Assessment of impacted canine patterns and correlations with craniofacial discrepancy

OBJECTIVE: The objective of this study was to determine the prevalence, spatial patterns, and craniofacial skeletal associations of impacted maxillary canines using panoramic and cephalometric analyses in a large patient cohort. MATERIALS AND METHODS: This retrospective cross-sectional study evaluated 9593 panoramic radiographs of individuals aged ≥ 14 years. Cephalometric analysis was achieved on subjects aged ≥ 18 years with skeletal maturity (Cervical Vertebral Maturation Index stage ≥ 6), comparing 94 cases with maxillary impacted canines (MIC) to 100 age- and sex-matched controls. Positional measurements (sector, depth, and angulation) were compared with skeletal patterns using independent t-tests, analysis of variance, and chi-square tests (α = 0.05). RESULTS: Analysis revealed a maxillary canine impaction prevalence of 2.02%, with a significant female predilection (54.1%) and a maxilla-to-mandible ratio of 4:1. The predominant spatial pattern was mesioangular inclination (67%) in Sector 0 (35.2%) at coronal depth (54.1%). Compared to controls, MIC cases exhibited significant maxillary skeletal deficiency (e.g., anterior nasal spine - posterior nasal spine [ANS-PNS]: 50.1 ± 5.1 mm vs. 53.1 ± 3.7 mm; p < 0.001) and vertical hyperdivergence (Sella-Nasion to Gonion-Gnathion angle [SN-GoGn]: 32.8° ± 6.2 vs. 29.8° ± 6.4; p = 0.001). Upper incisor inclination showed no intergroup difference. CONCLUSIONS: Maxillary canine impaction is strongly associated with maxillary skeletal deficiencies and vertical growth discrepancies. The common finding of mesioangular impactions in Sector 0 at coronal depth indicates a high risk for adjacent root resorption. We recommend incorporating cephalometric screening (focusing on ANS-PNS < 50 mm and SN-GoGn > 32°) into early adolescent assessments to identify at-risk patients and guide timely interceptive strategies such as maxillary expansion.