Predicting Outcome in Clear Aligner Treatment: A Machine Learning Analysis.

Background/Objectives: Machine learning (ML) models predicting the risk of refinement (i.e., a subsequent course of treatment being necessary) in clear aligner therapy (CAT) were developed and evaluated. Methods: An anonymized sample of 9942 CAT patients (70.6% females, 29.4% males, age range 18-64 years, median 30.5 years), as provided by DrSmile, a large European CAT provider based in Berlin, Germany, was used. Three different ML methods were employed: (1) logistic regression with L1 regularization, (2) extreme gradient boosting (XGBoost), and (3) support vector classification with a radial basis function kernel. In total, 74 factors were selected as predictors for these methods and are consistent with clinical reasoning. Results: On a held-out test set with a true-positive rate of 0.58, the logistic regression model has an area under the ROC curve (AUC) of 0.67, an average precision (AP) of 0.73, and Brier loss of 0.22; the XGBoost model has an AUC of 0.67, an AP of 0.74, and Brier loss of 0.22; and the support vector model has a recall of 0.61 and a precision of 0.64. The logistic regression and XGBoost models identify predictors influencing refinement risk, including patient compliance, interproximal enamel reduction (IPR) and certain planned tooth movements, for example, lingual translation of maxillary incisors being associated with the lowest risk of refinement and rotation of mandibular incisors with the highest risk. Conclusions: These findings suggest moderate, well-calibrated predictive accuracy with both regularized logistic regression and XGBoost and underscore the influence the identified factors have on the risk of refinement in CAT, emphasizing their importance in the careful planning of orthodontic treatment and the potential for shorter treatment times, less patient discomfort, and fewer clinic visits. Identification of at-risk individuals could support tailored clinical decision-making and enable targeted interventions.

Effect of electronic reminders on patients' compliance during clear aligner treatment: an interrupted time series study.

Patient compliance is relevant to achieving therapeutic goals during clear aligner therapy (CAT). The aim of this study was to evaluate the efficacy of remote electronic (e-)reminders and e-feedback on compliance during CAT using an interrupted time series (ITS) analysis. We used routinely collected mobile application data from a German healthtech company (PlusDental, Berlin). Our primary outcome was self-reported compliance (aligner wear time min. 22 h on 75% of their aligners were classified as fully compliant, min. 22 h on 50-74.9% of their aligners: fairly compliant; min. 22 h on < 50% of their aligners: poorly compliant). E-reminders and e-feedback were introduced in the 1st quarter of 2020. Compliance was assessed at semi-monthly intervals from June-December 2019 (n = 1899) and June-December 2020 (n = 5486), resulting in a pre- and post-intervention group. ITS and segmented regression modelling were used to estimate the effect on the change in levels and trends of poor compliance. Pre-intervention, poor compliance was at 24.47% (95% CI: 22.59% to 26.46%). After the introduction of e-reminders and e-feedback (i.e., post-intervention), the percentage of poorly compliant patients decreased substantially, levelling off at 9.32% (95% CI: 8.31% to 10.45%). E-reminders and e-feedback were effective for increasing compliance in CAT patients.Clinical Significance: Orthodontists and dentists may consider digital monitoring and e-reminders to improve compliance and increase treatment success.

Who Seeks Clear Aligner Therapy? A European Cross-National Real-World Data Analysis.

A key step prior to clear aligner therapy (CAT) is the clinical examination and case selection, which includes understanding the specific orthodontic problem to be managed and the wider evaluation of oral health. Seeking CAT may further differ along sociodemographic parameters or across countries, as may perceived orthodontic treatment needs and oral health. We aimed to characterize patients seeking CAT across five European countries. Anonymized real-life data from one large CAT provider (DrSmile, Berlin, Germany) was retrospectively sampled for the period 1 November 2021−31 December 2021. A total of 15,015 patients (68.4% females, 31.6% males, with an age range of 18−81 years, median 30.0 years) were included. The cross-national comparison revealed a significant difference in gender distribution (p < 0.001/Chi-square), with the highest proportion of males in Italy (434/1199, 36.2%) and the lowest in Poland (457/1600, 28.6%); generally, more females sought CAT. The largest motivational factor in all countries for seeking CAT was crowding, in both males and females. By and large, patients paid out of pocket for CAT. The prevalence of caries, periodontitis, and craniomandibular dysfunction as well as the numbers of missing teeth were generally low, albeit with significant differences between sociodemographic groups and countries for caries and periodontitis. Patients seeking CAT showed a low prevalence in oral conditions but differed in their sociodemographic characteristics across countries. Dentists and orthodontists should consider these country-specific differences when planning CAT.

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.