[Osaka Daigaku shigaku zasshi] The journal of Osaka University Dental Society最新文献

This study investigated morphological changes of CGRP-containing nerve fibers during wound healing of the rat oral mucosa following resection of the transverse palatine ridge and gingivectomy. The tissue was immunohistochemically examined at 0, 3, 7, 14, 21, 28 and 70 days after surgical injury. The following results were obtained. 1) The Transverse Palatine Ridge. At shorter survival periods (0 and 3 days), CGRP-containing nerve fibers adjacent to the surgical defect degenerated and decreased in number. By 7 days, tissue repair had advanced and the defect had been filled with granulation tissue. Thin nerve fibers were found in and around the granulation tissue, especially nearby newly proliferating blood vessels. At 14 days, extensive regeneration of thin nerve fibers was observed in the repaired tissue. Many of them were found singularly in deeper layers of the repaired tissue, and some in bundles reaching the base of the epithelium. Some of these sprouts appeared to have existed only transiently because their number somewhat reduced by 21 days. The defect was filled with scar tissue at 28 days and mucous structure did not return to normal even at 70 days. Nerve fibers neither regenerated to regain the original density nor formed subepithelial plexuses. 2) The Gingiva. At 0 and 3 days, CGRP-containing nerve fibers near the cut surface of gingiva degenerated and their number decreased. At 7 days, a few thin regenerating fibers were found entering the epithelium on the oral side. Sprouts were also seen around small blood vessels deep in the granulation tissue. By 14 days, the nerve fibers had gradually increased with progress of tissue repair. However, rapid, transient increase in number of fibers, like that observed for the palatine ridge, was not noted. By 21 days, the junctional epithelium had regenerated, and regenerating fibers had redistributed into and beneath the sulcal epithelium. At 28 and 70 days, the repaired marginal gingiva were indistinguishable from normal (and control) marginal gingiva as regards the histology and CGRP-innervation. There were, however, a few exceptions in which junctional epithelium did not fully recover. In these animals, regeneration of CGRP-containing fibers was barely discernible in or around the sulcal epithelium.

Prevalences of malocclusions were investigated in a sample of 3,520 girls recorded between 1984 and 1986 at a private high school. Also, proportions of students who had received and were under treatment were surveyed for 3,501 students in 1989. In addition, ratios of a number of those who were judged to reveal maxillary protrusion with respect to that of the whole sample examined were evaluated as a function of overjet. The results of the surveys are as follows. SURVEY I) A total prevalence of malocclusion was 57.9% in the Grade 7 (G7) and 56.4% in the Grade 10 (G10). Among malocclusions surveyed, maxillary protrusion was found in 8.1% of the G7 and in 7.8% of the G10. Deep overbite was determined in 7.9% of the G7 and in 7.6% of the G10, mandibular protrusion was found in 2.4% of the G7 and in 2.7% of the G10. Edge-to-edge incisor relationships were determined in 6.4% of the G7 and in 7.6% of the G10. Anterior open bite was found in 2.4% of the G7 and in 2.9% of the G10. Crowding was found in 37.3% of the G7 and in 33.9% of the G10. SURVEY II) Prevalence of students who had orthodontic treatment at the time of survey, was 6.4% in the G7, 7.0% in the G8, 6.0% in the G9, 6.0% in the G10, 5.4% in the G11, and 3.6% in the G12. Those who had had orthodontic treatment revealed proportions of 8.1% in the G7, 8.0% in the G8, 7.7% in the G9, 11.3% in the G10, 12.2% in the G11, and 13.7% in the G12 students. SURVEY III) A proportion of 73.5% of those who had overjets more than 6 mm were judged to have maxillary protrusion.

Metabolic and growth inhibiting activities in immunoglobulin (of anti-S. aureus L-form serum and anti-S. aureus coccal form serum) could be absorbed by cell membranes of S. aureus L-form and its coccal form, respectively. These activities could not be absorbed by cell membrane of Micrococcus luteus, Streptococcus pyogenes or Actinomyces viscosus. These findings suggested the existence of species-specific antigens of cell membrane. The membrane antigens of L-form related to the metabolic and growth inhibiting activities were stable to trypsin, heating and periodate, and were not solubilized by trypsin. A large part of the antigen in a typsin-insoluble membrane precipitate of L-form could be extracted by acetone and the subsequent use of chloroform-methanol (2: 1). A fractionation study of chloroform-methanol extract by using silicic acid calum indicated that more than two components were involved in metabolic and growth inhibiting activities.

During the 5-year period from 1984 to 1988, a total of 944 cases had been presented multiple (3 or more) primary malignant tumors in annual of the pathological autopsy cases in Japan. Forty-one cases (4.3%) had lip and oral cancer. Of this group, triple were described 36 cases, quadruple 3 cases and more discrete multiple 2 cases, respectively. It is more frequent in men than in women, the ratio being 12.7:1. The age range is from 34 to 86 years with a mean of 66.9 years. In these cases with oral cancer, the another primary site is almost always found in digestive system (90.2%), e.g. esophagus (36.6%), stomach (34.1%) and colon and rectum (34.1%).

Acrylic denture may be fractured easily because it has a relatively poor resistance to stresses of impact, and the thick acrylic denture base also uncomforted to denture wearers. In this study, for improvement of the mechanical properties, the FRP is applied to the denture base, and try to make a thin denture base. Using the visible light-curing system, the laboratory fabrication time is saved dramatically. To develop the visible light-cured FRP denture base, with various combination of matrix resins and reinforcements, the physical properties of FRP plates were investigated first. From the results of the bending test, hardness test, and manipulation considering, the sateen weave's glasscloth was choose as the reinforcement of the prepreg. The matrix resin of Bis-GMA/UDMA/3G at 48/48/4 wt% was determined. The 3 plies glasscloth included FRP plate is 0.8 mm thickness has the maximum bending strength about 50 kgf/mm2, which is about 5 times larger than that of acrylic resin. Succeeding the study of above, the FRP denture base was fabricated by using the 0.8 mm thickness 3 plies included prepreg. This repreg is manufactured in sheet form beforehand, which is ease to manipulate at laboratory. By using the visible light curing system, it is only taken 10 min. to make a FRP denture base. The following procedures of fabricating a FRP denture is the same as metalplate denture. The visible-light cured FRP denture has some advantages such as accuracy of fit, ease of fabrication and manipulation, and only 0.8 mm thickness but has superior strength.

The purpose of the present study was to explore the effect of local application with Vitamin D metabolite, 1,25 dihydroxycholecalciferol (1,25 (OH)2D3), on experimental tooth movement in rats. 1. According to Waldo's method, a piece of orthodontic elastic band was inserted between the upper first and second molars of Wistar male rats weighing 200 g. The amount of 20 microliters of 1,25 (OH)2D3(10(-12)-10(-7) M) was injected locally in the submucosal palatal area of the root bifurcation of the right first molar. The left side was injected with vehicle. The number of osteoclasts was counted in a 700 x 1050 micron 2 area of the inter-radicular septum. The number of osteoclasts was dose-dependently increased 2-fold at 10(-10) M 1,25 (OH)2D3 compared to that in the vehicle-injected side. The maximal increase of osteoclast number was observed 3 days after local injection of 10(-10) M 1,25 (OH)2D3 on experimental tooth movement. 2. The upper first molar of Wistar male rats was moved in a buccal direction by a helical spring. The amount of 20 microliters of the local administration of 10(-10) M 1,25 (OH)2D3 was repeated every 3 days until sacrifice at day 20. The tooth movement in the 1,25 (OH)2D3-treated rats was accelerated about 2-fold compared to that in the control rats. 3. The effect of bone formation in the rats receiving experimental tooth movement was examined by fluorescent labeling and quantitative histology. Thus, the local application of 10(-10) M 1,25 (OH)2D3 tended to prevent the decrease of the mineral apposition rate of the alveolar bone following orthodontic tooth movement. 4. Serum samples of these 1,25 (OH)2D3-treated rats was obtained from abdominal aorta 3 hours after the final injection. Serious effects were not found in the values for parameters such as calcium, phosphorus and alkaline phosphatase. These findings suggested that the local use of 1,25 (OH)2D3 on experimental tooth movement in the rats caused increase in osteoclasts number and accelerated tooth movement. However, no obvious side effects were noted. 1,25 (OH)2D3 was expected to stimulate mineral apposition rate of alveolar bone on the tension side.

The number of mutans streptococci in saliva and dental plaque has been reported to correlate with the incidence of dental caries. This report describes a simple and rapid diagnostic method for the detection of mutans streptococci in dental plaque using latex agglutination (LA) test. Latex particles (0.876 microns, diameter) were sensitized with partially purified antibodies against whole cells of Streptococcus mutans MT8148 (c), MT703R (e) and OMZ175 (f) and Streptococcus sobrinus B13 (d) and 6715 (g). Whole cells of mutans streptococci or dental plaque was extracted with a mixture of 8M sodium nitrite (5 microliters) and 2M acetic acid (5 microliters) for five minutes and neutralized with 2M sodium hydroxide (10 microliters), and the extract and the sensitized latex suspension (20 microliters) were mixed and the grade of agglutination reaction was read macroscopically after ten minutes standing at room temperature. The LA tests could detect 1.0 10ng of purified serotype antigen and 10(5)-10(6) CFU of live cells of mutans streptococci and specifically distinguish not only the mutans streptococci from the other streptococci but also S. mutans from S. sobrinus. However, cross-reactions were still observed among the serotypes c, e and f of S. mutans or between the serotypes d and g of S. sobrinus. Plaque samples were collected from 168 children (2 to 12 years of age) and the 0.1 mg (wet weight) were applied to the LA tests. At the same time, the total number of mutans streptococci in plaque and the serotypes of each isolate were determined. The results of LA reaction correlated significantly with the number of mutans streptococci in plaque (chi-square analysis; p less than 0.0001). The LA tests discriminated between S. mutans and S. sobrinus in dental plaque. It was found that the latex particles sensitized with anti-serotype c and/or e S. mutans antibodies were most effective in demonstrating mutans streptococci, and they were used in the following studies. The results of LA reaction correlated significantly with both the number of decayed tooth surfaces and the number of decayed and filled tooth surfaces. These results suggest that the LA test in mutans streptococci can be useful for the detection of mutans streptococci in dental plaque and also as a caries-activity test at dental clinics.

The Bite plane therapy has been accepted to be useful for treatment of the patients with the stomatognathic dysfunction. The purpose of this study is to make clear the influences of changing the vertical dimension and occlusal contacts of the bite plane on masticatory muscle activities in order to improve the bite plane therapy. The full arch bite plane with an interincisal distance of 5 mm was fabricated for each one of 30 subjects without stomatognathic dysfunction. The EMG activities were recorded from the anterior part of the temporal muscles, the masseter muscles and the anterior belly of the digastric muscles bilaterally while the subject exerted tapping and maximal voluntary clenching in a postural position. Four kinds of experiments were performed as follows. In Exp. 1, integrated EMG activities of each muscle were compared with and without the bite plane. In Exp. 2, the influences of changing the vertical dimension of the bite plane (2.5 mm, 5 mm and 7.5 mm) were tested in 17 subjects. In Exp. 3, the influences of changing the location of occlusal contacts of the bite plane were studied in 12 subjects. In Exp. 4, the influence of changing the body positions on EMG activities and mandibular positions was compared in 30 subjects between the sitting and supine positions. Furthermore, the influence of the same factor was compared with and without the bite plane which was adjusted in each position. The results were summarized as follows: 1. Wearing the bite plane mainly reduced activities of the temporal muscles. 2. The bite plane with an interincisal distance of 5 mm was most effective in reducing activities of the temporal muscles. 3. Wearing the bite plane with anterior occlusal contacts reduced activities of the elevator muscles significantly. 4. Significant differences in activities of the temporal and digastric muscles were recognized between the two body positions when the bite plane was not applied. However, no significant difference was recognized when the bite plane was inserted. Furthermore, those differences were correlated with the difference in the antero-posterior mandibular displacement between the two body positions while the subject tapped the teeth. These results suggest the possibility to control masticatory muscle activities by applying the bite plane with the proper vertical dimension and occlusal contacts. In addition, it is necessary to take a suitable body position for the patient who has a difference in the mandibular displacement between the sitting and supine positions when applying the bite plane.

The coccal form as well as the L form of Staphylococcus aureus could produce the metabolic and growth inhibiting antibodies of the L form in the rabbit sera.

It has been reported that prostaglandin E2 (PGE2) had anti-inflammatory and analgesic effects, although it was well known that PGE2 combined with bradykinin (BK) showed proinflammatory and algesic effects. On the other hand, it has recently been known that BK showed an indirect activating effect on cathepsin B, a lysosomal enzyme, which may be mediated through calcium ion-dependent steps, followed by production of enkephalins (EK), endogenous anti-inflammatory and analgesic peptides, in the rat incisor pulp. The purpose of the present study is to examine whether PGE2 could have an effect on activation or release of cathepsin B in the pulp tissue, or not. Intact whole pulps of the rat incisors were incubated with N alpha-benzoyl-arginine-beta-naphthylamide (BANA), a substrate for cathepsin B, in the presence or absence of BK and PGE2 in Hanks solution (pH 7.4), in order to determine the BANA-degrading activity and EK producing activity. Both hydrocortisone and lidocaine which were stabilizers for lysosomal membrane markedly inhibited the BANA-degrading activities in the presence of BK, and in contrast, retinol, a labilizer for lysosomal membrane, significantly enhanced the BK-induced BANA-degrading activity. PGE2, like hydrocortisone and lidocaine, inhibited the BANA-degrading activity, in a dose-dependent manner, regardless of the presence or absence of BK, as well as resulted in a decrease of EK production in the pulp. Furthermore, both arginine, a cleavage product of BK by carboxypeptidase B, and arachidonic acid, which were endogenous activators for soluble guanylate cyclase, enhanced the BANA-degrading activity in the pulp homogenate.(ABSTRACT TRUNCATED AT 250 WORDS)