Comparison of Premaxillary Dimensions in Patients with Palatally and Buccally Impacted Maxillary Canines and Those with Normally Erupted Canines: A Retrospective Cone-Beam Computed Tomography Study.

Objective: Research into the etiology of maxillary canine impaction (MCI) has focused primarily on the transverse dimensions of the maxilla in the premolar and molar regions. The aim of this study was to evaluate and compare premaxillary width, height, depth, and volume -assessed using cone-beam computed tomography (CBCT)- among individuals with palatal MCI, buccal MCI, and normally erupted maxillary canines. Methods: This retrospective study utilized CBCT records of patients with MCI. A total of 45 subjects were divided into three groups of 15 subjects each. Group I (palatal canine impaction), Group II (buccal canine impaction), and Group III (control group of normally erupted canines). Premaxillary width, height, depth, and volume were measured in axial, coronal, and sagittal planes using Horos software. All measurements were performed by a single calibrated examiner. One-way ANOVA with Tukey post-hoc analysis was applied; statistical significance was set at p<0.05. Results: Premaxillary height, depth, and volume were significantly greater in both palatal canine impaction (Group I) and buccal canine impaction (Group II) groups compared to controls (Group III). The increase was greatest in Group I, and this difference among the three groups was statistically significant (p=0.04 for height, 0.0005 for depth, and 0.04 for volume). Premaxillary width did not differ significantly among groups (p=0.38). Post-hoc analysis revealed that premaxillary depth was significantly greater in both palatal and buccal impaction groups than in controls (p=0.021 and 0.002, respectively), while premaxillary volume was significantly greater in the palatal than in the buccal canine impaction group (p=0.03). Conclusion: The findings of this study suggest that three-dimensional premaxillary morphology, as assessed by CBCT -particularly increased depth and volume- may be associated with MCI, with a more pronounced effect in palatal impaction. Premaxillary width did not demonstrate a significant association. These results indicate that localized anterior maxillary skeletal characteristics, rather than transverse maxillary deficiency alone, may influence the eruptive pathway of maxillary canines. These findings represent associations and do not establish causality. Prospective studies with larger sample sizes are warranted to validate these findings and to explore their clinical implications for early orthodontic intervention.