Stability and complications following mandibular supra-foraminal high oblique osteotomy

The aim of this study was to evaluate the results and complications following supra-foraminal high oblique osteotomy (SHOO) using patient-specific guides and implants (PSI). We selected consecutive patients who had undergone SHOO using PSI from May 2017 to December 2018 and had a minimum follow-up of 6 months. We collected the initial malocclusion and deformity, treatment planning, intraoperative and postoperative complications, stability, lower lip sensitivity, and temporo-mandibular joint disorders at 6 months. We also verified the amount of bone contact and mandibular sagittal repositioning on postoperative CT scans. One hundred and sixteen patients were included. Seventy-five (65%) had class II malocclusion and 18 (15.5%) had open bite. The mean sagittal displacement was 4.9 mm (2.6). At 6 months, 22 (19%) patients presented with malocclusion including 15 (13%) open bites, even though 10 of these patients had a normal overbite at preoperative assessment. Six (5%) of these patients required revision surgery for malocclusion. Mandibular secondary displacement was not statistically associated with initial malocclusion, amount of sagittal mandibular repositioning, profit classification, or intraoperative fixation adaptation. SHOO was associated in our series with poor occlusal stability due to a high rate of secondary displacements eventually requiring revision surgery.