Superficial skin sensitivity impairment and skeletal stability after sagittal split ramus osteotomy

Adjustable osteosynthesis miniplates are used to facilitate positioning of the mandible after bilateral sagittal split osteotomy (BSSO) to avoid skeletal relapse and occlusal discrepancies. The short Obwegeser BSSO reduces neurosensory disturbances. Adjustable osteosynthesis plates suited for the Obwegeser BSSO are not commercially available. This study tested adjustable miniplates for the short Obwegeser BSSO in advancement of the mandible and correction of facial asymmetry, assessing (1) sensitivity impairment of the lower lip and (2) skeletal stability.A prototype of L-shaped, 6-hole, 2.0-mm miniplate with 2 sliding holes was used. Five patients with facial asymmetry (group 1) and 10 patients with mandibular hypoplasia (group 2) were operated on. Sensitivity of the lower lip was quantified using the pain and thermal sensitivity test before the surgery (T0), 1 week after the surgery (T1), and 12 months after the surgery (T2). The length of the ascending ramus (group 1) and the corpus (group 2) was determined at T1 and T2 using cone beam computed tomographic scans and lateral skull radiographs, respectively.After the surgery, occlusion was adequate. There was no need for revisional surgery. At T2, no patient showed a pathologically reduced sensitivity of the lower lip. The length of the ascending ramus in group 1 and the length of the corpus in group 2 did not have statistically significant changes between T1 and T2.The current study revealed that the adjustable osteosynthesis plates especially designed for the short Obwegeser BSSO can be safely used for the advancement of the mandible and the correction of facial asymmetry, with a minimum risk for neurosensory disturbance and a high skeletal stability.