Effect of Micro-Osteoperforations on Orthodontic Tooth Movement with Clear Aligner Treatment.

Abstract

Background and Objectives: Micro-osteoperforation (MOP) is a relatively noninvasive procedure to expedite the rate of orthodontic tooth movement (OTM) by enahncing naturally occurring inflammatory response. This procedure is often combined with clear aligner treatment (CAT) in order to shorten the duration of aligner wear. However, the question yet remained whether the accuracy of OTM was maintained if the patients switched the aligners more frequently than recommended. The objectives of the study were to investigate the effect of MOPs on the accuracy of anterior OTM and to evaluate the differential effect of MOPs on gender, age, severity of the mal-alignment, and the likelihood of refinement treatment. Experimental Design and Methods: A de-identified sample of 105 patients who completed CAT and met the inclusion criteria was obtained from the private practice of Thomas Shipley (Peoria, AZ). The experimental group consisted of 46 CAT cases with MOPs and 3-day aligner change, and the control group consisted of 59 CAT cases with 14-day aligner change. For data collection, CloudCompare software was used to superimpose the post-treatment and prediction scans to the pre-treatment scans and to measure the actual and predicted amount of displacement of each anterior tooth of both arches. Using the transformation matrices from tooth-by-tooth alignment, the amount of linear and angular displacement in 3 different planes was obtained and used to calculate the linear discrepancy and the relative errors for the angular discrepancy. The difference of these values between the control and the experimental samples was analyzed using ANOVA, student’s t-test, Wilcoxon/Kruskal-Wallis rank sums test, and contingency analysis. Results: Statistical analyses showed no significant difference between the groups for the accuracy of anterior tooth movement in general, and the type of movement was unaffected by MOPs. No clinically significant difference was found between the predicted and the actual outcomes for varying gender, age, and severity of mal-alignment. On the other hand, a greater percentage of the experimental samples required refinement treatment. Conclusions: Compare to the 14-day aligner wear, the 3-day aligner wear with MOPs did not affect the accuracy of OTM. MOP had a negligible effect on the types of tooth movement, gender, age, and the severity of mal-alignment. The frequency of refinement treatment was higher for the 3-day aligner wear with MOPs possibly due to more severe mal-alignment and greater number of prescribed aligners of the experimental samples. In general, MOP can be a viable procedure to reduce the length of