Revisiting the supraforaminal horizontal oblique osteotomy of the mandible.

PURPOSE

Today, the most common orthognathic procedure for correction of mandibular deformities is the bilateral sagittal split osteotomy, also called sagittal ramus osteotomy. Permanent injury to the mandibular nerve (V3) is one of the main complications, with a reported incidence between 5% and 30%. Orthognathic surgery using sagittal ramus osteotomy of the mandible as the procedure of choice should be re-evaluated because of the complexity and the relatively high risk of damage to the inferior alveolar nerve. Surgical techniques that allow for accurate condylar positioning with a lower risk of inferior alveolar nerve injury should be considered. The aim of this study is to present a retrospective case series using the previously described horizontal osteotomy of the mandibular rami along with modern-day technical advances that make this procedure safe, reliable, and reproducible.

MATERIALS AND METHODS

We performed a modified approach to the supraforaminal horizontal oblique osteotomy of the mandible with a condylar positioning device, endoscopy, and a surgical navigation system. This technique was performed in 17 consecutive patients. Postoperatively, we measured the amount of surgical movement of the mandible, monitored the mandibular nerve, and evaluated bone healing during removal of the osteosynthesis plates.

RESULTS

In all 17 treated patients there was uneventful wound healing, and no patient had permanent nerve alteration. The mean movement of the mandible was 7.48 mm (SD, 2.1 mm), with a range from 3.0 to 10.5 mm. The mean follow-up was 19 months. The main purpose of the surgical navigation was the translation of the planned osteotomy line from the computed tomography scan to the surgical site during the operation. This was performed to prevent a large gap between the bone segments at the osteotomy site.

CONCLUSION

The supraforaminal approach with a condylar positioning device appears to be an appropriate way to prevent injury to the inferior alveolar nerve during orthognathic surgery of the mandible while maintaining centric positioning of the condyle and obtaining good bony union.