The use of arthrography in the diagnosis of temporomandibular joint synovial chondromatosis.

Synovial chondromatosis (SC) involving the temporomandibular joint (TMJ) is very rare and can occur in either or both cavities. Differentiation of the affected cavity in SC is therefore as important as making the diagnosis. This report presents a case of SC in which both cavities were thought to be affected, but arthrography using cone beam CT (CBCT) allowed us to see that involvement was limited to the superior joint cavity. In addition, we describe the usefulness of arthrographic CBCT for diagnosis and treatment planning in SC of the TMJ.

Clinicopathological studies of odontoma in 47 patients.

A 14-year retrospective study was performed on 47 odontomas from the files of the 1st Department of Oral and Maxillofacial Surgery at Nihon University School of Dentistry. Fifty-seven percent of the patients were male and 42.6% were female. The age distribution was 8 to 48 years with a mean age of 22 +/- 9.0 years. There were no particular symptoms associated with the odontomas, and 63.8% of our patients had no symptoms. However, 12 patients complained of swelling and 9 of pain. The tumor was found in the maxilla in 42.6% and in the mandible in 57.4%. According to the WHO histological type classification, 53.2% of the tumors were classified as compound odontoma and 46.8% as complex odontoma. The size of the tumor ranged from 5 mm to 42 mm in diameter. The average complex odontoma was much bigger than the average compound odontoma. Ghost cells were found 11 cases in our series. In addition, odontogenic epithelium was found in 16 cases. Twenty seven patients had impacted teeth in association with odontoma and 24 of the 27 teeth were removed at the time of surgical enucleation of the tumor, while 3 cases were treated by orthodontically assisted eruption. There was no recurrence in any of the studied cases.

Intraoral minor salivary gland tumors: a retrospective study of 129 cases.

From 1970 to 1996, 129 cases of intraoral minor salivary gland tumors were diagnosed at the Department of Pathology, Nihon University School of Dentistry. The diagnosis of each case was based on the 1991 WHO classification. Eighty benign and 49 malignant minor salivary gland tumors were found in the approximately 9,300 oral biopsies submitted during the 27-year period. Pleomorphic adenomas were the most commonly histologic type of the benign tumors identified and 51% of the malignant tumors were diagnosed as mucoepidermoid carcinoma. The most common primary location of the tumors was the palate. Sixty percent of all tumors occurred in females and the peak age for incidences of all tumors was found in the third, fourth, sixth and seventh decades. These results were compared with those of the studies in different world population groups.

p53 gene alterations and p53 protein in oral epithelial dysplasia and squamous cell carcinoma.

To examine the expression of p53 protein and gene alterations in oral epithelial lesions including epithelial dysplasias and primary squamous cell carcinomas, immunohistochemical and temperature gradient gel electrophoresis (TGGE) methods were applied to formalin-fixed and paraffin-embedded tissues. Morphologically normal mucosal epithelium stained negatively for p53 protein. Three out of 11 (27.3 per cent) epithelial dysplasias and 19 out of 57 (33.3 per cent) primary squamous cell carcinomas stained positively for p53 protein. Although more than half of the cases were positive for p53 protein in stage I, the positive cancer cases were found at other stages with variable frequency. Immunoreactive products were localized in the nucleus, especially in the basal and suprabasal layers. The analysis by TGGE revealed gene alterations in exons 5-8 in 3 out of 3 epithelial dysplasias and 17 out of 19 (89.5 per cent) primary squamous cell carcinomas which were immunohistochemically positive for p53 protein. These results suggest that p53 gene mutation may be involved in carcinogenesis in the oral squamous epithelium even in the early stage of the dysplasia-carcinoma sequence.

A case of osteoporosis with bilateral defects in the mandibular processes.

We carried out a detailed total body examination of a 62-year-old woman with osteoporosis who had bilateral defects in the mandibular processes. It was inferred that the defects in both articular heads were caused by resorption of small bone fragments following fracture. The quantity of bone salt was determined by microdensitometry, and a diagnosis of osteoporosis was then established. An improved bite was obtained by treatment consisting of tooth extraction and the preparation of partial dentures.

Preprosthetic surgery for severely atrophic maxilla with poor palatal vault form; report of two cases treated by hard palate compression through palatal vault osteotomy.

Two cases of severely atrophic maxilla with poor palatal vault form treated by Kitayama's modified palatal vault osteotomy technique are described. The advantages of this osteotomy technique are outlined in comparison with other surgical methods.