A 19-year-old male presented with chief complaints of protrusive lower front teeth and a large lower jaw. Extraoral examination reveals a concave profile, increased lower anterior face height, mild hypoplastic maxilla, positive lip step, hyperdivergent skeletal pattern, and a large mandible [Figure 1a-d]. Intraorally, he exhibits a Class III molar and canine relation, mild crowding of upper and lower anterior teeth, dental midlines matching, and reverse overjet of 3 mm [Figure 2a-e]. A cone beam computed tomography scan (CBCT) reveals the absence of skeletal asymmetry and no abnormality of the temporomandibular joint [Figure 3a-c].
From the clinical presentation and CBCT scan evaluation, it was apparent that the Class III deformity was primarily due to a prognathic mandible in both vertical and anteroposterior planes. A surgery-first approach was planned to perform a bilateral sagittal split setback osteotomy (BSSO) combined with a vertical reduction genioplasty to correct the vertical mandibular excess. In addition, the mildly hypoplastic maxilla was addressed by an autogenic bone transplant.
All teeth were bonded with 0.022" preadjusted brackets (Smartclip , 3M Unitek, St Paul, MN, USA) [Figure 4a-e] and ligated with 0.010 stainless steel ligature wire. A face-bow transfer recorded the relationship of maxilla to the transverse horizontal hinge axis of the mandible [Figure 5]. The patient was subjected to a BSSO set-back and vertical reduction genioplasty of the mandible and autogenic bone transplant of the maxilla. Postsurgically, extraoral images [Figure 6a-d] revealed fulfillment of the surgery objectives. One-week postsurgery, 0.014" NiTi wires were placed in the upper and lower arches [Figure 7a-c], and subsequently, wires were changed to 0.016 x 0.022 NiTi archwires, and the case was finished in 0.017 x 0.025" stainless steel with second-order bends. The overall treatment time was 6 months from start to finish. Treatment results: Six months after surgery, the fixed appliances were removed, and posttreatment photographic images [Figures 8a-d and 9a-e] and CBCT [Figures 10a-c and 11] showed excellent esthetic and occlusal results [Figure 10d]. Pre- and post-treatment superimposition of lateral cephalogram show correction of Class III to Class I skeletal relation.