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The aim of this study was to assess the release of metal elements from a Ti6Al4V modular endoprosthesis for mandibular reconstruction. Ten monkeys were included, seven of the animals had an endoprosthesis inserted and three served as controls. Mucosa, regional lymph nodes and distant organs, were assessed after the implant had been in place for 12 months, using light (LM) and transmission electron microscopy (TEM) and inductively coupled plasma optical emission spectroscopy (ICP). Blood was also drawn from all animals for elemental analysis using ICP. LM and TEM evaluation showed no detectable metal particles in the mucosa surrounding the endoprosthesis, nor in the regional lymph nodes and distant organs. Blood analysis revealed that titanium and vanadium were detectable in comparable amounts in the test (Ti: 1.63+/-0.54, Va: 0.42+/-0.08) as well as in the control group (Ti: 2.07+/-0.55, Va: 0.37+/-0.07). The amount of aluminum appeared to be higher in the control group (31.77+/-11.67) compared with the test group (20.41+/-9.13), but this difference was not statistically significant. ICP showed that no titanium, vanadium or aluminum was detectable in the mucosa surrounding the endoprosthesis. In addition, no titanium and vanadium were found in the lymph nodes and distant organs using ICP. On the other hand, using ICP, the aluminum content was found to be higher in the right regional lymph nodes and all examined distant organs as compared to the control group (lymph nodes: 11.55+/-22.15 vs. 0.36+/-0.61, lung: 6.24+/-11.28 vs. 1.40+/-2.15, liver: 1.66+/-0.99 vs. 0, kidney: 15.69+/-24.88 vs 0, spleen: 2.75+/-3.09 vs. 0.49+/-0.43). However, only for the kidney and liver the higher amount of aluminum was statistically significant. In conclusion, this study quantified the release of only aluminum in lymph nodes and distant organs, when using a modular endoprosthesis made of Ti-6Al-4V for mandibular reconstruction.

Unlabelled: Adverse effects on the soft tissues after Le Fort I osteotomies include: broadening of the alar base, loss of vermilion show of the upper lip and down sloping of the commissures. In theory, an alar cinch suture combined with a muco-musculo-periosteal V-Y closure (ACVY) should improve not only the nasal width, but would also improve the dynamics of some of the mimic muscles. To test the validity of this hypothesis, a prospective study was set up including 22 patients, using standardized full facial frontal photographs, taken immediately preoperatively and 18 months postoperatively. Sets containing three pictures were made: soft tissue in repose, maximum closed mouth smile and maximum smile. The landmarks, alare, crista philtri and cheilion were analysed. The preliminary results show that ACVY-closure does significantly improve the horizontal movement of cheilion with both maximum closed mouth smile and maximum smile, as well as the vertical movement of crista philtri with maximum closed mouth smile., Conclusion: The Le Fort I osteotomy with ACVY improves the orofacial dynamics.

Because the survival of endosseous implants in irradiated bone is lower than in non-irradiated bone, particularly if the irradiation dose exceeds 50Gy, a study was carried out to assess the irradiation dose in the anterior mandible, when intensity modulated radiation therapy (IMRT) is used. The hypothesis was that adequate IMRT planning in oropharyngeal cancer patients is allowing sufficiently low anterior mandibular bone radiation dosages to safely insert endosseous implants. Ten randomly selected patients with oropharyngeal cancer, primarily treated by intensity-modulated radiotherapy (IMRT), were included in this study. First, at five determined positions distributed over the anterior mandible, the appropriate radiation dosages were calculated according to the originally arranged fractionated radiation schedule. Second, for each patient an adjusted fractionated radiation schedule was established with an extra dose constraint which allowed a lower dose in the mandible taking into account that the anterior mandible needs protection against radiation-induced osteoradionecrosis. The goal for the adjusted fractionated radiation schedule was similar as that of the original fractionated radiation schedule, including a desired tumour target dosage of 70Gy and maximum mean local dosages for organs at risk. The data revealed a considerable and statistically significant, irradiation dose reduction in the anterior mandible without compromising the other constraints. As a result of this study it is strongly advised to maximize dose constraint to the anterior mandible when planning irradiation for oropharyngeal cancer patients, using IMRT. This would greatly facilitate successful implant treatment for this group of patients. The fractionated radiation schedules used, should also be used for the planning of the best implant positions by integrating them in the implant planning software.

The objective of this study was to determine the value of dynamic contrast-enhanced MRI (DCE-MRI) for the preoperative assessment of mandibular invasion in squamous cell carcinomas (SCC), adjacent or fixed to the mandible. DCE-MRI was performed with gadolinium diethylene triamine pentaacetic acid (Gd-DTPA). Data were obtained from 25 patients. From pharmacokinetic analysis of the tissue uptake of Gd-DTPA, the DCE-MRI parameters (k(ep), K(trans) and v(e)) were determined, with k(ep) representing the exchange rate constant, K(trans) the volume transfer constant and v(e) the volume of extracellular space per unit volume of tissue. The histology of the resection specimens was used as gold standard for the extent of mandibular invasion. SCC with medullary invasion showed higher mean k(ep) and K(trans) compared with SCC without medullary invasion (ANOVA, p<0.001). ROC analysis of k(ep) and K(trans) revealed reliable threshold values for medullary invasion. In conclusion, DCE-MRI can discriminate SCC with medullary invasion from SCC without medullary invasion and may serve as a valuable tool in preoperative tumour staging with regard to the delineation of medullary invasion.

High percentages (35-78%) of resected mandibles without bone invasion have been reported in squamous cell carcinoma (SCC), adjacent or fixed to the mandible, stressing the need for accurate imaging methods. The aim of this study is to determine the value of bone single photon emission computed tomography (SPECT) for the evaluation of mandibular invasion by SCC. Seventy-nine patients with SCC, adjacent or fixed to the mandible, were included. The results of bone SPECT were compared to the histology of the resection specimens. Bone SPECT was positive in all 50 patients with mandibular invasion and negative in 17 of 29 patients without mandibular invasion. In conclusion, a negative bone SPECT rules out mandibular invasion. Important clinical implications are then that further imaging is not necessary and that the resection can be kept limited. Inclusion of SPECT in the preoperative assessment of these patients will lead to a considerable reduction of unnecessary mandibular resections.

Objective: The concern that a sagittal split osteotomy of the mandibular ramus could compromise the subchondral vascularization and especially the venous outflow in the condylar area, which in turn could influence the structure of the condylar cartilage, prompted this preliminary study on goats., Study Design: A sagittal split osteotomy was performed in the mandibular ramus at 1 side in each of 6 young adult goats. The contralateral side served as control. The animals were killed after different postoperative periods, ranging from 1 to 15 days. Histomorphometric analyses were performed after perfusion of the vascular system with India ink., Conclusion: Based on the observed cartilage thickening, the sagittal split osteotomy may influence the condylar cartilage in the first days postoperatively through a disturbance of the vascular supply.

The impact of several clinical parameters on health related quality of life (HrQOL) was evaluated in patients with squamous cell carcinoma adjacent or fixed to the mandible with special emphasis on postoperative radiotherapy and type of mandibular resection. One-hundred and five returned EORTC-questionnaires were available for this study. Correlation analyses were used to determine the relationship between clinical parameters and HrQOL. Postoperative radiotherapy was the clinical parameter that affected HrQOL most. The type of mandibular resection had no influence on HrQOL. The affected QOL-items were all associated with eating problems, i.e. use of a feeding tube, use of nutritional supplements, swallowing, social eating, mouth opening and dry mouth. Postoperative radiotherapy should only be applied if strictly indicated. This implies that the application of postoperative radiotherapy may need reconsideration in cases without strict criteria for postoperative radiotherapy.

This study, conducted between 1999 and 2003, included all patients with odontogenic tumors referred from all dental clinics and other health facilities in Tanzania to the only 4 referral centers. Demographic data and clinical and histopathologic findings were recorded. Histopathologic specimens were examined by expert pathologists. Ameloblastoma had the highest relative frequency (80.1%) and an incidence rate of 0.68 per million, followed by odontogenic myxoma (7.0%) with an incidence rate of 0.07 per million. Follow-ups of between 6 months and 4 years were carried out. Two patients developed recurrences of ameloblastoma. The incidence of ameloblastoma in this exclusively black African population did not differ from that of European countries. This is contrary to the belief that ameloblastoma has a higher incidence in black Africans as compared to Caucasians.

Purpose: The aim of the study was to investigate the results of non-surgical treatment of condylar fractures in a group of 60 patients with 71 condylar fractures, in order to establish a protocol to select patients for surgical treatment of condylar fractures., Material: Out of a group of 91 patients treated in a non-surgical fashion, 60 patients with a total of 71 condylar fractures responded to the request for follow-up., Methods: Retrospective study, including clinical analysis of occlusion, asymmetry at rest and during mouth opening, maximum interincisal distance, signs of TMJ-dysfunction and analysis of radiographic data, i.e. shortening of the ascending ramus as measured on sequential orthopantomograms., Results: There were five patients (8%) with an unacceptable malocclusion of which one also had considerably limited mouth opening. Fifty-five patients (92%) had none or only minor signs of TMJ-dysfunction not requiring further treatment., Conclusion: Only in selected patients with shortening of the ascending ramus of 8mm or more and/or considerable displacement of the condylar fragment, surgical repositioning and rigid internal fixation should be considered.

The results are reported on six patients who underwent a modified quadrangular osteotomy to avoid dysaesthesia of the infraorbital nerve. The suggested modification served its purpose well, while the functional and aesthetic results were excellent.

The data of 2049 patients, who underwent maxillofacial orthopaedic surgery, were retrospectively analysed for major intra- and immediate postoperative complications. Immediate life-threatening complications were very rare. They can in most cases be avoided by good anaesthetic and surgical techniques and adequate postoperative care. The most frequently encountered problem in maxillary surgery is excessive blood loss, whilst a compromised airway due to swelling is the most frequent complication in mandibular surgery. Good co-operation between anaesthetist and surgeon is essential to prevent major intraoperative and immediate postoperative problems.

Eleven patients (9 UCLP, 2 BCLP) were treated with segmental osteotomies with or without osteotomies at the Le Fort I level and simultaneous bone grafting of the alveolo-palatal clefts at adult age. These patients were clinically and radiographically evaluated after a mean follow-up period of 59 months (range 39-110 months). One patient showed complete dentoalveolar relapse, whereas the skeletal stability after miniplate fixation proved to be adequate in all cases. Only one patient presented with a persisting oro-nasal fistula. In six cases, the alar base asymmetry had improved to such an extent that further nasal corrections were not necessary. The procedure described is a reliable technique to graft the alveolo-palatal cleft and reposition the dentoalveolar segments simultaneously in those adult cleft palate patients who had no previous alveolar bone grafting.

A technique is described involving the combined use of mandibular ramus osteotomies and body step osteotomies. The combined use of these osteotomies enables the surgeon to solve some of the most complicated skeletal and occlusal problems. The method has proved to be safe in that no complications have occurred in the 7 patients reported.

The use of segmental osteotomies to treat surgically severe malocclusion in cleft patients is discussed. The coordinated approach by orthodontist and surgeon is advocated and the advantage of such an approach is stressed. The method allows for the simultaneous correction of the skeletal deformity and closure of residual oro-nasal perforation. The relapse tendency in both antero-posterior and transverse dimensions appeared to be minimal as found in this study of 18 patients.

The incidence, multiple presentation and recurrence rate of aggressive cysts of the jaws is discussed, based on a study of 677 cysts in 651 patients. Cysts that are considered aggressive include: cysts in which carcinoma develops, unicystic ameloblastoma, keratocysts and calcifying odontogenic cysts. Based on literature studies and on our own material, the incidence and multiplicity of these lesions is calculated. Recommendations for treatment include careful preoperative assessment and treatment of suspicious lesions with excision of the overlying mucosa and fixation of the defect with Carnoy's solution. The cyst in which carcinoma develops should be treated as a true malignancy i.e. by resection. Long term follow-up is necessary to eliminate the possibility of recurrence.