The purpose of this investigation was to evaluate the new sandwich technique ”Single Filling”. This method is a modified sandwich technique to apply the composite resin directly onto noncured glass ionomer cement without an etching procedure. The tensile bond strength between the glass ionomer cement and the composite resin was measured using an Instron test machine to compare single filling with a conventional sandwich technique. The tensile bond strength by single filling was lower than that by a conventional sandwich technique but there was no significant difference between single filling and the conventional sandwich technique. The tensile bond strength between the glass ionomer cement and composite resin was greater than the cohesive strength of the glass ionomer cement.

The sexual dimorphism of mouse submandibular gland is mediated by androgens. In this study, the androgen receptor of mouse submandibular gland was purified and characterized. The androgen receptor from mouse submandibular gland was 6,450-fold purified by one-step affinity chromatography with testosterone-agarose and the purity was estimated to be 1.6% on the basis of the ligand-binding assay. However, silver staining and photoaffinity-labeling experiments with a synthetic androgen,[³H]R1881, revealed common 30, 46, 70, and 100 kDa species in the purified sample, indicating that the preparation consisted of a highly purified androgen receptor. Among these species, the largest one of 100 kDa seemed to be an intact receptor molecule, because the apparent molecular weight was in accord with that calculated from the cDNA sequence. The others seemed to be processed ones. Taking into account the domain structure of the androgen receptor, all species which were photoaffinity-labeled with[³H]R1881 appeared to retain a C-terminal steroid-binding domain. Thus, it is likely that the 30 kDa species was produced by cleavage at the site between the DNA-binding and steroid-binding domains, and the 46 kDa one between the N-terminal and the DNA-binding domains of the receptor. The occurrence of the 70 kDa product suggested the presence of an additional site, susceptible to proteolysis, in the N-terminal transactivation domain. An immunohistochemical study with polyclonal antibodies against the androgen receptor demonstrated that the receptor was localized in the ductal cells of the submandibular glands of both sexes. Moreover, the receptor existed in those of the sublingual gland.

Excised bullfrog sympathetic ganglia were pinned in a microperfusion chamber and single cells were impaled with IMK⁺-citrate filled microelectrodes (20-60MΩ). Superfusion with caffeine (2-3mM) Ringer caused abrupt membrane hyperpolarization which quickly returned to control resting potential. Repetitive rhythmic membrane hyperpolarization (RMH) began approximately 1-2 min later and continued at the same frequency during caffeine superfusion. RMH ceased immediately on changeover to caffeine-free Ringer. Caffeine induces an oscillatory Ca²⁺-activated GK⁺ in frog ganglion cells, and is evidentally as RMH. We examined the mechanism of intracellular Ca²⁺ oscillation and the effects of ryanodine and local anesthetics. The 10μM ryanodine, which selectively affected the Ca²⁺-release mechanism, irreversibly blocked the caffeine-induced RMH. Caffeine-induced RMH was reversibly blocked by 3mM procaine, 3mM cocaine, or 3.6mM lidocaine. Since adenosine triphosphate (ATP) reverses the procaine conduction block in frog nerve (Kuperman et al, 1964), we tested its effect on the procaine block of Ca²⁺-activated GK⁺ in 24 of 42 cells. One mM ATP restored RMH amplitudes to 125±5% of control, but did not restore RMH frequency. The results suggest that sympathetic ganglion cells have a Ca²⁺- induced Ca²⁺ -release system and procaine>cocaine>lidocaine depress the rise in intracellular Ca²⁺ concentration that triggers GK⁺, particularly since it is mediated though the P₂-receptor in the presence of extracellular ATP, which can increase cellular Ca²⁺, and reverse the procaine block.

The formation and development of upper and lower third molars were observed in 102 patients with malocclusion using longitudinal radiographs. In addition, the relationship between the eruption of the third molar and the posterior space was examined in 113 adult subjects. The following results were obtained:

1.Upper and lower third molar crypt formation was distinctly observed at the age of 9.9 on the average. Calcification of some crowns was observed at age 10.9 in the maxilla and at 10.8 in the mandible. Completion of full-crown formation was observed at age 13.3 in the maxilla and at l3.2 in the mandible. Commencement of root formation was observed at age 15.2 in the maxilla and at 15.5 in the mandible. 2. No significant difference was found at the time of third molar development between males and females or between left and right sides. 3. The bone width at the mandibular gonion region was larger in the group with earlier mandibular third molar development than in the group with later development. 4. For eruption of the third molar, it is necessary for Ptm’-Ms’ to be 25.7mm in males and 22.8mm in females in the maxilla and for Xi-L7 to be 27.5mm in males and 23.6mm in females in the mandible.

The present study aims to clarify primary factors involved in the occurrence of periodontal diseases. In three environmentally different districts in the Republic of Kenya, i. e., Nairobi, the capital, Kericho, a growing local town and Lodwar, a rural village, a total of 1,159 subjects from sucklings to the aged, of both sexes, were examined for periodontal condition and plaque deposition by the modifications of the periodontal index (PI) of Russell and the oral hygiene index-debris index (OHI-DI) of Greene and Vermillion, respectively. Information as to daily practice of oral hygiene was obtained by direct interview with participants. Periodontal disease tended to be more prevalent and severer with an increase in age in all three areas. The prevalence and severity were lowest in Lodwar, highest in Kericho and intermediate in Nairobi. Plaque deposition in the three areas showed the same regional differences in severity as in periodontal disease. In addition, the occurrence of periodontal disease correlated significantly with the extent of plaque deposition but not with daily oral hygiene practice. The occurrence of periodontal disease and its causative agent, dental plaque, are both affected primarily by the daily dietary consumption but not by the routine practice of oral hygiene.

This study was undertaken to examine the effect of palatal scar tissue on the growth of maxillofacial bones and to find what changes could be produced in surgically affected maxillofacial bones and soft tissues by application of orthopedic force during the early stage of development. Experimental dogs (four-months-old) were divided into 3 groups: (1) the group without operation, (2) the group which received only operation and (3) the group which received operation and maxillary expansion､ Cephalograms were obtained from these dogs. Plaster models of the maxilla were made and the palatal bones and soft tissues examined histologically. Linear analysis confirmed the effect of orthodontic force applied to the maxillofacial bones with scar tissue, as examined from the volume of osteogenesis and from histological differences in palatal epithelium and subepithelial tissues. This study suggests that early orthodontic treatment for growth control is helpful for subsequent growth of the surgically affected maxillofacial bones.

This study was designed to determine the relationship between the congenital anodontism and jaw size. Of 3,981 patients seen at the Department of Orthdontics, Iwate Medical University, 245 with congenital anodontism were examined. The relationship between congenital anodontism and jaw size was studied by longitudinal X-ray cephalometric analysis. Statistical analysis was carried out by Neyman’s method. The patients were divided into 3 groups by the magnitude of ANB angle. A large number of teeth were obviously missing in the maxilla in the ANB≦0°group. No difference was found in the number of missing teeth between the maxilla and mandible in the 0°<ANB≦4°group. There was obviously a large number of missing teeth in the mandible in the 4°<ANB group. In the group with a smaller mandibular size, teeth were missing mainly in the lower incisors area. These findings suggested that congenital anodontism was related to jaw size.

At an anatomical training session conducted in 1993, an accessory infraorbital foramen was found on one of the 82 sides in 41 Japanese cadavers. This accessory foramen existed medioinferiorly to the right infraorbital foramen and contained a nerve. We dissected this nerve to the proximal side and examined its route and origin. The nerve branched from the greater palatine nerve 5.6mm below the pterygopalatine ganglion in the pterygopalatine fossa. lt entered into the maxilla through the maxillary tuberosity, proceeded anteriorly to the medial wall of the maxilla, supplied a branch to the maxillary central incisor at 9.8mm posteriorly from the medial edge of the accessory infraorbital foramen and was then distributed in the face. From the route and distribution, we postulate that this nerve was an anterior branch of the superior alveolar nerve or posterior lateral nasal nerves.

This paper describes an orthodontic treatment for a boy,12 years and 3 months of age, having an anterior cross-bite as well as impacted maxillary right and left canines. These canines existed horizontally at areas of the upper right central, and right and left lateral incisor root apexes having severe root resorption. At first, the anterior cross-bite was corrected using the edgewise technique, and afterwards, canine traction was undertaken by anchoring to palatal bars soldered to metal bands on 64 46. Both lateral incisors were extracted after 5 months, and traction of the canine was allowed to continue. After 17 months, both canines were aligned at the regions of the lateral incisors. A very high risk is involved in such a treatment, therefore it is necessary to give, before treatment, complete information to the patient as to absolute conditions and consequences, including the loss of several teeth for the correction of malocclusion.

Pathological examinations undertaken in 1993 at the Department of Oral Pathology, Iwate Medical University, were statistically reviewed. Total number of biopsy materials examined amounted to 644 (including 65 from outside sources) and from 512 cases (230 males; 282 females). By histological classifications, 3biopsies were odontogenic tumors. Of nonodontogenic benign tumors, 27 were diagnosed as fibromas, 7 as papillomas, 7 as hemangiomas, 4 as lipomas and 3 were pleomorphic adenomas. The malignant tumors consisted of 41 squamous cell carcinomas (tongue 17, gingiva 11, buccal mucosa 5, hard palate 2, oropharynx 2), 3 malignant melanomas, 2 adenoid cystic carcinomas and 22 carcinoma in situ. Upon examination of the histological types of odontogenic cysts, 37 were radicular cysts, 14 were dentigerous cysts and 13 were primordial cysts. Of nonodontogenic cysts, 34 were diagnosed as salivary gland cysts, 31 as postoperative maxillary cysts and 4 as epidermoid cysts. Also found were 22 cases of hyperkeratosis, 18 chronic localized hyperplastic gingivitis, 27 with Sjögren’s syndrome, and 70 having chronic inflammatory (granulation) tissue.

Mandibular prognathism due to morphological and/or positional abnormality of the upper and lower jaws is often caused by narrowing and retrusion of the maxilla or hyperdevelopment and protrusion of the mandible. Orthopedic treatment has been regarded effective for patients with jaws in the developmental stage having this type of malocclusion. A girl,in the aged 10 years and 8 months, with jaws in the developmental stage with anterior protrusion of the mandible and narrowing of the maxillary dental arch, was treated by application of orthopedic force to the upper and lower jaws. Rapid maxillary expansion was applied to the upper jaw and a chin cap appliance to the lower jaw. Occlusion was then reconstructed using a multibracket appliance after tooth extraction. The following results were obtained:

1. Rapid maxillary expansion resulted in successful enlargement of the maxillary dental arch width. Even at 1 year and 6 months after expansion, the maxilla remained almost completely free from relapse. 2. There was no evidence of anterior displacement of the upper jaw due to rapid expansion of the maxilla. 3. Anterior crossbite associated with mandibular prognathism was corrected by swing back of the mandible mainly using a chin cap appliance. This treatment markedly improved the anteriorly protruding appearance of the lower lip and chin which had been obvious at the time of first examination. 4. Control of dental alignment and axis in the entire arch was facilitated by improvement of the maxillomandibular relationship.

Problems involved in tooth movement and changes in periodontal tissue following orthodontic treatment were studied in an elderly patient with Class Ⅱ malocclusion. The patient was a woman, 55 years and 4 months of age, who had undergone 2 years of orthodontic treatment for crowding of lower incisors. Her maxillary protrusion was corrected by extraction of the upper first premolars. The total period of active orthodontic treatment was 2 years and 4 months. This treatment decreased the overjet from 9mm to 2.5mm and overbite from 3mm to 2mm. The periodontal pocket depth and degree of alveolar bone resorption showed no significant change following treatment and remained in good condition. Although the patient was elderly, orthodontic treatment could be given without injury to the periodontal tissue. The patient had healthy periodontal tissue before treatment. Tooth extraction was performed after careful and appropriate treatment planning based on full mouth examination. The occlusal relationship between the upper and lower jaws was not affected by the treatment. An appropriate force system and appliances were chosen to ensure smooth tooth movement. These factors seem to have contributed to the successful results in this case.