Ultrasound to stimulate mandibular bone defect healing:A placebo-controlled single-blind study in rats

Purpose: Because of the limitations of the body to heal large maxillofacial bone defects, an attempt was made to stimulate mandibular defect healing with low intensity pulsed ultrasound in rats. This ultrasound consists of a 1.5-MHz pressure wave administered in pulses of 200 musec, with an average intensity over space and time of 30 mW . cm(-2).Materials and Methods: In 72 rats, a 5.0-mm-diameter circular mandibular defect was created. Three groups were studied: an ultrasound treatment group, a placebo treatment group, and a control group. Ultrasound and placebo treatment involved a daily treatment for 20 minutes at the site of the defect under general anesthesia. At 2 and 4 weeks, the region of bone growth within the defect was measured using microradiographs and the amount of defect heating was expressed as the percentage of defect closure.Results: At 2 and 4 weeks, there was no statistical significant difference in the percentage of defect closure between the groups.Conclusion: Low-intensity pulsed ultrasound does not stimulate bone defect healing in the case of a large mandibular defect in the rat. (C) 2004 American Association of Oral and Maxillofacial Surgeons.