Transmigration of impacted mandibular canines and its association with malocclusion and morphology: an analysis of seven cases.

AIM To investigate the morphologic parameters associated with cases of transmigrating mandibular canines. METHODS The orthodontic records of 3,500 patients were examined for the presence of transmigrating mandibular canines. Lateral cephalograms and study casts were analyzed for skeletal and dental parameters. Observations were made as to the sex and age of the subject, and side, location, and type of migration were recorded from the panoramic radiograph. RESULTS Seven cases were found to be associated with transmigrating mandibular canines. These included four females and three males between the ages of 14 and 21 years. All canines were unilateral, with three each of type 1 and type 2 and one type 4 case. Retained primary canines and second molars were observed in four cases. Two cases were associated with hypodontia and palatally displaced maxillary canines. Six cases had Class II malocclusions, with 5 cases having deep bite (> 40%) and a deep curve of Spee. Five cases showed increased lower anterior facial height and excess tooth material. CONCLUSION Dental Class II malocclusion with deep bite, deep curve of Spee, excess tooth material, and increased lower anterior facial height indicating an increase in space available apical to the mandibular incisors (resulting in a loss of canine guidance) may be predisposing factors in the etiology of the transmigrating canine.