Fracture healing has traditionally been thought to be a naturally optimized process with predetermined time-course for bone metabolism, and no one had had an idea that fracture healing may be manipulated to occur at a faster rate. In 1980s, the use of low-intensity pulsed ultrasound (LIPUS) was demonstrated with a significant promotion of bone healing and LIPUS has been used extensively for bone fractures in the limbs. On the other hand, the effectiveness of LIPUS for maxillofacial bone fractures has not been studied yet. In clinical orthodontics, there are many cases closely related to bone healing: the traumatic bone fracture in maxillofacial region, the osteotomy of jaw deformity, and the bone grafting in to alveolar cleft. The purpose of this study was to examine the benefit of LIPUS to the acceleration of maxillofacial bone healing.
Thirty-five patients received LIPUS after surgery served as subjects. Of total subjects, 11 patients had surgery for maxillofacial bone fracture fixation, 7 patients with jaw deformity had orthognathic surgery, and 17 patients affected by cleft lip and palate underwent alveolar cleft bone grafting. Five-seven days after surgery, the patient received 15 minutes of LIPUS (BR sonic-pro, ITO Co., Tokyo, Japan) per day for 14 days. A LIPUS signal was transmitted at a frequency of 1.0 MHz with a spatial-average intensity of 160 mW and pulsed 1: 4. In addition, we used the visual analogue scale (VAS) for pain assessment, and simple radiographs and computed tomography (CT) for evaluation of the bone healing.
In most cases, pain disappeared within one week after surgery. In the patients with bone fracture fixation or jaw osteotomy, bone healing was validated by plain radiographs and/or CT taken at 3 months after surgery, leading to stable occlusion. In the cases with alveolar bone grafting, early bone formation was observed from CT taken at 3 months after surgery. In addition, the catabolic effects of LIPUS exposure were not found at all.
In conclusion, LIPUS application might involve in acceleration of maxillofacial bone healing after surgery. Therefore, LIPUS may be a promising therapeutic tool for bone healing in maxillofacial region
