Association Between Canine Impaction and Skeletal Pattern in the Sagittal and Vertical Planes.

In the present study, the authors evaluated the association of canine impaction with different skeletal discrepancies in two planes of space (sagittal and vertical). Cephalometric and orthopantomographic radiographic images of 45 patients with one or more impacted canines were used in this retrospective study. Five radiographic morphologic parameters-ANB angle, canine angulation, angle between the Frankfort horizontal plane and the mandibular plane (FH-MP), Wits appraisal analysis, and axial inclination of the maxillary incisors in the sagittal plane-were recorded for comparison. Statistical analysis was performed using SPSS 9.0 statistical package (IBM). Impaction of the maxillary canine was more frequent than mandibular canine impaction in both males and females, and palatal impaction was more common than buccal impaction, with a higher significance in males (64.7%) than in females (50%). In the sagittal relationship, the highest frequency of impacted canines was found in patients with a Class III skeletal discrepancy (44.4%), followed by Class I (28.9%) and Class II division 1 (15.6%), while the lowest frequency was in Class II division 2 (11.1%). Comparison between sexes in the vertical plane showed that impacted canines occurred more frequently in hyperdivergent female faces (51.1%) and hypodivergent male faces (48.9%). The result of this study indicates a statistically significant association of impaction with canine, sagittal, and/or vertical dentofacial discrepancies. The results also showed a higher risk of having impacted canines in patients with certain dentofacial deformities. Therefore, canine impaction may be used to represent a substitute scale for the study of different malocclusion groups with respect to race and ethnicity.