The subjects, 91 male and 93 female, were physically normal and ranged from 20 to 60 years old. The three-dimensional facial contours of the subjects were measured by the Moiré topography, and some common features associated with aging were analyzed morphologically.

The following results were obtained:

1. The facial features of males showed distinct changes of aging in that the zygomatic and upper-labial region changed in a parallel manner:

both regions became fleshy to hide the underlying skeletal contours until 39 years of age; from 40 years of age, the shape of both regions resembled the underlying skeletal contours. This parallelism in the age-associated changes of the contour was statistically significant (p<0.05).

2. In treatment of edentulous patients whose labial region is deformed, the zygomatic region must be considered as a guide to lead to an esthetically restored facial contour.

3. We do not yet understand the age-dependent changes in the facial features of the female.

We have studied the bacterial characteristics of Staphylococcus epidermidis, to clarify the properties of specific glycoprotein (MW 24,000) which we observed in S. epidermidis slime by using SDS-polyacrylamide gel electrophoresis. We recognized the relationship between slime production and virulence of S. epidermidis in mice. Also, we observed the relationship between slime production and the activity of protease.

However, no relation between slime produciton and the activity of superoxide dismutase, and between slime production and the type difference of hemolysin of S. epidermidis were seen. These results demonstrate that the slime glycoprotein of S. epidermidis was closely related to protease activity and a virulence in the host.

Ninty-five strains of Capnocytophaga ochracea, isolated from dental plaque of 118 healthy adults, were tested for their susceptibility to 48 antimicrobial agents: 8 penicillins, 18 cephems, 2β-lactamase inhibitors, 2 aminoglycosides, 3 tetracyclines, 3 macrolides, 7 pyridone carboxylic acids, imipenem/cilastatin sodium, aztreonam, chloramphenicol, sulfamethoxazole-trimethoprim, and metronidazole.

All strains tested were susceptible to penicillins and cephems except ampicillin, cefotetan, latamoxef, and cefbperazone.

All strains showed more susceptible to aztreonam and new quinolones (norfloxacin, ofloxacin, enoxacin and ciprofloxacin) ;the minimum inhibitory concentration for isolates displayed more susceptible to imipenem/cilastatin sodium.

All strains were slighly susceptible to aminoglycosides, nalidixic acid, piromidic acid, pipemidic acid and sulfamethoxazole-trimethoprim, and some strains were relatively resistant to these antimicrobial agents.

The purpose of this study is to investigate the mechanism in the regeneration of the periodontal tissues after applying external injury to the tooth and gingiva.

The animals used in this experiment were 8 week-old male rats (Wistar-strain), and the periodontal tissues of the maxillary first molar were externally injured with a diamond point. Tooth reduction of the same area was also undertaken exposing the dentin surface, and the healing process was observed under a light and an electron microscope.

Complete epithelialization over the wound surface was observed 3-5 days following the initial wound. Afterwards, the regenerated epithelium differentiated into the sulcular and junctional epithelium. At 10-14 days, formation of junctional epithelium over the dentin surface was observed following epithelial attachment between it and the regenerated epithelium. Later, this junctional epithelium was found to move towards the coronal side, while connective tissue attachment formed over the exposed dentin surface. In this portion, cementum-like substance containing collagen fibers was found.

In conclusion, even after applying external injury which included tooth reduction around the healthy periodontal tissues of rats, they were capable of almost fully regenerating.

Epithelial attachment and connective tissue attachment containing cementum-like substance was thought to have formed on the exposed dentin surface.

Micro-calcific particles (MCPs) in human submandibular glands removed surgically were exmined histologically in a series of 113 cases. MCPs were classified into four types by its locations, i. e., intraluminar, intraepithelial, subepithelial and stromal MCPs. Histochemical findings suggested that main components of MCPs were calcium phosphate and mucopolysaccharide, and that histochemical nature of MCPs were different from that of early stage of sialoliths. The histologically detected frequency of each type of MCPs was as follows; intraluminar MCPs, 26.5%; intraepithelial MCPs, 12.4%; subepithelial MCPs, 17.7%; and stromal MCPs, 22.1%. MCPs had a tendency to be more frequent when parencymal atrophic change was severe in degree. Excepting for stromal MCPs, MCPs were more frequent in the striated duct and substantially less in the interlobular duct. Some cases suggested that intraluminar and subepithelial MCPs originated from intraepithelial MCPs which were formed by conglomeration of fine intracytoplasmic calcific granules. By electron probe x-ray microanalysis, calcium and phosphorus were principally detected in MCPs, and energy intensity of these two elements in MCPs was different from that in early stage of sialoliths. The results of the present examination do not lend support to the possibility that MCPs have direct relation to the development of sialoliths in the human submandibular glands.

The purpose of this study is to investigate the histological and colorimetric factors involved in light transmission of the marginal gingiva. “Light transmission” was regarded as the difference in light reflection between a black and white colored chip placed in the gingival sulcus of 68 healthy marginal gingivae of adult dogs. Histological variables measured under the light microscope included thickness of the marginal gingiva, width of the epithelial layer, width of the keratinized-parakeratinized layer, width of the connective tissue layer, length to the tip of the connective tissue papillae, width of the sulcular epithelium, capillary density, and melanin density. Color variables included gingival lightness, chromaticity, and hue.

Results using stepwise regression analysis showed the most involved factors of light transmission of the marginal gingiva to be melanin density and capillary density. When the samples were divided into those gingivae having melanin pigmentations from those without, the melanin group showed melanin and capillary densities to be most involved, while the non-melanin group showed mainly capillary density. In terms of the effect of color variables, light transmission tended to increase as gingival lightness increased and chromatcity decreased. However, no apparent correlation could be obtained between hue and light transmission.

Two different bone cell populations were isolated from trabecular surface of long bones of 18-day old chick embryos. One population (Pop.1) was supposed to be undifferentiated osteoblast and the other (Pop.2) was supposed to be rich in active osteoblast on the basis of following reasons: (1) Pop.1 had high replicative capacity and ALPase activity. (2) Pop.1 decreased ALPase activity when endogenous prostaglandin synthesis was inhibited by indomethacin and this inhibition was reversed by the addition of prostaglandin E_2. (3) Pop.2 had a higher ALPase activity than the cells isolated from periosteum-free calvaria which are generally thought to be osteoblastic cells, and had enhanced ALPase activity in response to prostaglandin E₂.

ALPase activities in both cell populations were dependent on their cell densities. The optimum ALPase activity was observed when the cell density was 3.0-4.0μg DNA per 2cm² of culture well in both cell populations.

This study concerned the bone mineral content during the healing process of the bone defect in the premolar mandibular region. The materials which were obtained from the excised mandibles were measured respectively with ¹²⁵I-photon absorptiometry in the 1st, 2nd, 3rd, 4th, 8th, 12th, 16th and the 24th week after the operation. The bone mineral content was then compared with the results obtained by photodensitometry, three-dimensional plots of digital displays and histological findings.

The bone mineral content obtained by ¹²⁵I-photon absorptiometry varied within a range of 0.058 to 0.197g/cm² over a period of 24weeks. The bone mineral content decreased during the 1st and 2nd week after surgery, and then increased from the 3rd to 8th week. Though the changes in bone mineral content fluctuated slightly after the 8th week, the highest mineral content was obtained during the 16th week. Bone mineral content decreased by osteoporotic changes during the 24th week after the operation. The changes in values obtained by ¹²⁵I-photon absorptiometry coincided with the histological fndings, threedimensional plots of the digital displays, and values obtained by photodensitometry.

Crude butanol extract of syngenic spontaneous squamous cell carcinoma of WHT/Ht mice demonstrated a lymphocyte blastogenesis in mixed lymphocyte-tumor antigen culture reaction and contained tumor associated antigen. In this paper, characteristics of crude butanol extract of WHT/Ht tumor were studied. Crude butanol extract was partially purified using DEAE-Sephacel column chromatography and four peaks were obtained. These peaks were called, P I~P IV and measured in mixed Iymphocyte-tumor antigen culture reaction. P Ⅲ (0.02M phosphate buffer, pH6.6, 0.5M NaCl eluents) showed a significant reactivity and the content of protein was 10¹μg. This protein was estimated to have a molecular weight of approximately 18K daltons by SDS-polyacrylamide gel electrophoresis.

However P I and P IV had a negative reactivity in mixed lymphocyte-tumor antigen culture reaction. These results suggested that P Ⅲ had an immunogenic, and P I and P Ⅳ had a suppressogenic antigen.

The relationship between permeability and morphology of the endothelial cells on the tumor blood vessels treated with heparin and hydrocortisone in the hamster tongue carcinoma induced by DMBA was discussed. Heparin (30mg/kg) and hydrocortisone (100mg/kg) were administered daily for one week. Tannic acid solution as a tracer was injected into the vascular system via the cardia, and then a fixative solution was perfused. The permeability and structure of endothelial cells in the tumor blood vessels were observed by transmission electron microscopy.

In two groups of golden hamster, physiological saline and heparin were injected. Some of endothelial cells which were irregular in shape had many existing luminal projections. A large amount of tannic acid leaked through those intercellular junctions. These endothelial cells were inactive because there were few organellae; there were also destructive findings in the hydrocortisone-injected group. The cells were spindle in shape with few luminal projections, and substantial amount of tannic acid leaked through the intercellular space.

From the above-mentioned results, it is suggested that tannic acid leaked readily through the intercellular space between the active endothelial cells in the saline and heparin-injected groups, and through the intercellular space between the inactive cells in the hydrocortisone injected group.

Plica-like structure of excretory duct of human sublingual minor salivary gland was reported. The plica-like structure was composed of regular-arranged projections of stratified squamous epithelium with surface parakeratinization. It is thought that the present plica-like structure is a form of malformation of the salivary duct.