Ultrasonic surgery--an alternative way in orthognathic surgery of the mandible. A pilot study.

The aim of this report is to present preliminary results and experiences using an ultrasonic bone-cutting device in bilateral sagittal split osteotomies of the mandible (BSSRO) with particular attention to possible damages to the inferior alveolar nerve (IAN). Seven patients with class II or class III malocclusion were treated by BSSRO with a conventional combined orthognathic and surgical approach. The osteotomy was carried out using an ultrasonic bone-cutting device. Subjective neurosensory deficits of the inferior alveolar nerve were assessed on 14 sides. Compared to the conventional techniques using saws, chisels and burs, the use of the ultrasonic device was more time-consuming, but the osteotomies were carried out at a high level of precision. In addition, this procedure offered the advantage of a blood-free surgical field and thus provided good control of the surgical procedure. Subjective neurosensory disturbances of the IAN showed a continuous decrease from 57.1% (eight sides) 2 months after the surgical procedure to 14.3% (2 sides) after 5 months and to 7.1% 7 months after BSSRO. Within the seven patients of this pilot study associated neurosensory disturbances were low. A possible advantage in terms of nerve protection is subject to a prospective study.