Anna-Lisa Söderholm

Erosion and Heterotopic Bone Formation After Alloplastic Temporomandibular Joint Reconstruction

Twenty-three temporomandibular joint arthroplasties using metallic condylar prostheses were performed because of severe ankylosis (8 patients), segmental mandibular resections in tumor surgery (9 patients), and after extensive trauma (2 patients). A clinical and radiological follow-up study showed heterotopic bone formation in 52% of cases and glenoid fossa resorption in 43%. In one patient with rheumatoid arthritis the condyle eroded through the skull base 10 months after surgery. Seven prostheses (30%) were removed and/or exchanged during the average 27.6-month follow-up.

Bone scanning for evaluating mandibular bone extension of oral squamous cell carcinoma

Inability to control the primary tumor in oral cancer, leading to local recurrence, results in low survival rates. The extent of bone involvement is therefore a critical factor in planning treatment. To evaluate whether uptake of 99mTc-DPC (dicarboxypropane-diphosphate) was reliable in demonstrating the extent of mandibular involvement, 13 consecutive patients with squamous cell carcinoma of the mandibular gingiva, floor of the mouth, and lower buccal sulcus were studied. Bone involvement, as judged from preoperative radiographs and bone scans, was compared with that determined through careful analysis of histologic sections of jaw specimens. The bone scan findings corresponded well with the histologic findings in 10 cases. In contrast to earlier studies, there were no false-positive findings. False-negative bone scans were seen in three cases in which there was infiltration of the upper cortex of the mandible. A negative bone scan, therefore, cannot guarantee absence of bone involvement. Nevertheless, bone scanning seems to provide valuable information for preoperative evaluation of evident tumor infiltration of bone.

Lag-screw osteosynthesis of mandibular condyle fractures: A clinical and radiological study☆

PURPOSE This study evaluates the clinical and radiologic results after open reduction and lag-screw osteosynthesis of fractured mandibular condyles. MATERIALS AND METHODS Eleven adult patients underwent surgery for displaced or dislocated mandibular condyle fractures via a submandibular approach. The repositioned fragments were fixed using lag screws designed by Krenkel or Eckelt. Maxillomandibular fixation was used postoperatively for 2.6 weeks on average (range, 1 to 4 weeks) in nine patients. RESULTS Slight transient weakness of the mandibular branch of the facial nerve occurred in three cases. Occlusal adjustment was needed in another three cases. Radiologically, the fracture line disappeared at 22.5 weeks on average (range, 8 to 38 weeks). Three screws had to be removed because of loosening. There were signs that the screws had migrated caudally from their original position in seven cases. Twenty-one months on average after operation (range, 8 to 31 months), patients were satisfied with treatment. Clinically, all patients had a stable occlusion and symmetry of the face. All had greater than 5-mm symmetrical lateral jaw excursions. Ten patients had wide (> 40 mm) painless mouth opening. Healing in malposition occurred in four cases and there was considerable shortening of the mandibular ramus in four cases. CONCLUSIONS Despite good clinical results, lag screws do not meet the needs for rigid internal fixation in the treatment of mandibular condyle fractures.

Non-Hodgkin's lymphomas presenting through oral symptoms

Non-Hodgkins lymphomas (NHL) presenting through oral symptoms are rare. Between 1976 and 1987, a total of 17 cases (7 male, 10 female) were diagnosed in our departments. The first symptom was an intraoral tumour mass in 9 cases, loosening of teeth in 2 cases and paraesthesia in another 2. Most tumours (13/17) were located in the lower jaw. In only 5 cases had the referring physician or dentist suspected malignancy. In 3 cases, the histological diagnosis was Burkitts lymphoma. The grade of malignancy was classified as low in 4 cases, intermediate in 3 and high in 8. None of the patients was HIV-positive. Nine patients died of their disease within 1-132 months (mean 18.3 months).

Rigid reconstruction plates for immediate reconstruction following mandibular resection for malignant tumors

Thirty-four primary alloplastic reconstructions of segmental mandibular defects caused by surgery for oral malignancy were performed during a 6-year period. Eighty-eight percent of the tumors were classified as stage III or IV. One third of the patients died during follow-up, nine with their primary reconstruction plate in place. During the follow-up, 12 patients required plate removal because of complications; four of them were treated with another plate. Nineteen of 21 patients alive at the end of follow-up were free of disease. Ten had their primary plate in place, and four had had a secondary plate installed because of plate fracture or screw loosening. Three patients had their mandible permanently reconstructed with bone. The functional and esthetic results were considered excellent or fair in a majority of the cases. Because the 5-year survival rate for patients with advanced mandibular malignancies is 15% to 20%, extensive, definitive reconstructive procedures during primary surgery are usually not justified.

Bridging of mandibular defects with two different reconstruction systems: An experimental study

To compare two different mandibular reconstruction systems, a 5-cm angular resection was performed in nine adult sheep. The defect was reconstructed using either a classic AO plate or the AO-THORP reconstruction system. The animals were killed 5, 9, and 14 weeks after operation. Serial sections with the plates and screws in place were prepared and studied histologically and with microradiography and fluorescence microscopy. Twenty-six percent of the 2.7-mm AO cortical screws were adequately fixed. The corresponding percentage for AO-THORP hollow screws was 73%. The main advantage of the latter system is the screw-plate locking principle, which allows plate stability to be maintained even if bone is resorbed under the plate. Whether the existence of a screw lumen is an advantage has not yet been established.

A simple method for establishing the position of the condylar segment in sagittal split osteotomy of the mandible.

When a rigid fixation of the mandibular sagittal split osteotomy is performed, the exact position of the condyle has to be maintained. We report a simple method for determining the preoperative position of the proximal segment. The method is fast and does not require additional technical equipment. Preliminary results indicate that a decrease in postoperative temporomandibular joint problems can be achieved by using this method. A follow-up will show whether the method also can decrease the incidence of skeletal relapse.

Radiologic follow-up of bone transplants to bridge mandibular continuity defects

Special radiologic imaging techniques were used to evaluate the results of nonvascularized bone grafts combined with rigid mandibular reconstruction plates. The radiologic findings divided 21 cases into three clearly distinct groups on the basis of resorption: slight (less than 15%), moderate (15% to 30%), and massive (more than 30%) (mean follow-up, 26 months). This division predicted the clinical results well. In contrast to earlier reports, it was shown that rigid plate bridging did not adversely influence the prognosis of the graft. Nor was early plate removal necessary to reach good ossification. Narrow-beam radiography and spiral tomography proved to be excellent tools for adequate evaluation of bone resorption and bony healing of mandibular grafts.

Bone resection in patients with mandibular sarcoma

Thirty-nine cases of mandibular sarcoma were reported to the Finnish Cancer Registry during the period 1953-1985. In 11 of these (nine osteosarcomas, one chondrosarcoma, one leiomyosarcoma), the pre- and postoperative radiographs were still available, and they were analyzed in order to evaluate the radicality of the primary surgical procedure in relation to recurrences during the follow-up. On the basis of several radiological details, the resection was considered inadequate in seven cases. One operation was probably inadequate because of rather scanty margins. In only three cases had an adequate primary resection with proper safety margins been performed. All of the seven patients with inadequate primary surgery had recurrence and five of them died of local disease or metastases, whereas only one of the three patients with adequate resection had recurrence in adjacent soft tissues. It is concluded, that radiological findings of mandibular sarcoma that often are missed include widening of the mandibular canal and disappearance of the lamina dura. Proper preoperative radiological examination resulting in more radical primary surgery would certainly decrease the recurrence and mortality rates in patients with mandibular sarcoma.

Primary reconstruction of the mandible in cancer surgery. A report of 13 reconstructions according to the principles of rigid internal fixation.

This study comprises 30 patients with extensive oral cancer invading the mandibular bone. In each case, large segmental composite resections were performed and the mandibles primarily reconstructed, according to the principles of rigid internal fixation. All but one of the reconstructions were successful and the functional and cosmetic results were excellent or good in 12 patients. The results indicate that primary reconstruction can be performed without major complications. Bone transplantation may be omitted or postponed to a later date. The fact that tracheostomy and intermaxillary fixation can be avoided, is a major advantage for these patients.