Abstract:
A system and method of installing dental implants to treat obstructed airflow via passive repositioning of the tongue. The present method includes the steps of installing one or more implants between the teeth along the mucogingival junction, such that the implants extend into the oral cavity and make contact with the undersurface of the tongue when the tongue is in a resting position. The positioning of the implants causes them to gently irritate the undersurface of the tongue, innervating the lingual nerve. Innervation of the lingual nerve causes the genioglossus to contract and repositions the tongue to a more anterior and superior position as compared to its resting position, vacating the airway and dilating the pharynx to improve airflow therethrough. Both the positioning and the size of the implants are customizable, thereby ensuring proper contact between the implants and the tongue regardless of topographical differences of patients&#39; oral cavities.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to dental prostheses. More specifically, the present invention relates to a method of installing dental prostheses having protuberances at specific locations within a patient&#39;s mouth. The protuberances rest against the base of the tongue, innervating the nerves within the tongue and thereby passively causing the tongue to reposition itself to a more anterior and superior position within the mouth. The repositioning of the tongue reduces the amount of airway blockage caused by the tongue as compared to its normal resting position. 
       BACKGROUND OF THE INVENTION 
       [0002]    Obstructive sleep apnea (OSA) is a disorder in which a sleeper&#39;s breathing is interrupted by the whole or partial blockage of the pharyngeal airway. During pharyngeal constriction, breathing may be shallow or may cease all together. Abnormal breathing can last for ten seconds to several minutes. Patients may snore, make choking noises, grind their teeth or have small spasms as they try to breathe. Over time, untreated OSA can lead to additional health problems, including bruxism, heart disease, high blood pressure, stroke, memory loss, and other forms of brain damage. Treatments for obstructive sleep apnea include oral dental devices that open up the throat to allow improved air flow, machines with oxygen masks that force air into the throat (continuous positive airway pressure), and lifestyle changes including dietary changes and exercise. 
         [0003]    Decreased muscle tone in the throat is the primary cause of OSA in most otherwise healthy patients. Decreased muscle tone creates two major issues that can result in the complete or partial blockage of the upper airway: constriction of the pharyngeal opening and migration of the tongue into the path of the airway. Decreased muscle tone causes the pharyngeal opening to constrict because when the muscles controlling the pharyngeal opening are less tone, they are more prone to relax, thereby reducing the diameter of the pharyngeal opening and thus reducing the rate that air can flow therethrough. Decreased muscle tone causes the tongue to migrate for much the same reason. The less tone the muscles of the tongue are, the more likely the tongue is to move from its natural resting position to a more relaxed posterior position that obstructs the flow of air through the upper airway. 
         [0004]    Oral dental devices or some mechanical support implants currently used in the treatment of OSA are designed to prevent airway closure by forcing the mandible forward and maintaining an open airway. This mandibular repositioning maintains the pharynx passageway in an open state, permitting continuous airflow through the passageways of the throat. While these oral dental devices may be helpful to some patients, they physically reposition the mandible without requiring any active participation by the patient&#39;s orofacial muscles. Proper muscle tone and strengthening of the orofacial muscles could reduce frequency of apnea episodes and increase the pharynx&#39;s ability to maintain dilation. However, because there is no active participation by the patient&#39;s orofacial muscles with the use of current mechanical support implants, the muscles are not toned or strengthened, forcing the patient to use the mechanical implants in perpetuity. 
         [0005]    Flexing tongue musculature can manipulate the size of the opening of the pharyngeal airway and maintain the tongue in a position in which it does not block the airway, obviating the need for mechanical movement of the mandible. The genioglossus, the exterior muscle of the tongue responsible for tongue protrusion and depression, is an important muscle for controlling both the constriction of the pharyngeal opening and the positioning of the tongue. When in flexion, the genioglossus moves the tongue forward, maintaining the tongue in a position out of the path of the airway, and also causes the muscles controlling the pharyngeal opening to dilate. 
         [0006]    Pharyngeal dilation can also be achieved via stimulated natural tongue protrusion without mechanical repositioning of the mandible. Motor innervation for all tongue muscles comes from the hypoglossal nerve (CN XII), except for the palatoglossus, which is supplied by the pharyngeal plexus (vagus nerve). Tongue motor function is voluntary and not regularly susceptible to reflex responses. Sensory experience of the anterior (front two-thirds) of the tongue is supplied by a branch of the trigeminal nerve (CN V 3 ) known as the lingual nerve. The hypoglossal nerve and lingual nerve are in communication along the anterior border of the hypoglossal muscle. Thus, stimulation of the lingual nerve across different portions of the tongue surface can be translated to the hypoglossal nerve and affect voluntary motor function of the extrinsic muscle structures. 
         [0007]    Dental tori, which are naturally occurring growths or accumulations of bone cells of the surfaces of the oral cavity, can trigger a reflex response in the tongue by impinging upon the various motor nerves of the tongue. This repositioning of the tongue in response to dental tori can in turn manipulate the size of the pharynx and increase the size of the airway. However, this is merely a side effect of the presence of the dental tori and it is impracticable to attempt to harness the natural formation of dental tori to influence tongue positioning and airway size for multiple reasons. First, there is no way to precisely control the formation of the dental tori because their growth is not well characterized. Second, although the tori themselves generally do not require treatment, the underlying cause of the dental tori, e.g. bruxism, often has a plethora of undesirable side effects and requires treatment. 
         [0008]    Alternatively, electrical stimulation of the genioglossus has also been shown to manipulate pharyngeal cross-section size. Stimulation across the anterior portions of the tongue produces contraction of the genioglossus and forward tongue protrusion, whereas stimulation of posterior areas of the tongue results in bunching of the posterior tongue and constricts the diameter of the pharynx. However, although electrical stimulation is useful in clinical settings, electrical stimulation of a user&#39;s oral cavity during sleep or while engaging in athletics would be cumbersome and potentially dangerous. Therefore, there is a need in the prior art for targeted and safe physical stimulation of the tongue to affect dilation of the airways of the throat and improve muscle strength. 
         [0009]    Therefore, there is a need in the prior art for a system and method of installation thereof that utilizes projections that resemble dental tori to passively reposition the tongue by triggering a natural reflex response in order to actively recruit tongue muscles in order to treat OSA, thereby obviating the need for treatment options utilizing mechanical support or electrical stimulation. 
       SUMMARY OF THE INVENTION 
       [0010]    In view of the foregoing disadvantages inherent in the known types of oral implants and methods of repositioning the tongue now present in the prior art, the present invention provides a new method of passively influencing the positioning of the tongue via installing dental prostheses in a patient&#39;s mouth that rest against and gently irritate the tongue, thereby innervating the motor nerves of the tongue and causing the tongue to reposition itself in order to increase the size of the opening of the pharyngeal airway. 
         [0011]    The present invention comprises a system of dental implants adapted to treat OSA and other such maladies associated with or caused by obstructed airflow and a method of installation thereof. The present method comprises the steps of installing implants into a patient&#39;s mouth such that the implants impinge upon the patient&#39;s tongue, gently irritating the tongue and triggering a reflex response that causes the tongue to reposition itself in response to the stimuli. The implants comprise at least one lower implant installed into the mandible of the patient and at least one upper implant installed into the upper palatal arch. The one or more lower implants are installed between the teeth of the mandible, along the mucogingival junction, such that the fastening portion of the implant does not make contact with the root of the patient&#39;s teeth nor the nerve extending between each of the tips of the roots. The one or more upper implants are installed behind and superior to the incisive papilla on the upper palatal arch. 
         [0012]    The lower implants are installed such that they extend horizontally into the oral cavity from the mandible. When the tongue is in its standard resting position, the undersurface of the tongue makes contact with the lower implants projecting from the interior surface of the mandible, generating an unconscious reflexive response that causes the tongue to automatically reposition itself in a more superior and anterior position that clears the airway and provides improved airflow therethrough. The present invention further comprises an upper implant that is installed behind and superior of the incisive papilla along the upper palatal arch. The upper implant assists in guiding the tongue to the improved resting position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    Although the characteristic features of this invention will be particularly pointed out in the claims, the invention itself and manner in which it may be made and used may be better understood after a review of the following description, taken in connection with the accompanying drawings wherein like numeral annotations are provided throughout. 
           [0014]      FIG. 1A  shows a view of the mandibular portion of a mouth having the present system installed therein. 
           [0015]      FIG. 1B  shows a view of the maxillary portion of a mouth with the present system installed therein. 
           [0016]      FIG. 2  shows an exploded view of an embodiment of an implant of the present system. 
           [0017]      FIG. 3  shows a perspective view of the mandibular portion of a mouth having the present system installed therein. 
           [0018]      FIG. 4  shows a vertical cross-sectional view of a mouth having the present system installed therein. 
           [0019]      FIG. 5A  shows a view of the mandibular portion of a mouth having the present system installed therein in an alternative configuration. 
           [0020]      FIG. 5B  shows a view of the mandibular portion of a mouth having the present system installed therein in an alternative configuration. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    Reference is made herein to the attached drawings. Like reference numerals are used throughout the drawings to depict like or similar elements of the system and method of installing dental prostheses for influencing the position of the tongue and thereby reducing airway obstruction. For the purposes of presenting a brief and clear description of the present invention, the preferred embodiment will be discussed as used for treating OSA. The figures are intended for representative purposes only and should not be considered to be limiting in any respect. 
         [0022]    The present invention comprises a method of installing a plurality of permanent or semi-permanent dental implants into the upper and lower portions of a patient&#39;s mouth in positions that cause the implants to impinge upon one or more of the nerves of the tongue, such as the lingual nerve. As the tongue makes contact with the implants, the nerve or nerves targeted by the present method are innervated by the contact with the implants, triggering an involuntary reflex response that causes the muscles of the tongue to contract. The contraction of the muscles causes the tongue to reposition itself within the mouth, clearing the tongue from the airway and dilating the pharyngeal opening, improving airflow through the airway. The present system thereby passively and effectively treats OSA, strengthening the muscles of the tongue without forced mechanical intervention. 
         [0023]    Referring now to  FIGS. 1A and 1B , there are shown views of the mandibular and maxillary portions of a mouth having the present system installed therein. The present invention comprises a method of installing a plurality of implants into the upper and lower portions of the mouth of a patient, wherein the implants are arranged in a set of one or more bilateral pairs of lower implants  131  installed into the mandible  157  of the patient and one or more upper implants  104  installed into the upper palatal arch  156  of the patient. The lower implants  131  are installed between the patient&#39;s teeth such that the implants do not make contact with the roots of the teeth nor the nerves extending from the tips of the roots. In an illustrative embodiment of the present invention, the bilateral pairs of lower implants  131  comprise a first lower implant  101  installed between the first molar  150  and the second bicuspid  151  along the mucogingival junction  155 , a second lower implant  102  installed between the second bicuspid  151  and the first bicuspid  152  along the mucogingival junction  155 , and a third lower implant  103  installed between the first bicuspid  152  and the cuspid  153  along the mucogingival junction  155 . The lower implants  131  are installed such that they extend horizontally from the mandible  157  into the oral cavity, thereby allowing the lower implants  131  to impinge upon the undersurface of the tongue, gently irritating the tongue when it makes contact with the lower implants  131 . 
         [0024]    The depicted configuration of the lower implants  131  is intended solely to be illustrative and should not be read as limiting in any way. Although not shown in the referenced figures, the lower implants  131  are installable between any of the teeth, including the incisors  154 , in any number and any arrangement. Furthermore, the lower implants  131  need not be arranged such that they occupy successive spaces between the teeth of the mandible. 
         [0025]    The one or more upper implants  104  are installed into the upper palatal arch  156  of the maxilla  158 . In an illustrative embodiment of the present method, a single upper implant  104  is installed into the upper palatal arch  156 , behind and superior to the incisive papilla  159 . The upper implant  104  assists in guiding the tongue when it is repositioning. Much as with the lower implants  131 , the upper implant  104  influences the positioning of the tongue by gently irritating the surface the tongue when the tongue is pressed thereagainst, thereby triggering a reflex response that causes the tongue to reposition itself out of the path of the airway. 
         [0026]    In an illustrative embodiment of the present invention, the exposed portion of the lower implants  131  are semi-spherical in shape and the exposed portion of the upper implant  104  is semi-ellipsoidal in shape. The size of the lower implants  131  and the upper implant  104  are customized to account for differences in the size and shape of patients&#39; mouths, thereby ensuring that the lower implants  131  are positioned to impinge upon the undersurface of the patient&#39;s tongue and the upper implant  104  is positioned to impinge upon the upper surface of the patient&#39;s tongue. For example, the first and the third lower implants  101 ,  103  have a diameter of 2 mm to 3 mm, the second lower implant  102  has a diameter of 4 mm, and the base portion of the upper implant  104  is an ellipse having a minor diameter from 2 mm to 4 mm and a major diameter from 0.5 inches to 1.0 inch. 
         [0027]    Referring now to  FIG. 2 , there is shown an exploded view of an embodiment of an implant of the present system. An illustrative embodiment of an implant  201  comprises a cap  202  or abutment that is securable to an abutment screw  203  or fastener via a connector. The removable attachment between the cap  202  and the abutment screw  203  allows for differently sized and shaped caps  202  to be interchangeably secured to the screw  203  in order to customize the installation of the present system for each user. In the depicted embodiment of the present invention, the connector comprises a threaded connector  204  extending from undersurface of the cap  202  that engages with a complementary threaded recess  205  in the screw  203 . In an alternative embodiment of the present invention, the connector comprises a snap connection. 
         [0028]    In the depicted embodiment of the implant  201 , the cap  202  has a semi-spherical shape. However, various embodiments of the implant  201  comprise differently shaped caps  202 . For example, one embodiment of the implant comprises a cap  202  having a semi-ellipsoidal shape. When installed into the mouth of a patient, the abutment screw  203  is used to secure the implant  201  into the mandibular bone or the hard palate of the patient and the cap  202  is left exposed, extending into the oral cavity. 
         [0029]    The implant  201  further comprises one or more shells  206  that are affixable over the cap  202 . In one embodiment, the shells  206  comprise a semi-spherical shape. In another embodiment, the shells comprise a semi-ellipsoidal shape. The shells  206  further comprise a hollow interior having a size and shape corresponding to the size and the shape of the cap  202  or another shell  206 , thereby allowing the shells  206  to be placed thereover. The shells  206  are bonded to the cap  202  or each other via an acrylic adhesive, permanently mounting the shells  206  thereto. The shells  206  have a surface area and a thickness, allowing for one or more of the shells  206  to be stacked in order to customize (i) the surface area of the exposed portion of the implant  201  so that it impinges upon a greater surface area of the tongue and (ii) the distance to which the exposed portion of the implant  201  extends into the oral cavity. Because the oral topography of each individual is unique, successive layers of the shells  206  can be bonded to the implant  201  in order to customize each individual implant  201  for each patient in order to accommodate for differences in distances between the interior surface of the oral cavity and the tongue of the patient. 
         [0030]    The removable connection between the cap  202  and the abutment screw  203  portions of the implant  201  provides a first degree of customization because differently sized and shaped caps  202  can be interchangeably affixed to the abutment screw  203  once the abutment screw  203  is installed within the mouth of a patient. The ability to bond a successive series of shells  206  over the cap  202  provides a further degree of customization, allowing the size and shape of the exposed portion of the implant  201  to be precisely tailored on a patient-by-patient basis. 
         [0031]    Referring now to  FIG. 3 , there is shown a perspective view of the mandibular portion of a mouth having the present system installed therein. The lower implants  301 ,  302 ,  303  are installed into the mandible  357  of a patient along the mucogingival junction  358 , between the roots  359  of the teeth such that the screw or fastener portion of the implants  301 ,  302 ,  303  does not make contact with the roots  359 , nor the nerves extending from the tips of the roots  359  (not shown). 
         [0032]    This arrangement places the implants in a spaced relationship, separated by one or more teeth. In an illustrative embodiment of the present invention, the implants comprise a first implant  301  disposed between the first molar  351  and the second bicuspid  352 , a second implant  302  disposed between the second bicuspid  352  and the first bicuspid  353 , and a third implant  303  disposed between the first bicuspid  353  and the cuspid  354 . However, this configuration for the installation of the implants is not intended to be limiting in any way. The implants are also installable between the other gaps between the teeth, e.g. between the central incisor  356  and the lateral incisor  355 , the lateral incisor  355  and the cuspid  354 , the first molar  351  and the second molar  350 , and the second molar  350  and the third molar  349 . 
         [0033]    Referring now to  FIG. 4 , there is shown a vertical cross-sectional view of a mouth having the present system installed therein. The lower implants  401  are installed into the mandible  450 , between the teeth  455 , such that the implants  401  extend horizontally therefrom into the oral cavity. When in its resting position, the lower implants  401  impinge upon the undersurface  455  of the tongue  451 . The impingement of the lower implants  401  on the tongue  451  gently irritates the undersurface  455  thereof, which in turn causes the innervation of the lingual nerve  453 . Innervation of the lingual nerve  453  then carries over to the hypoglossal nerve  454 , which controls the contraction of the genioglossus  452 . When the hypoglossal nerve  454  is innervated, it causes the genioglossus  452  to contract, clearing the tongue  451  from the airway. 
         [0034]    Referring now to  FIGS. 5A and 5B , there are shown views of the mandibular portion of a mouth having the present system installed therein in alternative configurations. Because the anatomy of each individual is unique, the present system is installable in a variety of different configurations in order to accommodate differences in the size of teeth, the distances between teeth, the thickness of the gingiva, the size of the tongue, the shape of the tongue, the location of the nerves of the tongue, and other such variables. Therefore, the present system is installable between any of the teeth and the configurations of the dental implants depicted in  FIGS. 1, 5A, and 5B  are intended solely to be illustrative. 
         [0035]      FIG. 5A  shows an illustrative configuration for the present system installed into a mandible  556 , wherein the first implant  501  is installed between the second molar  549  and the first molar  550 , the second implant  502  is installed between the first molar  550  and the second bicuspid  551 , and the third implant  503  is installed between the second bicuspid  551  and the first bicuspid  552 .  FIG. 5B  shows an illustrative configuration for the present system installed into a mandible  556 , wherein the first implant  501  is installed between the first molar  550  and the second bicuspid  551 , the second implant  502  is installed between the second bicuspid  551  and the first bicuspid  552 , and the third implant  503  is installed between the cuspid  553  and the lateral incisor  554 . In other configurations, the implants can be installed between any of the other gaps in the teeth not shown, e.g. between the lateral incisor  554  and the central incisor  555 . The positioning of the implants is completely determined on a case-by-case basis. It should be further noted that although the illustrative configurations of the present system are depicted as having three implants, no claim is made as to a specific number of implants utilized by the present method and system. The positioning of the implants and the number of implants necessary to elicit the desired reflex response of the tongue is dependent upon anatomy of the patient, which creates topographical differences in the oral cavity. 
         [0036]    The desired positioning for the implants can be determined experimentally prior to the installation of the abutment screws of the implants into the mouth of the patient by utilizing a mouth guard having projections thereon, wherein the projections correspond to potential installation points for the implants. This allows patients to try different configurations for the projections that elicit the desired reflex response in the tongue. Once this ideal positioning for the projections is achieved, the permanent solution represented by the installation of the implants can then be undertaken. When installing the implants, the locations of the projections on the mouth guard can serve as a guide for the installation of the implants. Once the implants are installed, the implants can be customized by affixing differently sized and shaped interchangeable caps to the abutment screws. The caps can then be further customized by bonding one or more shells to the caps, allowing each individual implant to be tailored for the specific anatomy of the patient. 
         [0037]    It is therefore submitted that the instant invention has been shown and described in what is considered to be the most practical and preferred embodiments. It is recognized, however, that departures may be made within the scope of the invention and that obvious modifications will occur to a person skilled in the art. With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. 
         [0038]    Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.