Date of Award

9-30-2022

Department

Department of Orthodontics

First Advisor

Heesoo Oh

Abstract

Introduction: This study was designed to analyze the cephalometric changes in adult Class III malocclusion treated with clear aligner therapy. Methods: In this retrospective study, thirty-six Class III adult patients treated with clear aligner therapy in private practice and a graduate orthodontic clinic were included in this study. Inclusion criteria included patients aged 18 years and older, Class III molar relationship that is end-on or greater, at least one anterior tooth that is in crossbite or incisors in an edge-to-edge bite, and complete records (initial and final lateral cephalograms) that are clear and traceable. Twenty-two cephalometric measurements were measured and analyzed by two calibrated judges. Results were categorized by skeletal vertical, skeletal anterior-posterior, dental vertical, and dental anterior-posterior. Descriptive analysis for mean, standard deviation, range, and percent was completed for demographic information, a paired T test to determine pretreatment and posttreatment cephalometric differences was performed, and a chi-square test for proportions was conducted. Results: No vertical changes were noted in upper and lower molar positions, and the upper incisor inclinations were maintained. On the other hand, lower incisors retroclined on average 5.6 degrees and retracted 1.78 mm. There was no change in the mandibular plane angle across different vertical pattern groups (normodivergent/hypodivergent/hyperdivergent patients). The only cephalometric variable that was statistically significant between different vertical pattern growers was the overbite. Conclusions: Adult patients with Class III malocclusion treated with clear aligners have good vertical control with no increase in mandibular plane angle and anterior face height. Clear aligner therapy is also good at maintaining vertical control for hyperdivergent patients. Finally, adult Class III dental camouflage treatment was resolved primarily through maintaining upper incisor inclination and lower incisor retroclination.

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