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Get PDFIn edentulous patients with maxillary defects, it is difficult to obtain sufficient retention, support, and stability of the obturator prosthesis, in addition, its mobility during various functions is considered to be large. A thorough understanding of the mobility of the obturator prosthesis is important to achieve successful results in the patient's oral rehabilitation.In this study, the ranges of movement of the obturator prostheses in three hemimaxillectomy edentulous patients were compared during tapping, chewing (biscuit), and opening and clenching jaw movements by simultaneously conducting three-dimensional measurements of three points that were established on the central incisor and the right and left first molars of the obturator prosthesis with a jaw movement tracking device having six degrees of freedom.This study indicates that the range of movement of the obturator prosthesis varied extensively from individual to individual. The ranges of movement were larger than those of normal complete dentures and differed considerably from each other when categorized according to the three functions and three measuring points in the patients.departmental bulletin pape
Get PDFIn order to understand the role of Latin adjectives, international anatomical names containing the same adjectives were chosen from among the names of structures in the head and neck: these names were assorted into groups according to the actual meanings of the adjectives. When the Latin adjectives indicated the name of the structure, they signified: belonging to the structure, entering into the formation of the structure, articulating with the structure, transmitting the structure, giving attachment to the structure, or some other relationship to the structure. And, furthermore, the structures that were indicated by the same Latin adjectives might be different. In the Japanese language, those adjectives that have different meanings in other internationally accepted anatomical names were sometimes translated into different words. Because of this, some Japanese anatomical names were more concrete than the corresponding Latin anatomical names. It seemed that compound words and abbreviations, which can be formed easily in the Japanese language, made such expression possible.departmental bulletin pape
Get PDFThe distribution of a readiness potential (RP), i.e., a negative-going slow cortical potential (SCP) preceding the onset of voluntary movements, was studied in association with self-paced voluntary jaw-closing and jaw-opening movements in 4 healthy human subjects. A negative-going SCP starting at ca.1.5-2.0 s preceding the onset of the self-paced jaw-opening and jaw-closing movements was found at all the recorded sites of Fz, Cz, Pz, F3, F4, F7, F8, C3, C4, T3 and T4. The RP was maximum in amplitude at Cz (ca.8µV), although there was no significant difference between Cz and either C3 or C4; it was smaller at T3 and T4 than at any of Fz, Cz, Pz, C3, and C4. The polarity, amplitude, and time course of the RP in association with jaw movements was virtually the same as those associated with voluntary unilateral extension of the middle finger, except for a contralaterally-dominant side asymmetry between C3 and C4 in the latter. There was neither rapidly increasing negative potential (NS'） in the RP recorded from any site, nor bilateral difference in the RPs coinciding with unilateral biting of a gauze pad. It is suggested that the motor cortex would be activated bilaterally in coordination even in the case of unilateral biting.departmental bulletin pape
Get PDFWe produced a monoclonal antibody against epithelioid cell granulomas (ECGs) by immunizing mice with a crude tissue extract of lymph nodes with sarcoidosis. The established antibody (ECM antibody) strongly reacted with epithelioid cells and Langhans' type giant cells of ECGs not only in cases of sarcoidosis, but also in cases of other granulomatous diseases such as tuberculosis and Crohn's disease. In this study, we used the ECM antibody to improve the histopathological diagnosis of Crohn's disease, in which the demonstration of ECGs is critical for diagnosis, but morphological identification of ECGs by hematoxyline and eosin (HE) staining is frequently difficult. When we examined the tissues removed at operation from 11 patients with Crohn's disease, we observed a total of 29 lesions of morphologically recognizable ECGs, all of which were immuonohistologically positive for the ECM antibody (granuloma pattern). In addition the ECM antibody revealed 43 nests of tiny inflammatory lesions (nested pattern) that could not be morphologically recognized as ECGs by HE staining only. Both the granuloma and nested patterns of ECM immunoreactivity were present in all cases of Crohn's disease we examined, but were absent in all 15 cases of ulcerative colitis that were used as controls.departmental bulletin pape
Get PDFTo investigate the effect of voluntary teeth clenching on the isometric and isokinetic exercises of the lower limbs, the association of muscle strength (peak torque, PT) and muscle activities (integrated electromyographic activity per unit of time, iEMG/s) of the three muscles of the triceps surae with teeth clenching during isometric and isokinetic plantar flexion were simultaneously measured for 12 healthy male volunteers using a Cybex 6000 Extremity Testing and Rehabilitation System and a surface EMG analyzing system. The statistical analysis demonstrated that for the isometric exercise, PT and each iEMG/s significantly increased in association with teeth clenching, and a positive correlation existed between the biting force and each variable. In contrast, no association was found with teethclenching for the isokinetic exercise. In this study, therefore, it was found that the effect of teeth clenching differed between the isometric and isokinetic exercises.departmental bulletin pape
Get PDFThe purpose of this work was to investigate the physiological tooth displacement in function. We developed the tooth displacement transducer Type M-3 and measured the three dimensional displacement of the upper and lower left first molars in function. The summary is as follows: 1. Magnesensors were used in the tooth displacement transducer Type M-3. Its total weight was 48.7 g. and the measuring pressure was kept less than 0.4 g. It was fixed at the labial surface of the anterior teeth using a paraocclusal splint. 2. The linearity error of the transducer was less than 2% within a range of ±200 µm. 3. The upper left first molar showed displacement in the palatal and apical direction during clenching at the intercuspal position with habitual occlusal force or during the biting of articulating papers. The displacement varied between 40 and 136 µm. 4. The lower left first molar showed displacement in the apical and lingual direction during clenching at the intercuspal position or during the biting of articulating papers. The displacement varied between 29 and 65 µm. 5. The upper left first molar showed displacement in the palatal and apical direction during mastication. The displacement varied between 68 µm and 79 µm. The upper teeth moved first in the apical direction, then moved toward the labial direction. 6. In the lingual direction, the lower left first molar showed displacement ranging from 11 to 71 µm and 17 to 39 µm in the buccal direction during mastication.departmental bulletin pape
Get PDFThis study focuses on overt and covert problems experienced by mothers with disabled pre-school children and the resources that are available for coping with them. The aim of this study is to facilitate the coping behaviors of these mothers in order to improve their life-styles and well-being. The scores of the Home Care Resources Inventory(HCRI) of mothers with disabled pre-school children were compared with those of a control group of mothers with normal kindergarten-aged children. The results of the HCRI survey indicated the following： ① The major source of strength for the mothers with disabled children was the availability of a social support network, which consisted mainly of their own mothers and grandmothers，② The mothers with disabled children had insufficient time and little respite for themselves, and ③Emotional support from mothers who shared the same experiences was effective for coping with problems associated with the acceptance of disabled children. The support of health care professionals, however, had little effect in helping the mothers who were under stress, though they could help to change such mothers' attitudes. There was a possibility to facilitate mothers' coping skills if mothers with disabled children could get effective support at appropriate times. These results support the concept of empowerment (Rappaport 1984, Kieffer 1984)1,2. Further study is needed on ways to introduce this concept into nursing as well as to systematize procedures in routine nursing practice for releasing maternal behavior.departmental bulletin pape
Get PDFDental students at Tokyo Medical and Dental University are taught to prepare teeth for full cast crowns with a wall taper of 2 to 5 degrees and an occlusal clearance of 1.2 to 1.5 mm. However, it is difficult to achieve such an ideal taper. The objective of this study was to examine the abutment taper and height of teeth prepared for crowns by final-year dental students under clinical supervision. To evaluate the degree of taper and height of the prepared teeth, shadowgraphs of 63 working stone dies were traced. The angles and height of the abutments were then measured on the same tracing. Only 12.7% (8 out of 63 abutments) of the prepared teeth fell within the ideal range of 2 to 5 degrees, and the average taper was 9.5 degrees (19.0 degrees convergence angle). The average abutment height varied from 4.8 mm to 6.9 mm and showed a close relationship with the abutment taper. The average taper, 9.5 degrees, of the present study was larger than the ideal taper; however, it was thought to be clinically acceptable as it is difficult to achieve the ideal taper intraorally.departmental bulletin pape
Get PDFTensile bond strength measurements and scanning electron microscopic observations have been performed to evaluate the adhesive properties of new dentin bonding systems. To date, however, it was impossible to compare previously reported data among researchers, because there was no standardization of in vitro test methods. There have also been few reports about the correlation among tensile bond strengths (TBS) and morphologicalfeatures of the adhesive interfaces of recent systems. Therefore, the purpose of this study was to investigate the relationship between TBS to bovine dentin, following the guidelines documented by the International Organization for Standardization (ISO), and the morphology of resin/dentin interfaces of nine commercially available and one experimental bonding systems. The nine recent bonding systems used in this study showed significantly higher mean TBS (ranging from 25.0 to 14.8 MPa) than did a system (PhB) marketed ten years ago (9.3 MPa). However,morphological features of the resin/dentin interface varied among the systems, and no statistically significant correlation was found between TBS and width of the hybrid layer (p = 0.62). In order to evaluate the quality of the resin/dentin interface, quantitative analyses are needed to clarify the saturation and polymerization of resin in the hybrid layer.departmental bulletin pape
Get PDFThe purpose of this study was to compare the microbicidal effect of gaseous ozone with that of ozonated water in order to determine its usefulness as a method for disinfecting dentures. Although a large number of research studies have been done on the bactericidal effect of ozone, little is known about its microbicidal effects on oral microorganisms. Therefore, we tested the effect of ozone on three standard strains of oral microorganisms: Streptococcus mutans (strain IID 973), Staphylococcus aureus (strain 209-P), and Candida albicans (strain LAM 14322). When the gaseous ozone injection method was used, the numbers of cells of all three strains decreased to 1/105 at 1min, and by 3 min they were below the detection limit. Thus, the microbicidal effect of gaseous ozone was ascertained in a short time. In contrast, when ozonated water at 1 ppm and 3 ppm was used, C. albicans decreased to 1/10. A 700 mg/h ozone production level was needed to prepare 1 ppm ozonated water, whereas 20 mg/h of ozone was required by the gaseous ozone generator. These findings indicate that direct exposure to gaseous ozone seems to be a more effective microbicide compared with ozonated water, and that gaseous ozone can be clinically useful for disinfection of dentures.departmental bulletin pape