Use of panoramic radiograph as a single radiographic technique to localize impacted maxillary canine

Objective: To develop a reliable method of diagnosing the position of a displaced maxillary canine on the basis of a single radiograph. Study design: Based on the criteria of selection, 50 subjects [19 males and 31 females] with a total of 67 impacted canines were evaluated. The ratio of the width of the displaced canine to the width of the homo-lateral central incisor [the canine-incisor index] and the ratio of the width of the displaced canine to the width of the contra lateral canine [caninecanine index] were calculated. The height of the crown of each displaced canine was classified in the vertical plane, relative to the adjacent incisor, as apical, middle or coronal. Results: The canine incisor index [CII] ranges for the labially and palatally impacted canines were 0.66-1.75 and 0.7-2.00 respectively. There was presence of an overlap in these ranges.The canine-canine index [CCI] for labially and palatally impacted canines were 0.875 -1.750 and 0.800-1.857 which again showed an overlap. A cut off point of 1.16 was determined. Conclusion: Provided that vertical restriction and the canine-incisor index were used, the panoramic radiograph can serve as a useful indicator as a single radiograph for determining the position of unerupted maxillary canines.