Correction of Unilateral Condylar Hyperplasia and Posterior Open Bite with Proportional Condylectomy and Fixed Orthodontic Treatment

A 29-year-old female patient with unilateral condylar hyperplasia (UCH) of the left side presented with facial asymmetry, maxillary transverse occlusal plane (MXTOP) cant, posterior open bite, and Class III relationship. Treatment consisted of proportional condylectomy of the left condyle for management of UCH, and fixed orthodontic treatment with intrusion of the left maxillary molars to correct the MXTOP cant and remaining chin point deviation (CPD). Proportional condylectomy with a 14-mm resection of the left condylar head improved the CPD from 11.5 mm to 7.8 mm and resolved the posterior open bite on the left side. However, it produced a Class II relationship on the right and left sides, posterior open bite on the right side, and anterior open bite. Fixed orthodontic treatment with 1.8-mm intrusion of the left maxillary molars using miniscrews corrected the MXTOP cant from 3.5 mm to 1.7 mm, reduced the remaining CPD from 7.8 mm to 3.7 mm, produced counterclockwise rotation of the mandible, and resolved the posterior open bite on the right side and the anterior open bite. After 16 months of total treatment, normal overbite/overjet and Class I relationship were obtained. Treatment results were well maintained after 5 years of retention. For the correction of UCH, it is important to determine the amount of condylar head resection and accurately simulate the correction of CPD and MXTOP cant through intrusion of the maxillary molars.