Maxillary canine transposition to incisor site: a rare condition.

Tooth transposition is defined as positional interchange of 2 adjacent teeth within the same quadrant. The incidence has been reported as about 0.4%, and the maxillary permanent canine has been reported as the tooth most frequently involved. Several etiologic factors like genetics, interchange in position of the developing tooth buds, trauma, mechanical interferences, and early loss of incisors have been associated with tooth transposition. Articles in the literature report various kinds of transpositions, but there are only a few reported cases of transposition of the maxillary canine to central incisor site. This kind of transposition has been suggested as resulting primarily by opportunistic canine migration into the space left from an early lost central incisor. However, there are only 2 long-term roentgenographic follow-up studies documenting maxillary canine migration and substantiating this hypothesis. This report shows 2 cases of this rare condition, with 1 of them documented with long-term records.