Gifu Shika Gakkai zasshi = The Journal of Gifu Dental Society最新文献

The statistics for prosthetic restorations used at the Prosthetic Department of Asahi University Hospital from April 1986 to March 1987 were compared with those obtained in earlier period (April 1983 to March 1984). A total of 2,360 prosthetic restorations were used. This was a 12.5% decrease compared to the previous period. No significant sex-related difference was found in the number of restorations used. The number of prosthetic restorations was decreased in patients in their forties who had the most restorations in the previous period. During the period investigated in this study, the number of prosthetic restorations was highest in the patients in their fifties and lowest in those in their eighties. By sex, prosthetic restorations were used most frequently in males in their fifties and in females in their thirties. The prosthetic restorations used during this period had almost the same proportions as in the previous period. Most frequently used were full cast crowns followed by facing crowns, as were during the previous period. The former amounted to 36.1% and the latter to 22.1%. Full dentures were the least used restorations and amounted to 5.2% of all the prostheses. The use of facing crowns had considerably decreased in patients in their forties, although this age group had the highest frequency of use during the previous period. Full cast crowns were most frequently used in patients in their thirties, removable partial dentures in those in their fifties and total dentures in those in their seventies.

We set a new basic plane on an orthopantomogram in order to measure the gonial angle and obtained the following: 1) Usable error difference in ordinary clinical setting ranged from 0.5 degrees-1.0 degree. 2) Because there is no great difference between the levels of the gonial on orthopantomograms, they are effective for investigation of the changes of side and degree. Thus, based on the above results, 100 cases were randomly selected from the Angle class III cases which were treated at our department of orthodontics in order to investigate the differences between the left and the right side and pre and post-treatment changes and obtained the following results: 1) Pretreatment differences between the right and the left sides were recognized in 88 cases. 2) 66 cases showed posttreatment improvement in the differences between both sides. Because orthopantomograms are applied at the end of treatment and for evaluation of the stability of occlusion. We will investigate if the occlusion is best harmonized at equal gonial angles on both sides, using a combination of EMG and measurement of occlusion force, and will also study various cases in more detail.

The patient was a 22-year-old female with a class III malocclusion characterized by maxillary constriction, dental crowding and mandibular protrusion. The treatment goals which were related to the chief complaints included correction of negative overjet, negative overbite, and dental alignment. Since the pre-existing crowding created some severe problems and prevented adequate posterior repositioning of the mandible and anterior teeth, extraction of the four first premolars were recommended to correct the overjet. This treatment resulted in greater posterior repositioning. The treatment was divided into three stages: 1) extraction of first premolar teeth, alignment, space closure and an increase in the overjet and overbite, 2) arch alignment and detailing of the occlusion with a full fixed appliance, and 3) retainers. At the end of the treatment, the patient had an acceptable dental alignment with a class I molar relationship and an improvement in facial appearance.

We investigated, using labeling techniques (tetracycline, calcein) and routine histopathological methods (H. E. and Azan stainings), the histological changes with passage of time in incomplete root and the periodontium of young dog teeth with torque loading applied. The maxillary left first, second and third incisor teeth were used as anchorage teeth, and the maxillary right second incisor was loaded with either 3 degrees or 9 degrees torque. The orthodontic forces of these are 20-30 g and 80-90 g, respectively. Some temporal disturbances (such as mild, moderate, or severe bendings of labial and palatal apexes) were observed in certain regions of the apex of the incomplete root. However, with subsequent development of the root, the disturbances were repaired and pulp of the teeth was normally formed. Furthermore, although periodontium was also temporarily disturbed, it developed normally with the passage of time.

An angle analysis and linear analysis are popularly used in clinical orthodontics. Downs analysis and Northwestern analysis are two methods of angle analysis, and the mean values reported by Iizuka in 1963 are still used. However in Japan each generation's constitution (height, weight) tends to increase year by year. For example, the mean height and weight of adult males (23 years old) have increased by 5.0cm and 7.6kg as compared with nearly 20 years ago. Therefore the mean of 20 years ago may not be appropriate. Analytical values at normal occlusion Japanese adults by Kayukawa, Iizuka, Ishikawa, Yamauchi, Miura, Iwazawa and, most recently by Asai in 1973. We obtained these values and determined the validity of currently used values.

The patient was a 9-year-old girl with a skeletal Class II malocclusion characterized by maxillary protrusion, excessive overjet and deep overbite. The patient's maxillary left central incisor was deeply impacted. During the first stage, a lingual arch was employed after surgical exposure. During the secondary stage, all four first premolar teeth were extracted and then edgewise mechanotherapy was performed. The total treatment time was 6 years. The malocclusion was treated satisfactorily and resulted in correction of the esthetic and functional flaws after 1 year out of retention.

The effects of masseteric denervation and bite raising on muscle fiber type differentiation were examined in the masseteric muscle of developing rats by histological and histochemical studies. Three-week-old Wistar rats had of their masseteric nerve at right side dissected, and a part of them were bite raised at anterior region one week after denervation for three weeks. The unoperated side and number of sham animals served as control. The animals were killed 3, 7, 10, 14, 21, 28, 35, 49 days later and then their masseter muscles were removed wholly and weighed them. After freezing of superficial and deep masseter muscles serial sections were made and HE staining carried out, ATPase staining and NADH-TR staining. On the photographs of the HE stained specimens, I measured the diameter of the muscle fibers. Gross findings on the denervated group, revealed the lower incisors shifted to unoperated side and on with the bite raising group, it shifted to the operated side. In denervated animals, the wet weight of the masseter muscle had decreased significantly. The masseteric muscle fibers in three-old-week control rats were undifferentiated on ATPase staining, but it became well differentiated on and after four-old-week. The superficial masseter of control mainly composed of type 2B fibers. In the deep masseter, about 10% type 1 and 2C fibers were found in limited area around the muscle spindles, and surrounded with type 2A and 2B fibers. In superficial masseter muscle of the denervated group, the percentage of type 2A fibers increased, and that of type 2B fibers decreased. The type 2C fibers were found from the 21st days after denervation. In deep masseter muscles, the percentage of type 1 and 2A fibers decreased, and that of type 2B and 2C fibers increased. In the denervated bite raising group, the composition of the muscle fiber type approached the control group. These results as above suggested, masseteric denervation causes degeneration of muscle fiber composition, and the possibility that early preventive treatment like bite raising may recover the muscle fiber composition normally.

The patient was a 12-year-old girl with a skeletal class III malocclusion characterized by mandibular protrusion, a high mandibular plane angle, severe negative overjet and deep overbite. The patient's mandibular first premolar teeth were extracted following the standards of edgewise mechanotherapy. The total active treatment time was 19 months, however, retention was needed until the patient was 19 years old. The malocclusion has been treated satisfactorily resulting in correction of the functional and esthetic flaws without orthognatic surgery.

This report presents the phonetic changes of a patient whose occlusal vertical dimension is extended. His chief complaint is esthetic restoration of his anterior teeth, but his occlusal vertical dimension is abnormally shortened by long-time attrition. Therefore we extended his occlusal vertical dimension, and reconstructed his occlusion, and carried out acoustic observations.

We investigated the localization of chondroitin sulfate and dermatan sulfate proteoglycans in the dental pulp and dentin of rats, using a combination of an immunohistochemical technique coupled with specific enzymatic digestion. Chondroitin 4-sulfate and dermatan sulfate were found to be widespread in pulpal connective tissue, predentin and dentinal tubules. The response to predentin was found to be particularly strong. Chondroitin 6-sulfate was stretched in pulpal connective tissue and predentin, but showed only a weak response.