Clinical Observation of the Postoperative Stability of Bone Segments In Short Lingual Osteotomy without Fixation Using the New “Physiological Position- ing Strategy”

The aim of this study was to evaluate the “Physiological Positioning Strategy (PPS)” as a new treatment modality for orthognathic surgery, which could manage the positioning of bone segments after osteotomy. In this study, 20 patients with skeletal mandibular prognathism were treated by surgery with PPS, jaw exercise was performed after one-day maxilla-mandibular fixation, and the process of bony healing was investigated for 1 year. Ramus and gonial angles were measured at various time points after surgery to examine the stability of the lateral aspect. As a result, the proximal bone segment was moved notably to clockwise rotation, but it then returned to the original position 3 months after surgery. The RAMUS was measured similarly in the frontal aspect; the bone segments were remarkably separated just after operation, but the gap diminished significantly with time. At 3 months post-surgery, the minute gap between bone segments was filled with new bone, and osseous healing was almost completely accomplished. These results show that PPS contributes to stability after surgical treatment with sufficient osseous healing and represents an effective new treatment modality for jaw deformities without complicated technique, mainly owing to the jaw exercise started soon after the surgery.