It has been reported that color selection by visual matching tended to lead to various problems, including mismatch of color. In none of the earlier studies, accuracy of visual color matching and other underlying problems had been examined in detaiL To formulate guidelines for color selection, colorimetric analysis was undertaken with the help of dentists who were requested to select color tones according to usual their clinical procedures.

The results showed that the accuracy of color matching was considerably influenced by distribution of color in adjacent teeth as a whole, and that the accuracy was dramatically diminished, as distribution of color in adjacent teeth became more complex. Difficulty in color selection was increased with a decrease in the lightness of tone. In such a case,dentists tended to select color tones from bluish to greenish shade. Although the accuracy of color matching did not depend on the term of clinical practice, experienced dentists tended to avoid selection of obviously different colors.

Aporcelain-fused-to-metal restoration is frequently used because of good esthetics and a wide range of applicability. However, there are still many problems in relation to color selection by visual matching and structure in general. For the purpose of determining objective guidelines for color evaluation, coloristic analysis was ulldertaken on patients’and dentists’attention to the color distribution of porcelain.fused-to-metal restoration. Color differences between the porcelain-fused-to-metal restoration and adjacent natural teeth were also studied. It was found that the patients’evaluation wa8 diverse, and only a few were very sensitive to the slightest color difference, indicating their high standard of color recognition. The color difference between the natural teeth and porcelain-fused-to-metal restoration, which satisfied the patients and doctors, was about 5, while in the coloration of marginal gingiva it was under 3.

The effect of slime protease obtained from Staphylococcus epidermidis on the cellular immunity was examined using lymphocytes from human peripheral blood and mouse spleen. Lymphocyte transformation of human peripheral blood was promoted by phytohemagglutinin(PHA)and concanavalin A(Con A)and blast transformation was suppressed dose-dependently by addition of S. epidermidis slime protease (25,50,100μg/ml)to the culture medium. Lymphocyte transformation of mouse spleen was promoted by PHA and Con A. Blast transformation was however suppressed dose-dependently by addition of S qpε(1εrmidis slime protease(25,50,100μ9/ml)to the culture medium. On the other hand, blast transformation of mouse spleen by lipopolysaccharide was suppressed dose-dependently by&eρidermid‘8 slime protease, but the suppression

was weaker than that of blast transformation in the presence of PHA and Con A.

In SDS-polyacrylamide gel electrophoresis and autoradiography, about 70,000dalton of surface membrane protein of lymphocyte disappeared after the treatment with S.epidermidis slime protease.

These results indicate that S. epidermidis slime protease may cause immunodeficiency and may thus result in secondary infection by S. epidermidis or other microorganisms.

Abstract:Beta-hemolytic streptococci were isolated by throat-swab once a month from　January,1984 through December,1988. The subjects were school aged children　accommodated in an institution because of weak physical condition or chronic diseases、Serum immunoglobulin M(lgM)and immunoglobulin G(lgG)antibodies were measured　by an enzyme-linked immunosorbent assay(ELISA), using group A streptococci(type T-4,T-6 and T-12), group B streptococci (type Ia, Ib, Ic, Ⅱ and Ⅲ), group C strept-ococci and group G streptococcal antigens. The results are ummarized as follows:

Group G streptococci were isolated more frequently than the other groups of beta-hemolytic streptococci in 1987 and 1988.Changes in the groups and types of beta-hemolytic streptococci, during this period, were found in 1530f 293 cases. Group and type-specific

IgM and IgG antibodies were confirmed in the sera from beta-hemolytic streptococci isolated children by ELISA. The children who had beta-hemolytic streptococci, of the same group or type, showed high levels of IgM and IgG antibodies, and those who had different groups and types also showed high levels immediately after isolation. These findings demonstrate the usefulness of ELISA as a serologic diagnosis of beta-hemolytic streptococcal infection.

For the purpose of analyzing the trends of group B streptococci(GBS), we investigated　the rates of isolation based on clinical specimens, sex and age, using 442 strams of GBS isolated from various clinical specimens at Kuji Prefectural Hospital in northern Japan from 1982 through 1989. All strains were serologically typed and their susceptibilities to penicillin(PCG), ampicillin(ABPC), cephaloridine(CER), cephalexin (CEX), tetracycline(TC), chloramphenicol(CP), erythromycin(EM),01eandomycin (OL)and lincomycin (LCM)were determined in terms of the minimum inhibitory concentrations of these antimicrobial agents. The results are as follows:

0f the 442 strains from clinical specimens,141 were isolated from urine(31.9%),119 by throat-swab(27.0%),66 from sputum(14.9%), and the remainning 116 from feces,otorrhea, pus and vaginal discharge. Serotype of GBS:Type W was dominant, followed by type I a and typeⅢ, type I c was isolated at a}lig}1 rate in 1986 but I b was isolated highly in 1989. Serotype of GBS by age:Type IV and I a were isolated frequently from the aged population;Type H and V were isolated from infants and schooLaged-children.Relationship between specimens and age:GBS were isolated frequently from school- aged.children by throat-swab;from the aged population, GBS was isolated from sputum and urine. The isolation rate of GBS, by age and sex:GBS isolated frequently from aged population, showed that the isolation rate of female was higher than that of male with the ratio of 6:4 . Of the 442 strains,106 (24.0%)were resistant to TC, but no correlation between resistance and serotype was observed. Resistant strains to EM, OL and LCM were predominate in typesⅢ, IV and V.Most of them were isolated from feces.

Immediate reconstruction of an edentulous mandible following excision of a mandibular cyst and odontoma was undertaken by combination of a reconstruction plate and a fresh autogenous iliac particulate cavernous bone. Nine months after the operation, an intra-oral prothesis was prepared in order to improve the masticatory function. Prosthetic management was aimed at by obtaining the maximum support and stability of the denture base and reducing the occulusal force. After wearing the prosthetic appliance, the masticatory function was evaluated by analyzing the mandibular movement,. masticatory electromyogram and masticatory efficiency. The results are summarized as follows:

No mandibular dislocation was found and a smooth mandibular movement was restored.In masticatory electromyographical analysis of the chewing cycie, high averages were obtained for the correlation coefficients of duration and duration per cycle on the recon-structed side.

The masticatory ability was evaluated by an experimental test food list for complete denture wearers and found to be as good as that for complete denture wearers.

A16-year-old girl with bilateral cleft lip and palate received preoperative orthodontic treatment, using an expansion plate and multi.bracket appUance, due to severe crowding and mandibular prognathism. Although the maxillary dental arch was remarkably narrow, the arch width was expanded by a slow expansion method during the preoperative orthodontic treatment. Thereafter, Inandibular prognathism was corrected by sagittal splitting osteotomy of the mandibular ramus and genioplasty. A removable temporary prosthodontic appliance was placed during postoperative orthod㎝tic treatment to obtain an esthetic and functional effect. The skeletal relapse was kept at a minimum during the postoperative orthodontic treatment. The stability of occlusion was obtained after the placement of a metal retainer.

As a result, improvement of occlusion, masticatory function and the facial contour was achieved, The patient has remained in good condition for 2 years and 9 months since operation.