LOCALISATION OF IMPACTED MAXILLARY CANINES USING PANORAMIC RADIOGRAPHS; A NOVEL TECHNIQUE THAT USES BICONDYLAR LINE AS REFERENCE

Purpose: To localize the impacted maxillary canines in the alveolus using panoramic radiographs. Methods: The present study was a retrospective radiographic chart review of 81 patients with 92 impacted maxillary canines from the Department of oral and maxillofacial surgery, PMS College of Dental Science and Research, Trivandrum. Of the 92 impacted maxillary canines, 57 were impacted buccally and 35 were impacted palatally. The ratio formed between the distance from the crown tips of impacted maxillary canine and ipsilateral central incisors were measured. We used these measurements to predict the position of the tooth and correlate this prediction with the actual approach used during surgery. Results: The ratio of the canines in the buccal group was 1.35± 0.144(range, 1.04 to 1.88). Palatal group has got little higher values with the mean ratio of 1.93± 0.52 (range, 1.29 to 3.22). The ratios were distributed over a scatter plot (Figure 2). The diagnostic test characteristics for the values greater than 1.45, greater than 1.50 and greater than 1.55 were taken. These values were used for constructing a receiver operating curve. There was a better sensitivity and specificity for the values greater than 1.50(sensitivity: 94.29%, specificity: 91.38%).  Logistic regression showed that if the ratio is more than 1.50, there is a chance of 19.3 times to get a canine palatally impacted. Conclusion: There is significant difference in the vertical position of buccal and palatal canines in the alveolus. Based on our values we found that palatally impacted canines are restricted more superiorly. Keywords: Localization, impacted maxillary canines, panoramic radiographs, bicondylar line