Comparison of the Effects of Three Different Surgical Procedures on the Rate of Orthodontic Tooth Movement in a Rat Model

Objectives: The aim of this study were to evaluate the effect of three different surgical procedures, corticotomy, corticision, and piezocision on the rate of tooth movement and alveolar response in a rat model.
Methods: 40 male (six week old) Wistar rats were divided equally into four groups based on the surgical procedure: Tooth Movement Only (Control), Corticotomy, Corticision, and Piezocision. A constant force of 10g was applied from the maxillary left first molar to the maxillary incisors using Sentalloy springs. Surgery was performed at the time of appliance placement, at day 0. Polyvinylsiloxane impression were taken and stone models made of the maxilla on days 0, 7, 14, and 21 to measure tooth movement. Micro-CT was performed on dissected maxilla on day 21 to evaluate tooth movement and alveolar response in all experimental groups. Static histomorphometry was performed on day 21 samples in order to calculate osteoclast number and osteoclast surface parameters.
Results: Tooth movement measurements from the stone models indicated that the Piezocision group had a significant increase in tooth movement at day 21 but was insignificant at day 7 and 14 when compared to the Control. Micro-CT analysis demonstrated significantly greater tooth movement in the Piezocision group (P<.0001) when compared to the Control. Bone Volume Fraction correlated with amount of tooth movement and showed a significant decrease in the Piezocision group (P=.0056). Tissue density followed the same trend (P=.0008). Static histomorphometry indicated that there was no significant difference in osteoclast numbers and osteoclast surface area between all groups.
Conclusions: The data suggests that Piezocision group significantly enhanced the rate of tooth movement over a three week period when compared to the Control. The rate of tooth movement correlated with the decrease bone volume fraction and tissue density but not with osteoclast number or surface area in the Piezocision group.