Autotransplantation for failing and missing anterior teeth.

We must congratulate the journal and the authors for publication of a case report of autotransplantation (Rao J, Fields HW, Chacon GE. Case report: Autotransplantation for a missing permanent maxillary incisor. Pediatr Dent 2008;30:160-6). This is a well established procedure in Europe where premolar transplantation dates back to the 1960s. We find autotransplantation of premolars a very important treatment option for children with failing and ankylosing anterior teeth following trauma and have also used it in cases of dilacerations, hypodontia and pathological root resorption following ectopic unerupted canines. This treatment option unfortunately seems to have disappeared off the list that pediatric dentists consider when faced with these clinical scenarios. Restorative dentists rely increasingly on the use of implants upon completion of growth with temporary restorations to tide the child through the period of growth. It should not be assumed, however, that implants are always the best restorative option and a number of long term studies (as reviewed by Zachrisson) have shown that their use in the anterior maxilla suffers from a number of problems which can lead to poorer esthetics than we imagine. These include: poor gingival contour with blue gingival discoloration, progressive infraocclusion and “root” exposure. They are also expensive to provide and maintain and frequently require additional bone grafting which adds to the complexity and reduces the success rates. Transplants when provided within an interdisciplinary team can be a highly successful long term option with a good esthetic outcomes. As pediatric dentists, we see a large proportion of children suffering from dental trauma and are proficient in its management. For us, a transplant is simply a controlled avulsion. In addition, the surgery is frequently best carried out by pediatric dentists as we understand the need for gentle handling of the periodontal ligament to prevent adverse outcomes. Transplants are a biological solution for a missing anterior maxillary tooth as they will induce bone into the area, have a good gingival contour, can be moved into a better position with orthodontics, and can be expected to last as long as any other tooth. Most importantly they provide a definitive solution while the child is still growing, therefore avoiding some of the difficulties of trying to temporize missing teeth in the anterior maxilla. In our experience we would advise a number of modifications described in the case report to enhance the long term success of the procedure. These include: 1. using a single rooted premolar which is easier to extract. Therefore less damage is caused to the periodontal ligament (PDL) and cementum. In addition only one root needs to revascularize, and if it becomes non vital it is easier and less time consuming to provide endodontic treatment. 2. waiting until the premolar to be transplanted has erupted into the mouth to minimize any damage to the PDL during its removal. 3. use of hand instruments to prepare the donor socket wherever possible to minimize any thermal damage caused to the bone. 4. delaying transplantation until the root length of the donor tooth is complete but with an open apex in order to minimize any complications if there is no further root growth as shown in the case reported. This tooth will now have a reduced root crown ratio with a poorer long term tooth survival, which will be exacerbated further by root resorption associated with orthodontic movement. 5. recommending little or no tooth preparation of the transplant to reduce the risk of pulpal necrosis in cases in which pulpal revascularization is the likely outcome. It is often possible to use composites with no tooth preparation to achieve an acceptable esthetic outcome in the short to medium term before definitive orthodontic treatment is undertaken to include the optimal position for the transplant. 6. use of a simple composite wire trauma splint for 7-10 days similar to avulsion guidelines. The importance of keeping the area clean to facilitate gingival healing cannot be underestimated and this we have found difficult to achieve with suture splints.