An analysis of clinical and imaging features of unilateral impacted maxillary central incisors: A cross-sectional study.

Background: This cross-sectional study sought to assess clinical features and 3-dimensional distribution of unilateral impacted maxillary central incisors and identify factors associated with the root morphology.

Methods: Cone-beam computed tomography (CBCT) images from 94 subjects exhibiting unilateral impacted maxillary incisors were selected and evaluated. Original CBCT data were reconstructed using Mimics software (version 17.0; Materialise, Belgium). Clinical features and 3-dimensional distribution of impacted maxillary central incisors and factors associated with the root morphology were observed and analyzed by 2 orthodontists.

Results: This patient cohort included 52 male patients and 42 female patients. Thirty-three incisors (35.11%) with dilacerated roots, 17 incisors (18.09%) with retained deciduous teeth, 15 incisors (15.96%) with supernumerary teeth, and 15 incisors (15.96%) with a history of trauma were identified in the study. Of the 94 impacted incisors, the most common were labially impacted (n = 65; 69.15%), followed by vertically impacted (n = 17; 18.09%) and palatally impacted (n = 12; 12.77%). Chi-square tests revealed that differences in subjects with supernumerary teeth, buccolingual position, sagittal position, and axial position in the upright and dilacerated root groups were statistically significant (P <0.05). Logistic regression analysis indicated that the incidence of dilacerations was higher in the inverted position than in the inclined position and horizontal position (P <0.05).

Conclusions: Labially impacted maxillary incisors were more common than vertically or palatally incisors. Dilaceration was most commonly observed in patients with inverted incisors. In clinical practice, CBCT is a valuable tool for diagnosing impacted maxillary central incisors and for making appropriate treatment plans for patients.