The objective of this study was to determine the socio-demography (age, race and gender) of a group of Malaysian patients who were diagnosed as suffering from oral lichen planus (OLP). The occurrence of malignancy was also investigated. A total of 77 clinical and biopsy records of patients with OLP were studied. Females were affected more than males, with the female to male ratio being 2 : 1. Middle-aged Indian and Chinese females tend to be affected by OLP when compared with the rest of the population. Only 19 patients returned for further follow-up. One adult Indian female with a six-year history of lichenoid reaction showed the presence of malignancy.

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The purpose of this study was to determine the oral health attitudes/behavior of Greek dental students. The subjects (n = 539) were officially registered students at the University of Athens Dental School. Their oral health behavior was assessed with the use of a 12-graded-item questionnaire. A significant increase per year of study was observed in the number of students reporting careful brushing of the teeth [OR : 1.1 (1.0-1.3)] and being able to clean their teeth well without the use of toothpaste [OR : 2.5 (2.0-3.1)]. Each year of education significantly increased the probability of disagreement with statements such as : “I think my teeth are getting worse despite my daily brushing” [OR : 1.5 (1.2-1.9)], “It is impossible to prevent gum disease with tooth-brushing alone” [OR : 1.3 (1.1-1.5)], and “I put off going to the dentist until I have a toothache” [OR : 1.3 (1.2-1.6)]. Examination of the summary questionnaire score revealed that females presented significantly higher total scores. All scores increased significantly in the fourth and fifth years of dental studies. During the years of university study, the score variation and favorable attitudes/ behavior toward oral health appear to reflect the variation in the students' educational training experience.

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Natural teeth with a healthy periodontal support exhibit stress transfer when functional forces are applied to them. These stress patterns show considerable variations during differing treatment modalities, which may influence both the tooth and supporting alveolar bone. The purpose of this study was to evaluate variations in the stress transfer under functional loads on first molars with periodontal furcation involvement, which were treated either with by root resection or root separation. This study used a two dimensional mathematical model of a mandibular first molar that was subjected to either a root separation or a root resection procedure. An evenly distributed dynamic load (600 N) was applied on two buccal cusps and distal fossae of the molar in centric occlusion. The analysis was performed using an IBM-compatible computer running standard analysis software. It was found that in the root resection model the stress values were maximum on the centre of rotation, and compressive stresses increased towards the middle of the cervical line. For the root separation model, the maximum shear stress values were observed in the distal portion, and a uniform stress distribution was observed in the mesial portion. Shear stress values for bone increased towards the centre in the bifurcation area. The outcomes of this study may be useful as a guide in clinical restorative procedures.

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In the treatment of diabetes-induced pathologies, beneficial results have been obtained with administration of antioxidants. Selenium is an antioxidant and essential trace element in living organisms. The aim of this study was to investigate the possible effects of selenium on the structural alterations of the mandible due to diabetes. In this study thirty-nine Wistar rats were used and a control, a selenium given control, a diabetic and a selenium given diabetes groups were formed. Experimental diabetes was induced by a single i.p. injection (50 mg/kg) of streptozotocin (STZ). The diabetic + selenium and the control + selenium groups were injected with a daily dose of 5 μ mol/kg/day sodium selenite (i.p.) for 4 weeks while the diabetic and the control groups were injected with distilled water. Mandibles of all the animals were excised and examined at the 5th week. High blood glucose level and low body weight in the diabetic group were not significantly affected by selenium administration. Furthermore, a negligible increase in blood glucose level was observed in the selenium given control group. Densitometric analysis revealed a significant reduction in bone density and presence of resorption in the diabetic and the selenium given control groups as compared to the selenium given diabetes and the control groups. In X-ray diffraction analysis, the reduction in peak intensity of the reflected light in both the diabetic and the selenium given control groups indicated a possible alteration in the crystallinity or a poor crystalline substance. Histological investigation showed that there was progressive resorption, trabecular and cortical irregularity and vascular proliferation in the diabetic and the selenium given control groups, whereas a more healthy appearance was detected in the selenium given diabetes group. The results of this study suggest the positive effects of selenium on diabetes-induced structural alterations in the mandible. However, the unexpected results in the selenium given control group necessitate further studies on the mechanism of selenium effects in organisms.

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The main objective of this in vitro study was to evaluate the effects of the operator's experience level and pre-flaring on the accuracy of the results of three different brands of a new generation of root canal measuring devices, as well as the comparison among them. Extracted human teeth were prepared and then actual length and electronic length measurements were made by three different operators according to a double-blind technique. Three different operators performed electronic measurements on each specimen separately with three different electronic root canal measuring devices using in vitro models. Measurements were repeated by all operators after the pre-flaring. Taking the clinical tolerance of ± 0.5 mm into account, there was no statistically significant difference between the accuracy of the instruments (P > 0.01). However, the results obtained from the Bingo electronic apex locator in pre-flared canals by the beginner operator were statistically significant (P < 0.01). All of the instruments had a clinically acceptable result at the tolerance of ± 0.5 mm. If the instruments are used in accordance with the manufacturer's instructions, experience with electronic root canal measurement is not essential. However, the operator has to be more careful when working on pre-flared canals.

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To reveal the characteristic features of the imprint cytology of ameloblastomas, we compared these features with the histopathological features of the same specimens. Twenty-five cases, histopathologically diagnosed as ameloblastoma, were used. Three cell types were recognized : small squamous epithelial cells which were polyhedral or spindle-shaped with some projections; naked cells with poorly defined cytoplasm showing tubular and palisade patterns in some areas; and large squamous epithelial cells with extensive wrinkled cytoplasm. Naked cells and small squamous epithelial cells were thought to correspond to the histopathological classifications of cuboidal to columnar cells, and polyhedral or spindle cells respectively. Large squamous epithelial cells were thought to be acanthomatous cells showing squamous metaplasia. Imprint cytology had characteristic advantages compared to fine needle aspiration cytology, and clearly reflected the histopathology of the lesions. Knowledge of the characteristic features of the cells observed in imprint cytology is important when undertaking cytodiagnosis using fine needle aspiration.

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Buccal mucosa carcinoma-derived cell line, HO-1-N-1, epithelial-like cells, was obtained in order to investigate the characteristics of oral cancer cells and examine the [Ca²⁺] i responses to stimulants, such as bradykinin (BK), histamine (HIST), thapsigargin (TG), epidermal growth factor (EGF) and transforming growth factor α (TGF α). Intracellular Ca²⁺ influx was observed by all stimulants that enhanced the [Ca²⁺] i response. However, intracellular Ca²⁺ release was not observed in response to growth factors. The [Ca²⁺] i response of BK (100 nM) was inhibited by 10 μ M of the BKB₂ antagonist, D-Arg- [Hyp³, Thi^{5, 8}, D-Phe⁷] -BK, and HIST (1 mM) was completely inhibited by 100nM of the H₁ antagonist, (+) -chlorpheniramine, in the presence and absence of extracellular Ca²⁺ (1.5mM).A retrospective evaluation of the reticular form of oral lichen planus was made on the basis of clinical and histopathological observations in 55 patients. Patients were re-examined once every six months over a 25-year period. Biopsies were taken from all lesions. No cases of complete remission and no cases of malignant transformation were recorded. Our findings suggest that the reticular form of oral lichen planus is not a precancerous lesion.

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The authors present an interesting and unusual histology of compound odontoma from an 18year-old female. Part of the subepithelial connective tissue beneath the enamel organ epithelium was replaced by a granular cell nodule, of a probable histiocytic nature. This case represents the first published report of odontoma accompanied by granular cells.

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