In recent years, the number of patient for whom it is too difficault to give dental treatments under local anestesia has been gradually increasing. For such patients, general anesthesia has been employed for various treatments. In this paper, we report the results of clinico-statistical observation of 2278 patients to whom dental treatments were given under general anesthesia at the dental hospital, School of Dentistry, Iwate Medical University, during the 15-year period between 1969 and 1983.

1. The number of patients receiving dental treatments under general anesthesia has been increasing every year, but there are only a few patients with a high risk.

2. As the agents of preanesthetic medication, atropine, hydroxyzine, and pethiolorfan have been most frequently employed.

3. As to the inductive means of general anesthesia, rapid induction was used in 90.1% of the patients who were given general anesthesia. The oraltracheal intubation method employed most frequently, followed by nasotracheal intubation.

4. The kinds of general anesthesia used in the dental treatments were GOF, m-NLA and GOE and the frequency of their use was 60.8%, 10.3% and 10.1%, respectively.

5. No patients developed serious complications during and/or after the application of general anesthesia.

Clinicopathological analysis was made of 193 cases of epulis examined in the Department of Oral Pathology, Iwate Medical University. They were classified histopathologically, and their location, sex predilection and age of patients were studied. The results were as follows:

1. They were classified histopathologically into 70 cases of epulis fibrosa, 55 cases of epulis osteoplastica, 25 cases of epulis granulomatosa, 16 cases of epulis teleangiectaticum, 14 cases of epulis hemangiomatosa, 4 cases of epulis fibromatosa, 3 cases of epulis congenita, and 6 cases with an unknown-histological diagnosis. No case of giant cell epulis was found in the present series.

2. Epulis was much more common in females than in males, by a ratio of 2:1. Furthemore such sex predillection in cases of epulis was more evident in the third to the sixth decades of life.

3. Most of the cases of epulis hemangiomatosa were found in females.

4. Most of the lesions were less than cherry-sized, and had a tendency to occur at the anterior region of both the maxilla and mandible.

5. Each histological type of epulis had its favorite age.

Age-related changes of rat submandibular gland were studied by light and electron microscope with special reference to the acinic cells. Male SD rats were studied. 2, 4, 6, or 12-month-old rats were used for the young and adult group and 22-month-old rats were used for the aged group. The acinic cells of the rat submndibular gland of the young and adult group were well developed, were rich in rough endoplasmic reticulum and Golgi complex, and had secretory granules composed of well defined amorphous material

Light microscopy of the acinic cells of the aged group showed some regressive changes, such as pyknotic and bizarre nuclei, irregularity in size, atrophy, vacuolar degeneration and a decrease in the stainability of PAS and toluidine blue stain, when compared to those of young and adult group.Ultrastrucuturally they were characterized by a decrease in the amount of rough endoplasmic reticulum, an increase in size and in the amount of lipofuscin granules, and many secetory granules being composed of loose amolphous material. Secretory granules of the aged cells sometimes fused to make a big secretory granule which might result in a vacuole under light microscopy.

This is a study of outpatients who visited our dental hospital, School of Dentistry, Iwate Medical University from January 1975 to December 1983. The following results were obtained.

1. Though the first-time outpatients numbered 6750 in 1975, they decreased to 5130 by 1978. From 1978 to 1983, the total number of first-time outpatients remalned constant.

2. There were slightly more females than males and the number of patients of both sexes increased in the 0 to 9 years of age group.

3. In 1983, in the Departments of Operative Dentistry and Endodontics, the patients decreased to one half of those in 1975, though the number of the patients decreased only slightly in the Departments of Prosthodontics and Oral and Maxillofacial Surgery. They had gradually decreased in the Department of Periodontology and increased in the Department of Orthodontics.

4. An analysis of the addresses of the first-time outpatients, showed that the patients had decreased markedly from the area under the care of the Morioka Health Center. Patients from other districts in Iwate Prefecture gradually increased due to referrals of first-time patients and those in the Departments of Orthodontics and Pedodontics. The number of patients from other prefectures was unchanged.

5. Outpatients, except the referrals and those in the Departments of Orthodontics and Pedodontics, decreased from 73% of all patients in 1975 to 38% of all patients in 1983.

6. 90% of all patients who visited our hospital were from Iwate Prefecture.

An ultrastructural study on rat gingival tissue was made, with particular attention to the junctional and sulcular epithelium. The animals used were 6 to 7 week-old male Wistar rats. The results were as follows: 1.The epithelium facing the tooth could be divided into 3 anatomical regions, i.e.,1)the sulcular region, 2)the junctional region, and 3)the transitional region between them. Furthermore, the junctional epithelium could be sub-divid into 3 areas, namely, the coronal side area, the apical side area, and the intermediate area between them.

2. The sulcular epithelium showed the histoarchitecture to be similar to that of the keratinized stratified squamous epithelium.

3.The junctional epithelium showed the structure of nonkeratinized stratified squamous epithelium, while the intercellar space contained many neutrophilic leukocytes, a few lymphocytes and Langerhans like cells. The coronal side area of the junctional epithelium showed partial degeneration, desqamation, and necrosis. The thickness of the junctional epithelial layer gradually decreased on the apical side area.

4.The basal cells of the transitional region between the sulcular and junctional epithelium were found to be tall and cylindrical in shape.

5.The histological significance of the above-mentioned findings are also discussed.

In order to clarify the alteration of percent distribution of histological constituents of the tongue upon the aging process, a study was made on the tongues from senescence accelerated mouse-prone/2 (SAM-P/2). Senescence accelarated mouse-resistant/2 (SAM-R/2), and ddY strain mice were used as control material. The tissues from three sites of each tongue were examined under light microscopy and the distributions of tissue constituents were determined using a point counting method.

No remarkable difference in comparisons between SAM-P/2 and the control materials upon aging process was revealed. The percent distribution of the muscular constiuent was the greatest in all the sites of every age group. And that of the fibrous constituent was higher in all three sites of the two-months of age groups, but especially in the anterior sites, that was the highest and varied widely from case to case. A little adipose tissue could be found in the posterior site of all mice strains, whereas none or only very little adipose tissue was noted in the anterior and middle sites. The authors conclude that the main senile alteration of the histological constituent on the tongue of the mouse is in that of muscular and fibrous constituents, and no alteration of the adipose constituent is noted in the tongue related to aging.

For the purpose of searching for an etiological agent, anaerobic bacteria were isolated from abscesses of 34 oral purulent inflammations. The isolates were identified according to the biochemical properties and metabolites recognized by gas liquid chromatograpy. In addition their susceptibility of them was detemined to 11 antibiotics: Benzilpenicllin, Ampicillin, Amoxicilln, Cephaloridine, Cephalexin, Cefoxitin, Cefmetazole, Minocycline, Josamycin, Clindamycin, Metronidazole.

Forty-two anaerobic bacteria were isolated from 30 of 34 oral purulent inflammations. The isolates were placed in 5 genera and 13 species: 2 Peptostreptococcus magnus and 4 Peptostreptcoccus asaccharolyticus, 7 Peptostreptococcus anaerobius, 4 Peptostreptococcus productus and 7 Veillonella parvula, 2 Veillonella dispar and 1 Propionibacterium acnes, 1 Propionibacterium granulosum and 2 Bacteroides fragilis, 1 Bacteroides intermedius, 2 Bacteroides oralis and 6 Fusobacterium nucleatum, 3 Fusobacterium mortiferum.

In the antibiotic susceptibility test, gram-positive anaerobic bacteria (Peptostreptococcuss, Propionibacterium) showed resistance to Benzilpenicillin, however gram-negative anaerobic bacteria (Veillonella, Bacteroides, Fusobacterium) were suscepttible. All strains were susceptible to Ampicillin and Amoxicillin. All strains were sensitive to Cephems. Veillonella, Bacteroides, Fusobacterium showed resistance to Jasamycin whereas Peptostreptococcus, Propionibacterium were susceptible. All strains were sensitive to Minocycline, Clindamycin. Propionibacterium showed high resistance to Metromidazole (MIC 100μg/ ml), however other strains were susceptible.

MIC was influenced by the inoculum size, and particularly the MIC of Propionibacterium obtained when using the two-point system method (at 10⁶ CFU/ml and 10⁸ CFU/ml inoculum size) rose remarkably: 0.1μg/ml to 0.78μg/ml for Josamycin, and 0.1μg/ml to 1.56μg/ml for Clindamycin.

We hope that further examination on inoculum size will be made in determining MIC of anaerobic bacteria.

The purpose of this study was to survey the prevalence of periodontal disease and caries levels of 50 severely disabled patients institutinoalized for mental deficiency in Iwate prefecture. Their ages ranged from 18 to 49, and they had no habits of oral hygiene.

The results obtained were as follows:

1)The degree and the distribution of caries of females were higher than those of males. Many females had extensive caries and stumps as compared with the males.

2)The degree and the distribution of periodontal disease of females were higher than those of males.Very severe inflammation of the gingiva was mainly observed around the stumps. The presence of alveolar bone resorption and the teeth mobility were not always of the same portion of gingival redness and gingival swelling.

The effects of methamphetamine and morphine on the vertical (VMA) and horizontal motor activity (HMA) in male mice of the ddY strain, weighing 24-28g, were investigated, using an optical movement counter developed by Itoh and collaborators. All measurments were taken at 10 min. intervals during the 180 min. period following administration of the drugs. The results are summarized as follows.

When administering methamphetamine;

1) With 0.1mg/kg, s.c., the VMA and HMA slightly decreased.

2) With 1mg/kg, s.c., the VMA and HMA increased.

3) With 10mg/kg, s.c., the VMA and HMA markedly increased, showing biphasic patterns that quantatively differ from the changes found in a low dose (1mg/kg)-induced VMA and HMA.

When administering morphine;

1) With any dose used in this study, the VMA decreased.

2) With a low dose (2mg/kg), the HMA decreased, but with a high dose (10mg/kg or more) the HMA increased dosedependently.

These results show that methamphetamine and morphine exert different effects on the VMA and HMA in mice, depending upon the dosage.

A case of bilateral supernumerary mandibular premolars found in a 28-year-old Japanese male is presented. In his left mandible, two supernumerary teeth erupted: one of them was bicusp-shaped and located in the first molar region, and the other was peg-shaped and located in the distoligual area of the premolar region Also a bicusp-shaped supernumerary tooth with a well-developed accessory cusp erupted in the lingual area of the rigth molar region. A panoramic X-ray examination revealed no impacted supernumerary tooth in the manbible and the maxilla. A review of the literature showed that 53 cases of bilateral supernumerary mandibular premolars had been reported in Japan. Clinical and anatomical analysis of these reported cases is also given.

A case of replantation of an intrusive-luxated tooth is reported. The patient was a 14-year-old boy, and he had knocked his maxillary anterior region against a desk at school. About 20 minutes after the injury he visited the dental clinic. Clinical and radiographic examinations revealed that his left maxillary incisor had completely intruded into the alveolar socket, but perforation of the nasal cavity, fructure of the alveolar bone or tooth-root was not noted. Under local anesthesia, the intrusive-luxated incisor was replanted and fixed by direct bonding method. Four days after the replantation, pulp extirpation and root canal filling were performed, since a clinical examination showed the replanted incisor was non-vital. Extirpated pulp tissue showed histopathologically necrobiotic or coagulation necrotic change with infection of the Gram-positive cocci. Two months after the replantation, the fixing appliance was removed, since the postoperative course was uneventful, and tooth movility of the incisor was in the normal range. In addition to the present case, treatment, prognosis and histopathology of luxated teeth are discussed.

This paper was investigated to examine the oral health, mainly concerning the periodontal findings, in 3 cases with Down’s syndrome. The follwing findings were obtained:

1) There was very severe inflammation in the periodontal tissue in the 3 cases. The gingival redness and the swelling were related to the local irritants such as dental plaque and calculus. However, the pocket depths and the alveolar bone resorption were not always correlated to the local irritants.

2)The degree and the distribution of the dental caries in Down’s syndrome patients were lower than those in age-matched disabled patients, who had been institutionalized at the same place.

3)The severe periodontal disease in Down’s syndrome patients was not so much caused by such factors as the reduction of resistance to infections, as compared to the local factors such as poor oral hygiene and microdontation.