Effect of low intensity ultrasound (Usbi) in the orthodontic dental movement. in vivo study in sprague-dawley rats

Abstract

The objective of this study was to analyze the effect of USBI wave application on the speed and distance of dental movement, and its effect at histological level in Sprague-Dawley rats. In this study twenty-three male Sprague-Dawley rats were randomly divided into three groups. Five rats were used as control without orthodontic tooth movement (MDO), nine rats were subjected to an orthodontic force application without USBI application, and nine were subjected to an orthodontic force application with USBI. The orthodontic forces were performed between the vestibular mesio aspect of the first upper left molar and upper central incisor, pulling the molar mesially, applying an approximate force of 50 grams for 21 days. In light of sedation problems these last two groups were composed of six and eight rats respectively. In the MDO group without USBI, there was a reduction in the space between molars and incisors of 2 mm. In the MDO group with USBI this reduction was 3.4mm, this difference being statistically significant. Histologically, the MDO c / USBI group showed a vascular perimeter and enlarged spinal spaces with respect to the other groups, however, no significant differences were found in the amount of osteoclasts. It was possible to quantitatively demonstrate that USBI is a form of efficient mechanical stimulation for MDO acceleration over an experimental 21-day period, where significant differences were observed in tooth movement between the control group, the group without USBI and the group with USBI. A greater vascularity was observed in the group with USBI, expressing larger vascular perimeters, which could be due to the stimulatory effect of ultrasound on angiogenesis.