Patent Publication Number: US-2013252195-A1

Title: Orthodontic expander system and method

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to an orthodontic appliance and methods for forming, installing, and adjusting such orthodontic appliance and, more particularly, to a maxillary palatal expander and methods for forming, installing, and adjusting such maxillary palatal expander. 
     BACKGROUND OF THE INVENTION 
     A palatal expander is used to widen the upper jaw so that the bottom and upper teeth will fit together better and is used to correct for a transverse maxillary deficiency, such as but not limited to cases of anterior crossbite (sagittal hypoplasia), where the upper teeth are posteriorly positioned relative to the bottom teeth, and posterior lingual crossbite (transverse hypoplasia), where the upper teeth are inside of the bottom teeth. 
     Posterior crossbite is a common malocclusion in young children, and can be caused by a variety of skeletal, muscular, behavioral (e.g., oral sucking and postural habits) and/or dental factors that cause, singly or in combination, insufficient maxillary arch width. Mechanical treatment modalities have long been used to correct maxillary constriction by expanding the posterior maxillary arch width. Rapid Palatal Expander (RPE) or Rapid Maxillary Expander (RME) are orthodontic appliances used to expand the maxillary arch and these appliances comprise tooth (molar) borne anchorage means (bands) bridged together by an adjustable screw. As the screw is turned, a bilateral force is generated to bilaterally expand the halves of the upper jaw about the medial or median palatine suture joining the maxillary bones (palatine process of maxilla). Conventional fixed appliances include the “Hyrax” (Hygenic Rapid Palatal Expander) appliance, a Haas appliance, a lingual Arch, or a W arch. 
     The Hyrax device, for example, comprises a screw member attached to the teeth by bands circumscribing the teeth. Initially, prior to installation, spacers (separating elastics) are inserted to create enough space for placement of the appliance orthodontic bands. Fitting of the orthodontic bands on the anchor teeth (e.g., maxillary first molars) is performed and an impression is made (e.g., an alginate impression or one-phase silicon). The spacers are then reinstalled about the molars. The orthodontic bands are placed in the impression and the impression is sent to the lab with the requisite prescription form. Following receipt of the formed RPE from the lab (e.g., including split acrylic plate and jack screw), the RPE is manipulated by turning the jack screw, such as by turning in one direction a prescribed number of times per days according to the orthodontist, to ensure proper operation. In a later appointment with the patient, the RPE is placed in the patient&#39;s mouth and the bands seated about the molars and removed. For a bonded RPE, the molars are then conditioned, such as by applying a pumice paste to the molars with a rotating brush head, and selected surfaces (buccal, lingual) of the molars are etched (e.g., orthophosphoric acid) to facilitate bonding. The RPE is then installed and the bands cemented to the teeth using a dental cement (e.g., glass ionomer bonding cement, composite resin, etc.). 
     Once installed, the expander is activated by rotation of a screw in the screw member using a metal key. The key is inserted into a depression in the screw and rotated. The jack screw conventionally comprises two opposing halves, each half having a threaded portion that receives an end of a double-ended screw. The screw has a central bossing with a plurality of holes (e.g., four holes) and each of these holes is dimensioned to accept the metal key. For a four-hole configuration, turning of the screw by 90° brings about a predetermined linear movement of the two opposing halves (e.g., based on the pitch of the threads of the screw). The force from the expanding screw is transferred through the arms of the device to the banded molars and ultimately removing the interdigitation of the median palatine suture. The appliance is left in for a therapeutically effective period and the patient, or patient&#39;s caregiver, activates the expander by rotating the screw a predetermined amount at a predetermined period appropriate to the expander jack screw configuration, age of the patient, and condition for which treatment is applied (e.g., a ¼ turn producing 0.25 mm of movement once per week; a ¼-½ turn a day producing 0.25-0.50 mm of movement a day, etc.). Following a desired expansion, a holding phase is performed, leaving the appliance in place for 3-4 months for stabilization, during which time the screw is locked in place to prevent the screw from backing up. 
     However, one problem with current bonded expanders, in pediatric applications, is that they tend to extract the baby teeth when removed. A bonded RPE tends to cause primary/baby teeth to become loose since the bonded RPE is cemented to the entire surface of the baby tooth. When the bonded RPE is removed from the patient&#39;s mouth, primary teeth might be extracted along with the removal of the bonded RPE. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the present invention, an orthodontic maxillary palatal expander device in accord with at least some aspects of the present concepts includes a mid-palatal bar having a first set of connection points configured to permit securement of the mid-palatal bar to the palate and a second set of connection points extending along at least a portion of a length of the mid-palatal bar, the first set of connection points comprising through holes in the mid-palatal bar. A screw assembly includes a left side member, a right side member, at least one arm connector formed in at least one of the left side member or right side member, at least one mid-palatal bar connector configured to releasably connect to the second set of connection points of the mid-palatal bar, and a screw mechanism adapted to, upon activation of the screw mechanism, cause outward lateral movement of the left side member and right side member. At least one arm, having a distal end and a proximal end, is provided, the proximal end being configured to connect to the at least one arm connector formed in the screw assembly. At least one tooth attachment member is provided and includes a connector configured to connect to the distal end of the at least one arm. 
     According to another aspect of the invention, a method for assembling an orthodontic maxillary palatal expander system includes the acts of measuring a length of a subject palate, selecting a mid-palatal bar for maxillary palatal installation in the subject palate, and adapting a profile of the mid-palatal bar to the subject palate. The method also includes centering a screw assembly along a medial line of the subject palate, the screw assembly comprising a left side member, a right side member, an arm connector formed in one of the left side member or right side member, at least one mid-palatal bar connector configured to releasably connect to the mid-palatal bar, and a screw mechanism adapted to, upon activation of the screw mechanism, cause outward lateral movement of the left side member and right side member. The method further includes the acts of measuring, using the subject palate, a distance from the arm connector to a tooth, selecting an arm for connection, at a proximal end, to the arm connector, and for connection, at a distal end, to a tooth attachment member, securing the proximal end of the arm to the arm connector and connecting the mid-palatal bar to the screw assembly. 
     According to yet another aspect of the invention, a method for adjusting an installed orthodontic maxillary palatal expander system, includes the acts of disconnecting a screw assembly attached to a first attachment point on a mid-palatal bar, moving the screw assembly to a second attachment point on the mid-palatal bar, and connecting the screw assembly to the second attachment point on the mid-palatal bar. 
     According to another aspect, a kit for an orthodontic maxillary palatal expander includes at least one mid-palatal bar, the at-least one mid-palatal bar comprising at least one connector configured to removably secure a screw assembly and at least one screw assembly. The kit also includes a plurality of lateral side members, each of the plurality of lateral side members comprising at least one arm connector, and a plurality of arms, each of the plurality of arms comprising a first connector at a proximal end and a second connector at a distal end. The kit further comprises a plurality of tooth attachment members. 
     Additional aspects of the invention will be apparent to those of ordinary skill in the art in view of the detailed description of various embodiments, which is made with reference to the drawings, a brief description of which is provided below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of an installed orthodontic appliance in accord with at least some aspects of the present concepts relative to the maxilla and mandible. 
         FIG. 2  is an exploded isometric view of the installed orthodontic appliance of  FIG. 1  in accord with at least some aspects of the present concepts. 
         FIG. 3  is an exploded isometric view of the orthodontic appliance of  FIG. 2  in accord with at least some aspects of the present concepts. 
         FIG. 3A  is an exploded isometric view of another example of an orthodontic appliance in accord with at least some aspects of the present concepts. 
         FIGS. 4A-4B  are, respectively, representations of views of successive stages of treatment with an orthodontic appliance in accord with at least some aspects of the present concepts, with the perspective being a view upward toward the maxilla from the mandible. 
         FIG. 4C  is an example of another orthodontic appliance in accord with at least some aspects of the present concepts. 
         FIG. 5  is an illustration of one type of connection between a screw assembly and a mid-palatal bar in accord with at least some aspects of the present concepts. 
         FIG. 6  is an illustration of another type of connection between a screw assembly and a mid-palatal bar in accord with at least some aspects of the present concepts. 
         FIG. 7  is an illustration of still another type of connection between a screw assembly and a mid-palatal bar in accord with at least some aspects of the present concepts. 
         FIG. 8  is an illustration of yet another type of connection between a screw assembly and a mid-palatal bar in accord with at least some aspects of the present concepts. 
         FIG. 9  is a cross-sectional view from the Quadrant 1 to Quadrant 2 of the maxilla showing an example of an installed orthodontic appliance in accord with at least some aspects of the present concepts. 
         FIGS. 10A-10B  are, respectively, representations of views of successive stages of treatment with an orthodontic appliance in accord with at least some aspects of the present concepts. 
     
    
    
     While the invention is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. 
     DETAILED DESCRIPTION 
     While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated. For purposes of the present detailed description, the singular includes the plural and vice versa (unless specifically disclaimed); the words “and” and “or” shall be both conjunctive and disjunctive; the word “all” means “any and all”; the word “any” means “any and all”; and the word “including” means “including without limitation.” 
       FIG. 1  is provided to show a view of an installed orthodontic appliance in accord with at least some aspects of the present invention relative to the maxilla  10  and mandible  20 . Shown are a band  110   a  about the first molar (tooth 14 in the International Tooth Numbering System) and a tooth attachment member  110   b  about the first pre-molar (first bicuspid, tooth 12) in a simulated adult mouth with normal dentition, representing generally an idealized condition prior to treatment with the expander, neglecting for simplicity angulation of teeth, separation of the central incisors, etcetera.  FIG. 1  illustrates an example of maxillary transverse hypoplasia where the upper teeth do not properly fit “over” the bottom teeth. Expansion of the upper arch in accord with the maxillary palatal expander disclosed herein can alter the maxilla so that the upper teeth can properly “drape” over the lower teeth. As shown in  FIG. 1 , the tooth attachment members  110   a,    110   b  are bands, but the tooth attachment members in accord with the present concepts are not limited to bands and may include any mechanical attachment (e.g., bands, brackets, abutment members, etc.) adapted to impart therapeutic forces to the teeth and in turn to the maxilla, particularly, but not limited to, forces acting against circumaxillary sutures, the lingual/palatal, mesial, and/or distal surfaces of the teeth. 
       FIG. 2  shows an exploded isometric view of an example of an orthodontic appliance  100 , in accord with at least some aspects of the present concepts, showing a general spatial relation of the orthodontic appliance  100  relative to the maxilla  10  and mandible  20 . The tooth attachment members  110   a,    110   b  from  FIG. 1  are shown, as are the opposing tooth attachment members  110   c,    110   d  that are provided for attachment to corresponding teeth (e.g., the first pre-molar (tooth 5) and the first molar (tooth 3) in Quadrant 1 (top right)). It is to be noted that, in accord with the present concepts, the anchorage of the tooth attachment members need not necessarily possess bilateral symmetry and the teeth selected for anchorage of the respective tooth attachment members could differ on one side (e.g., Quadrant 2 (top left)) versus the other side (e.g., Quadrant 1 (top right)). Moreover, it is not necessary that the same number of tooth attachment members  110   a - 110   d  and arms  120   a - 120   d  be provided on opposing sides of the maxilla, although such does represent a typical installation. The illustrations and examples provided herein shall not be viewed as limiting in this regard. By way of example, the tooth attachment members  110   a - 110   d  (or any number of tooth attachment members, whether one or more than one) may advantageously comprise bonded tooth attachment members where banding of one or more teeth is not preferred. 
     The tooth attachment members  110   a - 110   d  depend, respectively, from arms  120   a - 120   d  which are in turn connected to a screw assembly  130 . The screw assembly  130  is itself movably and/or releasably attached to the mid-palatal bar  140 . In the example shown, a retaining screw  150  is shown to be passed through an opening  142  in a proximal portion of the mid-palatal bar  140  for installation into a suitable portion of the palatine process in the anterior maxilla (e.g., not in the incisive foramen or incisive canals). The openings  142  are also used, in at least some aspects of the present concepts, to facilitate attachment of the screw assembly  130  to the mid-palatal bar  140  and, for this reason, some aspects of the mid-palatal bar  140  comprise a plurality of spaced-apart openings  142 . In one aspect, for example, the openings are spaced apart by 1.0 mm. In other aspects, the openings are spaced apart within a range of 1.0 mm-2.0 mm. Yet further, the openings may be spaced apart at distances greater than 2.0 and may be spaced apart equidistant from one another or may be spaced apart by one or more different distances (e.g., some openings spaced apart from one another by a first distance and other openings spaced apart from one another by a second distance). 
     It at least one aspect of the present concepts, the diameter of the openings are about 6.0-7.0 mm (e.g., about 0.25 inches). In other aspects, the diameter of the openings are within a range of about 3.0 mm-9.0 mm. Yet further, the diameter of the openings may vary in one or more locations along the mid-palatal bar (e.g., the diameter need not be uniform along the mid-palatal bar). The attachment of the screw assembly  130  to the mid-palatal bar  140  is further discussed below. Alternatively, or in combination, a distal opening  142  in the mid-palatal bar  140  could be employed to retain a distal end of the mid-palatal bar  140  via a retaining screw  150 , dimensioned for insertion through an opening in the mid-palatal bar, installed into a posterior portion of the palatine process or horizontal plate of palatine bone if skeletal anchorage is specifically desired. A variety of screws are available and the present concepts are utilizable with any convention screw. Moreover, it is to be understood that the openings in the mid-palatal bar noted herein need not necessarily be circular in shape and could comprise a different shape (e.g., a slot) and the device used to optionally attach the mid-palatal bar to the palate may comprise a device other than a screw 
     As noted above, it is not necessary that the same number of tooth attachment members  110   a - 110   d  and arms  120   a - 120   d  be provided on opposing sides of the maxilla and the present concepts include configurations having one or more arms in Quadrant 1 and one or more arms in Quadrant 2. For example, the orthodontic appliance  100  may comprise, in one configuration, a single arm and a corresponding tooth attachment member on one side of the mid-palatal bar  140  (e.g., Quadrant 1) and two arms and corresponding tooth attachment members on the other side of the mid-palatal bar  140  (e.g., Quadrant 2). Yet further, the present concepts include, generally, an orthodontic appliance  100  having only one arm (e.g., arm  120   a ) and a corresponding tooth attachment member (e.g.,  110   a ), where the mid-palatal bar  140  being secured to the palatine process or horizontal plate of palatine bone via a plurality of screws  150 . 
     In further aspects of the present concepts, the mid-palatal bar  140  may be seated to the maxilla or biased against the palate by the arms (e.g.,  120   a - 120   d ), which are secured to a plurality of teeth by respective tooth attachment members (e.g.,  110   a - 110   d ). Thus, it is not necessary for the mid-palatal bar to be positively fastened to the palate using screws as noted in the example above. 
     In another aspect of the present concepts, a plurality of mid-palatal bars  140  may be provided. The plurality of mid-palatal bars  140  may be seated to the maxilla or biased against the palate by the arms (e.g.,  120   a - 120   d ), as noted in the example above, or one or more than one of the plurality of mid-palatal bars  140  may be secured via one or more screws into the palatine process. 
     In yet another aspect of the present concepts, the aforementioned arms (e.g.,  120   a - 120   d ) and tooth attachment members (e.g.,  110   a - 110   d ) be omitted entirely in favor of dual palatal bars (e.g.,  140   a,    140   a ′ (not shown)) attached via screws (e.g.,  150 ) into the top left and top right palatine process on either side of the palatal suture (with one or more central screw assembly or assemblies  130 , potentially disposed as separate anterior and posterior screw assemblies, to provide for differential anterior/posterior expansion). Similarly, the aforementioned arms (e.g.,  120   a - 120   d ) and tooth attachment members (e.g.,  110   a - 110   d ) be omitted entirely in favor of dual palatal bars (e.g.,  140   a,    140   a ′ (not shown)) attached via screws (e.g.,  150 ) into the alveolar bone. 
       FIG. 3  shows an exploded isometric view of an example of an orthodontic appliance  100  in accord with at least some aspects of the present concepts. As shown, each tooth attachment member  110   a - 110   d  comprises a connector  115  (see, e.g., tooth attachment member  110   d ). The connector may comprise any type of connector adapted to removably affix an arm to the respective tooth attachment member. In at least one aspect, the connector  115  is a male connector (e.g., protruding member) dimensioned to matingly engage a correspondingly dimensioned female connector  124  integrated into a distal portion of each of the arms  120   a - 120   d.  Alternatively, the connector  115  on the tooth attachment member may comprise a female connector (e.g., a recessed member, bracket, etc.) dimensioned to matingly engage a correspondingly dimensioned male connector  124  integrated into a distal portion each of the arms  120   a - 120   d.  Thus, contrary to conventional bands, these disclosed tooth attachment members (e.g.,  110   d ) are unique in that they comprise, for example, male connectors. In accord with at least some aspects of the present invention, a tool kit for installation of an orthodontic appliance  100  can comprise a plurality of tooth attachment members of varying sizes, shapes, connectors and/or compositions. At the opposite or proximal end of each arm  120   a - 120   d  is provided another connector  125  dimensioned to matingly engage a connector  126  integrated into the screw assembly  130 . As shown, each of the connectors  126  on the screw assembly  130  are female connectors and the proximal portions of the arms  120   a - 120   d  are male connectors  125  dimensioned for insertion into the female connectors  126 . The connectors can be dimensioned for an interference or frictional fit or, alternatively, with clearance to permit application of a bonding agent, such as a surgical adhesive. In at least some aspects of the present invention, one or more of the connectors between the arms  120   a - 120   d  and the screw assembly  130  or one or more of the connectors between the arms  120   a - 120   d  and the tooth attachment members  110   a - 110   d  can be welded together. For example, the tooth attachment members (e.g.,  110   a - 110   d ) could comprise weldable “buttons” (e.g., the male ends of the bands) configured such that an oral health care provider can weld the connectors onto conventional bands available on the market or, alternatively, tooth attachment members may be provides with the connectors (e.g., male connectors) already welded to the tooth attachment members, which is presently preferred. 
     However, in an alternative configuration, the connector on the proximal portion of one or more of the arms  120   a - 120   d  comprises a female connector and the corresponding connector  126  on the screw assembly  130  comprises a male connector. In one example, female connectors  125  provided as connectors on the proximal portion of one or more of the arms  120   a - 120   d  could attach to an outer portion  135  of anterior lateral member  133  and/or posterior lateral member  134 , which are support pins passing through openings  138  in right side member  131  and left side member  132 . In such a configuration, the connection would need to occur outside of the working area of the anterior lateral member  133  and/or posterior lateral member  134  which permit outward movement of the right side member  131  and left side member  132 . In other words, a connection of the one or more of the arms  120   a - 120   d  to the outer portion  135  of anterior lateral member  133  and/or posterior lateral member  134  should not impede movement of the right side member  131  and left side member  132 . The anterior lateral member  133  and posterior lateral member  134  prevent relative rotation between the right side member  131  and left side member  132  and permit the right side member  131  and left side member  132  to slide outwardly relative thereto. 
     Bosses, protrusions, or the like may be optionally formed on surfaces of the anterior lateral member  133  and posterior lateral member  134 , between the right side member  131  and left side member  132 , to prevent inward motion of the right side member  131  and left side member  132  past a predetermined point. In yet another aspect, anterior lateral member  133  and posterior lateral member  134  may comprise an integrated gear rack with a ratchet integrated into the right side member  131  and left side member  132  so that, once the right side member  131  and left side member  132  have been extended past a tooth of the gear track, it is prevented from moving inwardly. In such a configuration, to facilitate removal following completion of therapy, the ratchet could be manually moved using a tool, such as a pin, the arms could be cut, or the gear rack could only provide securement for a predetermined portion of the anticipated therapeutic treatment. 
     Optionally, one or more tooth attachment member(s) (e.g.,  110   d ) may be integrated with a respective arm (e.g.,  120   d ) and/or a respective screw assembly connector  135  by a dental cement, surgical adhesive, or the like. 
     As shown in  FIG. 3 , posterior lateral member  134  comprise an opening  151  centrally disposed between the right side member  131  and left side member  132 . A screw  150  is then able to be passed up through the opening  151  and through a corresponding selected opening  142  in the mid-palatal bar  140  for securement into the palatine process or horizontal plate of palatine bone. Alternatively, the mid-palatal bar  140  is secured to the palatine process or horizontal plate of palatine bone using one or more other screws  150  inserted through other holes in the mid-palatal bar  140  and, in lieu of the configuration of  FIG. 3 , a bolt (not shown) is used to secure the screw assembly  130  to the mid-palatal bar  140 , with the end of the screw terminating in a threaded hole of the mid-palatal bar  140 . The opening  151  may be threaded or, alternatively, may lack threading and possess a diameter equal to or slightly greater than the major diameter of a screw inserted therethrough. 
     A nut member  136  of the screw assembly  130  is provided with a plurality of openings  139  (e.g., 4 openings spaced 90° apart to permit a full revolution of the nut with 4 turns) about a circumference thereof, the openings  139  being adapted dimensionally to receive a head of a tool utilized to activate the orthodontic appliance  100 . When the head of the tool is inserted into the exposed opening  139 , the nut  136  may be rotated posteriorly to cause a corresponding outward expansion of the right side member  131  and left side member  132 . When the nut is rotated a full quarter-turn of 90°, another opening  139  is exposed and such newly exposed opening would be used for the next scheduled activation of the orthodontic appliance  100 . The pitch and/or lead of the screw  137  may be optionally selected so that smaller angular rotations of the nut member  136  cause a desired degree of expansion of the right side member  131  and left side member  132  and a greater number of openings  139  may then be utilized (e.g., 8 openings spaced 45° apart to permit a full revolution of the nut with 8 turns). In this way, an oral health care provider may selectively tailor the operation of the screw assembly  135  by appropriate selection of a screw and nut combination having a desired pitch and/or lead and number of openings  139 . The screw  137  comprises left-handed and right-handed threading on opposing sides of the nut member  136  so that rotation of the nut member  136  in a single direction causes bidirectional outward movement of the right side member  131  and left side member  132 . The screw  137  may comprise two separate screws having different threads on opposing ends. The screw assembly  130  may optionally utilize a gear system where the screw nut comprises a gear that acts upon gears attached to the screw(s)  137 . 
       FIG. 3A  shows a variant of  FIG. 3  wherein two additional arms  120   e - 120   f  and corresponding tooth attachment members  110   e - 110   f  are provided. In  FIG. 3A , the attachment members  110   e - 110   f  are abutment members configured to abut against the lingual or palatal surfaces of the cuspids or incisors (teeth 5-12 in the International Tooth Numbering System). The anterior surfaces of the tooth attachment members  110   e - 110   f  are advantageously curved to approximate the profile of the teeth against which the respective tooth attachment members abut. The tooth attachment members  110   e - 110   f  may comprise, by way of example, stainless steel, cobalt-chromium, nickel-titanium, acrylic resin, or other suitable dental materials, inclusive of gold or gold alloys. The distal ends of the arms  120   e - 120   f  each comprise a male connector dimensioned to be connected to female connectors  141  provided at anterior portions of each of the right side member  131  and left side member  132 . 
       FIG. 4A  shows a “before” representation showing the maxilla and upper teeth (teeth 1-16 in the International Tooth Numbering System), with the initial position of the teeth, prior to the installation of the orthodontic appliance  100 , the maxillary teeth being represented by the cross-hatched teeth and the mandibular teeth being represented without cross-hatching. It is to be noted that the view represented is that of an upward view from the mandible toward the maxilla, so the left-hand side of the drawing in fact corresponds to the top right quadrant of the maxilla and the right-hand side of the drawing in fact corresponds to the top left quadrant of the maxilla. As shown, the tooth attachment members  110   a,    110   c  are attached about the first molar (teeth 3, 14 in the International Tooth Numbering System), the tooth attachment members  110   b ,  110   d  are attached about the second bicuspid (teeth 4, 13 in the International Tooth Numbering System), and the tooth attachment members  110   e,    110   f  are disposed to abut against the cuspids (teeth 6, 11 in the International Tooth Numbering System). The arrows adjacent the left and right side of the orthodontic appliance  100  on either side of the median line represent the direction of movement (outward expansion) of the right side member  131  and left side member  132 . The arrow about nut member  136  shows that the rotation of the nut member  136  (front-to-back rotation, also known as anterior-posterior advancement) causes a corresponding rotation in the screws  137 , which causes the outward movement of the right side member  131  and left side member  132 . A temporary anchorage device (TAD) or mini-screw  150  passing through an opening in the mid-palatal bar  140  (e.g., a threaded opening) is shown to attach the mid-palatal bar  140  to the palatine process. The screw assembly  130  is, in turn, connected to the mid-palatal bar  140  via a bolt inserted through opening  151  in the posterior transverse member  134 . 
       FIG. 4B  shows a later stage in treatment, subsequent to the initial condition represented in  FIG. 4A , where the alignment of the maxillary teeth (cross-hatched) are shown to better correspond to the alignment of the mandibular teeth (not cross-hatched). The tooth attachment members  110   a,    110   c  are again shown to be attached about the first molar (teeth 3, 14 in the International Tooth Numbering System), the tooth attachment members  110   b,    110   d  are attached about the second bicuspid (teeth 4, 13 in the International Tooth Numbering System), and the tooth attachment members  110   e,    110   f  are disposed to abut against the cuspids (teeth 6, 11 in the International Tooth Numbering System). In  FIG. 4B , it can be seen that the teeth have assumed a more normal profile and, in concert with the progress achieved during therapy, the position of the screw assembly  130  is advantageously adjusted to optimize the treatment. In  FIG. 4B , the screw assembly  130  is shown to be in a different position that is shown in  FIG. 4A , as the screw assembly has been moved in a posterior direction by one more opening  142 , from a fifth opening from the posterior end to a fourth opening from the posterior end. 
       FIG. 4C  shows another representation, which could follow the sequence of  FIGS. 4A-4B , or could be independent thereof, showing an orthodontic appliance  100  in accord with aspects of the present concepts unilaterally acting on only Quadrant 1 (maxillary right) of  FIG. 4C , with tooth attachment members  110   c,    110   d,  and  110   f  respectively engaging the first molar (tooth 14 in the International Tooth Numbering System), the second bicuspid (tooth 13 in the International Tooth Numbering System), and cuspid (tooth 11 in the International Tooth Numbering System). The arrow adjacent the left side of the orthodontic appliance  100  represents the direction of movement of the left side member  132  relative to the palatal plate  140  and, in this example, represents expansion of the left side member  132 . The right side member  132  moves, as indicated, but does not act on any teeth. 
     Significantly, the orthodontic appliance  100 , comprising the mid-palatal bar  140 , is adaptable to serve as a skeletal anchorage point for a variety of orthodontic devices and is configurable by selection of arm(s), position, band(s), screw assembly (if required), etcetera, to effect the expansion and/or distalization/protraction of a single tooth or a plurality of teeth (unilateral or bilateral) and may provide for anterior and/or posterior expansion. For example, in  FIG. 4C , the tooth attachment members  110   e  and  110   a  could be omitted, together with the corresponding arms, and the screw assembly could be attached via an arm to only tooth attachment member  110   b  to distalize the first pre-molar (tooth 4), with the screw assembly  130  (or other base member attached to a selected portion of the mid-palatal bar  140 ) used to apply an appropriate force vector to the tooth attachment member  110   b.    
     Although the screw assembly  130  may be connected to the mid-palatal bar  140  by a bolt  150  inserted through an opening  142  in the mid-palatal bar  140  (e.g., via opening  151  in the posterior lateral member  134 ), other connection interfaces between the screw assembly  130  and the mid-palatal bar  140  are presently envisaged, as are shown by way of example in  FIGS. 5-8 . In at least some aspects of the present concepts, it is desired to enable utilization of conventional screw systems, such as those used in the Hyrax appliance, while creating or providing opportunities or structure (e.g., a slot, groove, or opening) utilizable to secure the screw assembly  130  in place relative to the mid-palatal bar  140  (see, e.g.,  FIG. 9 ). 
     For example, the mid-palatal bar  140  may define a track along its length, or at least a portion thereof, having bearing surfaces in which a protruding member (not shown) of the screw assembly  130  matingly engages and slides within. A fixation screw/bolt or set screw/bolt may be provided to enable securement of the screw assembly  130  along a desired position on the mid-palatal bar  140  by frictional engagement of the screw/bolt to the mid-palatal bar  140 . In this manner, numerous of the openings  142  in the illustrations of the mid-palatal bar  140  in  FIG. 4C , for example, can be omitted and only those openings required for securement to the palatine process or horizontal plate of palatine bone are retained. 
       FIG. 5  shows an example of one type of connection interface between the screw assembly  130  and the mid-palatal bar  140  wherein a bottom surface of the mid-palatal bar  140  has formed thereon or attached thereto one or two sawtooth rack(s)  161  corresponding to one or two similarly dimensioned sawtooth rack(s)  160  formed on or attached to an upper surface of the right side member  131  and/or left side member  132 . As the right side member  131  and left side member  132  slide laterally outwardly in expansion (or contraction), the sawtooth racks  160 ,  161  do not impede lateral movement. However, the system of the screw assembly  130  and the mid-palatal bar  140  can be adapted, utilizing the depicted components, to prevent movement in an undesired direction (either back-to-front or front-to-back) depending on orientation of installation. In this configuration, the screw assembly  130  is permitted vertical movement equal to the height of the sawtooth racks. 
       FIG. 6  shows another example of a connection interface between the screw assembly  130  and the mid-palatal bar  140  wherein a bottom surface of the mid-palatal bar  140  has formed thereon or attached thereto one or two rack(s)  171  corresponding to one or two similarly dimensioned rack(s)  170  formed on or attached to an upper surface of the right side member  131  and/or left side member  132 . As the right side member  131  and left side member  132  slide laterally outwardly in expansion (or contraction), the racks  170 ,  171  do not impede lateral movement. However, the system of the screw assembly  130  and the mid-palatal bar  140  can be adapted, utilizing the depicted components, to prevent unintended movement in a back-to-front or front-to-back direction. 
       FIG. 7  shows yet another example of a connection interface between the screw assembly  130  and the mid-palatal bar  140  wherein a through-hole  180  (optionally threaded) is provided in an anterior portion of the left side member  132 . A bolt  150  is shown to be inserted up through a bottom of the left side member  132  and up into a non-threaded opening  142  in the mid-palatal bar  140 . This configuration assumes that the vertical engagement of the bolt  150  tip into the opening  142  is sufficient to retain the screw assembly  130  vertically in engagement with the mid-palatal bar  140 . Of course, both the opening  142  and the opening  180  can be threaded or, alternatively, the through-hole  180  is not threaded and the opening  142  is threaded. To reposition the screw assembly in a different position along the mid-palatal bar  140 , the bolt  150  can be backed out sufficient to disengage the screw assembly  130  from the mid-palatal bar  140  and the screw assembly is repositioned at the next opening  142  in the mid-palatal bar  140 , at which point the bolt  150  is again used to secure the screw assembly  130  to the mid-palatal bar  140 .  FIG. 8  shows a similar configuration wherein a screw is used in lieu of a bolt. 
       FIG. 9  shows a cross-section of an installed orthodontic appliance  100 , similar to the example shown in  FIG. 8 , wherein a through-hole  180  is provided in the left side member  132  between the screw  137  and the posterior lateral member  134 . A screw  150  is inserted into or screwed into the through-hole  180 , depending on threading, and screwed into a threaded opening  142  in the mid-palatal bar  140  and into the palatal process. Alternatively, a bolt  150  could be used to secure the screw assembly  130  to the mid-palatal bar  140 . The cross-sectional view is from the right side of the mouth, along the median of the mouth, looking to the left. An anterior screw  150  is shown to attach the mid-palatal bar  140  into the palatal process. Arms  120   c,    120   d  are shown to attach the screw assembly  130  to the bands  110   c,    110   d,  respectively. 
       FIGS. 10A-10B  show a sequence of movement of the orthodontic appliance  100 . In  FIG. 10A , the screw assembly  130  is shown to engage the mid-palatal bar  140  through the opening  142  that is represented by a solid line (the unused openings  142  are represented by dashed lines). As with the prior figures, representations of arms  120   a - f  are shown outwardly depending from the screw assembly  130  and contacting along the tooth line, represented by a first profile line P 1 . Profile line P 3  represents, for this example, an idealized or end state of therapy. In  FIG. 10B , representing a later stage of therapy, forces are shown to be applied along multiple axes, as indicated by the arrows. Moreover, the orthodontic appliance  100  is shown in a more forward position that in  FIG. 10A . The screw assembly  130  is shown to engage the mid-palatal bar  140  through the opening  142  that is represented by a solid line (the unused openings  142  are represented by dashed lines), which is now indicated as the middle of the three illustrated openings  142 . 
     In accord with the present concepts, an oral health care provider, defined herein as any oral health care provider including, but not limited to, an orthodontist, general dentist, pediatric dentist, oral and maxillofacial surgeon, etcetera)is able to dynamically modify an installed orthodontic appliance  100 , as the screw assembly  130  may be moved anteriorly or posteriorly and/or the arms (e.g., any one or more of  120   a - 120   f  or other arms) may be changed mid-treatment by simply disconnecting the arm(s) and replacing the arm(s) with other arm(s) having a desired property or properties (e.g., a different shape, stiffness, material, etc.). Such change-out of one or more arms may be necessitating, for example, by a repositioning of the screw assembly anteriorly or posteriorly from an initial position. In this manner, a force vector acting on an individual tooth is able to be readily changed during treatment to not only increase or decrease a force applied, but also the change a direction of application of the force. If desired, a temporary truss member having a soft surface may be installed to maintain consistent pressure against the maxilla during any change-out of one or more arm(s). Thus, if the oral health care provider notices that there needs to be more expansion in a certain area, he or she can readily change the positions of the arms/appliance as long as the support is provided on the remaining arms and/or temporary support(s) to prevent relapse of the teeth. The degree of support that is required depends in part on the duration of treatment. For example, for a treatment lasting 14 days of activation, where little bone growth has occurred to strengthen the mid-palatal region during the activation stage of treatment, the teeth would tend to relapse quickly. However, if the bands were to be left on the teeth over 3-4 months, bone growth is sufficient to enable maxillary stability while one or more arms are moved, reconfigured or changed out and/or while the appliance is moved. Thus, in accord with the present concepts, oral health care providers are able to dictate not only which teeth should be expanded, but are able to dynamically adjust expansion in all phases of treatment. 
     Significantly, an important feature of the present concepts is that the orthodontic appliance  100  may be clinically fabricated from component parts. In this respect, the present concepts include a kit of parts comprising a plurality of sizes and configurations of mid-palatal bars  140 , screw assemblies  130 , right side members  131 , left side members  132 , screws  137 , screw nuts  136 , tooth attachment members  110   a - 110   n  (where n represents any number), arms  120   a - 120   n  (where n represents any number), bolts and screws  150 , posterior lateral members  134 , and anterior lateral members  133 . Each component itself may advantageously comprise a plurality of different variations. For example, the arms  120   a - 120   f  may comprise a plurality of arms of different shapes, diameters, materials, material properties (rigid, semi-rigid, etc.) and/or lengths configured for specific teeth and even for specific teeth at specific phases of treatment. The provision of connectors between the screw assembly  130  and the arms as well as between the tooth attachment members  110 - 110   f  and the arms permits the oral health care provider to dynamically adjust the arms during treatment to optimize a force vector based on a position of the right side member  131  and left side member  132  relative to the teeth to which force is applied. Likewise, as previously noted, the screws  137  may be selected with different pitches/leads to permit different degrees of lateral expansion for a predetermined angular rotation of the screw nut  136 . Different mid-palatal bars  140  may be provided in the kit to allow flexibility for different palatal sizes. A length (anterior-posterior) of the mid-palatal bar will range depending on the length of the patient&#39;s palate. In at least some aspects, the mid-palatal is about 1 mm-2 mm in thickness and comprises stainless steel. Other biocompatible materials conventionally utilized in dental applications, such as but not limited to titanium, surgical stainless steel, or even composite materials, plastics or resins, and/or combinations of the foregoing, may also be utilized for the mid-palatal bar. It is desired that the mid-palatal bar  140  be sufficiently malleable so as to at least generally conform to a contour of the patient&#39;s palate. With such a kit, an oral health care provider can fabricate, in the office, a dental appliance consistent with the patient&#39;s needs without having to retain a laboratory to perform such service. 
     In accord with a method of fabrication of an orthodontic appliance  100  in accord with at least some aspects of the present concepts, a first act S 200  includes use of a measuring device (e.g., a ruler supplied with the kit, such as a pre-sterilized, packaged disposable ruler) to measure the length (anterior-posterior) of the palate intra-orally. This is a new concept of measuring the anterior-posterior (A-P) length of the palate due to the advent of the mid-palatal bar. Conventionally, laboratories only measured the transverse width of the palate to see which size jackscrew would fit. In accord with the present concepts, the measurements of the palate is intended to permit sizing of a mid-palatal bar extending from the canine region to the distal region of the maxillary second molars, while avoiding the incisive foramen and the greater and lesser palatine nerves. Following this measurement, an act S 210  includes selection of a mid-palatal bar (e.g., based on material, size, pre-dimensioned openings, etc.) from the kit that best approximates the measured length of the palate. In act S 220 , the health care provider manually adapts the mid-palatal bar  140  around the palate (e.g., digitally or with an orthodontic plier) so that the mid-palatal bar follows the contour of the palate. In act S 230 , a temporary anchorage device (TAD) (e.g., mini-screw, 3 mm-4 mm) can be used to secure the mid-palatal bar to the palate, if needed for maximum skeletal anchorage. As previously noted, the mid-palatal bar  140  is not necessary required to be secured to the palate, since it is retained/suspended by arms extending from the jackscrew to the banded teeth. However, the mid-palatal bar  140  can be advantageously secured to the palate via TADs to provide skeletal (cortical bone) anchorage of the palate during expansion. 
     In act S 240 , the tooth attachment members (e.g.,  110   a - 110   d ), such as orthodontic bands, are sized to and cemented to the teeth in regions of the maxilla where expansion is needed using conventional protocols for sizing and cementing orthodontic bands. In act S 250 , the practitioner decides where to place the screw assembly  130  relative to the mid-palatal bar  140  and secures the screw assembly  130  to the mid-palatal bar  140  with bolt  150 . Then, in act S 260 , the practitioner uses a measuring device (e.g., a sterile plastic ruler from the kit) to measure intra-orally a distance from the screw nut  136  (center of jackscrew) to the tooth attachment members (e.g., bands) around the teeth to determine an approximate length of the arms to be utilized. The actual length of the bar(s) may be greater than the measured length(s) as such bars are not necessarily linear and may be curvilinear or may have convoluted shapes, but the measured length should comport to the end-to-end distance of the arm(s). Additionally, another factor in selection of the arms is the amount of compressive forces or spring tension (e.g., “give”) in the arms before the desired force profile is achieved upon expansion, which in turn can impact the practitioner selection of arms. In act S 270 , the arms (e.g., rigid arms, semi-rigid arms, etc.) are selected from the kit of available orthodontic appliance  100  parts, and slight bends or adjustments are made, as necessary, digitally or using an orthodontic plier, to achieve a desired arm profile, to the extent an existing arm in the kit does not have the desired profile. 
     In act S 280 , the arms are secured, at opposite ends to the tooth attachment member (e.g., band) and to the screw assembly, such as by snapping, clipping, or sliding the male and female ends of the connecting members together, which may be performed intra-orally. As noted above, the connectors at each of these attachment points could be male or female, with mating components having a connector member of the opposite type. Thus, for example, an arm may comprise female connectors at both sides and each of the tooth attachment member and the screw assembly comprise male attachment members. Following completion of act S 280 , the screw assembly  130  is connected to the mid-palatal bar  140  and to the tooth attachment members. 
     As noted above, to activate the expander, either in the office or out of the office (e.g., by a patient or a patient&#39;s parent) a key or tool is used to turn the screw nut  136 , which effects expansion of the expander in accord with instructions/protocol by the oral health care provider. 
     Likewise, as noted above, the oral health care provider may, dynamically change the location of the screw assembly  130 , anteriorly or posteriorly, and thereby change direction and magnitude of forces acting on the teeth and on the mid palatine suture and/or circumaxillary sutures. The oral health care provider may also or alternative dynamically change the location of the screw assembly  130  laterally (right or left) to thereby change direction and magnitude of forces acting on the teeth and on the mid-palatine suture and/or circumaxillary sutures. As also noted above, the oral health care provider may remove one or more arms from the tooth attachment member(s) (e.g., orthodontic bands) and screw assembly  130  and rearrange or replace the arm(s) according to the desired direction and location of expansion. 
     In still additional variants on the present concepts, reversible pull headgears (i.e., a “facemask”) can also be attached to this orthodontic appliance  100  and brackets can be placed on the maxillary teeth (e.g., buccal or labial surfaces) while this orthodontic appliance  100  is in place. 
     In an act S 290 , the orthodontic appliance  100  is removed from the patient&#39;s mouth by, for example, removing the arms from the bands to the screw assembly, permitting the mid-palatal bar  140  and attached screw assembly to be removed as a unit. 
     In an alternative method, the orthodontic appliance  100  can be fabricated extra-orally. To do this, an impression of the maxillary arch is taken utilizing conventional techniques. For example, first a correct size impression tray is selected to ensure it fits correctly in the patient&#39;s mouth is correct with about 3-4 mm of space between the tray, teeth, and soft tissues when positioned in place. Utility rope wax is placed around the top border of the maxillary tray to extend its height and ensure proper fit. Then, alginate and water are mixed together to the required consistency and the maxillary tray is loaded with the mixed alginate. The tray is then placed directly onto the palate and seated against the maxillary teeth. The tray is pressed up into the hard palate with the tray seated so that it is parallel with the occlusal plane, at which point the maxillary arch should be completely embedded in the alginate material. After a short time, the alginate begins to gel and set up and the tray can be removed by pressing down to break the seal formed by the set alginate material. The maxillary impression can then be inspected for detail and rinsed, disinfected for use, and poured in dental stone to serve as a representative model of the patient&#39;s maxillary arch. Or course, this is merely one example and other methods of obtaining the maxillary arch are acceptable for use in accord with the present concepts. 
     The maxillary impression can then itself be used to guide the assembly of the orthodontic appliance  100  comprising the mid-palatal bar  140 , screw assembly  130 , and arm(s)  120 . Following extra-oral construction of the orthodontic appliance  100 , the orthodontic appliance  100  is then delivered intra-orally and adjustments are made as needed. 
     In accord with the present concepts, an oral health care provider can both evaluate a patient and deliver an orthodontic appliance  100  in the office in the same day without the need for multiple office visits (e.g., without the need to send off a prescription to be fabricated elsewhere, with the attendant delays) and saving chairside time and cost to both the patient and provider while starting orthodontic treatment earlier. 
     Each of these embodiments and obvious variations thereof is contemplated as falling within the spirit and scope of the claimed invention, which is set forth in the following claims. For example, although a mid-palatal bar is discussed and shown, the mid-palatal bar can generally include other forms of fixation, such as mid-palatal rails (e.g., substantially parallel mid-palatal bars) used in combination with a screw assembly configured to move along, and to be selectively secured to, such rails.