Effect of single versus fractionated doses of x-radiation on incisors in rats.

This study compares the effect of single vs fractionated doses of X-radiation on the incisor of the rat. The results showed that fractionated doses are more damaging than a single dose and that three fractionated doses have a stronger effect than five.

Dentinoenamel junction area of a resorbing permanent incisor studied by means of scanning electron microscopy.

The surfaces of enamel and dentin that had become separated from each other presumably in the region of the dentinoenamel junction were examined. The enamel surface at the junction was scalloped; the scallops were made of enamel rods. The dentinal surface showed a mirror image picture, tubular in nature. Both surfaces were granulated, which may indicate that apatite crystals from the two tissues intermingle there.

Tumors and tumor-like lesions of the oral cavity and related structures in Israeli children.

The present study comprises a total of 966 biopsies of the oral cavity and related structures obtained from children aged < or =15 years and examined at the Division of Oral Pathology of The Hebrew University. These cases represent 7.15% of the total number of biopsies (13508) during a fifteen-year period (1978-1992). Seven hundred and seventy six (776) biopsies (80.3%) represented inflammatory processes, cysts, pulp pathology and congenital malformations. The remaining 190 biopsies (19.7%) comprised neoplastic and tumor-like lesions: 18 (9.5%) were benign odontogenic neoplasms, 77 (40.5%) were benign non-odontogenic neoplasms, 18 (9.5%) were malignant tumors and the remaining 77 cases (40.5%) were tumor-like lesions.

Squamous odontogenic tumor. Review of the literature and case report.

Squamous odontogenic tumor (SOT) is a rare, benign odontogenic tumor affecting both jaws in all age groups. The tumor is composed of squamous epithelial islands surrounded by a mature connective tissue stroma. This tumor may occasionally be misdiagnosed as ameloblastoma, squamous cell carcinoma, verrucous carcinoma and keratoacanthoma. A conservative surgical approach is the recommended treatment. An additional case is reported and the literature reviewed.

Gaucher's disease affecting the mandible and maxilla. Report of a case.

Gaucher's disease is a rare autosomal, recessive disorder characterized by deficiency of lyzosomal hydrolase glucocerebrosidase, and showing predilection for Ashkenazi Jews. A case of Gaucher's disease affecting both jaws and initially diagnosed by mandibular biopsy is described.

Lichen planus: exploring its malignant potential.

Almost any area of the mouth may be affected by LP, but the most frequent locations are the cheeks, tongue and gingiva. The eight cases in our study illustrate the proliferative epithelial changes to verrucous or squamous cell carcinoma that can appear in oral LP. We also found a predisposition of LP in women. We urge, therefore, that clinicians monitor LP patients closely at three- to six-month intervals and attempt treatment for early resolution.

Structural changes in odontodysplasia.

Report is made of a histologic and scanning electron microscopic (SEM) study of teeth affected by odontodysplasia. The enamel was found to be thinner than normal, and the entire surface showed numerous depressions. The prismatic orientation, diameter, and density were found to be normal. Although the mantle dentin remained normal, the rest of this tissue showed a tendency to globular formation. The orientation, density, size, and shape of the dentinal tubules appeared to be normal. The cementum, in general, was normal, but in some instances appeared to be scalloped or globular. The pulp consisted of normal tissue but was found to be larger than normal. The presence of denticles was an outstanding feature.

Primary mineralization in the interface between bone and methyl methacrylate implants in rat mandibles. A correlative light and scanning and transmission electron microscope study.

Self curing polymethylmethacrylate implants were administered into rat mandibular bone. Tissue reaction was studied after different periods with light microscopy and transmission and scanning electron microscopy. Formation of fibrous tissue in the interface between implant and bone was associated with initial bone resorption and followed by the occurrence of primary calcification in a collagen rich matrix after 4-8 weeks. The features of primary mineralization comprised appearance of hydroxyapatite crystals within matrix vesicles and formation of calcospheritic structures. The occurrence of calcifying fronts after the intraosseous administration of polymethylmethacrylate suggests a favourable relationship between bone and the implant material.

Odontodysplasia. Report of two cases and review of the literature.

Odontodysplasia is a rare developmental anomaly affecting the tooth structures in both deciduous and permanent dentitions. The enamel is thin and uneven in thickness, and the detinal tissue surrounds very large pulp chambers. Denticles are present in the pulp organ. The maxilla is involved twice as frequently as the mandible. Most of the affected teeth are in the anterior segments; however, all other teeth can be affected. The cause is unknown. Because of the tendency of the affected teeth to develop abscesses, the most common treatment is extraction. Two additional cases are reported, and the literature is reviewed.

Simultaneously occurring salivary gland tumors of different types.

Two cases of simultaneously occurring salivary gland tumors of the parotid gland are reported. Both patients were women in the sixth decade of life. In the first patient, a carcinoma in pleomorphic adenoma and an oncocytoma were found in the right parotid gland. The second patient had an adenoid cystic carcinoma associated with a sebaceous cell adenoma. The addition of these cases to the previously published data brings the total number of simultaneously occurring salivary gland tumors of different types to ten.