This study evaluated the association between planned anterior tooth movements, attachment use, and the need for refinement in clear aligner (CA) therapy using logistic regression. A retrospective analysis was conducted on 116 patients and 696 anterior teeth treated with Invisalign®. For each tooth, planned movement magnitudes (extrusion, intrusion, rotation, angulation, inclination) and the presence of attachments were recorded. Refinement was defined as a binary outcome. Multivariable logistic regression and independent t-tests were used to assess associations and compare movement magnitudes between refined and non-refined teeth. In tooth 11, greater planned rotation was associated with a modest but statistically significant reduction in refinement likelihood (OR = 0.92, p < .05). Attachment use emerged as a significant factor for teeth 12 and 21, decreasing refinement risk in tooth 21 (OR = 0.05, p < .01), yet increasing it in tooth 12 (OR = 4.95, p < .05). For tooth 22, increased planned extrusion reduced the probability of refinement (OR = 0.34, p < .05), whereas higher degrees of rotation and inclination were associated with increased refinement rates (OR = 1.13 and OR = 1.52, respectively; p < .05). No statistically significant predictors were identified for canines (teeth 13 and 23). These findings underscore the heterogeneity in biomechanical response among maxillary anterior teeth during CA. Specifically, lateral incisors demonstrated a greater susceptibility to refinement needs in the presence of complex movements such as rotation and inclination. These results support the adoption of individualized, tooth-specific treatment planning strategies to enhance predictability and minimize the need for refinement in CA therapy.
Tuğba Haliloğlu Özkan (Wed,) studied this question.