Age as a factor in the complication rate after removal of unerupted/impacted third molars at the time of mandibular sagittal split osteotomy

Purpose: This study was designed to investigate the effect that the presence of an unerupted third molar has on the mandibular sagittal split osteotomy (SSO). Patients and Methods: One operator performed 139 SSOs (70 right side and 69 left side) in 70 patients during a period of 6 months. Data related to gender, age, presence or absence of unerupted third molar teeth, split difficulty during SSO, fracture complications of the segment, neurovascular bundle involvement at surgery, removal of unerupted third molar teeth, and the postoperative recovery of nerve function were recorded. Results: The SSOs evaluated as technically difficult were significantly more prevalent in mandibles with unerupted third molar teeth. All fractures (4) occurred in the younger age group (<20 years) with unerupted third molars present at the time of surgery. Although inferior alveolar nerve recovery was slower in the patients in whom the unerupted third molar teeth were present at the time of surgery due to increased frequency of neurovascular bundle manipulation, the recovery rates at 1 year were equal. Conclusions: The presence of unerupted third molar teeth increases the degree of difficulty of the SSO. Fracture of proximal and/or distal segments during SSO tend to occur more frequently in the younger age group (<20 years) with an unerupted third molar present. © 2002 American Association of Oral and Maxillofacial Surgeons.