The effect of low-intensity pulsed ultrasound on maxillofacial bone healing

Objectives: Low-intensity pulsed ultrasound (LIPUS) has been shown to accelerate long bone fracture healing. The purpose of this study was to examine benefits of LIPUS for the acceleration of maxillofacial bone healing after orthognathic surgery, alveolar cleft bone grafting and jaw fracture. Methods: Twenty-one patients received LIPUS after surgery: 7 patients had orthognathic surgery, 6 patients alveolar cleft bone grafting, and 8 patients maxillofacial bone fracture fixation. LIPUS treatment was started 5 or 7 days after surgery. The patient received 15 minutes of LIPUS (BR sonic-pro, ITO Co., Tokyo, Japan) per day (frequency =1.0 MHz ; spatial-average intensity=30 mW/cm2, pulsed 1: 4 [2 ms on and 8 ms off]) for 14 days. In addition, we used the visual analogue scale (VAS) for pain assessment, and simple radiographs (panoramic radiograph and cephalogram) and computed tomography (CT) for evaluation of the bone healing. Results: In almost all cases, pain disappeared within a week after surgery. In the patients of jaw osteotomy, bone healing was confirmed by simple radiograph after three months, leading to stable occlusion. In cases of alveolar bone grafting or bone fracture fixation, early bone formation was observed from CT after three months. In addition, the side effects of LIPUS such as radiation, induced inflammation and delayed bone union, were not found at all. Conclusion: LIPUS application accelerated maxillofacial bone healing as well as long bone healing. Therefore, LIPUS may be a promising therapeutic tool for bone healing in dentistry.