The purpose of this study was to evaluate the biomechanical stability of various rigid internal fixation systems for subcondylar fractures.
Fifteen identical synthetic polyurethane mandibles with a cancellous bone structure (Synbone (R), Switzerland) were used. The left condylar processes were cut with a band saw to mimic subcondylar fractures directed perpendicularly to the long axis of the ramus, and the right sides were cut to mimic oblique fractures to the ramus. The fixation systems used were a single 4-hole titanium mini-adaptation plate (Synthes), double fixation with the same plates, a single 5-hole titanium mini-dynamic compression plate (Synthes), an Eckelt lag screw (R) system (Martin), and a Wurzburg lag screw plate (R) system (Leibinger). Biomechanical testing was done as described by Haug et al.(1996). The bone models were held with a custom-made jig to keep the occlusal plane horizontal. The canine region was pressed with a cantilever beam design using a servohydraulic testing machine (Autograph, Shimadzu) at a rate of 1mm/sec. The force-displacement curve, maximum load for breakage, and stiffness were measured.
In perpendicular fractures, double mini-plate fixation and Eckelt lag screw fixation provided the best stability. The maximum loads of the former and the latter were 46.7±9.5N and 44.7±11.6N, respectively. Their stiffness was 4.1±1.1N/mm and 4.7±1.9N/mm, respectively. Single mini-plate fixation was weakest, i. e., 13.2±2.4N maximum load and 1.3±1.0N/mm stiffness. In oblique fractures, double mini-plate fixation also had the best tolerance for load and stiffness, i.e., 55.1±11.6 N and 5.2±2.7N/mm, respectively. The Eckelt lag screw, however, showed considerably less fixation strength than that for perpendicular fractures, i.e., 22.8±11.3N for load tolerance and 1.0±0.2N/mm for stiffness.
In this laboratory setting, double mini-plate fixation proved superior in both types of fractures with regard to resistance to movement and breakage strength. The Eckelt lag screw showed good stability for perpendicular fractures; however, stability was weak for oblique fractures. Not only single mini-plate fixation but also minidynamic compression plate fixation or a Wurzburg lag screw plate system may provide insufficient fixation strength for this type of fracture on early functional loading.

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The patient was a 40-year-old woman with a swelling in the left submandibular region. She was admitted on an emergency basis at her first visit because of severe pain on swallowing, trismus, and general fatigue.
Computed tomography (CT) demonstrated a large neck abscess involving the masseter and submandibular spaces. Surgical incision and drainage of the spaces were performed in addition to antibiotic administration. However, symptoms rapidly exacerbated the following day. CT demonstrated a diffuse collection of mediastinal fluid. A second drainage of both neck spaces and the mediastinum was performed. Immediate surgical drainage through a neck incision proved effective, and clinical symptoms rapidly resolved.
In this patient, CT findings played an important role in the diagnosis and management of deep neck infection with regard to the timing of surgical intervention.

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We report a characteristic case of aspergillosis of the maxillary sinus in which natural discharge of a mass of mycotoxin and choanal flow occurred during follow-up after presentation. The patient was a 47-year-old woman who presented with discomfort and mild tenderness of the left cheek region and discomfort of the left maxillary molar region. The clinical diagnosis was maxillary sinus mycosis. Radical Caldwell-Luc operation was performed on the left maxillary sinus with the patient under general anesthesia. Histological examinations revealed sinus aspergillosis. After operation, the patient's progress has been good, without relapse.

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We describe a case of ossifying fibroma of the mandibular coronoid process in a 30-year-old woman. The patient presented with a chief complaint of a noticeable swelling of the right side of the face. On the basis of the clinical and radiographic findings, as well as the history of gradual progression, a benign fibro-osseous lesion of the right mandibular coronoid process was clinically diagnosed. Under general anesthesia, coronoidectomy was performed through an intraoral. approach. The histopathological diagnosis was an ossifying fibroma of the right mandibular coronoid process. Radiographic and clinical examinations showed no sign of recurrence 16 months after surgery.

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We encountered a rare case of oncocytoma of the submandibular gland.
A 73-year-old man complained of a gradually growing mass in the right submandibular region. The tumor was elastic soft and mobile, with a clear margin. Echography revealed a hypoechoic lesion, CT scans showed a welldefined homogenous submandibular mass, and MRI scans demonstrated a high-intensity mass on Ti and T2-weighted images in the right submandibular region. The tumor exhibited an intense uptake of ^99mTc pertechnatate. Histopathological examination showed that the tumor cells consisted of large cells with eosinophilic granular cytoplasm. On the basis of these findings, we diagnosed the tumor as an oncocytoma.
The postoperative course has been uneventful for 9 years.

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Myofibroblastic sarcoma is an extremely rare malignant tumor in the oral and maxillofacial region. We report a case of myofibroblastic sarcoma probably induced by irradiation for maxillary sinus cancer. The patient was a 61-year-old man whose present history was as follows. In October 1989, he presented with pain in the left maxillary molar region. A squamous cell carcinoma of the left maxillary sinus was diagnosed, and he was treated with external irradiation of 50Gy combined with chemotherapy. Left maxillectomy was done in February 1990.
The postoperative course was satisfactory. However, in June 1998, he presented again with a tumor arising in the posterior region of the defect on the left side of the maxilla. Although histopathological examination of a biopsy specimen revealed granulation tissue with inflammatory changes, the tumor grew rapidly. The tumor was therefore suspected to be malignant and was resected under general anesthesia. Histopathological examination revealed atypical and spindle tumor cells with immunohistochemically positive staining for a-smooth muscle actin, desmin, vimentin, and muscle specific actin, but negative staining for h-caldesmon.
On the basis of these histopathological and clinical findings, a final diagnosis of a myofibroblastic sarcoma of the maxillary region was made. The lesion was strongly suspected to be a radiation-induced tumor. The patient was followed up for 4 years 5 months after operation. The subsequent course was satisfactory, with no signs of recurrence or distant metastasis.

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Basaloid squamous cell carcinoma (BSCC) was first reported by Darier in 1922. The clinical and histological characteristics were described by Wain et al in 1986. BSCC is now considered a histologically distinctive variant of squamous cell carcinoma. This paper describes, with reference to previous articles on BSCC, a BSCC arising in the maxillary gingiva of a 71-year-old man. The tumor was surgically removed by a partial maxillectomy. Chemotherapy and radiotherapy were given postopratively. The details of the tumor, as well as the clinical procedure and prognosis, are discussed in this paper.

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Mesenchymal chondrosarcoma is rare malignant tumor of skeletal and extraskeletal origin. This neoplasm shows aggressive local behavior and has a high metastatic potential. The long-term prognosis is poor.
We report a mesenchymal chondrosarcoma occurring in the mandible of a 46-year-old man who had a painless mass in right side of the mandible, measuring 45×15 mm. Pathological examination of a biopsy specimen suggested a spindle cell sarcoma, but the diagnosis was unable to be confirmed. Mesenchymal chondrosarcoma was diagnosed on histopathological examination of the resected specimen. This tumor does not respond to chemotherapy or radiation. Complete resection is essential for a good outcome. The patient was closely observed without any additional treatment, and there has been no evidence of recurrence or metastasis 1 year 4 months after operation.

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Wegener's granulomatosis (WG) is a systemic disease characterized by necrotizing granulomatous inflammation of the respiratory tract, kidneys, and other organs. The most characteristic oral manifestation of WG is an unusual form of hyperplastic gingivitis. Because the clinical appearance of the affected gums resembles overripe strawberries, the gingivitis is referred to as “strawberry gums”. We report a case of WG showing typical strawberry gums with middle ear and nasal involvement. A 43-year-old woman was referred to our department because of gingival swelling after an operation for otitis media, which had not been diagnosed as WG at that time. The gingival surface appeared granular, resembling over-ripe strawberries. A gingival biopsy specimen showed microabscesses and multinucleate giant cells, characteristic findings of strawberry gums. The clinical appearance and histopathological findings suggested a diagnosis of WG. The diagnosis was supported by a positive anti-neutrophil cytoplasmic antibody test (cANCA). The patient responded to treatment with steroids and immunosuppressants, and the strawberry gums disappeared. The typical findings of strawberry gums were the initial diagnostic sign of WG.

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In some patients, reconstruction is not performed immediately after resection of malignant maxillary neoplasms to increase the chances for early detection of postoperative tumor recurrence. In such patients, maxillary prostheses are employed at the site. Use of maxillary prostheses allows amelioration, to a certain extent, of masticatory, swallowing, and articulative functional disorders. However, satisfactory results with this type of prosthesis have not previously been obtained with respect to esthetic disturbances, such as buccal concavity and elevation of the upper lip. We have utilized an inflatable balloon maxillary prosthesis to address these issues, with excellent results. The results are summarized in this report.

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