Maxillofacial Fixation Implants Having a Registration Member Relative to the Anterior Nares and Anterior Nasal Spine

Abstract

A maxillofacial fixation implant having a registration member positioned so as to abut, surround and/or engage with the anterior nares and the anterior nasal spine of a human skull, and the method of designing, manufacturing and utilizing the implant, wherein the implant has an upper anchor implant portion adapted for affixation to the upper portion of a maxilla and a lower anchor implant portion adapted for affixation to separated bone segments of the maxilla.

Claims

1. A maxillofacial orthognathic fixation implant, adapted and structured to be positioned onto a human skull having an anterior nares, an anterior nasal spine and a maxilla, each having a surface configuration, wherein the maxilla is divided by osteotomies into an upper maxilla portion and a lower maxilla portion, the implant comprising: upper anchor implant portions adapted, configured and structured to be positioned and affixed onto an upper maxilla portion; lower anchor implant portions adapted, configured and structured to be positioned and affixed onto a lower maxilla portion, wherein the lower anchor implant portions are joined to the upper anchor implant portions; and a registration member joined to and connecting the lower anchor implant portions, the registration member adapted, configured and structured to be positioned onto a lower maxilla portion in such manner as to abut or surround an anterior nasal spine and to extend into an anterior nares, the registration member having an inner surface matching the surface configuration of a maxilla over the area of contact.

2. The maxillofacial orthognathic fixation implant of claim 1, wherein the registration member is U-shaped and comprises a pair of upper end portions connected by a lower transverse portion.

3. The maxillofacial orthognathic fixation implant of claim 2, wherein the pair of upper end portions are configured to extend into an anterior nares.

4. The maxillofacial orthognathic fixation implant of claim 1, further comprising a dental split connected to the registration member.

5. The maxillofacial orthognathic fixation implant of claim 1, wherein the registration member is circular and comprises a lower transverse member and an upper transverse member.

6. The maxillofacial orthognathic fixation implant of claim 5, wherein the upper transverse member is configured to extend into an anterior nares.

7. The maxillofacial orthognathic fixation implant of claim 1, wherein the registration member is U-shaped and comprises an upper transverse portion.

8. The maxillofacial orthognathic fixation implant of claim 7, wherein the upper transverse portion is configured to extend into an anterior nares.

9. The maxillofacial orthognathic fixation implant of claim 1, wherein the upper implant anchor portions and the lower implant anchor portions are provided with apertures and wherein the registration member is not provided with apertures.

10. The maxillofacial orthognathic fixation implant of claim 1, wherein the upper implant anchor portions, the lower implant anchor portions and the registration member are provided with apertures.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIGS. 1 and 2 illustrate two embodiments of the implant showing the registration member as a U-shaped member surrounding the anterior nasal spine from below and partially extending into the anterior nares.

[0008] FIGS. 3 and 4 illustrate two embodiments of the implant comprising a dental splint and showing the registration member as a U-shaped member surrounding the anterior nasal spine and partially extending into the anterior nares.

[0009] FIGS. 5 and 6 illustrate two embodiments of the implant showing the registration member as a circular member surrounding the anterior nasal spine and partially extending into the anterior nares.

[0010] FIG. 7 illustrates an embodiment of the implant showing the registration member as a U-shaped member surrounding the anterior nasal spine from above and partially extending into the anterior nares.

SUMMARY OF THE INVENTION

[0011] The invention is a maxillofacial fixation implant having a registration structure or member adapted and structured so as to be positioned to abut, surround and/or engage with the anterior nares and the anterior nasal spine of a human skull, and the method of utilizing the implant to fix separated segments of the maxilla resulting from trauma, malformation and/or orthognathic procedures. For example, in orthognathic procedures, the implant may comprise a pair or set of upper anchor implant portions adapted for affixation to the upper portion of a maxilla and a pair or set of lower anchor implant portions adapted for affixation to the lower portion of a maxilla, the lower portion of the maxilla having been separated by an osteotomy from the upper portion of the maxilla.

[0012] The size and 3-D configuration of the implant is determined using 3-D imaging to create the fixation implant such that the lower and upper anchor implant portions conform to the surface configuration of the maxilla, and to create a central registration member conforming to the surface configuration in the lower area of the anterior nares and/or the anterior nasal spine.

[0013] The registration member may be substantially U-shaped or substantially circular. Mounting apertures to receive fixation screws are provided at locations on the lower and upper anchor implant portions. Preferably no apertures, or only a small number of apertures, are located on the registration member.

DETAILED DESCRIPTION OF THE INVENTION

[0014] The invention in various embodiments is a maxillofacial orthognathic fixation implant 10 having a registration structure or member 13 adapted and structured to be positioned to abut, surround and/or engage with the anterior nares 31 and/or the anterior nasal spine 32 of a human skull, and the method of designing, manufacturing and utilizing the implant 10, wherein the implant 10 comprises a pair of upper anchor implant portions 12 adapted for affixation to the upper portion 33 of a maxilla and a pair of lower anchor implant portions 11 adapted for affixation to the lower portion 34 of a maxilla, the lower portion 34 of the maxilla having been separated by an osteotomy 35 from the upper portion 33 of the maxilla.

[0015] The size and 3-D configuration of the implant 10 is determined using 3-D imaging to create the fixation implant such that the inner surface of the lower and the upper anchor implant portions 11/12 conform to the surface configuration of the maxilla over the contact area, and to create a central registration member 13 having an inner surface conforming to the surface bone configuration in the lower area of the anterior nares 31 and the anterior nasal spine 32. In this manner the inner surface of the implant 10 will substantially mate with or match the surface configuration of the bone on which it is positioned. The registration member 13 may be substantially U-shaped or substantially circular. Mounting apertures 14 to receive fixation screws are provided at locations on the lower and upper anchor implant portions 11/12. Preferably, no such apertures 14, or only a minimal number, are located on the registration member 13, as providing apertures 14 on the registration member 13 are typically not required.

[0016] A first set of embodiments is shown in FIGS. 1 and 2, wherein the fixation implant 10 is shown disposed on a human skull, the lower portion 34 of the maxilla having been separated from the upper portion 33 of the maxilla by osteotomies 35. The implant 10 comprises a pair or set of lower anchor implant portions 11 structured, configured and adapted to be affixed onto the maxilla lower portion 34 by fixation screws (not shown) through apertures 14 and a pair or set of upper anchor implant portions 12 connected to the lower anchor implant portions 11 and structured, configured and adapted to be affixed onto the maxilla upper portion 33 by fixation screws (not shown) through apertures 14. Critically, the implant 10 further comprises a centrally or medially located registration member 13, the registration member located between and connecting the two lower anchor implant portions 11.

[0017] The registration member 13 of the embodiments shown in FIGS. 1 and 2 is generally or substantially U-shaped in configuration, comprising a lower transverse portion 21 and two upper end portions 22. The registration member 13 is adapted, configured and structured to abut or partially surround the anterior nasal spine 32. The lower transverse portion 21 of the registration member 13 is adapted, configured and structured to be positioned beneath the anterior nasal spine 32 and the upper end portions 22 are adapted, configured and structured to be positioned one to each side of the anterior nasal spine 32, such that the upper end portions 22 preferably extend a short distance into the anterior nares 31 so as to rest on the bone structure defining the lower part of the anterior nares 31. The upper end portions 22 may be joined directly to the lower transverse portion 21 joined to the lower transverse portion 21 or in combination with end segments of the lower anchor implant portions 11.

[0018] Because the implant 10 is particularized for a particular patient with computer aided custom design, the overall configuration and contouring of the implant 10, and especially its interior surface, directly conforms, matches or mates with the surface configuration and contour of the maxilla over the areas of direct contact. Proper positioning of the implant 10 prior to affixation to the maxilla is easily accomplished by matching the medially located registration member 13 to the maxilla or skull area adjacent the anterior nasal spine 32 and anterior nares 31. Improper relative positioning will be readily noticed since the implant 11 will not rest on the maxilla in a nested or stable manner.

[0019] FIGS. 3 and 4 illustrate alternative embodiments of the implant 10 wherein the implant 10 further comprises a dental splint connected to the lower transverse portion 21 of the registration member 13.

[0020] FIGS. 5 and 6 illustrate alternative embodiments of the implant 10 wherein the registration member 13 is a generally or substantially circular member formed by the combination of a lower transverse member 21 joined to an upper transverse portion 23 such that no ends are present, i.e., the registration member 13 is either a continuous member or the lower and upper transverse portions 21/23 are joined by combining with short end segments of the lower anchor implant portions 11. The lower transverse member 21 as before resides below the anterior nasal spine 32 while the upper transverse portion 23 resides above the anterior nasal spine 32. Preferably, portions of the upper transverse portion 23, formed such as folds or short tabs, extend into the anterior nares 31 so as to rest on the bone structure defining the lower part of the anterior nares 31. In this manner the anterior nasal spine is surrounded by the registration member 13.

[0021] FIG. 7 illustrates an alternative embodiment of the implant 10 wherein the implant 10 comprises a pair of lower anchor implant portions 11, which will be affixed to the maxilla lower portion 34 by fixation screws (not shown) through apertures 14, and upper anchor implant portions 12 formed to the lower anchor implant portions 11, which will be affixed to the maxilla upper portion 33 by fixation screws (not shown) through apertures 14. The implant 10 further comprises a centrally or medially located registration member 13, the registration member 13 joined to and connecting the two lower anchor implant portions 11.

[0022] The registration member 13 is generally or substantially U-shaped in configuration and comprises an upper transverse portion 23. The registration member 13 is configured to abut or partially surround the anterior nasal spine 32, the upper transverse portion 23 being positioned above the anterior nasal spine 32, and is preferably configured such that one or more portions of the upper transverse portion 23, such as in the form of folds or tabs, extend or overlap over a short distance into the anterior nares 31 so as to rest on the bone structure defining the lower part of the anterior nares 31.

[0023] It is understood that equivalents and substitutions for certain elements described above may be obvious to those of skill in the art, and therefore the true scope and definition of the invention is to be as set forth in the following claims.