INTRODUCTION: Correct positioning of the maxillary central incisors (MxCIs) is a vital component of smile esthetics and the success of orthodontic treatment. This study investigated the efficacy of Invisalign SmartTrack aligners in achieving the mesiodistal tip of MxCIs, with an objective comparison to the ClinCheck (Align Technology, San Jose, Calif) prediction. METHODS: A total of 174 MxCI teeth from 87 adult patients were selected from the Australasian Aligner Research Database. All patients exhibited pretreatment overlapping MxCI crowns and were treated with Invisalign SmartTrack aligners. The pretreatment tooth position, the planned mesiodistal tip movement using the ClinCheck software, and the achieved posttreatment tooth position were analyzed. RESULTS: In the planned mesial root tip MxCI group, the mean planned and achieved mesial tips were 2.53° (standard error [SE], 0.29°) and 2.22° (SE, 0.42°), respectively, indicating an undercorrection of 0.31° (SE, 0.38°) (P >
0.05). For the planned distal root tip MxCI group, the mean planned and achieved distal tips were 2.09° (SE, 0.22) and 0.39° (SE, 0.36°), respectively, indicating a mean undercorrection of 1.70° (SE, 0.39°) (P <
0.001). There was no statistically significant association between the presence of attachments and the efficacy of the mesiodistal tip for MxCIs (P >
0.05). No significant relationship was found (P >
0.05) between the 1- or 2-week wear schedule and the efficacy of achieving the mesiodistal tip for MxCIs. CONCLUSIONS: The overall percentage accuracy of mesiodistal tip movements for MxCIs when using Invisalign SmartTrack aligners was 53.3%. The presence of attachments and the influence of a 1- vs 2-week wear schedule were not found to have any significant influence on the efficacy of achieving planned mesiodistal tip movements for MxCIs.