Correlation between radiographic parameters for the prediction of palatally impacted maxillary canines

Objective: This study aimed to identify radiographic parameters on routine orthopantomograms to aid in early diagnosis of palatally impacted canines. Design: Split-mouth case-control study. Setting: Single-centre university dental hospital. Methods: Thirty-three individuals with palatally impacted canines and non-impacted contra-lateral teeth were recruited. Radiographic variables angle A, angle B, angle C, distance D, sector class and depth of vertical impaction were measured for both groups. Mann–Whitney U test and Spearman’s correlation coefficient were used to analyse significant differences and association between variables with sector class and depth of vertical impaction, respectively. Logistic regression analysis determined radiographic parameters as predictors of palatal impaction. Results: Significant differences were seen between sector class, depth of vertical impaction and the radiographic parameters between cases and controls (P ⩽ 0.001). For cases, strong correlation was found for angle C between the impacted canine and occlusal plane (r = −0.28, P = 0.022) and perpendicular distance D of impacted canine to the occlusal plane (r = 0.81, P ⩽ 0.001) with the depth of vertical impaction. Logistic regression analysis showed the odds of canine impaction increase with an increase in angle B and angle C. Conclusions: Our study showed that greater depth of vertical impaction, sector class, increased perpendicular distance and reduced angulation from occlusal plane resulted in palatal impaction of permanent maxillary canines. The odds of palatal canine impaction increase nearly twofold with every 10 increase in angle B and angle C.