Orthognathic correction device and orthognathic correction method

An orthognathic correction device includes a first retainer, a second retainer and at least two elastic members. The first retainer is configured to be removably worn on the maxillary dental arch of a patient and has at least two first connection parts fixed on the left and right buccal surfaces of the first retainer. The second retainer is configured to be removably worn on the mandibular dental arch of the patient and has at least two second connection parts fixed on the left and right buccal surfaces of the second retainer. The elastic members couple the first and second retainers worn and retained on the maxillary and mandibular dental arches of the patient, respectively, so as to drive the second retainer to move relative to the first retainer, thereby adjusting the relative position between the mandible and the maxilla of the patient.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims priorities of China Patent Application No. 201510135110.3, filed on Mar. 26, 2015, the entirety of which is incorporated by reference herein, and China Patent Application No. 201610159772.9, filed on Mar. 21, 2016.

BACKGROUND OF THE INVENTION

Field of the Invention

The present application relates to an orthognathic correction technology, and in particular to an orthognathic correction device and an orthognathic correction method.

Description of the Related Art

In general, a patient will require orthognathic correction if his temporomandibular joint (TMJ) between the maxilla and the mandible is not in the optimum position, causing an abnormal relative position between the maxilla and the mandible.

Currently, doctors often do an osteotomy to cut the patient's maxilla, mandible, or both, and then to reconstruct the broken bones in the needed positions, so as to achieve orthognathic correction. However, many patients fear the intrusive nature and risks associated with this surgical method and are often hesitant to choose this option.

BRIEF SUMMARY OF THE INVENTION

In view of the aforementioned problems, an object of the invention is to provide an orthognathic correction device, and in particular, to provide a patient removable orthognathic correction device that can be used to achieve orthognathic correction without the surgical method feared by many patients.

An embodiment of the invention provides an orthognathic correction device, including a first retainer, a second retainer and at least two elastic members. The first retainer is configured to be removably worn on the maxillary dental arch of a patient, and has a first left buccal surface with at least one first left connection part fixed thereon and a first right buccal surface with at least one first right connection part fixed thereon. The second retainer is configured to be removably worn on the mandibular dental arch of the patient, and has a second left buccal surface with at least one second left connection part fixed thereon and a second right buccal surface with at least one second right connection part fixed thereon. At least one elastic member is configured to couple the first left connection part to the second left connection part, and at least one elastic member is configured to couple the first right connection part to the second right connection part, such that the elastic members drive the second retainer to move relative to the first retainer, thereby adjusting the relative position between the mandible and the maxilla of the patient when the first retainer and second retainer are retained on the maxillary and mandibular dental arches, respectively.

Another embodiment also provides an orthognathic correction method, including: coupling a first retainer with a maxillary dental arch of a patient, wherein the first retainer is configured to be removably worn on the maxillary dental arch, and the first retainer has a first left buccal surface with at least one first left connection part fixed thereon and a first right buccal surface with at least one first right connection part fixed thereon; coupling a second retainer with a mandibular dental arch of the patient, wherein the second retainer is configured to be removably worn on the mandibular dental arch, and the second retainer has a second left buccal surface with at least one second left connection part fixed thereon and a second right buccal surface with at least one second right connection part fixed thereon; and coupling at least one elastic member to the first left connection part and to the second left connection part, and coupling at least one elastic member to the first right connection part and to the second right connection part, so as to drive the second retainer to move relative to the first retainer, thereby adjusting a relative position between a mandible and a maxilla of the patient.

Another embodiment also provides an orthognathic correction method, including: coupling a first retainer with a maxillary dental arch of a patient, wherein the first retainer is configured to be removably worn on the maxillary dental arch, and the first retainer has a first left buccal surface with at least one first left connection part fixed thereon and a first right buccal surface with at least one first right connection part fixed thereon; providing at least one second left connection part fixed on a left buccal surface of a mandibular dental arch of the patient, and providing at least one second right connection part fixed on a right buccal surface of the mandibular dental arch; and coupling at least one elastic member to the first left connection and to the second left connection part, and coupling at least one elastic member to the first right connection part and to the second right connection part, so as to drive the mandibular dental arch to move relative to the first retainer, thereby adjusting a relative position between a mandible and a maxilla of the patient.

Another embodiment also provides an orthognathic correction method, including: coupling a second retainer with a mandibular dental arch of a patient, wherein the second retainer is configured to be removably worn on the mandibular dental arch, and the second retainer has a second left buccal surface with at least one second left connection part fixed thereon and a second right buccal surface with at least one second right connection part fixed thereon; providing at least one first left connection part fixed on a left buccal surface of a maxillary dental arch of the patient, and providing at least one first right connection part fixed on a right buccal surface of the maxillary dental arch; and coupling at least one elastic member to the second left connection part and to the first left connection part, and coupling at least one elastic member to the second right connection part and to the first right connection part, so as to drive the second retainer to move relative to the maxillary dental arch, thereby adjusting a relative position between a mandible and a maxilla of the patient.

DETAILED DESCRIPTION OF THE INVENTION

In order to illustrate the purposes, features, and advantages of the invention, the preferred embodiments and drawings of the invention are shown in detail as follows.

In the following detailed description, the orientations of “on”, “above”, “under”, “below”, “left” and “right” are used for representing the relationship between the relative positions of each element as illustrated in the drawings, and are not meant to limit the invention. Also, the relationship between the relative positions of each element can be referred to the orthogonal coordinates including an X-axis, a Y-axis, and a Z-axis as shown in the drawings. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples for the purpose of simplicity and clarity.

FIGS. 1A and 1Bare schematic views illustrating the relative relationship of a patient's skull40, maxilla10and mandible20in common cases, wherein the maxilla10is fixedly connected to the skull40and the mandible20is movably connected to the skull40via the temporomandibular joint30. Also, the patient's maxillary dental arch12and mandibular dental arch22are connected to the maxilla10and the mandible20, respectively. When the patient's temporomandibular joint30between the maxilla10and the mandible20is not in the optimum position, it may cause the mandible20with respect to the maxilla10to be prognathic (FIG. 1A) or retracted (FIG. 1B), so that a malocclusion of the maxillary and mandibular dental arches12and22will happen. Consequently, the appearance of the patient's teeth, oral functions such as chewing, pronunciation, and oral health concerns such as dental cavities and wear of teeth, may also be adversely affected.

As described above, an object of the invention is to provide an orthognathic correction device, and in particular to provide a patient removable orthognathic correction device that can be used to achieve orthognathic correction without the surgical method feared by patients.

FIG. 2is a schematic view illustrating the relative relationship of an orthognathic correction device and a patient's maxillary dental arch12and mandibular dental arch22according to an embodiment of the invention. As shown inFIG. 2, the orthognathic correction device primarily includes a first retainer100, a second retainer200, and several elastic members500. Moreover, there are several first brackets302, first arch wires304, and first connection parts306disposed on the first retainer100, and there are several second brackets402, second arch wires404, and second connection parts406disposed on the second retainer200.

The first retainer100has a first teeth receiving part R1and a first occlusal face B1opposite to each other. Also, the second retainer200has a second teeth receiving part R2and a second occlusal face B2opposite to each other. The first occlusal face B1corresponds to the second occlusal face B2. The first and second teeth receiving parts R1and R2form receiving spaces for accommodating the maxillary and mandibular dental arches12and22, respectively.

It should be appreciated that the first retainer100and the second retainer200are removable retainers (also known as movable retainers), so that the patient can freely wear or remove the retainers depending on situations and according to demand, and can still brush his teeth normally. In some embodiments, the first retainer100and the second retainer200may comprise thermoplastic, synthetic resin or other materials suitable for use in oral applications.

As shown in the embodiment ofFIG. 2, the first retainer100further has a first left buccal surface100aand a first right buccal surface100bopposite to each other. The first brackets302are mounted on the first left buccal surface100aand the first right buccal surface100b(e.g. the first left buccal surface100aand the first right buccal surface100beach have five first brackets302thereon). The first arch wires304(e.g. two first arch wires304) respectively pass through the first brackets302on the first left buccal surface100aand the first right buccal surface100band are fixed by the first brackets302. Moreover, the first arch wires304each has first connection parts306(e.g. four first connection parts306, each having a hook structure) attached, and the first connection parts306are located between the first brackets302.

Similarly, the second retainer200further has a second left buccal surface200aand a second right buccal surface200bopposite to each other, wherein the second left buccal surface200acorresponds to the first left buccal surface100aof the first retainer100and the second right buccal surface200bcorresponds to the first right buccal surface100bof the first retainer100. The second brackets402are mounted on the second left buccal surface200aand the second right buccal surface200b(e.g. the second left buccal surface200aand the second right buccal surface200beach have five second brackets402thereon). The second arch wires404(e.g. two second arch wires404) respectively pass through the second brackets402on the second left buccal surface200aand the second right buccal surface200band are fixed by the second brackets402. Moreover, the second arch wires404each has second connection parts406(e.g. four second connection parts406, each having a hook structure) attached, and the second connection parts406are located between the second brackets402.

In some embodiments, the first and second brackets302and402may comprise stainless steel, Ni—Ti alloy or plastic ceramic materials. The first and second arch wires304and404as well as the first and second connection parts306and406may comprise stainless steel or Ni—Ti alloy material.

As shown inFIG. 2, the elastic members500are used to couple the first connection parts306(i.e. the first left connection parts) on the first left buccal surface100ato the second connection parts406(i.e. the second left connection parts) on the second left buccal surface200aand are used to couple the first connection parts306(i.e. the first right connection parts) on the first right buccal surface100bto the second connection parts406(i.e. the second right connection parts) on the second right buccal surface200b(e.g. the left buccal surface and the right buccal surface of the first and second retainers100and200are respectively arranged with three elastic members500), so that the elastic force of the elastic members500can drive the second retainer200to move backward and upward (along a direction between the Y-axis and the Z-axis) or move forward and downward (along a direction between the -Y-axis and the -Z-axis) relative to the first retainer100. Accordingly, the relative position between the patient's mandible20connected to the second retainer200and the patient's maxilla10connected to the first retainer100can be adjusted, thereby achieving orthognathic correction.

It should be noted that when the method of the elastic members500coupling the first and second connection parts306and406on the corresponding buccal surfaces of the first retainer100and the second retainer200changes, it may generate an elastic force for driving the second retainer200to move backward and upward (along a direction between the Y-axis and the Z-axis) or move forward and downward (along a direction between the -Y-axis and the -Z-axis) relative to the first retainer100. In some embodiments, the elastic members500may be annuluses, such as rubber bands or spring coils made of Ni—Ti alloy material, having the same or different elastic force.

Specifically, when the numbers and elastic force of the elastic members500arranged on the left and right buccal surfaces of the first retainer100and the second retainer200match each other, it may make the left and right buccal surfaces of the first retainer100and the second retainer200bear uniform force, thus preventing the mandible20connected to the second retainer200from rotating with respect to the maxilla10connected to the first retainer100along a virtual central axis C (parallel to the Y-axis inFIG. 2) of the patient's mouth, and resulting in the relative movement between the mandible20and the maxilla10being only along the direction between the Y-axis and the Z-axis or the direction between the -Y-axis and the -Z-axis inFIG. 2. However, in some embodiments, the numbers and elastic force of the elastic members500arranged on the left and right buccal surfaces of the first retainer100and the second retainer200may not match, accommodating different conditions of different patients.

Moreover, the locations and numbers of the first and second brackets302and402, the numbers and lengths of the first and second arch wires304and404, the locations and numbers of the first and second (left and right) connection parts306and406, and the numbers of the elastic members500are not limited to the embodiment ofFIG. 2, but can be adjusted according to requirements.

Still referring toFIG. 2, the orthognathic correction device may further include a first central connection part308(e.g. a hook structure) fixedly mounted on the labial surface100cbetween the first left buccal surface100aand the first right buccal surface100bof the first retainer100. Also, at least one elastic member500can be used to couple the first central connection part308and a first connection part306on the first left buccal surface100aor the first right buccal surface100b,and then to couple the first connection part306and the corresponding second connection part406(with a position posterior to the first connection part306) on the second retainer200, so that the elastic force of the elastic member500can drive the second retainer200to move relative to the first retainer100along the X-direction or the -X-direction as shown inFIG. 2, thereby correcting horizontal asymmetry between the maxilla10and the mandible20. Similarly, as shown inFIG. 2, the orthognathic correction device may further include a second central connection part408(e.g. a hook structure) fixedly mounted on the labial surface200cbetween the second left buccal surface200aand the second right buccal surface200bof the second retainer200. Also, at least one elastic member500can be used to couple the second central connection part408and a second connection part406on the second left buccal surface200aor the second right buccal surface200b,and then to connect the second connection part406and the corresponding first connection part306(with a position posterior to the second connection part406) on the first retainer100, thereby correcting horizontal asymmetry of the maxilla10and the mandible20.

In some embodiments, the material and assembly methods of the first and second central connection parts308and408are the same as the first and second connection parts306and406.

FIG. 3Ais a schematic view illustrating a first retainer100according to an embodiment of the invention being worn on a patient's maxillary dental arch.FIG. 3Bis a schematic view illustrating a second retainer200according to an embodiment of the invention being worn on a patient's mandibular dental arch.

As shown inFIGS. 3A and 3B, it should be appreciated that when the first retainer100and second retainer200are worn on the maxillary and mandibular dental arches, they are substantially covering the entire crown of the maxillary and mandibular dental arches. More specifically, the first retainer100and the second retainer200are designed according to the undercut structure of the maxillary and mandibular dental arches, so that the first retainer100and the second retainer200can conformably cover the entire crown of the maxillary and mandibular dental arches, thus strengthening the retention of the first and second retainer100and200engaging with the maxillary and mandibular dental arches. Thus, it can prevent the first retainer100and the second retainer200from easily separating from the maxillary and mandibular dental arches during orthognathic correction.

Referring toFIG. 3A, a thickened part102and several thickened parts104are formed on the first occlusal face B1of the first retainer100. Specifically, the position of the thickened part102corresponds to two incisors12A and two lateral incisors12B of the maxillary dental arch (seeFIG. 2), and the positions of the thickened parts104correspond to the (left and right) canines12C, first premolars12D and second premolars12E, respectively, of the maxillary dental arch (seeFIG. 2). Furthermore, the thickened part102forms a guiding surface which starts from the top of the incisors12A and12B and gradually descends toward a palatal side T, and the thickened parts104also form guiding surfaces which start from the thickest parts of the thickened parts104(corresponding to the centers of the canines12C, the first premolars12D and the second premolars12E) and gradually descend toward the thinnest parts of the thickened parts104(located in adjacent places of the aforementioned teeth). The guiding surfaces of the thickened part102and the thickened parts104may be flat or curved.

Similarly, referring toFIG. 3B, several thickened parts204are formed on the second occlusal face B2of the second retainer200. Specifically, the positions of the thickened parts204correspond to the (left and right) first premolars22A and second premolars22B, respectively, of the mandibular dental arch (seeFIG. 2). The thickest parts of the thickened parts204correspond to the centers of the first premolars22A and the second premolars22B.

Note that the term “thickened part” used in the present disclosure represents, for example, that the regions of the first occlusal face B1corresponding to the thickened parts102and104each have a greater thickness than the other regions of the first occlusal face B1(having no thickened part), and the regions of the second occlusal face B2corresponding to the thickened parts204each have a greater thickness that the other regions of the second occlusal face B2(having no thickened part).

In some embodiments, the first retainer100and the thickened parts102and104may be integrally formed in one piece. Alternatively, the thickened parts102and104may be formed of synthetic resin, glass ionomer or other wear-resistant materials suitable for use in oral applications, and then be bonded to the first occlusal face B1of the first retainer100. Similarly, the second retainer200and the thickened parts204may be integrally formed in one piece. Alternatively, the thickened parts204may be formed of synthetic resin, glass ionomer or other wear-resistant materials suitable for use in oral applications, and then be bonded to the second occlusal face B2of the second retainer200.

When the patient wears the orthognathic correction device as described above, and the first occlusal face B1of the first retainer100contacts the second occlusal face B2of the second retainer200, several subunits202and202′ (FIGS. 2 and 3B) of the second retainer200corresponding to two incisors and two lateral incisors of the mandibular dental arch may contact the thickened part102(FIG. 3A) on the first retainer100, and the thickened parts204(FIG. 3B) on the second retainer200may contact the thickened parts104(FIG. 3A) on the first retainer100.

FIG. 4is a schematic view illustrating the working principle of an orthognathic correction device according to an embodiment of the invention. With the above structural design, when the first occlusal face B1of the first retainer100contacts the second occlusal face B2of the second retainer200, the thickened parts102and104on the first occlusal face B1can be used as guiding blocks, and the subunits202,202′ and the thickened parts204on the second occlusal face B2can contact the guiding surfaces of the guiding blocks102and104(in order to simplify the drawing, only one guiding surface and one contact point are depicted inFIG. 4). In this state, the elastic force exerted by the elastic members500(FIG. 2) can drive the second retainer200to slide along the guiding surfaces relative to the first retainer100(as the arrow indicates inFIG. 4), thereby leading the mandible20connected to the second retainer200to move relative to the maxilla10connected to the first retainer100and bring the temporomandibular joint30back to the appropriate location, so as to achieve t orthognathic correction.

When the elastic force of the elastic members500drives the second retainer200to move backward and upward (along the direction between the Y-axis and the Z-axis) relative to the first retainer100, it may improve the case that the patient's mandible20is prognathic with respect to the maxilla10as shown inFIG. 1A. Conversely, when the elastic force of the elastic members500drives the second retainer200to move forward and downward (along the direction between the -Y-axis and the -Z-axis) relative to the first retainer100, it may improve the case that the patient's mandible20is retracted with respect to the maxilla10as shown inFIG. 1B.

Although the guiding blocks and the guiding surfaces are formed on the first occlusal face B1of the first retainer100in the aforementioned embodiments, they may also be formed on the second occlusal face B2of the second retainer200.

The locations and numbers of the thickened parts102,104of the first retainer100and the thickened parts204of the second retainer200are not limited to the embodiments ofFIGS. 3A and 3B, but can be adjusted according to the different conditions of different patients.

Furthermore, in cases where the patient's mandible20is prognathic with respect to the maxilla10, the second molar12F of the maxillary dental arch12is often likely to obstruct the second molar12C of the mandibular dental arch22(FIG. 1A), resulting in the second retainer200placed on the mandibular dental arch22becoming stuck when it is coupled to the first retainer100placed on the maxillary dental arch12, so that the mandible20cannot smoothly move backward and upward (along the direction between the Y-axis and the Z-axis) relative to the maxilla10during orthognathic correction.

Referring toFIGS. 3A and 3B, it is therefore that the first occlusal face B1of the first retainer100may further have two openings106formed thereon for exposing the left and right second molars12F of the maxillary dental arch12, and the second occlusal face B2of the second retainer200may further form two spacers206thereon corresponding to the openings106, respectively, of the first retainer100. It should be noted that, when the first occlusal face B1of the first retainer100contacts the second occlusal face B2of the second retainer200, the spacers206can abut the second molars12F through the openings106, so as to increase the space between the first retainer100from the second retainer200, thus preventing the second retainer200from becoming stuck against the first retainer100. Therefore, the orthognathic device of this embodiment can smoothly adjust the relative position between the mandible20connected to the second retainer200and the maxilla10connected to the first retainer100, so as to achieve orthognathic correction. It should also be realized that the orthognathic device of this embodiment may further cause a rotation of the mandible20.

In this embodiment, the spacer206can also be regarded as a thickened part, and the manufacturing method thereof is the same as the thickened parts204. Moreover, in some embodiments, the locations and numbers of the spacers206and the openings106can also be adjusted. In some embodiments, the openings on the first occlusal face B1or the second occlusal face B2can also be omitted.

Although, in the aforementioned embodiments, the orthognathic correction device includes a first retainer100and a second retainer200, the orthognathic correction device in some embodiments may also include a single retainer (a first retainer100or a second retainer200) configured to be removably worn on the maxillary dental arch or the mandibular dental arch. In these cases, there may also be at least two connection parts (i.e. left and right connection parts) fixed on the left buccal surface and the right buccal surface of the other dental arch without a retainer (for example, if the retainer is worn on the maxillary dental arch, at least two connection parts can be fixed on the left and right buccal surfaces of the mandibular dental arch; conversely, if the retainer is worn on the mandibular dental arch, at least two connection parts can be fixed on the left and right buccal surfaces of the maxillary dental arch), and the occlusal face of this dental arch without a retainer may further form thickened parts (guiding blocks) thereon. Therefore, by using elastic members to couple the connection parts on the retainer and the connection parts on the dental arch without a retainer so as to drive the mandible to move relative to the maxilla, the purpose of orthognathic correction can also be achieved. Moreover, the dental arch without a retainer may also have a central connection part on its labial surface between the left and right buccal surfaces, and the central connection part can be coupled to the connection part on the adjacent left or right buccal surface and then be coupled to the connection part on the corresponding left or right buccal surface of the retainer worn on the other dental arch by an elastic member, so as to correct horizontal asymmetry between the maxilla10and the mandible20as described above.

Although, in the aforementioned embodiments (seeFIG. 2), the first teeth receiving part R1of the first retainer100is shaped to encase all (maxillary teeth) of the maxillary dental arch12and the second teeth receiving part R2of the second retainer200is shaped to encase all (mandibular teeth) of the mandibular dental arch22, the first teeth receiving part R1may also be shaped to encase a part (of maxillary teeth) of the maxillary dental arch12and the second teeth receiving part R2may also be shaped to encase a part (of mandibular teeth) of the mandibular dental arch22.

Furthermore, please refer toFIGS. 5A and 5B, whereinFIG. 5Ais a schematic view illustrating a first retainer100′ according to another embodiment of the invention being worn on a patient's maxillary dental arch, andFIG. 5Bis a schematic view illustrating a second retainer200′ according to another embodiment of the invention being worn on a patient's mandibular dental arch. As shown inFIGS. 5A and 5B, the first retainer100′ may also expose the occlusal surface O1of the maxillary dental arch12instead of covering it almost entirely as in the embodiment ofFIG. 3A, and the second retainer200′ may also expose the occlusal surface O2of the mandibular dental arch22instead of covering it almost entirely as in the embodiment ofFIG. 3B. It should be realized that, by using several elastic members500(seeFIG. 2) described above to couple the first connection parts306on the buccal surfaces of the first retainer100′ to the second connection parts406on the buccal surfaces of the second retainer200′, the orthognathic correction can also be achieved.

As shown inFIGS. 5A and 5B, there may also be at least one first lingual connection part306′ fixed on the lingual surface of the first retainer100′, and there may also be at least one second lingual connection part406′ fixed on the lingual surface of the second retainer200′. The first and second lingual connection parts306′ and406′ may have the same material as the first and second connection parts306and406in the embodiment ofFIG. 2. In this embodiment (FIGS. 5A and 5B), the first retainer100′, the first connection parts306, and the first lingual connection parts306′ may be integrally formed (e.g. by metal molding) in one-piece, and the second retainer200′, the second connection parts406, and the second lingual connection parts406′ may be integrally formed (e.g. by metal molding) in one-piece, but the invention is not limited thereto.