Reinventing the wheel: a modern perspective on the bilateral inverted 'L' osteotomy

摘要

The bird-face deformity of a severe class II, high Frankfort mandibular plane angle with significant retrogenia, often associated with diminutive condyles and reduced posterior face height, poses many challenges to the orthognathic surgeon. Of greatest concern in these patients is the degree of mandibular advancement required and the potential for relapse. The sagittal split osteotomy is the workhorse of mandibular surgery but does not allow significant lengthening of the ramus, which is desirable in this group of patients. An inverted 'L' osteotomy of the mandible to facilitate ramus lengthening is therefore indicated in the management of this group, but is a procedure that has largely fallen out of favour due to the need for an extraoral approach and intermaxillary fixation. The advent of distraction osteogenesis promised to be the answer for these cases, but with nearly 20 years of experience with these techniques, it is clear that it does not represent the panacea that was hoped for. We present a series of four cases of bimaxillary surgery consisting of maxillary osteotomy and bilateral inverted 'L' osteotomy of the mandible carried out via an intraoral approach (average advancement 10.5 mm), where internal semi-rigid fixation was employed to obviate the need for intermaxillary fixation. We highlight the indications for this procedure and why it is ideally suited to this group of patients and argue that the procedure should be reintroduced to the armamentarium of the orthognathic surgeon.