Treatment of Maxillary Impacted Canine that Transposed with Lateral Incisor.

Objective:To explore the orthodontic treatment of maxillary impacted canine which is transposed with lateral incisor.Method: Two mixed dentition maxillary impacted canine that transposed with lateral incisor cases were treated by modified nance combined with straight wire arch.First,the canine crown was retracted buccally and distally with the hook of the modified nance at higher maxillary alveolus level,the lateral incisor root was moved mesially and tooth body was palately moved at the same time.The canine crown and root of lateral incisor could fhus be separated in the coronal direction.Then,the forming arch was used to keep the coronal and vertical distance of two teeth,the second order bend of the wire on the transposed canine was changed continuously,the cross transposed teeth were corrected into normal order step by step.Results: Two maxillary impacted canine and transposition with lateral incisor cases were treated successfully after about 27 months treatment.The pulp and periodontal attachment were normal.Conclusion: The key to treat maxillary canine-lateral incisor transposition is to create sufficient space between the canine and the lateral incisor so that the transposed teeth are reordered to their normal position without interference.The combination of modified nance with straight wire technique is valid method.