Accuracy of clear aligners in the orthodontic rotational movement using different attachment configurations.

OBJECTIVE: To evaluate the accuracy of dental rotational movements using clear aligners with different attachment configurations. MATERIALS AND METHODS: This retrospective study analysed 212 teeth from 89 patients undergoing Invisalign treatment. Digital models were analysed after the virtual treatment plan (ST1) and after the first treatment phase (ET1) to evaluate the effective clinical rotational movement. The rotational movements of incisors, canines, and bicuspids were measured using data from the Clincheck Movements Table. ST1 and ET1 were compared to determine the actual rotational movement achieved (ST1-ET1). The presence or absence of attachments (rectangular or optimized) on teeth was analysed. The accuracy of rotational movements among attachment types was compared using the Kruskal-Wallis test. Multiple linear regressions were conducted with accuracy as the dependent variable and tooth type, gender, and age as predictors. RESULTS: Optimized attachments had the highest median accuracy (70%), followed by rectangular (65%), and without attachment (63%), with no significant differences (p = .5). There were no significant differences across age groups, genders, or tooth types. Baseline accuracy was 68.62% (95% CI: 56.03-81.20, p < .001). Age was a significant predictor (estimate = -0.30, 95% CI: -0.58 - -0.03, p = .032), indicating decreased accuracy with increasing age. The model's R2 was 0.046, with an adjusted R2 of 0.003, indicating minimal variance explained. CONCLUSION: The addition of attachment configurations to clear aligners improves rotational accuracy, but not significantly. Further advancements in these configurations are needed to enhance the performance of the aligners.

Invisalign appliance: aesthetic and efficiency.

BACKGROUND: The patients' request for treatment with clear aligners is constantly increasing. The aligners permit to the clinicians a valid way to solve a lot of orthodontic cases but the patients' compliance and the clinicians' capabilities and knowledge of the technique is fundamental for the outcome. METHODS: Seventy-two digital models of 18 consecutive patients treated with Invisalign and Smart Track aligners for 14 weeks were analyzed. The operator positioned 24 points on each model and were obtained the values of arch depth and perimeter of arch before and after the treatment. The variations of measurement were calculated with t student test. RESULTS: A decrease of arch depth and perimeter was found from t0 to t1 and the most relevant difference was observed in the upper arch depth with a decrease of 1.3 mm and in the upper arch perimeter with a difference of 1.1 mm. CONCLUSIONS: There was always a decrease of the values of arch depth and arch perimeter at the end of the treatment, especially in the upper arch. These changes must be considered by the clinicians to perform a better treatment to obtain the most predictable results and a patient's higher satisfaction.