Factors Influencing Patient Compliance during Clear Aligner Therapy: A Retrospective Cohort Study

Compliance is highly relevant during clear aligner therapy (CAT). In this retrospective cohort study, we assessed compliance and associated covariates in a large cohort of CAT patients. A comprehensive sample of 2644 patients (75.0% females, 25.0% males, age range 18-64 years, median 27 years), all receiving CAT with PlusDental (Berlin, Germany) finished in 2019, was analyzed. Covariates included demographic ones (age, gender) as well as self-reported questionnaire-obtained ones (satisfaction with ones' smile prior treatment, the experience of previous orthodontic therapy). The primary outcome was compliance: Based on patients' consistent use of the mobile application for self-report and aligner wear time of ≥22 h, patients were classified as fully compliant, fairly compliant, or poorly compliant. Chi-square test was used to compare compliance in different subgroups. A total of 953/2644 (36.0%) of patients showed full compliance, 1012/2644 (38.3%) fair compliance, and 679/2644 (25.7%) poor compliance. Males were significantly more compliant than females (p = 0.000014), as were patients without previous orthodontic treatment (p = 0.023). Age and self-perceived satisfaction with ones' smile prior to treatment were not sufficiently associated with compliance (p > 0.05). Our findings could be used to guide practitioners towards limitedly compliant individuals, allowing early intervention.