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Treatment of mandible fractures using bioabsorbable plates.

This study evaluated the short-term outcome of treating fractures of the mandible with bioabsorbable plates. Sixty-nine fractures of the mandible in 49 patients were treated by open reduction and internal fixation using bioabsorbable plates and 2.4-mm, 2.0-mm, and 1.5-mm pretapped screws. The duration of intermaxillary fixation ranged from 0 to 23 days, with a mean of 4.6 days. Patients were evaluated for complications during the follow-up period, which ranged from 1 to 18 months. Six patients (12.2 percent) experienced complications. These included infection (four patients), premature occlusal contact (one patient), and temporomandibular disorder (one patient). Except for one case, all complications were minor and adequately managed with incision and drainage, elastic traction, physical therapy, and medication. Delayed infection (osteomyelitis) developed in a symphysis fracture and was treated by saucerization and antibiotics. The fracture line subsequently showed complete consolidation. Bioabsorbable plates can be selectively used for internal fixation in mandibular fractures, with the advantage that they do not need to be removed.

Absorbable Implants↗

Pediatric chin injury: occult condylar fractures of the mandible.

The diagnosis of occult mandibular condylar fractures in children is often missed or delayed on initial examination when children present with a laceration to the chin. A clue to the diagnosis of this type of skeletal injury to the mandible is the knowledge of a commonly occurring pattern of injury associated with chin trauma. Chin laceration, fracture of the parasymphyseal region near the chin, and fracture of the condyles are often concomitant injuries of the mandible. This article reviews three case reports of children who sustained a chin laceration, fracture in the region near the chin, and fracture to the mandibular condyles secondary to chin trauma that were not initially diagnosed on clinical examination.

Child↗

Five-year experience with the transoral endoscopically assisted treatment of displaced condylar mandible fractures.

BACKGROUND: From April of 1998 to May of 2003, the minimally invasive transoral approach for endoscopically assisted reduction and osteosynthesis of 62 displaced condylar mandible fractures was performed in 58 patients. METHODS: By means of limited transoral incision, the endoscopically assisted reduction and fixation of condylar fractures was performed using 30- and 45-degree angled endoscopes. Twenty-five fractures were condylar and 37 were subcondylar. The condylar neck of the proximal fragment was displaced medially in 17 fractures and laterally in 45 fractures. Four patients presented bilateral condylar mandible fractures. Using angled endoscopes, good visibility of the fracture site was obtained, which allowed for precise anatomical reduction in all patients. An angulated drill and screwdriver facilitated miniplate fixation by means of the transoral approach. The mean operating time was measured in the last 30 consecutive cases: 1 hour 5 minutes. RESULTS: Postoperatively, all patients showed quick recovery to preinjury occlusion. Normal temporomandibular joint function was noted 6 months after surgery in all patients. CONCLUSIONS: The transoral endoscopically assisted treatment using an angulated drill and screwdriver is the method of choice for surgical management of displaced condylar fractures, even in fractures with medial override. Facial nerve injury and visible scars are avoided by using the transoral approach.

Adult↗

Closed reduction and fluoroscopically assisted percutaneous stabilization of displaced subcondylar mandible fractures.

BACKGROUND: Displaced subcondylar fractures of the mandible are difficult to treat. Open reduction with internal fixation carries significant risks including devascularization of the condylar segment, facial nerve injury, and scarring. Closed treatment with mandibular-maxillary fixation alone accepts a misaligned fracture and relies on joint remodeling. Both techniques carry risk for long-term temporomandibular joint arthritis and pain. In no other area of fracture treatment in adults is nonanatomic fracture reduction accepted as the standard of care when there is a misaligned joint. The purpose of this study was to evaluate closed reduction and fluoroscopically assisted percutaneous stabilization of subcondylar fractures. METHODS: Fresh cadaver dissections were performed after fractures were created. Kirschner wires were placed in the condylar segment as "joysticks" to manipulate the condylar segment. Fluoroscopy confirmed that the condylar segment was easily manipulated. Seven patients with subcondylar fractures were treated. Two Kirschner wires were placed in the condylar segment and, along with jaw manipulations, were used to reduce the fractures in six of the seven patients. RESULTS: Manipulation of the condylar segment with the "joystick" was possible. Reductions were obtained in six of seven cases and additional Kirschner wires were used to stabilize the condyle with the fracture aligned, joint reduced, and mandibular height restored. All patients were placed in mandibular-maxillary fixation for 2 to 3 weeks. After release of mandibular-maxillary fixation, the mandible was midline through the arch of rotation in the patients who were treated. There were no complications from the procedure. CONCLUSIONS: Closed reduction of subcondylar fractures with a Kirschner wire "joystick" is possible in most cases. This method achieves anatomic reduction and restores mandibular height utilizing minimally invasive techniques with no need for novel equipment or expensive plating systems. There is minimal risk associated with the procedure and minimal additional operative time is required. The advantages of a reduced fracture are substantial and easily obtained with this minimally invasive technique.

Adult↗

Xanthic variant of non-ossifying fibroma (so-called xanthofibroma) of the mandible. An ultrastructural study.

An unusual case of a 37-year-old female with xanthomatous bone tumor of the right molar area of the mandible was presented. The tumor was asymptomatic and found to be a well-demarcated intraosseous radiolucent lesion on radiographic examination. Histologically the tumor consisted of two cell types, fibroblastic and xanthomatous cells. There was no osteoid, bone or cartilage formation. However, numerous psammomatous calcified bodies were seen in the fibrous area. Ultrastructural study showed fibroblastic cells in different stages of proliferation as the basis of the tumor which transform itself into xanthomatous cells. From the clinicopathologic findings, our case was thought to be a xanthic variant of non-ossifying fibroma (so-called xanthofibroma) of the mandible.

Adult↗

Ameloblastic odontosarcoma (ameloblastic fibro-odontosarcoma) in the mandible.

A case of ameloblastic odontosarcoma (ameloblastic fibro-odontosarcoma) originating in the mandible is reported. The patient was a 23-year-old Japanese male with diffuse swelling of the mandible from the left premolar to the ramus region. A biopsy specimen showed the histopathological features of ameloblastic fibrosarcoma. Histologic examination of the surgical specimen revealed various amounts of dysplastic dentin and dentinal matrix which were closely associated with both mesenchymal and epithelial components throughout the lesion. In addition, a small amount of abortive enamel matrix, which was in close contact with ameloblastoid cells of epithelial nests, was found by extensive sampling of the resected specimen. Therefore the present case was diagnosed as ameloblastic odontosarcoma. After 2 years, the patient died of uncontrollable local recurrence and extension to the cranial base.

Adult↗

Production of keratinizing cysts within mandibles of rats with autogenous gingival epithelial grafts. A histologic study.

A method for the consistent production of epithelial-lined cysts in the mandibles of rats is described. Attached gingiva from the interdental papilla was excised and implanted into prepared cavities in the mandible. The animals were examined at time periods varying from 0 to 45 days later. Twenty-seven of the 28 animals examined after 7 days or longer had developed cysts. An interpretation of the pathogenesis of these cysts was made based on histologic observations and measurements of the cysts at the various time intervals.

Animals↗

Comparison of the ultrastructure of a malignant tumor of the mandible containing giant cells with Paget's disease of bone.

Distinction between lesions of the jaws containing giant cells can be difficult. This study reports the results of the study of the ultrastructure of 30 patients with Paget's disease in comparison with a patient diagnosed as having malignant giant cell tumor of the mandible. The ultrastructure of the malignant giant cell tumor of the mandible was found to contain nuclear inclusions morphologically identical with the 12-15 nm tubules characteristic of the nuclei of osteoclasts in Paget's disease of bone. No clinical or laboratory signs of Paget's disease was found in this patient. A search of the literature failed to produce reports of identical nuclear inclusions in soft tissue giant cell tumors, osteosarcomas, reparative granulomas containing giant cells or in osteitis fibrosa cystica. Such nuclear inclusions have been reported in benign giant cell tumors of bone, one another in malignant giant cell tumor and cases of polymyositis. These observations raise the question of a possible virus associated with the tumor since there are recent reports of immunological evidence for the presence of a virus in Paget's disease, and viruses have been suspected in polymyositis.

Adult↗

Benign fibrous histiocytoma of the mandible.

A very rare case of benign fibrous histiocytoma of the mandible is presented. A 49-year-old woman was admitted because of left buccal swelling and pain. Panoramic radiograph showed well-demarcated soap-bubble appearance without sclerotic rim in the left mandibular bone. A yellowish-white and partly brown solid tumor was noted in the excised mandibular bone specimen. The tumor histologically consisted of spindle cells, in which areas showing a storiform pattern and other areas composed of histiocytic cells with erythrophagocytosis and foam cells were mixed. Immunohistochemically, the tumor cells were positive for vimentin, CD68, alpha-1-antichymotrypsin and alpha-1-antitrypsin. From these findings the tumor was diagnosed as a primary BFH of the mandible. No recurrence has been noted 2 years and 11 months after surgery.

Antigens, CD↗

Hypothetical mortality risk associated with spiral computed tomography of the maxilla and mandible.

In the present study, dose measurements have been conducted following examination of the maxilla and mandible with spiral computed tomography (CT). The measurements were carried out with 2 phantoms, a head and neck phantom and a full body phantom. The analysis of applied thermoluminescent dosimeters yielded radiation doses for organs and tissues in the head and neck region between 0.6 and 16.7 mGy when 40 axial slices and 120 kV/165 mAs were used as exposure parameters. The effective dose was calculated as 0.58 and 0.48 mSv in the maxilla and mandible, respectively. Tested methods for dose reduction showed a significant decrease of radiation dose from 40 to 65%. Based on these results, the mortality risk was estimated according to calculation models recommended by the Committee on the Biological Effects of Ionizing Radiations and by the International Commission on Radiological Protection. Both models resulted in similar values. The mortality risk ranges from 46.2 x 10.6 for 20-year-old men to 11.2 x 10(-6) for 65-year-old women. Using 2 methods of dose reduction, the mortality risk decreased by approximately 50 to 60% to 19.1 x 10(-6) for 20-year-old men and 5.5 x 10(-6) for 65-year-old women. It can be concluded that a CT scan of the maxillofacial complex causes a considerable radiation dose when compared with conventional radiographic examinations. Therefore, a careful indication for this imaging technique and dose reduction methods should be considered in daily practice.

Adult↗

Immediate/early function of Brånemark System TiUnite implants in fresh extraction sockets in maxillae and posterior mandibles: an 18-month prospective clinical study.

BACKGROUND: The advantages of placing implants in fresh extraction sockets and putting them in immediate/early function are many. A predicable protocol opens the possibility of performing a single surgical procedure, giving the patient a temporary prosthesis immediately, and minimizing the shrinkage of hard tissue and soft tissue recession. PURPOSE: The aim of the present study was to develop a strict protocol for and to evaluate the feasibility of immediate/ early function on implants placed in fresh extraction sockets located in maxillae and posterior mandibles, including defects around the implants treated according to a regenerative procedure. MATERIALS AND METHODS: Nineteen patients were treated after tooth extraction according to an immediate function protocol and were observed for 18 months. Fifty Mk IV TiUnite (Nobel Biocare AB, Göteborg, Sweden) implants were installed in partially edentulous areas in maxillae (n = 17) and posterior mandibles (n = 5). Implants were installed directly into the alveoli, and the temporary prostheses were connected immediately after surgery (n = 11) or within 7 days, that is, an "early function" procedure (n = 11). Thirteen implants did not require any type of regenerative procedure, whereas the remaining 37 implants had filling with autogenous bone, 4 of which also had a resorbable membrane. Standardized intraoral radiographs were taken for evaluation of marginal bone level, and 38 of the implants were systematically checked by resonance frequency analysis. RESULTS: All patients were followed for 18 months, and none of the 50 implants failed. However, one implant showed signs of failure after 6 weeks, but once the occlusal load was removed, the implant regained its stability completely, no longer demonstrated symptoms, and could be used successfully for prosthetic rehabilitation. The mean value of the implant stability quotient was 60 at baseline (range 45-75) and 63 after 6 months (range 46-75). The marginal bone resorption was 0.9 mm (SD 1.1 mm; n = 48) 18 months after implant insertion (1 year after final prosthesis). CONCLUSION: The immediate placement of implants into fresh extraction sockets combined with immediate/early function procedures seems to be a safe and reliable procedure when using a strict protocol.

Adult↗

Metastasis of thyroid carcinoma to the mandible. Case report.

Metastatic tumours to the jaw bones are uncommon. The incidence of jaw bone metastasis is difficult to assess accurately since the usual method to determine the distribution of a metastatic tumour has been by a radiographic skeletal survey in which the jaws are rarely included. At times, metastatic lesions of the orofacial region may be the first evidence of dissemination of a known tumour from its primary site. A case of metastatic follicular carcinoma of the thyroid to the mandible is presented. The present case emphasizes the importance of considering metastasis in the differential diagnosis of a radiolucent lesion in the mandible in a patient with a history of any malignant disease.

Adenocarcinoma, Follicular↗

Parathyroid hormone related protein in oral squamous cell carcinomas invading the mandible.

AIM: To assess parathyroid hormone related protein (PTHrP) as a candidate biochemical marker of invasion of the mandible by oral squamous cell carcinoma. METHODS: Tumour PTHrP concentrations were quantitated by immunoassay, and PTHrP was detected by immunohistochemistry, in a cohort of 24 primary squamous cell carcinomas of the mandible. RESULTS: PTHrP was identified in all tumours examined, but no correlation was found between scores of the intensity and/or consistency of staining or tumour PTHrP concentrations and the histological classification of tumour invasion. CONCLUSION: Although PTHrP was present in all squamous tumours studied, there was no correlation between PTHrP expression and pattern of tumour invasion. However, tumour derived PTHrP may act locally to influence tumour growth and differentiation and resorption of bone.

Biomarkers, Tumor↗

Radiologic and pathologic characteristics of benign and malignant lesions of the mandible.

Mandibular lesions develop from both odontogenic and nonodontogenic origins and have varying degrees of destructive potential. Common benign cystic lesions include periapical (radicular) cysts, follicular (dentigerous) cysts, and odontogenic keratocysts. Benign solid tumors represent a broad spectrum of lesions such as ameloblastomas, odontomas, ossifying fibromas, and periapical cemental dysplasia. Malignant tumors that often involve the mandible include squamous cell carcinomas, osteosarcomas, and metastatic tumors. In addition, vascular lesions such as hemangiomas and arteriovenous malformations may develop, further expanding the differential diagnosis. Because mandibular lesions have a wide range of pathologic features but similar imaging appearances, familiarity with embryologic characteristics and secondary findings is crucial. Patient age at manifestation, prevalence, location within the mandible, cystic or solid appearance, border contour, and effect of the lesion on adjacent structures are all considerations in making the diagnosis. Despite this information, however, many lesions are impossible to differentiate without biopsy. In such cases, defining the degree of malignant potential is very helpful. Although imaging will not always provide a specific diagnosis, it should help narrow the differential diagnosis, thereby helping to guide patient treatment.

Diagnosis, Differential↗

Ewing's sarcoma of the mandible.

Ewing's sarcoma of the mandible occurs rarely; there have been less than 50 reported cases in the past 30 years and none of these have been in the otolaryngologic literature. They usually present in the second decade of life with pain and swelling of the soft tissue overlying the mandible. The diagnosis can only be made by an adequate mandibular biopsy, although x-rays and clinical presentation are helpful. Current treatment consists of radiation therapy and sequential adjuvant chemotherapy.

Adolescent↗

Ewing's sarcoma of the mandible.

Ewing's sarcoma is an uncommon neoplasm that primarily occurs in the long bones of the lower and upper extremities. Only 2% involve the mandible, and the maxilla is involved one eighth as often as the mandible. The most common site of metastases is the lung. Increasing pain is the most common presenting symptom. A case of mandibular involvement is presented. The combination of a large, soft tissue mass adjacent to an area of bone destruction in a young male should suggest the diagnosis. The previously poor five- and ten-year survival rates of 8 and 4% respectively, may have promise of marked improvement. This improvement lies in a changing philosophy of treatment. Four-drug chemotherapy combined with prophylactic whole-lung irradiation has been added to local irradiation of the tumor bed. Five-year survival figures of 20 to 30% appear obtainable. Although extensive surgical resection of the primary tumor in the long bones has for the most part been replaced by local irradiation for control, surgery in mandibular cases may still be the treatment of choice.

Child↗