Investigation of transmigrated and impacted maxillary and mandibular canine teeth in an orthodontic patient population.

PURPOSE: The objectives of the present study were to determine the frequency and gender difference of transmigrated and impacted canines and to evaluate the characteristics and treatment protocols in a Turkish orthodontic patient population.

MATERIALS AND METHODS: We designed a retrospective study composed of pretreatment and post-treatment dental casts, intraoral photographs, and full mouth periapical and panoramic radiographs of 2,215 patients (1,275 females and 940 males). Observations were made regarding impacted mandibular and maxillary canines, retained deciduous canines, patient gender and age, side and number of transmigrated canines and associated pathologic features, and treatment of the impacted canines and transmigrated canines. The Pearson chi(2) test and Fisher's exact test were used to determine the potential differences in the distribution of canine impaction and transmigration when stratified by gender.

RESULTS: The frequency of patients with impacted and transmigrated canines was 5.1% and 0.3%, respectively. None of the patients with a transmigrated mandibular canine had any pathologic changes; however, the maxillary transmigrated canine was associated with impacted mesiodens. All transmigrated canines were unilateral and impacted. Four canines migrated from the left to right, and 2 migrated from right to left. Of 6 patients, 2 had retained primary canines and 4 had exfoliated primary canines. Three of the transmigrated mandibular canines were type 1 and 2 were type 2. In the treatment protocol, 4 impacted mandibular canines and 78 maxillary canines were surgically exposed for orthodontic treatment, 4 of 6 transmigrated canines were surgically removed, and 2 were observed periodically.

CONCLUSIONS: If the diagnosis of canine impaction and transmigration in patients is made earlier, it is possible that the tooth might have been in a better position for orthodontic eruption into the arch. Careful patient selection and preparation are therefore essential, as is cooperation between the orthodontist and oral surgeon.