Transmigrant mandibular canines: a record of 28 cases and a retrospective review of the literature.

The transmigrant mandibular canine is a rare phenomenon. Most authors have described singular cases of unilateral or bilateral occurrence; however, a few authors have published more cases. This paper describes 28 cases exhibiting transmigratory canines. The observations are compared with observations from 39 earlier reports. Women are affected more than men. The left canine undergoes transmigration more commonly than does the right canine. Transmigration and impaction appear to be more common. Most of the patients do not have any symptoms, and these canines are often discovered at the radiological examination before orthodontic treatment. The etiology is obscure; however, abnormal displacement of the tooth bud in embryonic life is a commonly accepted explanation. Prolonged retention of the deciduous canine is a good clinical sign for a thorough radiological examination, preferably including an orthopantomographic radiograph. This would help in preventive measures. However, once established, a transmigrated canine requires surgical extraction. If possible, and if space is available and the patient is willing, all orthodontic efforts should be made to restore the normal position of this functionally very useful tooth in the human dentition.