Ameloblastoma :: surgery
The design and rapid prototyping of surgical guides and bone plates to support iliac free flaps for mandible reconstruction.
Section of Prosthodontics, Department of Oral Science, Alma Mater Studiorum University of Bologna, Bologna, Italy. email@example.com
Most cited papers:
The results of transplantation of intercalary allografts after resection of tumors. A long-term follow-up study.
Paseo de la Florida, Madrid, Spain.
We reviewed the results of 104 intercalary allograft procedures that had been performed, between April 1974 and August 1992, in 100 patients, usually after resection of a segment of bone because of an osseous neoplasm. The median duration of follow-up was 5.6 years. Retention of the graft and return to essentially normal function were the measures of success and, on that basis, eighty-seven (84 per cent) of the 104 reconstructions were successful. Of the fifteen limbs in which the reconstruction failed, four were salvaged with insertion of a second allograft and three, with use of some other technique. Of the 104 allograft procedures, eight (including two in patients who had a recurrent tumor) were followed by an amputation; thus, the ultimate rate of salvage was 92 per cent for the entire series. Thirty-one grafts failed to unite at one junction with the host or both, within one year after the operation, and this necessitated eighty-one additional operative procedures to achieve a good result. Life-table regression analysis showed that age, gender, anatomical site, and length of the graft were not associated with significant differences in the over-all outcome. Infection (p = 0.0001); fracture (p = 0.002); stage of the lesion (p = 0.007); and use of adjuvant chemotherapy or radiation, or both (p = 0.008), all had an adverse effect on the survival of the allograft. Despite the relatively high rate of non-union that necessitated additional operations, these data indicate that transplantation of allografts for the treatment of intercalary defects has a high rate of success and usually results in a functional limb.
A number of important factors must be considered in planning the treatment of ameloblastoma. It is essential to distinguish among the three clinical types of ameloblastoma--the intraosseous solid or multicystic lesion, the well-circumscribed unicystic type, and the rare peripheral (extraosseous) ameloblastoma--because they require different forms of treatment. Unicystic ameloblastomas in which the tumor extends into the lumen of the cyst or involves only the cystic lining can be expected to be removed completely by enucleation. This approach, however, is inadequate if the tumor has invaded the periphery of the fibrous connective tissue wall. Ameloblastomas may invade the intertrabecular spaces of cancellous bone but do not invade compact bone, although they may erode it. Ameloblastomas in the posterior part of the maxilla should be treated more extensively than similar lesions in the mandible because of the proximity of the posterior maxilla to vital structures and the difficulty in treating any recurrences. This article discusses the treatment of ameloblastoma based on these pathologic and anatomic considerations and includes brief discussions of the role of cautery, cryotherapy, and radiotherapy.
Department of Oral and Maxillofacial Surgery, University Hospital Freiburg, Germany.
PURPOSE: Microvascularized fibula transplants have become established in reconstruction of the mandible. However, because of the limited diameter of the fibula compared with the height of the mandible, the vertical distance between the reconstructed segment and the occlusal plane can be substantially large. This is a particular problem in nonatrophic or dentate mandibles, especially when rehabilitation with dental implants or an implant-borne denture is contemplated. The large leverage forces resulting from the high vertical dimension of the prosthetic construction can lead to overloading of the osseointegrated implants and endanger the longevity of the prosthetic restoration. This article describes experience with a new method of circumventing this problem. PATIENTS AND METHODS: This procedure was used in eight patients. A fibula graft corresponding to at least twice the length of the mandibular defect was harvested, halved perpendicular to its length, and the resulting struts folded on top of each other to form a "double barrel." The struts are then fixed to each other with screws and plates and stabilized in the defect using a reconstruction plate. RESULTS: Compared with the conventional one-strut fibula transplant, the "double-barrel" graft achieved more bone height and appreciably reduced the vertical distance to the occlusal plane. CONCLUSIONS: This technique creates better conditions for prosthetic rehabilitation. In comparison with the iliac graft, the fibula is easier to harvest, more reliable regarding anastomosis, and is associated with less postoperative morbidity.
In a clinical material consisting of 31 cases of mandibular defects, caused by tumour resection or by trauma, reconstruction has been carried out by means of a stabilizing titanium splint and autologous bone and marrow transplantation, the longest period of observation being 9 years. The functional results obtained are assessed with reference to the cause of resection. Different technical procedures are described and the objectives and the planning of reconstruction of the lower jaw are discussed.
Department of Oral and Maxillofacial Surgery, Dental Centre, University College Hospital, Ibadan, Nigeria.
OBJECTIVE To establish the incidence of odontogenic tumours in Nigeria we present our experience during the 15-year period 1980-94. DESIGN Retrospective review of histopathological specimens and case notes. SETTING Teaching hospital, Nigeria. SUBJECTS 128 Patients with histologically confirmed odontogenic tumours out of a total of 415 with tumours of the mouth and jaw. MAIN OUTCOME MEASURES Incidence, treatment, and recurrence rate. RESULTS Ameloblastoma (n = 21, 16%) and adenomatoid tumour (n = 16, 13%). Patients' ages ranged from 8 to 75 years (mean 33 for ameloblastoma, 31 for fibromyxoma, and 22 for adenomatoid tumour). The corresponding male:female ratios were 3:2, 2:3, and 1:1, and maxilla:mandible ratios 1:9, 1.1:1, and 2:1. The more radical the resection of ameloblastomas the less likely were they to recur. CONCLUSION Further research is required to explain the high incidence of odontogenic tumours in Nigeria, particularly ameloblastomas.
An investigation into the length of time which elapses after the treatment of an ameloblastoma before a recurrence becomes visible, has established that this only exceeds 5 years in 5% of cases. In this study the findings after a follow-up period of at least 5 years after conservative or radical therapy have been extracted from the literature and compared with those of the authors' own series of 84 cases. It is concluded that the recurrence rate is 75% in the cases of multilocular ameloblastomas treated conservatively. Following radical therapy the recurrence rate is 15%. Conservative treatment of unilocular ameloblastomas can be expected to result in a recurrence rate of 20%.