Tooth Anchored and Damon System Comparison for Differences in Maxillary Expansion Analyzed With Three-dimensional Images

Objectives: The purpose of this study was to compare tooth anchored versus Damon system in terms of the effects on maxillary expansion using three-dimensional imaging (cone beam computed tomography - CBCT) in terms of tooth and bone movement.
Methods: CBCTs from 29 patients treated for maxillary expansion were taken from the University of Alberta Graduate Orthodontic Program database. These patients were randomly assigned to one of two groups (12 with tooth anchored expander; 17 with Damon System). CBCTs were reconstructed, transported and visualized using the software platform AVIZO®. Twenty-six landmarks were chosen and the coordinates were then obtained and analyzed using linear and angular measurements. Ten additional images were first analyzed three times to determine the reliability and measurement error of each landmark using intraclass correlation coefficient (ICC). Descriptive statistics was done using SPSS statistical package to determine any relationships.
Results: ICC values were excellent (>0.992) for all landmarks in all axis having the highest measurement error of 1.38 mm in the y-axis for the left infraorbital foramen landmark. Paired sample test and ANOVA show that there were no statistical significant differences between the two techniques to expand the maxilla. Of note from the descriptive statistic is that the tooth anchored technique showed a difference of 7mm between the distance right and left U6 pulp chamber, 6mm between the right and left U6 mesial buccal root and alveolar bone around the root while Damon system had a difference of 3mm for all three values.
Conclusions: The tooth anchored technique demonstrated higher expansion values in the maxilla. Both treatment techniques showed no difference in terms of dental angulation changes in terms of expansion in the posterior sections. Thus, both techniques could be used when expanding the maxilla.