Canine transmigration: comprehensive literature review and report of 4 new Australian cases

Canine transmigration is a rare dental anomaly unique to the mandibular arch, involving intraosseous migration of the unerupted tooth across the midline. Currently, there is a lack of consensus on the definition of transmigration. This report suggests a unified definition of transmigration, that being when a canine has crossed the midline by more than half its length. Numerous publications reporting mandibular canine transmigration therefore cannot be considered as being truly transmigrated. Here we undertake a comprehensive review of the literature, and report 4 new cases of transmigrated mandibular canines, 2 of which present with unique features. One case shows a vertically positioned transmigrated canine, whereas the other shows a horizontally transmigrated canine underlying an impacted canine. Furthermore, this cohort is the first to be reported in an Australian population.