Evaluation of Condylar Position after Orthognathic Surgery for Treatment of Class II Vertical Maxillary Excess and Mandibular Deficiency by Using Cone-Beam Computed Tomography

STATEMENT OF THE PROBLEM In orthognathic surgeries, proper condylar position is one of the most important factors in postoperative stability. Knowing the condylar movement after orthognathic surgery can help preventing postoperative instabilities. PURPOSE The aim of this study was to evaluate the condylar positional changes after Le Fort I maxillary superior repositioning along with mandibular advancement by using cone beam computed tomography (CBCT). MATERIALS AND METHOD This cross-sectional study was conducted on 22 subjects who had class II skeletal malocclusion along with vertical maxillary excess. Subjects underwent maxillary superior repositioning (Le Fort I osteotomy) along with mandibular advancement. The CBCT images were taken a couple of days before the surgery (T0), and one month (T1) and 9 months (T2) after the surgery. The condyles positions were determined from the most superior point of the condyle to three distances including the deepest point of the glenoid fossa, the most anterior-inferior point of the articular eminence, and the most superior point of the external auditory meatus in the sagittal plane. RESULTS The mean mandibular advancement was 4.33±2.1 mm and the mean maxillary superior repositioning was 4.66±0.3 mm. The condyles displaced inferiorly, anteriorly, and laterally between T0 and T1. They were repositioned approximately in the initial position in T2. No correlation was observed between the mandibular and maxillary movement and the condylar positions. CONCLUSION The condyles displaced in the inferior-anterior-lateral position one month after the bilateral sagittal split osteotomy for mandibular advancement in combination with the maxillary Le Fort I superior repositioning. It seems that the condyles adapted approximately in their initial position nine months after the surgeries.