The purpose of this study is to clarify the adaptation mechanism of the muscle function when the bite raised 5 and 10mm.

Changes in the muscle function of the masseter, temporal and digastric muscle of an adult dog was examined by electromyogram (EMG). EMG was recorded using simultaneous surface electrodes, at intervals of 1, 2, 3, 4, 7, 14 and 28 days. Analysis of an EMG was used to determine the duration and frequency of bursts, power spectrum and integrated EMG.

Muscle spasms occurring due to raising the bite were observed when the mandibular was in a resting position. However, when the bite was raised 5mm, the spasms decresed whthin 3days. A similar phenomena was observed within 4 days when the bite was raised 10mm.

These EMGs showed an increased frequency and a shortened duration of the spasms.The peak value of the power spectrum shifted to the low band, and muscle excitation incresed at the isometric contraction when the mandibular was pulled down against the biting force.

From the view point of these findings, it is suggested that the adaptation of both the mandibular reflex and the myoneural system takes place in a comparatively short time.

The effect of 24-h fasting on spontaneous motor activities, vertical (VMA), horizontal (HMA), and wheel running motor activity (WRA), induced by the administration of methamphetamine and apomorphine to male ddy mice, weighing 18-22g, was examined. Also the effect of 24-h fasting on the cage-climbing activity and the levels of brain monoamine-related substances was examined.

The results obtained are summarized as follows.

1)With fasting the VMA showed a marked increase but the HMA showed only a slight increase. No increase in the WRA was noted.

2)When methamphetamine (2mg/kg, s. c.) was administered to fasting mice, the VMA increased significantly more than that of mice which were fed, regardless of pretreatment with or without haloperidol (0.025mg/kg, s. c.). When fasting mice were pretreated with haloperidol, the HMA decreased slightly and the WRA increased slightly although the HMA and WRA in fasting mice showed the same patterns as those of mice which were fed and pretreated without haloperidol.

3)When apomorphine (0.1 and 0.5mg/kg, s. c.) was administered to fasting mice, all the VMA, HMA and WRA decreased at an early stage during the experiment regardless of pretreatment with or without haloperidol. The same results were noted in mice which were fed.

4)The cage climbing activity in fasting mice receiving apomorphine at 1mg/kg, s. c. showed the some pattern as that of mice which were fed.

5)When measuring brain monoamine-related substances in fasting mice, using the HPLC-ECD method, the concentrations of DA, NE, 5-HT and 5-HIAA in the corpus striatum increased and 3-MT decreased. The concentration of MHPG in the hypothalamus increased, and the concentration of 3-MT in the nucleus accumbens decreased.

These results suggest that fasting may modify the activities of the central dopaminergic, adrenergic and serotonergic neurons.

A questionnaire was sent to 42 maxillary prosthesis wearers in order to evaluate the relationship between maxillofacial defects and functional recovery. For 37 patients who responded to the questionnaire, those having maxillary defects were classified according to the HS classification, while those having mandibular defects were classified according to the amount of mandible that remained after resection and surgical reconstruction. These patients were then evaluated mainly in terms of mastication and pronunciation recovery rate. Masticatory ability was based upon the “Matsuura Evaluation Chart of Masticatory Ability,” while pronunciation was judged upon the ability to carry on daily conversation.

The results revealed that as the defect of the hard palate and alveolus of the maxilla increased, mastication and pronunciation disability also increased. Occlusal relationship concerning the number of anchored teeth was also thought to be a factor in the recovery of mastication. No apparent relationship seemed to appear between the defect of soft palate, the degree of mouth opening and the recovery rate of mastication and pronunciation. In mandibular defects, the number of anchored teeth, the occlusal relationship, the mandibular deviation, and the degree of surgical damage upon the tongue all had an apparent effect on functional recovery.

This study concerns the relationship of craniofacial morphology to the degree and form of septal deviations of the osseous nasal septum by statistically analyzing both the lateral and postero-anterior cephalograms. This is a study of 176 females, 16 to 23 years of age. The results were as follows:

1. The inverse correlation was investigated between the degree of septal deviation and the mandiblar size (Gn-Cd) in all of the subjects.

2. When comparing the severe deviation group (29 cases) with the non-deviation group (26cases), most of the former showed normal occlusion and maxillary protrusion, while anterior crossbite was found in most of the latter. The size of the mandible (Gn-Cd) was significantly shorter in the deviation group.

3. From both the cluster and discriminant analyses, it can be said that the degree of septal deviation had some relationship to the growth of the nasomaxillary complex and the cranial base.

4. Depending on the deviations of the osseous nasal septum, it was classified into 3 types (type C, type K, and type S). When comparing the craniofacial morphology in type C to the non-deviation group, the facial width was found to be wider than in the non-deviation group, thus indicating a tendency of imbalanced growth in the horizontal and vertical directions.

5. The size of the mandible was shorter in type K, and the antero-posterior length of the cranial base and maxilla were longer in type S than in the non-deviation group. It can be said that the relative growth toward the antero-posterior direction of the maxilla was greater than that of the mandible.

From the above it was determined that an imbalance growth potential of the septal components to the surrounding tissues (i. e, the cranial base and nasomaxillary complex) found in adolescents, which might cause various forms of deviation in the osseous nasal septum.

In an attempt to observe the fate of elastic fibers in a salivary gland with atrophy, 59 cases of human submandibular salivary glands with marked fibrosis were histologically examined. In 19 cases frequent periductal prolifertion of the elastic fibers was found, and two histological patterns of elastic fiber-proliferation were noted: 1)elastic fiber-proliferation was in close contact with the duct epithelium, and 2)collagenous tissue lay between the duct epithelium and layer of elastic fiber proliferasion. The former was frequently seen in cases with sialolithiasis, and the latter was frequently seen in irradiated cases.

The purpose of this investigation is to clinicaly evaluate “The GLUMA Composite System (013-LG)”. Fifty three teeth of twenty nine patients who agreed to participate in this study were selected. A cavity was prepared in these teeth and filled, following the manufacturer’s instruction.

At a week, a month and three months after filling, the condition of those teeth was observed and recorded. The following points were observed: gingival reaction, pulpal response and the condition of the filling, Each preparation was especially observed as to the stability of color, staining, surface roughness, marginal adaptation, fracture and the rate of drop-out from the cavities.

The evaluation is classified into three groups, excellent, acceptable and unacceptable. Excellent indicates that there was no clinical problem. Acceptable means that it is accepted climically in spite of a few problems. Unacceptable means that it is necessary to re-restore or give pulp treatment.

The results were as follows.

1. Of all the composite fillings forty-eight cases were excellent.

2. Three cases were acceptable. Two of them had rough, stained surfaces and the other showed slight pain with cold water.

3. Two cases were unacceptable. Fillings fell off the cavities.

Coagulase-negative staphylococcus (C-NS) seems to be one of the pathogenic bacteria in opportunistic infections. Of 315 strains, 157 strains of C-NS were isolated from inpatients and from healthy persons used as controls to study on their bacteriological characteristics. Staphylococcus epidermidis was isolated from most of them (89.8%). It produced an elastolytic enzyme that seemd to be a pathogenic factor in their infections. Elastolytic ennzyme was detected by a bacteriological and biochemical analysis, in 68.8% of S. epidermidis.

The enzyme from S. epidermidis was partially purified by using two assays: Sephadex G-100gel chromatography and CM-Toyopearl ion exchange chromatography. The results were; (1)the elastolytic enzyme hydrolyzed porcine elastin and Suc-(Ala)₃-PNA, (2)molecular weight was found to be 22,500, (3)the isoelectric point was betweem 9.4 and 9.5, (4)characteristics of the elastolytic enzyme indicated that there is a similarity to that of thiol protease, however, they were different from those of other elastases.

Four guinea pigs were given an intracutaneous injection of the elastolytic enzyme to detect the pathogenic mechanism of the enzyme. Deep ulceration and abscesses were observed in the skin of the back. These histopathological findings indicate that the enzyme is deeply associated with the pathogenicity of C-NS.

Strains of Candida albicans, serotype A were isolated from patients with and without denture stomatitis, and proteolytic activity of each was tested using the original as well as 2 modifications of Staib’s Serum-Protein-Agar method. Aerobic growth characteristics and acid production were measured after culturing for 72 hours, at 37℃ in Sabouraud’s dextrose liquid media by titration of colony forming units and measurement of pH in the respective supernatants. Each of 3 strains of C. albicans, serotype A with low or high proteolytic activity was then tested for its ability to produce palatal candidosis in the rat. Results were as follows:

1. Three different Candida aspecies were identified of which C. albicans, serotype A was the most frequent.

2. Strains of C. albicans, serotype A isolated from patients with denture stomatitis type Ⅱ tended to have a higher proteolytic activity than those isolated either from controls or patients with denture stomatitis type I.

3. There was no difference noted in either the acid production or growth characteristics of C. albicans, serotype A strains isolated from patients with or without denture stomatitis.

4. Strains of C. albicans, serotype A with high proteolytic activity produced palatal candidosis more frequently than those with low proteolytic activity.

Results of this study suggest that proteolytic activity of C. albicans, serotype A may play a role in the pathogenesis of denture stomatitis.

Recently, one method of treating mandibular dysfunction has been through the use of relaxing the masticatory muscle by the use of frontal EMG biofeedback training. The effectiveness of this training method was evaluated by measuring and comparing the mean amplitude summation and total power value of the masseter microvibration (MV), as well as the power values of β₁ and β₂.

Results showed the masseter MV to be comparatively higher in all 4 categories during biting than the resting state, while a lower total power value of the masseter MV and β₁ power values were apparent due to frontal EMG biofeedback training. Furthermore, frontal EMG biofeedback training displayed no significant differences between the left and right masseter muscle MV parameters in regards to the above mentioned 4 categories.

In conclusion, by analyzing the various parameteters of masseter MV, it can be said that frontal EMG biofeedback training can be used as a method of relieving mandibular dysfunction symptoms which are thought to be brought about by psychological stress.

Human papillomavirus (HPV) infection of the oral papillomas was histologically examined by using the HPV scoring system.

Five of seventeen oral papillomas were jugded to be HPV infeced. Two of the five papillomas were found to be HPV antigen positive by the PAP method. The authors thought that the scoring system was a useful method for diagnosing the HPV infection because it is simple and easy to use, but a slight change of scoring in the histological findings may be required for a more reliable diagnosis of oral lesions.

This paper reports a rare case of a fused deciduous tooth consisting of two upper incisors and a supernumerary tooth found in a 6-year-old girl with good general health. Macroscopic and X-ray examinations showed nearly complate fusion between two upper incisors and the supernumerary tooth, and more than ½ of each root was absorbed. No significant changes in number and form of the permanent teeth were noted by X-ray photographs. Histopathologic and contact microradiographic examinations revealed that the enamel, dentin and cementum of three deciduous teeth were united. It is well known that various developmental disturbances occur not only in permanent teeth but also in deciduous ones, however, the review of the literature in Japan yields only four cases of fused teeth composed of three deciduous teeth.

Immediate reconstruction of the mandible was undertaken by the combined use of a cast pure-titanium reconstruction plate integrated with a mandibular condyle and a fresh autogenous iliac bone graft. Two examples with a postoperative follow up over 2 years are presented. The reconstruction resulted in restration of not only the satisfactory mandibular movement but also in a satisfactory aesthltic structure of the mandible.