To evaluate the effects of attachment template sectioning on bonding accuracy and the initial biomechanical response during en-masse anterior retraction with clear aligners.

Thirty three-dimensional printed maxillary extraction models were assigned to full-arch, single-tooth, or sectional template groups. Attachment deviations were assessed using digital scanning, model registration, and three-dimensional measurements. Representative bonded attachments from each group were incorporated into finite element models to simulate anterior retraction after maxillary first-premolar extraction.

Mean attachment deviations were 0.041 mm, 0.080 mm, and 0.056 mm in the full-arch, single-tooth, and sectional groups, respectively. The full-arch and sectional templates showed greater bonding accuracy than the single-tooth templates. Deviations generally increased toward the posterior region. Finite element analysis demonstrated tooth- and direction-specific changes in buccolingual, mesiodistal, and vertical displacement, with the most pronounced alterations in the single-tooth-template model.

Template sectioning affected attachment bonding accuracy and initial displacement patterns during anterior retraction. Full-arch and sectional templates may be preferable for simultaneous bonding of multiple attachments, whereas the lower positioning stability of single-tooth templates should be considered during localized rebonding.