Skeletal stability after sagittal split ramus osteotomy with physiological positioning in patients with skeletal mandibular prognathism and facial asymmetry

The correction of deformities of the jaw in patients with facial asymmetry is challenging because of the high rate of relapse, which may partly be caused by skeletal interference and inappropriate seating of the condylar head. We evaluated outcomes in 30 patients who were treated by short lingual osteotomy with physiological positioning. Nine had facial symmetry (absolute displacement of the menton < 2 mm), 14 had minor asymmetry (displacement of >2 to <4 mm), and 7 severe asymmetry (displacement of >4 mm). The postoperative position of the menton (Me) was stable in each group, but deviated by 3.56 mm in those with severe asymmetry. This deviation remained immediately after operation and after more than one year in this group, which implies that the Me was not on the mandibular midline. The lateral swing of both sides of the proximal segment did not change immediately after operation in any group. Although short lingual osteotomy with physiological positioning can result in skeletal stability, it is important to assess the association between the dental arch and the mandible using computed tomography to ensure a good outcome in patients with a skeletal class III deformity and facial asymmetry.