Ultrasound: Assessment of the distraction osteogenesis wound in patients undergoing mandibular lengthening

Purpose: Common methods of assessment of the clinical distraction osteogenesis (DO) wound consist of serial physical examinations, plain radiographs, and computed tomography (CT). Ultrasound (US) is an inexpensive and efficient method of imaging that provides detailed assessment of bone formation across a defect. It has proved to be useful for the evaluation of long bone DO healing. The purpose of this study was to determine the efficacy of US for evaluation of bone formation in the mandibular distraction wound. Patients and Methods: Ten patients underwent mandibular expansion (18 sides) with semiburied, unidirectional distraction devices. The wounds were assessed with plain radiographs and US immediately before device removal. Estimates of bone formation, using a semiquantitative bone fill score, were made for plain radiographs and US. US beam penetration depth, in millimeters, was also measured. During removal of the distraction device, bone formation and mandibular stability were assessed by the surgeon and graded on a semiquantitative scale. Results: US bone fill scores correlated with intraoperative assessment of bone formation and stability (r = 0.758, P = .0018) at all 18 mandibular sites. Plain radiographic scores also correlated with bone formation (r = 0.592). However, in 14 of 18 sides, plain radiographs underestimated bone formation compared with US and operative findings. Conclusion: The results of this study indicate that US is an accurate noninvasive technique that may prove to be useful in assessing the mandibular DO regenerate in patients. (C) 2003 American Association of Oral and Maxillofacial Surgeons.