Association Between the Three-Dimensional Index and Panoramic Angular Parameters (α and θ Angles) in Impacted Maxillary Canines

Abstract

Abstract

Introduction: Impacted maxillary canines are among the most common orthodontic anomalies and often require comprehensive radiographic assessment for accurate diagnosis and treatment planning. The KPG index is a CBCT-based three-dimensional classification system used to evaluate the severity of canine impaction.

Aim: To assess the association between the KPG index and angular parameters (alpha and theta angles) in maxillary impacted canines.

Materials and Methods: This retrospective study included 30 patients with impacted maxillary canines treated at the Department and Clinic of Orthodontics, School of Dental Medicine, University of Sarajevo. Cone-beam computed tomography (CBCT) scans and panoramic radiographs were analyzed. The KPG index was determined from CBCT images, while alpha and theta angles were measured on panoramic radiographs. Correlation analysis was performed to evaluate the relationship between the KPG index and angular parameters.

Results: The mean KPG index was 13.17, the mean alpha angle was 32.93, and the mean of theta angle was 53.87. A statistically significant moderate positive correlation was found between the KPG index and alpha angle. No statistically significant association was observed between the KPG index and theta angle.

 Conclusion: The alpha angle showed a significant positive association with the KPG index and may represent a useful adjunctive parameter in the assessment of impacted maxillary canines. In contrast, the theta angle was not significantly associated with impacted severity. Although panoramic radiographs provide valuable diagnostic information, CBCT-based three-dimensional imaging remains the gold standard for evaluating impacted maxillary canines and supporting orthodontic treatment planning.