[Transplantation of impacted canines]

Techniques for dental transplantation today are taking better advantage of the potential for healing of the periodontal ligament than in the past and have reduced the risk of ankylosis and root resorption to below 1.5%. The resulting improvement in prognosis has made it possible to more confidently plan procedures that include orthodontic treatment. Transplantations can offer a good end result in certain clinical situations that would otherwise be difficult to manage: ectopic teeth, transpositions, tooth trauma sequellae, advanced decay or advanced periodontitis, implanted hard to treat impacted teeth, and idiopathic ankylosis. This article describes the biological principles for transplantation using double periodontal ligament stimulation, explains the surgical techniques and provides several examples to expand on the treatment of impacted canines, whether or not they present with idiopathic ankylosis. Dental ankylosis is the fusion of the bone with the root. The idiopathic type occurs spontaneously before the eruption of the affected tooth. The etiology is unknown. Because the tooth becomes part of the process of osseous remodeling, it is progressively resorbed and then replaced by bony tissue. This process takes place rather quickly and weakens the tooth. Additionally, an early diagnosis makes it possible to plan a transplantation under favorable circumstances, as that is the only way to halt the ankylosis and to achieve an adequate implantation. In rare cases, the location of the ankylosis is surgically accessible and can be eliminated before resuming orthodontic traction.