The Journal of Osaka University Dental School最新文献

Combined orthodontic treatment with orthognathic surgery and partial glossectomy were simultaneously performed in an adult male patient with mandibular prognathism and open bite from the lower right to the left first molars. Total active treatment period was 15 months. During the retention period, a tooth positioner was given to obtain proper interdigitation from set-up models. The post-surgical occlusion has been stable without any complication of the mandible and the tongue.

Survey of dental health condition was performed at a special nursing home for the elderly with senile dementia (28 subjects, 83.3 +/- 6.8 year-old; SD group) or without senile dementia (68 subjects, 84.6 +/- 7.2 year-old; NSD group). There was no difference in number of teeth survived between SD and NSD groups. However, the elderly in SD group had more unfunctionable and/or unrestorable teeth (C4) and less sound and filled teeth (SFT) than those in NSD group. Number of teeth of the elderly in 85- to 89-year-old group was smaller than those of not only younger but older age groups, irrespective of senile dementia. Lower canines showed the highest survival rate among all kinds of teeth in SD as well as in NSD group.

The purpose of this study is to examine the bending profiles of composite resin coating cast clasps. The cobalt-chromium alloy cast clasps were made using tapered wax pattern. Silane coupling method (Silicoater MD, Kulzer Co.) was used to attach composite resin to metal surface. The breakage and the bending rigidity of composite resin coating clasps were evaluated. Results were as follows: 1) After the repeated bending test to the tips of clasp arm at 10,000 times in 0.25 mm deflection, neither crack on composite resin surface nor separation at resin/metal interface was observed in any specimen. 2) There was no significant difference in the bending rigidity of clasp arms between before and after composite resin coating. From these results, it was demonstrated that the composite resin coating cast clasp was available in clinical cases and coating with composite resin had little influence on the bending rigidity of clasp arms. Therefore, it was suggested that our clasp designing and fabricating system to control the bending rigidity of clasp arms could be applied to composite resin coating clasps.

A new sectional partial denture utilizing lock mechanism (lock denture) has been developed. Utilizing the lock mechanism, two parts of sectional partial denture are locked together easily and tightly. A lock denture has been constructed for an upper removable partial denture, has been worn for over three months and has clinically been proven to obtain good function and esthetics.

Previously, we reported methods for isolating chondrocytes from the craniofacial cartilage and culturing them in vitro. The cells actively synthesize glycosaminoglycan (GAG), a marker of the differentiated phenotype of chondrocytes and respond well to PTH and glucocorticoids. It has been suggested that chondrocytes produce somatomedin-like growth factors which support their own growth and GAG synthesis. In the present study, we reported studies on the effect of conditioned medium obtained from cultures of rabbit craniofacial chondrocytes on GAG and DNA syntheses in the same chondrocyte cultures. Serum-free medium, conditioned by exposure to rabbit chondrocytes from mandibular condyle, nasal septum and sphenooccipital synchondrosis in monolayer culture stimulated not only the synthesis of GAG by the same cells but also their own DNA synthesis. The stimulation of the syntheses of GAG and DNA by the conditioned-medium factor were concentration-dependent. In addition, these three kinds of conditioned media stimulated GAG and DNA syntheses of other types of chondrocytes. These findings suggest that rabbit chondrocytes from the craniofacial complex release factors into the culture medium that enhance their own growth and expression of the differentiated phenotype of chondrocytes as well as that of costal chondrocytes.

To investigate the effect of malocclusion on mandibular movements during speech, the location, width and height of the envelope of motion during speech were analyzed in 25 normal subjects and 60 subjects with malocclusion using the Sirognathograph Analyszing System. Location of the envelope of motion was closely related to the specific types of malocclusions. It is suggested that the analysis of the envelope of motion during speech has diagnostic values in speech function and dental treatments.

It was examined whether the tannin-fluoride preparation (HY preparation), which might have a caries-reductive, plaque inhibiting and astringent action, could reduce the incidence of gingival inflammation around abutment teeth. Zinc oxide eugenol cement mixed with the HY preparation was packed in the cavity prepared in the resin base facing the abutment tooth. Gingival crevicular fluid (Periotron units:GCF), gingival index (GI), plaque index (PlI) and probing depth around the abutment teeth were measured over a 3 month period. The following results were obtained: 1. GCF decreased at month 1 and showed low values at months 2 and 3. 2. GI showed a decreasing tendency. 3. PlI and probing depth did not show obvious changes. These results indicate that the tannin-fluoride preparation reduces gingival inflammation around abutment teeth.

The diagnostic arthroscopy was performed on 47 temporomandibular joints from 40 patients having anterior disc displacement without reduction with restricted mouth opening or painful anterior disc displacement with reduction. All patients were outpatients and subjected to arthroscopic examination under local anesthesia. Previous to arthroscopy, routine clinical and radiographic examination, and magnetic resonance imaging were carried out for all joints. Adhesion was better observed by arthroscopic examination, perforation was suggested by magnetic resonance imaging as well as arthroscopic examination, and bone change was better observed by magnetic resonance imaging. However diagnostic arthroscopy should be considered as an invasive examination, it is practical to the clinician and patient as complementary to decide the indication of arthroscopic surgery, open surgery (diskectomy) or maintenance of conservative treatment.

The fabrication of laminate veneer requires many complicated procedures and skills to obtain good accuracy and shape. Thus, the use of CAD/CAM is subjected to in laminate veneer fabrication in order to reduce complication and time consuming. In this study, CAD/CAM system of laminate veneer fabrication was developed. The system consisted of laser displacement meter, computer-controlled scanning machine and personal computer. This system is able to measure tooth shape with three dimension, design and manufacture laminate veneer shells of ABS resin with satisfied accuracy and shape.

Eosinophilic granuloma of bone is not uncommon in the craniofacial region (Anderson and kissane, 1977), and it sometimes occurs in organs such as the lung, stomach and spleen. However there are only few reports on solitary eosinophilic granuloma of bone occurring in oral soft tissue. In this report, we describe a case of eosinophilic granuloma of bone occurring in the soft tissue of a 40-year-old woman.