Tooth Transplantation to Bone Graft in Cleft Alveolus

Transcription

1 Tooth Transplantation to Bone Graft in Cleft Alveolus Soren HiLLeRurp, D.D.S., Lic.opont. ERIK DAHL, D.D.S., DR.ODONT. OLE ScHwarTz, D.D.S., Lic.opont. ERIK Huorting-Hansen, D.D.S., DR.ODoONT. Autotransplantation of teeth has developed from a last resort operation into a well tested and relatively predictable clinical procedure. This article documents four cases where autologous teeth were successfully transplanted into bone from the iliac crest grafted to an alveolar cleft. The possibility of tooth transplantation should be considered when planning dental rehabilitation for patients with cleft. In recent years many questions concerning the surgical technique and timing of secondary bone grafting in cases of cleft lip and palate have been clarified, and the procedure has been widely accepted as an integrated part of the rehabilitation (Jackson, 1972; Boyne and Sands, 1972, 1976; Harle, 1973; Koberg, 1973; Abyholm, 1981; Hall and Posnick, 1983; Freitag and Fallenstein, 1984). When secondary bone grafting is performed before eruption of the canine, the teeth adjacent to the cleft can be seen to migrate into the bone graft, or they may be aligned orthodontically (Eldeeb et al, 1982). However, in some cases, for various reasons, a tooth will be missing in the cleft area. When planning the treatment for such patients it should be taken into account that tooth transplantation has developed into a safe and predictable procedure (Slagsvold and Bjercke, 1974; Kristerson and Kvint, 1981; Schwartz et al, 1985a, 1985b). The present article describes four cases where autologous teeth were successfully transplanted into bone from the iliac crest grafted to the alveolar cleft. Our aim with the paper is twofold: 1. to introduce autologous tooth transplantation as a new treatment modality of dentoalveolar reconstruction in cleft patients, and 2. to demonstrate that grafted bone from the iliac crest has the capacity of forming the The authors are affiliated with the Royal Dental College and the University Hospital (Rigshospitalet), Copenhagen, Denmark. Dr. Dahl is Associate Professor, Department of Orthodontics; Dr. Hjgrting-Hansen is Professor and Chairman; Dr. Schwartz is Assistant Professor, and Dr. Hillerup is Associate Professor, Department of Oral and Maxillofacial Surgery. 137 alveolar part of a periodontal ligament, apparently as had it been jawbone. MATERIAL AND METHODS Four patients with complete cleft lip and palate are described in which a tooth has been transplanted into a bone grafted alveolar cleft. The primary surgical management consisted of closure of the clefts of the lip and the palate by conventional surgical methods within the first two years of life. Bone grafting was performed as a late secondary procedure using cancellous bone from the iliac crest. Tooth transplantation was performed under local anesthesia by the following procedure: vestibular and palatal mucoperiosteal flaps were elevated in the bone grafted area. A socket was prepared with a slowly rotating burr with continuous irrigation of saline. The tooth selected for transplantation was gently extracted with forceps and immediately placed in the slightly overextended socket prepared in the recipient area. The tooth was fixated with a suture or splinted loosely to the neighboring teeth. Primary closure was performed with interrupted silk 4-0 sutures. The fixation was removed after 7 to 14 days. Endodontic treatment was performed in all cases but one. The treatment involved pulpectomy and deposit of calcium hydroxide to induce apical closure. This was followed by a permanent root filling. The follow-up examinations comprised clinical examination, i.e., inspection, gingival probing, percussion and mobility test, and dental radiographs. Observation time was from 1% to 4 years.

2 138 Cleft Palate Journal, April 1987, Vol. 24 No. 2 CASE STUDIES Case 1 was a 16-year-old boy with a complete leftsided cleft lip and palate. The left upper lateral incisor was missing (Fig. 1A, 1C). Orthodontic closure of the space in the upper arch was considered inappropriate, and it was decided to bone graft the alveolar cleft, await healing, and to transplant one of the lower second bicuspids which should be extracted for orthodontic reasons. Four months after bone grafting, the left lower second bicuspid was transplanted into the cleft region. Endodontic treatment was started 2 months later. Follow-up examination showed healing with periodontal reattachment without pocket formation. The radiologic examination revealed osseous healing of the socket with normal periodontal radiolucency and lamina dura. There was no sign of ankylosis. Figure 1E shows the condition 2% years after tooth transplantation. Case 2 was a 15-year-old girl with complete bilateral cleft lip and palate. Bone grafting to the right side was performed at age 14 years (Fig. 2A, 2B, 2C). Seven months later the cleft on the left side was grafted, and a left lateral incisor in palatal malposition was transplanted to the bone grafted area on the right side (Fig. 2D, 2E, 2F). The follow-up examination showed satisfactory healing. Four years after transplantation the tooth was in good position with gingival pockets 2 mm or less. The radiologic examination showed obliteration of the pulp chamber and the root canal. The periodontal radiolucency and the lamina dura appeared normal, and there was no indication of ankylosis. Case 3 was a 15-year-old boy with complete unilateral cleft lip and palate. The alveolar cleft was bone grafted at age 14 years. The lateral incisor was missing on the cleft side, and two mandibular bicuspids had to be extracted for orthodontic reasons. Fifteen months after bone grafting, the lower left second bicuspid was transplanted into the bone grafted region. Follow-up examination showed uneventful healing and the tooth in good position with gingival pockets of normal depth. The radiologic examination showed that the root formation had continued. The apex was almost closed, but there was no evidence of pulp obliteration of the coronal part of the pulp. Electrometric pulp test gave no reaction, and endodontic treatment was performed. Figures 3C and 3D show the condition 2 years after the transplantation; the tooth has been given incisor shape by grinding and direct bonding of a composite resin material. Case 4 was a 17-year-old boy with complete bilater- E FIGURE 1 Case 1: A and B, cleft region before and after tooth transplantation; C, radiograph before tooth transplantation; D, 3 months after; and E, 2% years after tooth transplantation.

3 Hillerup et al, TOOTH TRANSPLANTATION TO BONE GRAFT FIGURE 2 Case 2; A, cleft region after secondary bone grafting to right side; B and C, malposed left lateral incisor; D and E, dental arch after transplantation of palatally malposed left lateral incisor to right side; and F, healing with root canal obliteration 4 years postoperatively. FIGURE 3 Case 3: A, open cleft with unerupted canine and malformed lateral incisor with internal resorption to be extracted; B, right canine being aligned before bone grafting; C and D, lower left second premolar in position in bone graft 2 years after transplantation. 139

4 140 Cleft Palate Journal, April 1987, Vol. 24 No. 2 al cleft lip and palate. Bone grafting was carried out at age 15 years. Both upper lateral incisors were missing, and 20 months after bone grafting a severely malpositioned maxillary second bicuspid was transplanted into the bone grafted region on the right side. The clinical healing was uneventful in spite of damage to the periodontal ligament during the extraction. Radiologic follow-up initially showed normal periodontal healing and no signs of ankylosis. Endodontic treatment was started with a deposit of calcium hydroxide and the tooth was root filled. However, suspicion of ongoing external root resorption was raised at the radiographic check after 1% years (Fig. 4B). DISCUSSION The four cases of tooth autotransplantation documented in this article were carried out at 4, 7, 15, and 20 months after bone grafting, all with successful clinical healing, and they have been followed up for a period ranging from 18 months to 4 years. Three of the cases exhibited no signs of morbidity to give expectation of future loss of the transplants, i.e., progressive inflammatory root resorption or ankylosis. In Case 4, the 1% year follow-up dental x-ray film raised suspicion of external root resorption, possibly caused by the damage to its periodontal ligament during surgery. The clinical and radiologic appearance of the periodontal attachment to the grafted iliac bone was indistinguishable from that of teeth in jawbone in general, indicating that a grafted tooth with its dental part of the periodontal ligament is capable of inducing a fully formed alveolar periodontal ligament in an incorporated iliac bone graft. This observation is interesting considering the different histomorphogenesis of jawbone formed by intramembranous ossification and iliac bone formed by endochondral ossification. There is no indication that transplanted teeth with clinical and radiologic healing into grafted bone have a prognosis that differs from that of transplanted teeth in general, and bearing in mind that transplanted teeth are at greatest risk of resorption and loss during the first year, we expect three of the four transplanted teeth discussed in this study to serve in function for a number of years to come. After the first four cases documented in this article we have autotransplanted another five teeth into bone grafts in patients with cleft palate, all with a favorable outcome. One of these teeth was extracted during the bone grafting operation, cryopreserved in a special storage medium in liquid nitrogen for a period of 7 months awaiting healing of the bone graft, and successfully transplanted back into the cleft region. Schwartz et al (19852) showed that more than 50 percent of autotransplanted one-rooted teeth were still in function after 20 years. Adding known favorable prognostic factors-such as tooth type (onerooted tooth), stage of root development (open apex), age of patient (<15 years), and surgical technique (no extraoral storage of tooth, experienced surgeon-autotransplantation of teeth appears as a safe and predictable clinical procedure (Slagsvold and Bjercke, 1974; Kristerson and Kvint, 1981; Andreasen, 1981; Kristerson and Andreasen, 1984; Schwartz et al, 1985a, 1985b). Apart from solving the problem of a missing tooth in the cleft area, a tooth transplantation to the bone graft may even provide the new alveolar bone with functional stimulation and prevent atrophy of the grafted bone, as otherwise often happens (Freitag and Fallenstein, 1984). Dental treatment planning in patients with cleft-in particular extraction policy-should be conducted with the possibility of tooth transplantation in mind. Cryopreservation of extracted teeth for later transplantation into the bone grafted cleft alveolus is a future treatment alternative of surgical dental rehabilitation. The method is now under investigation (Schwartz et al, 1985; Schwartz, 1986). FIGURE 4 Case 4: bone grafted cleft, A, before and B, after tooth transplantation. The radiolucency indicated by arrow is interpreted as external inflammatory root resorption.

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