Effects of clear aligner therapy for Class II malocclusion on upper airway morphology and daytime sleepiness in adults: A case series

Abstract

To evaluate the effects of clear aligner therapy (CAT) on the upper airway dimensions and on daytime sleepiness in adults with dentoskeletal Class II malocclusion. This study was conducted from August 2017 to February 2019. Inclusion criteria were healthy adults≥18years old, Angle Class II division 1 malocclusion, first-molar relationship of end-to-end or greater, overjet<10mm, and presenting for multi-arch comprehensive orthodontic treatment with aligners. Treatment mechanics included mandibular dentoalveolar advancement with Class II elastics without maxillary sequential distalization programmed into aligners. Post-treatment changes in dentoskeletal and upper airway dimensions were assessed using CBCT images. The treatment effect on daytime sleepiness was evaluated using an Epworth Sleepiness Scale (ESS). Eight subjects were included in this pilot study (mean age at treatment initiation=44.6years [SD=15.3]). The mean treatment duration was 12.2months (SD=3.4). No statistically significant treatment changes were observed in upper airway dimensions or dentoskeletal cephalometric analyses. Subjects with excessive daytime sleepiness at pre-treatment reported an improvement post-treatment, but no significant difference in the mean ESS score was found. Treatment of Class II division 1 malocclusion in adults by mandibular dentoalveolar advancement using CAT has no statistically significant effects on the airway and dentoskeletal measurements, or daytime sleepiness.