Changes in the distribution of surface glycoconjugates of human oral mucosa epithelial cells in response to the degree of keratinization can be determimed by lectin histochemistry. Paraffin blocks of normal human oral mucosa (gingiva, palate, and buccal mucosa) were sectioned at 4 μm and were reacted with five biotinylated lectins (RCA-1, PNA, UEA-1, SBA, and DBA), followed by peroxidase-labeled avidin. The oral epithilia were divided into (a) non-keratinized, (b) para-keratinized, and (c) ortho-keratinized types by both H&E staining and by the Pauly reaction. In both non-and ortho-keratinized epithelia, lectin-binding patterns were similar to those shown in the epidermis of the skin. However, the glycoconjugate expression of epithelial cells in the para -keratinized type differed from that of the epidermal type. PNA Staining, observed on the surface of spinous cells in the epidermis, was not detected in the cells of the thickened para-keratinized layers and was also completely absent in the hyper-parakeratotic condition. DBA binding, on the other hand, was not evident in any epidermal cells of skin and epithelial cells of non-and ortho -keratinized mucosa, but was detectable on the surface of the differentiated cells. These findings indicate that in the human oral epithelia the expression of cell-surface glycoconjugates corresponds to the degree of keratinization. Particularly, the change in both PNA and DBA binding is a unique phenomenon for the para-keratinization process.

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The basis for the motor effects by intracortical microstimulation (ICMS) is that there are three oro-facial motor cortical areas in cats: the anterior part of the coronal gyrus (area C), the lateral wall of the presylvian sulcus (area P) and the ventral bank of the cruciate sulcus (area M). In order to investigate the functional differences among these three motor cortical areas, single neuronal activities were recorded in these cortical areas before, during and after mastication. In 8 conscious cats, 70% of the neurons in areas C and P, and 60% in area M showed changes in their neuronal activities before or during mastication (MR neurons). The activity of 70% of MR neurons in area M changed before mastication or before movements of the jaw, tongue and lip (pre -movement type); whereas 35% in area C and 50% in area P were the pre -movement type. The activity of 60% of the MR neurons in area C changed following oro-facial movements during mastication (post-movement type), and only 45% in area P and 20% in area M were the post-movement type. Most MR neurons in these cortical areas received inputs from the tongue, perioral and mandibular regions. These findings suggest that areas M and P may be involved in the initiation of masticatory movement, and that area C may control masticatory movement by integrating motor outputs and sensory inputs.

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The purpose of the present study is to clarify the ethnic relationship between the Chinese and the Japanese from the dental anthropological point of view. A PTC tasting test as well as other oral traits was carried out in their off spring. The group of children who were examined, consisted of 272 Uigur, 244 Kazak, 403 Xibo, 373 Mongolian, 355 Han (Beijing), 359 Han (Leshan) and 233 Han (Hong Kong). The control group consisted of 250 Japanese.
The following results were obtained.
1. The difference in gender of the percentage of PTC non-tasters was not significant among these populations.
2. The frequency of PTC non-tasters was 36.8% in the Uigur, 25.4% in the Kazak, while only 7.0% in the Xibo, 9.9% in the Mongolian, 7.9% in the Han (Beijing), 7.0% in the Han (Leshan), 7. 7% in the Han (Hong Kong) and 14.0% in the Japanese.
3. The gene frequency of PTC recessive gene (t) in the Uigur was larger than that of PTC dominant gene (T), while the gene frequency of t in the Xibo, the Mongolian, the Han and the Japanese children was smaller than that of T.
Thus, it is suggested that the Uigur and the Kazak are closer to the Caucasoids than the Xibo, the Mongolian, the Han and the Japanese.

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The aim of this study is to establish an efficient method for observing the odontoclast whose location has often been difficult to find. To evaluate the feasibility of this method, sequential observations by stereoscopic, light, and transmission electron microscopies were made to detect tartrate-resistant acid phosphatase (TRACPase) activity in the healthy human transitional deciduous teeth.
The results of the stereoscopic microscopy showed that the positive TRACPase reaction which was presented as a mass of small dots was observed in the regions on the surface of resorbed root and in the pulp chamber wall. Further observations with the light and transmission electron microscopes demonstrated that the major part of the TRACPase-positive region belonged to the resorbing odontoclasts, while the remaining part belonged to the resting odontoclasts and their precursor cells. In conclusion, by using this method, it will be possible to easily localize the exact location of the odontoclast. Furthermore, it can also be expected that this method will facilitate future investigations on odontoclasts.

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Oral and dental sensory functions to discriminate the thickness of foods with different textures were evaluated in healthy university students. These results were compared with the discriminative ability of finger tactile sensation and visual function. Material that was 3 mmthick was used as the standard and was compared with a series of material that were thicker and thinner by 0.2mm increments. The discriminative abilities were the same in the cases of raw carrots, boiled fishpaste and bean curd. The discriminative thresholds of the upper-lower incisors, tongue-upper incisors and lip-lip were lower than the threshold for the tongue-cheek. When 10mm thick material was used as the standard and was compared with a series of 0.2mm thicker materials, the discriminative ability of the upper-lower incisors and the fingers was less sensitive in casesof soft foods than that of hard foods. The ability to discriminate using vison was better than by oraland fingers tactile sensations. These results suggest that the oral sensory discriminative abilityof food thickness was different among oral parts, and texture of food significantly affect this sensory discriminative ability.

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