof. Thus, the methods and apparatuses of the presently disclosed subject matter, or certain aspects or portions thereof, may take the form of program code (i.e., instructions) embodied in tangible media, such as floppy diskettes, CD-ROMs, hard drives, or any other machine-readable storage medium wherein, when the program code is loaded into and executed by a machine, such as a computing device, the machine becomes an apparatus for practicing the presently disclosed subject matter. In the case of program code execution on programmable computers, the computing device generally includes a processor, a storage medium readable by the processor (including volatile and non-volatile memory and/or storage elements), at least one input device, and at least one output device. One or more programs may implement or utilize the processes described in connection with the presently disclosed subject matter, e.g., through the use of an application programming interface (API), reusable controls, or the like. Such programs may be implemented in a high level procedural or object-oriented programming language to communicate with a computer system. However, the program(s) can be implemented in assembly or machine language, if desired. In any case, the language may be a compiled or interpreted language and it may be combined with hardware implementations. 
     Some embodiments of the present methods comprises communicating or transmitting the results of the sleep titration to an entity (e.g., a dentist), such as, for example, in the form of either a scale reading or protrusion amount (e.g., an optimal mandibular displacement), such as, for example, from either max retrusion or distance from when the teeth are end to end. Some embodiments of the present methods comprises receiving and/or accessing the results of the sleep titration (e.g., performed using one or more of the present protruders, positioning devices, and/or apparatuses) from, for example, an entity (e.g., a dentist or physician). Some embodiments comprise producing, prescribing, and/or ordering an oral appliance based on the results (e.g., an oral appliance for the patient with the optimal mandibular displacement). Some embodiments comprise adjusting and/or calibrating an oral appliance (e.g., a commercially-available oral appliance, such as, for example, a MAS appliance available from SomnoMed, Canada, U.S.A., Australia) to have a mandibular displacement corresponding to an optimal mandibular displacement. In some embodiments, trays  58  and  60  may be used in and/or may be used to make or produce the oral appliance. For example, upper and lower trays  58  and  60  can be coupled with a screw, clamp, adhesive, or the like to statically fit together at a specified displacement (e.g., optimal mandibular displacement). After the patient has been given the produced oral appliance, such as a mandibular protrusion retainer, check-ups may be carried out as desired to ensure useful functioning. Some embodiments of the present oral appliances comprise an oral appliance that has been adjusted to cause an optimal mandibular displacement when worn by a patient, the optimal mandibular displacement for the patient having been determined by a sleep titration performed with an embodiment of the present protruders, devices, and/or systems. 
     In some embodiments, controller  94  may include and/or house batteries sufficient to motorize the protruder  10 , and electronics sufficient to control or send control signals to protruder  10  and/or transmit data (e.g., to workstation  92  or PSG device  96 ). Controller  94  may be coupled to (e.g., in electronic communication with) protruder  10  via a cable and may be expected to reside under a pillow or on a night stand during the patient study. Protruder  10  may have a wired or wireless bidirectional connection to a control module (e.g., workstation  92  or other control module) that allows a technician to alter the displacement amounts and regulate device status from another room. Protruder  10  may also have a unidirectional connection to a PSG  96  to permit logging of activity over time and generation of a single inclusive report or data stream (e.g., to workstation  92 ), which may include a single or multiple output jack, such as, for example, similar to output jacks on CPAP machines, which will interface with PSG devices  96  to provide data output. 
     Workstation  92  may include the software component with which a technician interfaces to control and receive status information on protruder  10 . Workstation  92  and/or appropriate software may be configured to communicate with controller  94  either wired or wirelessly to provide or enable bi-directional status and control data. The software may be configured to display status information like force and position, as well as control movement or position of protruder  10  to retract or extend lower appliance  20  and the patient&#39;s mandible relative to upper appliance  18  and the patient&#39;s maxilla. The software component may comprise an application configured to separately or solely control protruder  10  (as opposed to jointly controlling protruder  10  and PSG device  96 ), and may, for example: include the capability to increase or decrease relative displacement of lower appliance  20  relative to upper appliance  18 ; set the increments at which to move linear actuator  17  of motor  16 ; and/or reset protruder  10  (e.g., lower appliance  20 ) to the rest position. The software may also be configured to include safety features and restrictions on protruder  10 , such as, for example, to prevent extending or retracting the jaw beyond pre-set limits and/or to prevent protruder  10  from exerting a force on mandible in excess of a predetermined maximum (e.g., a force equivalent to 2 kilograms). 
     Coupling components may be achieved through additional unmentioned parts, structures, or configurations that permit the components to be coupled in the manner described. Two components that are coupled may include the two components being integral with one another, if such a configuration would permit the two components to interrelate in the manner claimed. When a first component has or includes a second component, it can include embodiments in which the first and second components are connected together or through other parts. Also, it should be understood that various portions or components of embodiments disclosed herein may be used in other embodiments disclosed herein. For example, the present disclosure includes embodiments of mandibular protruders, mandibular positioning devices that may be suitable for use in embodiments of the present mandibular protruders, and apparatuses that may be suitable for use with embodiments of the present mandibular positioning devices and/or in embodiments of the present mandibular protruders. 
     In one example, the present disclosure includes various embodiments of a mandibular protruder (e.g.,  10 ) comprising: an upper mounting bracket  12  having an upper dental appliance  18 ; a lower mounting bracket  14  having a lower dental appliance  18 , the lower mounting bracket configured to be coupled to the upper mounting bracket such that relative motion of the lower mounting bracket and the upper mounting bracket is constrained to linear motion in an anterior-posterior direction; a mandibular positioning device  19  configured to be coupled to upper mounting bracket  12  and lower mounting bracket  14 , the mandibular positioning device having a drive motor  16  configured to adjust the relative position of lower mounting bracket  14  and upper mounting bracket  12  if the mandibular positioning device is coupled to upper mounting bracket  12  and lower mounting bracket  14 ; an upper release mechanism configured to release upper dental appliance  18  from mandibular positioning device  19  if mandibular positioning device  19  is coupled to upper mounting bracket  12 ; and a lower release mechanism configured to release lower dental appliance  20  from mandibular positioning device  19  if mandibular positioning device  19  is coupled to lower mounting bracket  14 . 
     In another example, the present disclosure includes various embodiments of a mandibular protruder (e.g.,  10 ) comprising: an upper mounting bracket  12  having an upper dental appliance  18 ; a lower mounting bracket  14  having a lower dental appliance  20 , the lower mounting bracket configured to be coupled to the upper mounting bracket such that the lower mounting bracket can move linearly relative to the upper mounting bracket; a drive motor  16  coupled to one of upper mounting bracket  12  and lower mounting bracket  14 , the drive motor configured to effect relative displacement of lower mounting bracket and the upper mounting bracket; and an initial position adjustment mechanism  50  configured to adjust an initial position of the other of the upper mounting bracket and the lower mounting bracket. 
     In another example, the present disclosure includes various embodiments of a mandibular positioning device (e.g.,  19 ) comprising: a drive motor  16  having a connector  46  configured to be coupled to a mounting bracket (e.g.,  12  or  14 ) of a first dental appliance (e.g.,  18  or  20 ); an adjustment mechanism  50  having a connector  52  configured to be coupled to a mounting bracket (e.g.,  12  or  14 ) of a second dental appliance (e.g.,  18  or  20 ); and a housing  48  having a sidewall with at least a first opening and a second opening, the housing coupled to drive motor  16  and the adjustment mechanism  50  such that the housing encloses at least a portion of each of the drive motor and the adjustment mechanism, the drive-motor connector extends out of the housing through the first opening, and the adjustment-mechanism connector extends out of the housing through the second opening. In some embodiments, adjustment mechanism  50  is configured to linearly adjust the position of the adjustment-mechanism connector. In some embodiments, drive motor  16  is configured to linearly move the drive-motor connector in a direction substantially parallel to the direction in which the adjustment mechanism can adjust the adjustment-mechanism connector. 
     In another example, the present disclosure includes various embodiments of an apparatus for use with a mandibular positioning device (e.g.,  19 ), the apparatus comprising: an upper mounting bracket  12  having an upper dental appliance  14 ; a lower mounting bracket  14  having a lower dental appliance  20 , the lower mounting bracket configured to be coupled to the upper mounting bracket such that relative linear motion of the lower mounting bracket and the upper mounting bracket is permitted; and a relative position indicator for indicating relative position of the lower dental appliance and the upper dental appliance; where the apparatus is configured such that the lower mounting bracket can be coupled to the upper mounting bracket and such that the upper mounting bracket and the lower mounting bracket can be independently coupled to a first connector (e.g.,  46 ) and a second connector (e.g.,  52 ) respectively of a mandibular positioning device. 
       FIG. 13  depicts a polymeric bag  150  that is configured to fit around device  19  to reduce and/or prevent contamination of device  19  during use. In the embodiment shown, bag  150  has a first end  152  and a second end  154 . Second end  154  includes an opening  156  and a flap  158  comprising an (e.g., pressure-sensitive) adhesive  158 . Bag  150  is configured to permit device  19  to be inserted through opening  156  such that flap  158  can be folded over to cover opening  156  and adhesive  160  will hold flap  158  over opening  156 . First end  152  includes extended portions  162  and  164  configured to permit connectors  46  and  52  to extend out of bag  150  when device  19  is disposed in bag  150  (e.g., during operation of device  19  and/or protruder  10 ). More particularly, in the embodiment shown, extended portion  162  includes a hole  166  configured to permit connector  46  to extend out of hole  166 , and extended portion  164  has a hole  168  configured to permit connectors  52  to extend out of through hole  168 . Polymeric bag  150  can comprise, for example, a plastic or other liquid- and/or gas-impermeable material that is configured to reduce contaminate of device  19  and/or protruder  10  generally, such as with body fluids and/or the like. In the embodiment shown, bag  150  is disposable (e.g., after a single use) and is a single-use bag. 
     Alternatively or additionally, some embodiments can comprise: a polymeric bag (not shown), configured to fit around at least one (e.g., both) of upper dental appliance  18  and lower dental appliance  20 , and/or two bags each configured to fit around one of upper dental appliance  18  and lower dental appliance  20 . In some embodiments, the polymeric bag is configured to fit between dental impression material and the at least one of upper dental appliance  18  and lower dental appliance  20 . In some embodiments, a polymeric bag is configured to fit around device  19 . Some embodiments of the present methods comprise disposing a positioning device (e.g.,  19 ) in a polymeric bag (e.g.,  150 ) such that a drive-motor connector (e.g.,  46 ) and/or an adjustment-mechanism connector (e.g.,  52 ) extend out of the polymeric bag; coupling an upper mounting bracket (e.g.,  12 ) having an upper dental appliance (e.g.,  18 ) to one of the drive-motor connector and the adjustment-mechanism connector, and a lower mounting bracket (e.g.,  14 ) having a lower dental appliance (e.g.,  20 ) to the other of the drive-motor connector and the adjustment-mechanism connector (e.g., such that the upper mounting bracket and lower mounting bracket are coupled by a rail system (e.g.,  22 )); and/or actuating the device to displace a patient&#39;s mandible relative to the patient&#39;s maxilla. 
       FIGS. 14A and 14B  depict an alternate embodiment  10 A of the present protruders.  FIGS. 14C-14F  depict upper mounting bracket  12   a  and lower mounting bracket  14   a  of protruder  10   a . Protruder  10   a  is substantially similar to protruder  10 , above, except where noted. Components of protruder  10   a  are numbered similarly to similar components of protruder  10  (e.g., connector  46   a  and connector  46 ), and such similarly numbered components are substantially similar, except where otherwise noted. The description of protruder  10   a  will therefore focus on the differences between protruder  10   a  and protruder  10 .  FIG. 14F  depicts a cross-sectional view of alternate housing  48   a.    
     In the embodiment shown, rail system  22   a  (e.g., guides  23   a ) is spaced apart from upper dental appliance  18   a  and lower dental appliance  20   a . More particularly, at least one of (e.g., both of upper mounting bracket  12   a  and lower mounting bracket  14   a  includes an elongated planar portion (e.g., elongated planar portion of upper mounting bracket  12  that extends from upper dental appliance  18   a  to the end of bracket  12  that couples to connector  46   a ) having a length, and rail system  22   a  has a length that is less than (e.g., less than 30, 40, 50, 60, 70, 80, 90 percent of) the length of the elongated planar portion. Additionally, in the embodiment shown, housing  48   a  includes a back portion  200  that is openable or removable by way of clips  204  that are configured to extend through openings  208 . Housing  48   a  is also configured to include enlarged portions  212  and  214  adjacent to the holes through which connectors  46   a  and  52   a  extend. In the embodiment shown, enlarged portions  212  and  214  are larger than the respective holes, and are configured to receive a seal between housing  48   a  and respective connectors  46   a  and  52   a.    
     In the embodiment shown, one or more (e.g., two) pointers  34   a  are each coupled to (e.g., integral with) the top of a guide  23   a , such that, for example, the pointer need not extend beyond or be disposed between the guide  23   a  closes to trays  58   a  and  60   a , thereby permitting a reduction in the length of rail system  22   a . Additionally, in the embodiment shown, the upwardly extending portion (through which hole  75   a  passes) of upper mounting bracket  12   a  that is configured to be coupled to connector  46   a  has a maximum width that is less than the distance between the inner edges of opposing guides  23   a  of rail system  22  (guides  23   a  on opposite sides of upper mounting bracket  12   a ). Similarly, in the embodiment shown, the downwardly extending portion (through which hole  79   a  passes) of lower mounting bracket  14   a  that is configured to be coupled to connector  52   a  also has a maximum width that is less than the distance between the inner edges of opposing guides  23   a  of rail system  22   a  (guides  23   a  on opposite sides of upper mounting bracket  12   a ). In contrast, protruder  10 , above, is configured such that the upwardly extending portion (through which hole  75  passes) of upper mounting bracket  12  that is configured to be coupled to connector  46  has a maximum width that is greater than the distance between the inner edges of opposing guides  23  of rail system  22 ; and such that the downwardly extending portion (through which hole  79  passes) of lower mounting bracket  14  that is configured to be coupled to connector  52  has a maximum width that is greater than the distance between the inner edges of opposing guides  23  of rail system  22 . 
     In the embodiment shown, lateral portions  70   a  and  72   a  of upper dental appliance  18   a  (tray  58   a ) and lower dental appliance  20   a  (tray  60   a ) are relatively shorter than lateral portions  70  and  72  of trays  58  and  60 , respectively. More particularly, trays  58   a  and  60   a  are configured to receive a patient&#39;s upper and lower teeth, respectively, such that at least one of lateral portions  70   a  and  72   a  terminate anterior to (e.g., extend no further back than) one or more of the patient&#39;s molars (e.g., third molar, second molar, and/or first molar). In the embodiment shown, device  19   a  (e.g., housing  48   a , as shown) comprises one or more (two, as shown) indicators  216  that indicate which side of device  19   a  should face upwards during use, and thereby which of connectors  46  and  52  should correspond to upper mounting bracket  12 . 
       FIG. 14H  illustrates cross-sectional view of a seal  218  suitable for use in some embodiments of the present mandibular protruders (e.g.,  10 ). In the embodiment shown, housing  48   a  (see also  FIG. 14G ) is sectioned parallel to the longitudinal axis of connector  46   a , however, seal  218  is also suitable for use around connector  52   a . For example, in the embodiment shown, protruder  10   a  comprises a first seal  218  disposed around drive-motor connector  46   a  between housing  48   a  and drive-motor connector  46   a  (as shown, in enlarged portion  212 ); and a second seal  218  disposed around adjustment-mechanism connector  52   a  between housing  48   a  and adjustment-mechanism connector  52  (as shown, in enlarged portion  214 ). In the embodiment shown, seal  218  is donut-shaped (such that connector  46  extends through the center opening) and comprises a seal body  222  and a coil spring  226  coupled to seal body  222 . More particularly, seal body  222  comprises an annular opening (e.g., around connector  46   a , as shown) into which coil spring  226  is received. In the embodiment shown, coil spring  226  has an oval-shaped cross-section. Seal  218  may comprise a U-N130 series seal available from BAL SEAL ENGINEERING, U.S.A., and may be referred to by BAL SEAL by part number X572322. 
       FIGS. 15A-15D  depict various views of an adjustment-mechanism connector or rod  52   a  suitable for use in embodiments of the present protruders (e.g.,  10   a ). Connector  52   a  is substantially similar to connector  52 , above, except where noted. The description of connector  52   a  will therefore focus on the differences between connector  52   a  and connector  52 . Connector  52   a  comprises an enlarged portion  258 ). Portion  258  has a length that is equal to, between, or less than any 30, 40, 50, 60, 70, 80, 90 percent of the overall length of connector  52   a . In the embodiment shown, enlarged portion  258  has a cross-section that is larger than the cross-section of the relatively smaller portion of connector  52   a  that extends out of housing  48   a . Enlarged portion  258  is thus configured to limit the displacement of connector  52   a  relative to housing  48   a  because enlarged portion  258  is too large to exit housing  48   a  during actuation of the adjustment mechanism. In the embodiment shown, connector  52   a  includes longitudinal protrusions  55   a  that extend the full length of enlarged portion  258 . 
       FIGS. 16A-16B  are cutaway-perspective and side cross-sectional views, respectively, of another embodiment  19   b  of the present positioning devices. Device  19   b  is substantially similar to device  19   a , above, except where noted. Components of device  19   b  are numbered similarly to similar components of device  19   a  (e.g., connector  46   b  and connector  46   a ), and such similarly numbered components are substantially similar, except where otherwise noted. The description of device  19   b  will therefore focus on the differences between device  19   b  and device  19   a .  FIG. 16C  depicts a cross-sectional view of housing  48   b . Housing  48   b  of device  19   b  includes a protruded portion  262  that is configured to receive a plug  266  (e.g., a female plug, as shown). Female plug  266  is wired to drive motor  16  such that a male plug (not shown) can be removably coupled to female plug  266  to apply voltage and/or send control signals to drive motor  16  (e.g., from controller  94  and/or workstation  92 ). Additionally, in the embodiment shown, device  19   b  includes an enlarged knob  56   b  that is configured to be turned by hand (e.g., knob  56   b  has a transverse dimension that is at least twice as large as the diameter of screw  54   b.    
     Referring now to  FIGS. 17A-17B ,  FIG. 17A  is a cutaway perspective view of another embodiment  19   c  of the present positioning devices; and  FIG. 17B  is a side view of another embodiment of the present protruders  10   c  that includes positioning device  19   c . Device  19   c  is substantially similar to device  19   b , with the exception that plug  266   c  of device  19   c  has a circular configuration in which a plurality of pins are arranged in a circular shape. 
     The various illustrative embodiments of devices, systems, and methods described herein are not intended to be limited to the particular forms disclosed. Rather, they include all modifications and alternatives falling within the scope of the claims. 
     The claims are not intended to include, and should not be interpreted to include, means-plus- or step-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase(s) “means for” or “step for,” respectively. 
     Examples 
     In a clinical study of 67 patients, subjects were labeled a favorable candidate (predicted success) if a minimum of 5 minutes of REM sleep in the supine position was achieved with less than 1 event for every 5 minutes within the REM sleep period. Additionally, for subjects that demonstrated in a baseline study that they spent the majority of the night in the lateral position (e.g., &gt;50%), subjects were labeled a favorable candidate (predicted success) if REM sleep in the supine position was not achieved and a minimum of 5 minutes of REM sleep in the lateral position was achieved with less than 1 event per 5 minutes. Alternatively, subjects were labeled as unfavorable candidates (predicted failures) if more than 1 event was observed for every 5 minutes within the REM period at near maximum protrusion (within 1 mm). Otherwise, subjects were labeled as inconclusive due to inadequate data. The study found that the sensitivity and specificity of the test was 86% and 92%, respectively. Only 9% of patients were found to have inadequate data. In the study, to apply the above criteria, and provide an interpretation of the titration study, the scored data from the polysomnogram was compared and reviewed alongside the corresponding position data from the titration device. 
     The efficacy of using the output from a technician controlled RCMP titration device to determine the geometry of an oral appliance was determined. The geometry was determined by selecting the minimal amount of protrusion where the number of events in REM, in either supine or lateral depending on the patient, met the criteria. Testing was performed by a dental investigator and/or one or more sleep physicians as described below on 67 different subjects with symptoms of obstructive sleep apnea. 
     Each subject received a two night baseline, pre-treatment, respiratory evaluation in the home using a portable sleep monitor. Each subject was then evaluated by the dental co-investigator and fitted with upper and lower dental titration trays filled with the impression material. The dentist measured the maximum retrusion and protrusion values from the scale on the titration trays. On the night of the titration study, the values provided by the dentist, for maximum retrusion and protrusion, were entered into the RCMP titration software. The titration trays were attached to the mandibular positioner and the position of the trays was adjusted by the manually adjustable knob to near full retrusion. The trays were then inserted into the subject&#39;s mouth and used for the duration of the titration study. Once the patient was asleep, the technician protruded the mandible step wise at a minimum 0.2 mm per step, using the RCMP titration device, until all evidence of pharyngeal obstruction (apnea or hypopnea) was eliminated in non-REM and REM sleep or until maximum protrusion was reached. 
     The study was scored by a polysomnographic technologist to identify respiratory disturbances (using 4a scoring rules). The results of the RCMP titration were reviewed without knowing patient specific information or other clinical data related to the subject to make a prospective prediction regarding therapeutic outcome. A strict set of prospectively determined criteria for the prediction were followed. Subjects were labeled a favorable candidate (predicted success) if a minimum of 5 minutes of REM sleep in the supine position was achieved with less than 1 event for every 5 minutes within the REM sleep period. Additionally, for subjects that demonstrated in a baseline study that they spent the majority of the night in the lateral position (e.g., &gt;50%), subjects were labeled a favorable candidate (predicted success) if REM sleep in the supine position was not achieved and a minimum of 5 minutes of REM sleep in the lateral position was achieved with less than 1 event per 5 minutes. Alternatively, subjects were labeled as unfavorable candidates (predicted failures) if more than 1 event was observed for every 5 minutes within the REM period at near maximum protrusion (within 1 mm). Otherwise, subjects were labeled as inconclusive due to inadequate data. 
     For subjects labeled favorable candidates (predicted success), the protrusive position at which the obstruction was removed (as recorded on the scored PSG data) was recorded by the technician and forwarded to the dental co-investigator. For subjects labeled unfavorable candidates (predicted failure) and inconclusive, a 70 percent of full protrusion was recorded as the sham position for use by the dental co-investigator. The positions, actual and sham, were used to manufacture the subjects&#39; permanent mandibular repositioning appliance (MRA) (e.g., a Somnomed MAS Acrylic oral appliance). The subject and the dental co-investigator were blinded to the results of the RCMP polysomnographic study (i.e., to the prediction of favorable or unfavorable candidate) made by the clinical co-investigator. An outcome, post-treatment, respiratory evaluation during sleep using the same portable monitor used for baseline studies was performed on two nights in the home with the mandibular repositioning appliance (MRA) in place at the target protrusive distance. 
     Successful treatment with MRA was defined prospectively as achieving a respiratory disturbance index with the appliance set at target protrusion (number of apneas and hypopneas per hour) by the automated analysis on the post treatment portable monitoring test less than 10/hr. 
     Twenty-five subjects were predicted to be failures with oral appliance therapy and thirty-six were predicted to be therapeutic successes, and six inconclusive. All patients who were predicted successes were therapeutic successes, and 7 of the 25 predicted failures were found to therapeutic successes. Overall the outcome was as follows: sensitivity: 74.4%; specificity: 100%; positive predictive value: 100%; negative predictive value: 62.1%. The positive predictive value at target protrusion was 93.8%. The results demonstrate that the predictive criteria utilizing only REM sleep stages, and prioritizing the use of supine, provides effective method of selecting candidates that will be successful with oral appliance therapy and their target protrusion distance. 
     Additionally, the same set of data were analyzed by a second strict set of criteria for the prediction. Subjects with a baseline RDI between 10 and 20 hr-1 were labeled a favorable candidate (predicted success) if either a minimum of 5 minutes of REM in the supine position or REM the lateral position was achieved with less than 1 event for every 5 minutes within the REM period. Subjects were labeled as unfavorable candidates (predicted failures) if more than 1 event was observed for every 5 minutes within the REM period at near maximum protrusion (within 1 mm). Otherwise, the subjects were labeled as inconclusive due to inadequate data. 
     Twenty-nine subjects were predicted to be failures with oral appliance therapy and thirty-two were predicted to be therapeutic successes, and six inconclusive. All patients who were predicted successes were therapeutic successes, and 11 of the 25 predicted failures were found to therapeutic successes. Overall the outcome was as follows: sensitivity: 72%; specificity: 100%; positive predictive value: 100%; negative predictive value: 83.7%. The positive predictive value at target protrusion was 92%. The results demonstrate that the predictive criteria utilizing only REM sleep stages, and treating supine and lateral equivocally for patients with mild-moderate sleep apnea, provides effective method of selecting candidates that will be successful with oral appliance therapy and their target protrusion distance. 
     Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.