The Impact of Malocclusion Severity on the Number of Prescribed, Used Aligners and Treatment Duration; A Retrospective, Singe‐Centre, Cohort Study

OBJECTIVE: To assess the impact of baseline malocclusion severity on the number of prescribed, used aligners and treatment duration. MATERIALS AND METHODS: An unrestricted, independent search was conducted on the Invisalign ClinCheck database of a private practice for patients without any missing anterior teeth and whose treatment was finished between April 2021 and December 2024. Descriptive statistics were generated, and the feature selection Boruta algorithm (random forest algorithm) was implemented to identify important predictors for the number of aligners (prescribed, used) and treatment duration. RESULTS: A total of 404 patients were included (age: 29.57 [10.7] years). Mean numbers of prescribed, used and unused aligners were 72.21 (37.52), 65.63 (30.40) and 6.57 (14.09), respectively. Important predictors of the numbers of the prescribed and used aligners were relatively similar and included molar and canine relationships, maxillary crowding, overjet, presence and number of missing or extracted posterior teeth, overbite, presence and number of teeth in posterior crossbite and midline discrepancies. Treatment duration was associated with baseline maxillary crowding, molar and canine relationships, overjet, overbite, midline discrepancies and the presence and number of missing or extracted posterior teeth. CONCLUSIONS: Factors related to the baseline malocclusion severity significantly affect the number of prescribed, used aligners and treatment duration. This information could be used for informed practice and patient communication, including future evaluation of the biological and environmental footprint of aligners.