Chin Surgery V: Treatment of the Long, Nonprojecting Chin

Abstract

Background: Correction of the long, nonprojecting chin requires both vertical reduction and sagittal augmentation. Wedge excision-based therapy reduces chin height and allows for advancement of the distal segment, but it is associated with at least a 10 percent incidence of mental nerve injury. The authors propose two innovative ways to correct the long, nonprojecting chin. Methods: There are two approaches, intraoral and extraoral. With the intraoral approach, following a gingivobuccal incision, a single horizontally oblique osteotomy is made at least 6 mm beneath the mental nerve foramina. The vertically long genial segment is freed and the posterior edge is contoured with a side-cutting burr. The contoured jumping genial segment is secured to the mandible with countersunk screws and contoured in situ to preserve the lower 8 to 10 mm. With the extraoral approach, following a submental incision, the anterior and posterior surfaces of the symphysis are cleared (a double-armed suture is placed through the posterior musculature). A reciprocating saw is used to remove the lower border of the symphysis to reduce the vertical excess. The tagged musculature is resuspended, and a tapered, textured implant is secured to the new symphysis. Results: Aesthetic outcomes using these two techniques were good and there were no complications. Representative patients, operated on by the senior author, illustrate these techniques. Conclusions: Both the intraoral one-cut in situ contoured jumping genioplasty and the extraoral vertical reduction/sagittal augmentation genioplasty reduce excess chin height, control sagittal advancement, provide pogonion projection, and avoid the risks of a standard wedge. Both techniques provide custom projection at the lower pole of the new symphysis.

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