Long-term Follow-up after Surgical Treatment for Skeletal Mandibular Protrusion with Severe Mandibular Deviation and Multiple Prosthetic Treatment

Abstract

Occlusal malfunction and esthetic problems often become issues in patients with skeletal discrepancy of jawbones. Inappropriate prosthodontic treatment was frequently observed in this type of patients. In this situation, unexpected occlusal stress occurs on a certain area of teeth, resulting in collapsed occlusion in an early stage. Therefore, correction of skeletal discrepancy through orthognatic surgery followed by appropriate prosthodontic treatment is crucial in terms of esthetics, occlusion and periodontal health. In addition, it is essential to establish correct tooth position and intimate occlusion for avoidance of relapse after orthognathic surgery. A female patient (32 years and 3 months) visited our clinic complaining mandibular protrusion and asymmetry. Fifteen teeth had been prosthodontically treated, and her anterior overjet was －7.0 mm. We diagnosed her as long face type skeletal manidibular protrusion with anteroinferior overgrowth on the left side mandible. Cephalometric analysis presented ANB: －3°, Ul-SN plane: 112°, IMPA: 86.1° and Gonial angle: 130.9°, with wide mandibular plane angle in addition to dental compensation in the anterior segment. Typical dental compensation found with mandibular protrusion was observed. After conducting preoperative orthodontic treatment using multi-brackets for 1 year and 4 months, sagittal splitting ramus osteotomy was performed. This procedure was followed by 1-year postoperative orthodontic treatment for detailing. Postoperative analysis showed improvement in overjet (＋2 mm), overbite (＋1.5 mm), maxillary incisor angulation (U1-SN108°) and mandibular incisor angulation (IMPA90.5°). By immediately replacing the defective restorations to appropriate ones after correction of skeletal discrepancy and occlusion, stable occlusion and esthetics were obtained. Ten-year follow-up after insertion of retainers shows favorable prognosis.