Kokubyo Gakkai zasshi. The Journal of the Stomatological Society, Japan最新文献

The aims of this research were to examine the effectiveness of feedback (FB) study of cavity preparation using a virtual reality system (VRS) and to discuss the evidence from an educational standpoint Thirty-nine dental undergraduate students of the fifth grade of Tokyo Medical and Dental University were randomly divided into the FR group and no-FR group (FB group n=21, no-FR group n=18). All subjects of each group performed cavity preparation of class II on the lower left first molar using VRS (DentSim) four times every week (EXO-3). At session EXO, all subjects performed a pre-test to assess their basic skill leve. At sessions EX1 and EX2, the FR group received feedback from the instructor based on a computer-assessment system. The no-FR group practiced their self-judgment without any feedback. At the last session, EX3, the preparation test was administered. All cavity preparations were graded by the VRS. The results showed that the FR group obtained significantly higher scores than the no-FR group, such as total score, outline shape, outline centralization, outline smoothness, wall incline, wall smoothness, proximal clearance, and box width. By session EX2, the FR group tended to spend longer preparation time than the no-FR group, however, at session EX3, there was no difference between both groups. These resdlts confirmed the effectiveness of cavity preparation with feedback study using VRS. It is suggested that this method of learning cavity preparation techniques is suitable for novice undergraduate dental students at the initial stage of cavity preparation practice.

Hemokinin-1 (HK-1) is a novel peptide described as a member of the tachykinin family. Substance P (SP), a representative member of the tachykinin family, has been well characterized and is thought to play a part in inflammation and pain. While several studies indicate that HK-1 is involved in inflammation and pain, the biological functions of HK-1 are not fully understood. In the present study we investigated the expression of HK-1 mRNA (TAC4) and SP mRNA (TAC1) in the dorsal spinal cord of rat after inducing peripheral inflammation by administering complete Freund's adjuvant (CFA) into the hind paw, using real-time RT-PCR. In the behavioral studies, the thresholds of withdrawal response of the hind paw to thermal stimulation significantly decreased on the ipsilateral side, but not on the contralateral side, 6 hours after CFA injection and thermal hyperalgesia persisted until 4 days after CFA injection. The level of HK-1 mRNA expression significantly increased on the bilateral sides of the dorsal spinal cord 6 hours after CFA injection and returned to the base level 1 day after injection. On the other hand, the level of SP mRNA expression did not change in the spinal cord 6 hours and 1 day after CFA injection. These results indicate that HK-1 may contribute to inflammatory pain, in the early phase, in a different manner from SP.

Photodynamic diagnosis (PDD) is a form of cancer detection based on the administration of an exogenous photoactivated compound that accumulates in malignant cells, followed by appropriate photo-irradiation. 5-aminolevulinic acid (5-ALA), which is one of these compounds, is a prodrug of the photosensitizer protoporphyrin IX (PpIX). This report describes a spectroscopic study of 5-ALA-generated PpIX fluorescence in human oral cancer cell lines. After transplanting five human oral squamous carcinoma cell lines into scid mice, the degree of tumor differentiation was evaluated by hematoxylin-and-eosin staining. Two, one, and two cell lines were poorly, moderately, and well differentiated, respectively. Under cell culture conditions, well and moderately differentiated cancer cells showed higher positive staining rates of AE1/AE3 than poorly differentiated ones in immunohistochemistry. 5-ALA-induced PpIX fluorescence intensities of five cell lines, which were cultured in Dulbecco's Modified Eagle's Medium (DMEM) treated with or without deferoxamine mesylate (DFO), were measured. In all cell lines, the maximum 5-ALA-generated fluorescence intensity was found in the presence of DFO. The fluorescence intensity varied with the degree of tumor differentiation in the following order: poorly differentiated, moderately differentiated, well differentiated. These results suggest that the fluorescence intensity of oral cancer cells differs according to the degree of tumor differentiation. However, even with well differentiated cancer cells, addition of DFO could increase the photodynamic sensitivity of 5-ALA as a result of greater cellular accumulation of PpIX.

Objective: Distraction osteogenesis has been widely used for the craniofacial region and even applied to alveolar bones to reduce the cleft width of cleft lip and/or palate patients. However, there have been no reports on the limitations on the total amount of lengthening that can be accomplished by distraction osteogenesis in this area. Therefore, we investigated how different extents of distraction osteogenesis affect the healing process using a canine cleft palate model.

Methods: Six beagle dogs were used in this study. A bony segment including the canine was prepared and translocated into a 10-mm bone defect area, imitating a cleft, at a rate of 1 mm/day for six or ten days, resulting in two groups (6- and 10-mm groups). Canine pulpal blood flow was monitored for 100 days by Doppler flowmetry. The animals were then sacrificed and the regenerated bone area was evaluated using peripheral quantitative computed tomography (pQCT) and a histological process. Statistical significance was confirmed by the Mann-Whitney rank sum test.

Results: Pulpal blood flow recovered to the original levels significantly earlier in the 6-mm group. It was shown by pQCT evaluation that cortical bone density in the regenerated bone was significantly higher in the 6-mm group. The amount of regenerated bone in histological sections was also significantly higher in the 6-mm group than in the 10-mm group.

Conclusion: We revealed that the amount of bone lengthening affects the progress of healing. These results suggest the importance of limited distraction osteogenesis in the maxillofacial area.

It has been planned to give pre-clinical practice in the clinic, so-called inclusive clinical practice phase I, for fifth-grade students in the School of Dentistry, Faculty of Dentistry, Tokyo Medical and Dental University, to give them the clinical training needed to perform dental practice and clinical practicum for comprehensive patient care, namely inclusive clinical practice phase II. This study analyzed the educative efficiency of the class on nosocomial infection control (NIC) by comparing achievements pre- and post-test, and discussed appropriate education planning on the NIC for dental students. Sixty-two fifth-grade students in the 2007 academic year sat the pre- and post-tests; the mean score and standard deviation of these tests were 5.30 +/- 1.26 (n = 56) and 8.59 +/- 1.18 (n = 59), respectively. There was a statistically significant difference between them (paired t-test, p < 0.01). Another finding was that students with high scores in the post-test did not necessarily achieve high ratings in the pre-test. It is suggested that the introduction of pre- and post-tests and the clarification of main points in the class as a theme of NIC could be a useful tool for increasing the comprehension of students on the theme. Since students at lower grades will attend clinical practice in the university hospital, it is thought that students should be given NIC training early in the clinical course, and the current curriculum should be improved to increase the opportunity for students to study this important issue.

This study examines the psychological states and QOL in oral cancer patients during the perioperative and postoperative survival periods. Those patients who were scheduled for and had undergone primary surgery at the Oral and Maxillofacial Surgery Section, Tokyo Medical and Dental University Hospital, Tokyo, Japan were selected for this study. They took two different kinds of tests, i. e. the Hospital Anxiety and Depression Scale (HADS) and the Japanese-language version of the Functional Assessment of Cancer Therapy Head and Neck (FACT-H & N) version 4. In a longitudinal study, interval assessments were done at one day before surgery, one week after surgery and one month and six months each after being discharged from the hospital, respectively. In a cross-sectional study, outpatients during the postoperative follow-up periods were evaluated. Statistically, before surgery psychological anxiety became highest, while after surgery depression grew and QOL in the somatic and specific domains decreased. After discharge from the hospital, the patients with longer-term postoperative survival had better psychological states and QOL. These results provide important information regarding psychological states and QOL in oral cancer patients for caring and supporting based on perioperative and postoperative periods.

The aim of this study was to survey the current state of the temporomandibular joint disorder treatment in our clinic and to confirm the therapeutic outcomes. The subjects in this study were recruited from among the patients with temporomandibular disorders who attended the Temporomandibular Disorder Special Clinic, Department of Oral Surgery, Hitachi Yokohama Hospital during one year period from February 2007 to January 2008. A total of 100 consecutive outpatients diagnosed with temporomandibular disorders were selected for the study. Pain intensity and the degree to which daily function was limited before and after treatment were evaluated using the Visual Analogue Scale (VAS). The Beck Depression Inventory-II (BDI-II) score was evaluated simultaneously, and the correlation with changes in symptom was evaluated. The median (25th, 75th percentiles) of pain intensity (VAS value) before treated was 45 (25.0, 65.0) and the degree of limitation of daily function (VAS value) was 15 (0.0, 50.0). The median (25th, 75th percentiles) of pain intensity at 4 weeks after was 10 (0.0, 30.0), and significantly lower than that before treatment (p = 0.000). The degree of limitation of daily function was 0 (0.0, 10.0), also significantly lower than that before treatment (p = 0.000). The BDI-II score decreased from 8 (2.0, 11.8) before treatment to 5 (2.0, 11.0, p = 0.024) and showed no significant correlation with the improvement in outcomes by primary treatment for temporomandibular disorders.