Mouth breathing involves the intake of air via the oral cavity rather than the nasal cavity even though it is considered to be a physiological phenomenon that resting breathing usually occurs via the nasal cavity, thus maintaining humid conditions within the oral cavity. On the other hand, customary mouth breathing has often been considered to be apt to cause not only multiple incisor caries or severe gingivitis but also dysgenetic jaw and face during the growth period. However, none of these considerations has been though of a anything more than theoretical, and very few demonstrative studies have been made of the relationship of mouth breathing to both qualitative and quantitative plaque formation. The main purpose of the present study was to clarify the variation in plaque formation in the case of sustained mouth breathing compared with nasal breathing. Various clinical examinations were, therefore, made using two adult Macaca irus monkeys, particularly with regard to plaque formation in the same oral cavity during respective periods of repeated nasal and mouth breathing. Also, special efforts were made to evaluate temporal and quantitative plaque formation, using standardized photography of seven intraoral sites, together with planimetry for quantification of any plaque formed. In this experiment, five of the seven sites chosen showed significant increases in plaque formation due to mouth breathing, i. e. on the labial and palatal surfaces of the upper central incisors, the palatal surface of the upper central incisors, the palatal surface of the upper molars, the labial surface of the lower central incisors, and the buccal surface of the lower molars. A characteristic tendency toward plaque formation was observed on the labial surface of the upper central incisors: plaque formation began to occur from the proximal surface and cervical area during nasal breathing, while during mouth breathing plaque formation began to occur near the incisal edge and then extended to the proximal surface and cervical area. The acceleration of plaque formation by mouth breathing compared with nasal breathing can be ascribed to (1) decrease in lingual, buccal and labial self-cleaning action of tooth surfaces, and (2) dryness of tooth surfaces due to mouth breathing.

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Suppuration out of periodontal pockets is considered to be a clinical sign of periodontal disease activity. On the other hand, the increasing realization of bacterial specificity in periodontal disease has focused upon the use of bacterial parameters to determine the disease activity. The purpose of this study was to examine the relative proportions of subgingival microflora between suppurative and non-suppurative periodontal pockets.
Seven subjects with adult periodontitis were selected for this study. They underwent clinical examination, provided that other parameters except suppuration were excluded. The materials were obtained from average 4 suppurative and non-suppurative pockets of each subject for bacterial examination. Bacterial samples from 12 suppurative and 15 non-suppurative pockets were subjcted to dark field microscopy and anaerobic incubation. These bacteria were identified by motility and morphology, Gram stain, biochemical and gas chromatographic analyses.
The results were as follows:
1. Total culturable numbers of facultative microbes between suppurative and non-suppurative pockets were 10⁷ and 10⁸, respectively (p>0.05).
2. The proportion of Spirochetes to the numbers of total anaerobes in suppurative and non-suppurative pockets was 13.1% and 6.0%, respectively (p<0.005). Black-pigmented Bacteroides was 23.9% and 6.0% (p<0.001) and Fusobacterium nucleatum was 18.3% and 9.3%, respectively (p>0.05).
From these results, it was suggested that suppurative pockets were more active lesions than non-suppurative pockets. To clarify this point, longitudinal study is further required.

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The purpose of the present study was to evaluate the blastogenic responses of gingival lymphocytes stimulated by phytohemagglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM) in human periodontal disease. And then, the differences between the gingival lymphocyte and peripheral blood lymphocyte (PBL) response were examined.
Gingival tissues were obtained during periodontal surgery or extraction from seven patients, who included four patients with adult periodontitis (AP), and three with rapidly progressive periodontitis (RPP). Gingival lymphocytes and PBLs were isolated by collagenase treatment and Ficoll-gradient procedure. Viable cells (2×10⁵) from gingival lymphocytes and PBLs were suspended in each well of microcultureplate and maintained in RPMI 1640 containing 10% fetal calf serum. The microcultures were stimulated by optimal dose of PHA (10μg/ml), Con A (5μg/ml) and PWM (10μg/ml) and incubated for 96h at 37°C in a humid 95% air and 5% CO₂ environment. Tritiated thymidine (0.5μCi) was added to each well 24h before harvesting for measurement of DNA synthesis.
The response of stimulated and unstimulated gingival lymphocytes was low as compared with PBLs. The activity of PBL unstimulated culture in RPP was lower than that of AP. But the CPM of PHA stimulated PBLs in RPP was similar to that of AP. The response of gingival lymphocytes in unstimulated cultures was the same level between AP and RPP, while the activity of PHA stimulated gingival lymphocytes in RPP was higher than that of AP.

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This study was performed to develop a intraoral telemetry system of measuring toothbrushing pressure applied to tooth surface and to investigate relationship between toothbrushing pressure and plaque removal. Two sequential experiments were carried out in this study as follows.
In the first experiment, a microtransducer constructed in a pontic of temporary resin bridge was used to determine the brushing pressure exerted on the buccal surface of the upper pontic of first molar.
Five different kinds of toothbrushing method (Scrubbing, Rolling, Fones, Horizontal and Vertical) were carried out using soft, medium and hard toothbrushes. The buccal surface of pontic of maxillary first molar of the plastic jow model was brushed by ten subjects, and then the toothbrushing pressures were measured. Next, the toothbrushing pressures applied to the buccal surface of pontic of maxillary first molar were determined for three subjects. Significantly greater mean brushing pressures were obtained during every brushing procedure as increasing a diameter of toothburush bristle for Scrubbing (mean 1243g/cm²) and Fones (846g/cm²).
In the second experiment the relationship between toothbrushing pressure and plaque removal was investigated on Scrubbing and Rolling. A micro transducer was constructed within an acrylic stent suitable for placement between the subjects teeth, maxillary right second premolar and first molar. Three kinds of toothbrushes which differ in diameter were used twelve subjects participated in this experiment. It was revealed that hard brush was more effective for plaque removal and that brushing pressure had a tendency to show higher value for Scrubbing (74%) and Rolling (70%).

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Based on the speculation that immune responses in gingiva were different among periodontitis patients in their generations, this immunohistological study on movement of immunoglobulin-bearing cell populations was carried out with peroxidase anti-peroxidase staining. Patients were devided into three groups by their age; younger generation (under 35 years old), middle generation (36-50 years old) and older generation (above 51 years old). The clinically normal gingiva and gingivitis were used as control. The results obtained were as follows.
IgG-bearing cells were predominant in inflammatory cells. IgA- and IgM-bearing cells were fewer than IgG-bearing cells, but existed in all cases. IgE-bearing cells were always noted in all cases of younger generation, but observed in half of middle and older generations. The ratios of 4 classes of immunoglobulin-bearing cells to the infiltrating cells in middle and older generations were compared with those in control. Then the ratios of IgG- and IgE-bearing cells were significantly higher in middle and older generations. Conversely the ratio of IgM-bearing cells was higher in control. The ratios of IgG-, IgA- and IgE-bearing cells in younger generation increased more significantly than in control. The ratio of IgE-bearing cells was significantly higher in younger generation as compared with that in middle and older generations. These findings suggested that production of IgE was accelerated in gingiva of periodontitis, especially in younger generation, and that the further aproach to clarify the specificity of IgE was necessary.

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An exohemagglutinin (exoHA) was found in culture medium of Bacteroides gingivalis 381. The exoHA was purified about 3000-fold from culture fluid by ultracentrifugation followed by gel filtration on Sepharose CL-4B and by an affinity chromatography on arginine-agarose. Hemagglutination-inhibition experiments revealed that the activity of exoHA was inhibited by L-arginine and its derivatives although the activity was unaffected by sugars tested. The proteins and glycoproteins examined also exhibited inhibitory activity. When the bovine submaxillary mucin was chemically modified by β-elimination and bovine serum albumin was also modified by guanidination, the inhibitory activity on hemagglutination was significantly enhanced.
These results suggest that the hemagglutination of the isolated exoHA may be specifically inhibited by either L-arginine, its derivatives or proteins containing arginine residue.

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The purpose of this study is to detect superoxide dismutase (SOD) in periodontopathic Bacteroides gingivalis. Superoxide anion (O₂^-) produced by NADP H-oxidase of white blood cell membrane, oxygendependent bactericidal reagent, is specifically antagonized by SOD.
Escherichia coli, facultative anaerobic bacterium, has two kinds of SOD (one contains manganase and another contains iron at their active site). Until recently, it was considered that strict anaerobic bacteria do not have SOD, but it is reported that strict anaerobic bacteria, for example Clostridium and Bacteroides possess SOD activity.
Bacteroides gingivalis was cultured in anaerobic condition, sonicated for 30min, and the portion of SOD activity was obtained by adding ammonium sulfate. The SOD activity was measured by cytochrome C method and by nitroblue tetrazolium (NBT) reducing activity in polyacrylamide gel electrophoresis (PAGE).
The results obtained were as follows;
1. Bacteroides gingivalis had significant SOD activity, and its enzymatic activity determined by cytochrome C method was 27units/mg protein.
2. The NBT reducing activity of Bacteroides gingivalis, located in polyacrylamide gel electrophoresis between the portion of supper-zinc SOD and the portion of SOD activity of Escherichia coli.

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The present study was undertaken to determine whether the suspected periodontopathogenic Bacteroides, Fusobacterium and Actinomyces including the cariogenic St. mutans are inhibited by clinically used NaF and chlorhexidine. In addition, the effect of NaF and chlorhexidine combination was tested.
The minimum inhibitory concentration (MIC) was determined with a ager dilution technique according to Japanese Society for Chemotherapy. The effect of NaF and chlorhexidine combinations was examined using a checker board method.
The MIC of NaF on GAM medium was shown in this study, analysis of which indicated that Actinomyces was relatively more resistant to growth inhibition by NaF than were the other tested strains, St. mutans, Bacteroides and Fusobacterium. On the other hand, the susceptibility of all tested strains to chlorhexidine was sensitive. Bacterial growth was inhibited by the NaF and chlorhexidine combibination. The grater inhibition by their combination suggests an additive effect.
Data obtained in the present study with anaeroic gram-negative organisms support and extend previous information regarding the antibacterial effect of NaF, chlorhexidine and their combination against gram-positive organisms.

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It has been reported that human peripheral blood monocytes in vitro release calcium from fetal rat calvaria and from synthetic hydroxyapatite (HA) (SATO et al., 1984).
In this paper, we examined the effects of lymphokine on the release of calcium from HA by human monocytes.
Peripheral blood was collected from patients with periodontal disease (PPD) and from clinically healthy individuals, and peripheral blood leukocytes (PBL) were isolated by differential centrifugation using Sodium metrizoate-Ficoll. Then the monocytes were separated by the method based on adherence to plastic. PBL were cultured with phytohemagglutinin or dental plaque and afterwards culture supernatants (PBL-sup) were separated and used as a source of lymphokines (Osteoclast-activating factor: OAF and others).
Assay of calcium from HA was done as follows: PBL supernatants were to a mixed suspension of monocytes and HA mixed cultured in 5% CO² at 37°C for 24 to 72 hours. The quantity of released calcium from HA was measured by atomic absorption analysis.
Human monocytes induced the release of calcium from HA, and its level was increased more significantly by addition of PBL supernatants from PPD than from healthy subjects. And Nitro Blue Tetrazorium reduction activity and [³H] Thymidine incorporation activity of monocytes were increased too by addition of PBL-sup.
These results suggest that bone resorption activity of human monocytes is activated by lymphokines, perhaps by what is called “OAF”.

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The scanning conditions of the microdensitometer as well as the geometrical conditions at a time of the x-ray photographing have influenced upon the bone trabecular pattern analysis using the wiener spectrum methods. The present study was performed to investigate the influence of the scanning aperture size and the x-ray projection angles to the bone trabecular analysis using the wiener spectrum. In this study, for the scanning aperture size, a test chart with spatial frequency elements (3.86, 4.63, 5.55l/mm) and a decalcified edentulous mandibular bone were radiographed using a standardized geometry. This obtained radiographs were scanned using 100μ to 1000μ in height and 25μ to 125μ in width aperture size. For the x-ray projection angle, a experimental model of the mandibular bone and a dried mandibular bone were radiographed using the x-ray projection angle 0°to 10°. Then the scanning performed using the 1000μ×75μ aperture size.
The result showed that the correlation between spatial frequency and the wiener spectrum became closer as the width and height of the scanning aperture size were increased. The fluctuations in the R.M.S. values of the mandibular bone model has become significant at a x-ray projection angle of 3°or over.
The findings suggested the following:
1. As the size of the scanning aperture height decreased, so the reproducibility in the scanning region got low.
2. The recognition of the trabecular pattern became weak as the size of the scanning aperture width became smaller.
3. For the bone trabecular pattern analysis, the variation of the x-ray projection angle should be held within the range of 3°.

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Root planing followed by demineralization of root surfaces has been reported to aquire a new fibrous attachment more coronally. In addition, the management of diseased cementum has recently been cotrovertible, since endotoxins may penetrate into cementum, but may be absorbed only to cementum surfaces. The purpose of this study is to reexamine the cementum of extracted human teeth with advanced periodontal disease.
Extracted teeth including the gingiva and bone were divided longitudinally and their fractured cementum surfaces were observed from coronal exposed cementum to apical cementum corresponding to junctional epithelium by scanning electron microscope. Subsequently, SEM specimens were prepared for transmission electron microscope and examined.
The results with SEM and TEM showed that there occurred a great damage in the whole of the exposed cementum. However, the change hardly occurred in the cementum corresponding to periodontal pocket except at only superficial layer. These observations indicated that the sacrifice of excessive amounts of cementum corresponding to pocket could be unwarranted.

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Many studies have shown that removal of supra-gingival plaque by toothbrushing prevents periodontal disease. However few observations have been reported about the effect of toothbrushing on more harmful subgingival plaque.
The purpose of the present study was to evaluate;
1. the extent of subgingival plaque removal by toothbrushing
2. the effect of toothbrushing (Bass method) on the composition of subgingival microbial flora using darkfield microscope and scanning electron microscope (SEM).
[Materials & Methods]
Exp. 1; Thirty-two teeth with periodontal disease were extracted, after careful toothbrushing by the operator. They were stained and the distance of the non staining area from the gingival margin to the coronal border at subgingival zone was estimated.
Exp. 2; Fourteen proximal surfaces of seven anterior teeth with periodontal disease were selected. The teeth were covered with metal inlays, one side of the inlay was made as “overhanging” to keep that side off from toothbrushing, which was termed as “non-brushing site”. The other side of the inlay was made flatter to facilitate toothbrushing and was termed as “brushing site”.
Darkfield microscope and scanning electron microscope were used to compare the subgingival microbial flora at “brushing site” and “non-brushing site”.
[Results]
Exp. 1; Subgingival plaque was removed as far as 2.22mm below the gingival margin on the average by toothbrushing, irrespective of the degree of GI and probing depth.
Exp. 2;
Darkfield assessment; On “brushing site” the percentage of spirochetes decreased significantly from 42.3% to 25.1%, while coccoid cells increased significantly from 24.7% to 48.0% after brushing.
Observation by SEM; On “non-brushing site”, mature subgingival plaque was observed, which was in accordance with previous studies. On the other hand, on “brushing site”, two types of plaque adhesion were observed. One type of plaque adhesion was similar to that on “non-brushing site”. In the other, little plaque was observed on the root surface from gingival margin about 2mm below, and in the deeper area plaque was spread on the surface.
The experiment indicated that toothbrushing removes a part of subgingival plaque and the composition of subgingival microbial flora is affected by toothbrushing.

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Oral condition of whole inhabitants in Hirashima Island (Hirashima I.) was investigated by an oral examination and a written inquiry. 299 inhabitants (55.0% of the whole) underwent our examination. One and two years before this investigation, we had made examinations of oral state in Enoshima Island (Enoshima I.), the same small island in Nagasaki Prefecture as Hirashima I.
The purpose of this study is to obtain the basic data of oral state in Hirashima I. and to compare them with the results in Enoshima I.
The results of the examination in Hirashima I. were as follows:
1. Mean number of missing teeth of men after 40 years old and of women after 20 years old increased rapidly with age. The mean value of missing teeth of women between the age of 30 and 59 was significantly higher than the men of the same age bracket.
2. Mean PI of both men and women showed the values between 1 and 2 in all age brackets.
3. Mean GI of both men and women increased with age.
4. Mean values of probing depth in middle and upper age bracket of both men and women was higher than in younger age bracket. Mean values of probing depth in menial interproximal site were significantly higher than those in the center of buccal site.
5. Mean SBI of both men and women as well as mean values of probing depth was significantly higher in mesial interproximal site than in the center of buccal site.
6. From the results of a written inquiry, Hirashima I. was in (slight) lower state of the consciousness of oral hygiene than Enoshima I.

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Using CPITN (Community Periodontal Index of Treatment Needs) of WHO, periodontal status of 1195 female students aged between 12 and 17 was investigated. Index teeth in each sextant were scored by Code 0-4 (0: no signs of disease, 1: gingival bleeding after gentle probing, 2: supra- or subgingival calculus, 3: existence of pathologic pockets of 4 or 5mm deep, 4: existence of pathologic pockets of 6mm or more). Evaluation of each sextant was made by the worst finding in each area and the probing force adopted was adjusted between 20 and 25g by preliminary training of examiners. Average time requiredto measure one subject was within one half min.
Significant difference in the rate of persons affected existed between 12/14y group and 15/17y group. Eighty five percent of the subjects had some kinds of periodontal diseases and were required to accept periodontal treatments (TN I-III). There was a tendency that lower teeth were more susceptible to periodontal diseases than upper teeth. Difference between left and right was not detected. Depth of the periodontal pocket in upper posterior teeth was the largest among sextants. Accumulation of supraor subgingival calculus was the largest in lower incisor. Subjects with high caries scores tended to have high CPITN value.
The CPITN is simple and valuable method to survey periodontal status of large groups and at the same time to indicate the treatment need of each person. The index is especially useful for the primary screening of periodontal diseases and for international comparison of periodontal conditions in large groups.

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In order to know the condition of oral hygiene of periodontal patients at the initial visit in our clinic, we made an investigation on 200 patients (100male, 100 female) concerning the condition of the accumulation of plaque and its relationship to the stage of the periodontal disease and also to the results gained from the questionnaires for periodontal patients. From the investigation the following results were gained:
1. The average percentage of plaque control record (P. C. R.) at the initial visit was 62.9% and almost all patients had P. C. R. of over 50%.
2. Statistical difference between male and female was not significant.
3. There was a tendency that the increse of P. C. R. was accompanied by the increse of age.
4. Relationship between P. C. R. and the stage of the periodontal disease was not significant.
5. Patients who have the symptoms of masticating trouble and food impaction showed higher percentage of P. C. R. than others.
6. No relationship was found between P. C. R. and periodontal treatments which was experienced in the past. Rather higher average of P. C. R. was recognized.
7. As the brushing times per day increased, the lower the P. C. R. became.
8. There was a tendency that the higher the level of oral hygiene concept of patient swas, the lower their P. C. R. became.

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An initial periodontal therapy is known to improve the local environment associated with periodontal inflammation. The purpose of this study was to evaluate the minute changes of alveolar bone after the initial preparation using photographic subtraction radiography. Five patients with the severe gingival inflammation and the moderate alveolar bone resorption were examined. The mesial and distal alveolar bone of lower incisor, cuspid, premolar and/or first molar were objected to the standardized intraoral radiography. The severity of inflammation was measured by the amount of gingival crevicular fluid (GCF) using “Periotron®”. These examinations were performed were at initial visit, after tooth brushing instruction, and 1-, 3-, and 6-mouth after scaling and root planing. The subtraction images of each stage were produced by the initial radiographs as reference. Results were as follows:
1. After the establishment of complete plaque control, scaling and root planing, the significant decrease in GCF was observed.
2. In all areas with severe inflammed gingivae (GCF≥51) at the initial visit, improvements of alveolar bone were observed after scaling and root planing. On the other hand, in the areas with mildly and moderately inflammed gingivae (GCF<50), improvements of gingival inflammation were not always accompanied by the changes of alveolar bone.
The results indicated that the improvement of alveolar bone was accelerated by the rapid resolution of severe inflammation of gingiva.

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Relationship between the change of clinical symptoms and the value of salivary occult blood test paper on periodontalily involved patients (20 patients with gingivitis and 37 patients with periodontitis) was examined by means of Salivaster Bld (salivary occult blood test paper) which is said to have easinss and high confidence as salivary examination technique.
The results obtained were as follows.
The value of Salivaster Bld have a tendency of decrease as improving of clinical symptoms. After plaque control, scaling and root planing, a correlation was estimated between the value of Salivaster Bld and PCR value, PD value and the amount of GCF on patients with gingivitis; between the value of Salivaster Bld and PD value and GBI value on patients with periodontitis.
Whereas during periodontal therapy, a correlation was estimated between the value of Salivaster Bld and the amount of GCF on patients with gingivitis; between the value of Salivaster Bld and GI value, GBI value and the amount of GCF on patients with periodotitis.

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The present investigation was conducted to assess the effect of tetracycline, locally administered using root canal syringe, on subgingival microfiora. Eight adult volunteers with clinical diagnosis of periodontitis were used in the study. Each volunteer had at least a pair of teeth with periodontal pockets of 4mm or more. Tetracycline was formulated in hydrophilic paste at a concentration of 3 percent. The tetracycline paste or placebo was delivered into periodontal pockets using a root canal syringe every 2 days for 2 weeks on double blind basis. Subgingival bacterial samples were obtained with paperpoints from each sites and the bacterial examination consisted of phase-contrast microscopic counting.
During the 14-day application of tetracycline, periodontal pockets of test sites showed a significant reduction in total cell counts. The concomitant reduction of spirochetes and an increase in coccoid cells were also statistically significant. Pocket depth, gingival index and sulcular bleeding index in experimental sites were improved significantly during the trial. These data suggest that the syringe delivery system of tetracycline is effective in controling subgingival plaque and in reducing periodontal inflammation.

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Periodontal disease are characterized by various alterations of supporting structures. Therefore, the systematic collecting and recording data from the patients are important steps of the serial periodontal treatment for diagnosing and treatment planning. Many methods for periodontal examination, such as evaluations of gingival inflammation, gingival exudate, X-ray image and oral photography, have been considered and utilized. Sevral standardizing ways for taking oral photographs were tried to utilize since before, but there were still difficulty to handle them in practice due to the complexity of operation and uncertainty of their fixation. Thus, a standardized apparatus of oral photography has been developed in our department to utilize for practice.
The purpose of this study was to evaluate the precision and the applicability of our apparatus in practice. Five dental students were picked out for the evaluation of precision. Standardized photographs were taken at the median interdental papilla of lower jaw four times on different days, one examiner measured the area that was established on the magnified print (×7). The average coefficient of variation of each material was calcularted. With the same method as the precision evaluation, morphologic alteration of interdental papilla which was occurred gingivitis experimentally was studied for the evaluation of applicability. Five dental students were examined for three weeks. The photographs were taken on Day 0, Day 7, Day 14, Day 21. Control data were acquired from the same students for another three weeks when they were controled on plaque free by professional tooth cleaning.
The results of the precision test, the average coefficients of variations were 1.52%. The alterations of the established area in controled phase were -1.50% (Day 7), -0.94% (Day 14) and -1.13% (Day 21). In experimental phase, those were -0.78%, -1.09%, and 0.37% on respective dates.
Those were no statistical differences between control and experimental phase. The results domonstrated that our standardizing method has good precision and applicability for one of the periodontal recordings.

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This investigation was performed to study the effect of a nonsurgical treatment on Generalized Juvenile Periodontitis. The patient was a healthy 18 year old female. In Japan, the case who involved severe periodontal destruction was very rare. Both her sister (20 years old) and her brother (13 years old) were affected by Localized Juvenile Periodontitis.
The patient was instructed to rinse her mouth with 0.2% chlorhexidine for 2min. twice a day and was instructed mechanical plaque control. Furthermore the plaque control program involved administration of 200mg of minomycin 2 times per day during the first 4 weeks of the treatment. Four weeks later, antibiotics administration was stopped, and only mechanical plaque control was continued, and mechanical debridement started.
The patient was reexamined at one month after the plaque control phase with antibiotics administration and at 3 months after mechanical debridement. The clinical parameter involved oral hygiene index, bleeding index, probing pocket depths, probing attachment level and standerized radiography. The first month following the plaque control phase with administration of minomycin, probing attachment level showed greater improvement than had been thought. The instrumentation after this plaque control program, moreover resulted in resolution of these clinical periodontal conditions. It suggests that nonsurgical therapy in Generalized Juvenile Periodontitis may bring great improvement.

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