Search

An objective method to recognize patient psychology using heart rate variability (HRV) has recently been developed and is increasingly being used in medical practice. This study compared the potential of this new method with the use of conventional surveys measuring anxiety levels in patients undergoing impacted third molar (ITM) surgery. Patient anxiety was examined before treatment in 64 adults who required ITM surgery, using two methods: measurement of HRV and conventional questionnaire surveys (state section of the State-Trait Anxiety Inventory (STAI-S) and Dental Fear Survey (DFS)). Both methods were assessed for their respective abilities to determine the impact of personal background, the amount of information provided, and the surgical procedure on patient psychology. Questionnaires and HRV yielded the same finding: dental experience was the single background factor that correlated with patient anxiety; the other factors remain unclear. The STAI-S showed a significant relationship between the information provided to the patient and their anxiety level, while the DFS and HRV did not. In addition, HRV demonstrated its ability to assess the effects of the surgical procedure on patient psychology. HRV demonstrated great potential as an objective method for evaluating patient stress, especially for providing real-time information on the patient's status.

Aims: The present study investigated changes in the student evaluations of a medical ethics class after studying in dental school for an additional 3 years.Materials and Methods: A problem-based learning medical ethics class in which students discuss the “right to death with dignity” using video material as a trigger was offered to third-year students at the School of Dentistry. At the end of the class, each student submitted a report describing their own opinions of the ethical questions raised as well as their impression of the class. Three years later, the same students were surveyed regarding cognitive changes in class evaluations. The changes in class evaluations were statistically analyzed with reference to the contents of the initial report (P < 0.05). Results: Student evaluations of the class rose 3 years later. One reason for the evaluation rise was considered to be the growth in their reflection capacity during additional years of learning experience in the dental school. Students whose report demonstrated that they were engaged by the ethical dilemma tended to raise their evaluation of the class. On the other hand, students who mentioned the difficulty of the task or the shocking images in the video material in their initial report did not raise their evaluation later. Thus, students’ perception of the task or setting in the class appeared to have a continuing effect on their evaluation. Conclusion: The results confirmed that student evaluations of a class would change after additional years of learning experience.

Background: To practice holistic therapy, health professionals must understand not only biological information but also psychological and social aspects of patient complaints at the first visit medical interview. However, few studies have investigated psychological and social causes associated with the patient’s complaint. Although patients’ complaints are expected to be related to their background and behavior, research on this issue has been limited. Aim: This study investigated the proportions of biological, psychological, and social causes contributing to patients’ complaints as well as the influences of new outpatients’ backgrounds on reasons for visiting our hospital. Methods: We analyzed health questionnaires from 5129 new outpatients visiting our hospital. Patients’ reasons for visiting the dental hospital were classified into three categories: “biological,” “psychological,” and “social.” We subdivided biological reasons based on the patient’s explanatory model. Descriptions of psychological reasons were subdivided into several groups. Results: Biological, psychological, and social reasons for visiting our hospital were given by 86%, 6%, and 8% of patients, respectively. Compared to men, significantly more women gave psychological reasons, while significantly more men gave social reasons. Patients who had attended another dental clinic were significantly more likely to indicate a psychological reason. Among patients who had attended another dental clinic, the most common reason for visiting our hospital was dissatisfaction. Patients who had not previously consulted any medical clinic tended to present explanatory models. Patients without a surgical history or systemic disease and those not taking medication showed similar tendencies. Conclusion: These findings suggest that a patient’s background affects their behavior.

The purpose of this study was to investigate the effectiveness of the Communication Studies Program at Tokyo Dental College as a tool in behavioral education. The number of Patient Community members who had participated in multiple sets of the program for third-year students in the same year within the 3-year period spanning 2016 to 2018 (152, 148, and 129 students in 2016, 2017, and 2018 respectively), and the period during which they had participated in multiple sets were investigated. Comments on student behavior, including on hairstyle, clothes, and attitude, were also analyzed. The total number of members who had participated in multiple sets (1 set comprised 1 lecture and 2 training sessions) was 5; and their comments were more favorable during the second (sets 3 and 4) than the first half of the 1-month program (sets 1 and 2). During the first half, the students were criticized for speaking softly, having bad posture, not concentrating, and having an attitude inappropriate for a medical worker; but in the second half, they were praised for beginning to adopt the proper attitude for a medical worker, speaking louder, having better posture, and a very serious attitude. These findings suggest that the Communication Studies Program is effective in improving student behavior.

Aim Self-efficacy is considered to be an important factor influencing behavior change; however, there are no existing tools to measure self-efficacy in the context of oral health among older adults. The purpose of the present study was to develop the Geriatric Self-Efficacy Scale for Oral Health (GSEOH) for use with older adults, and to evaluate its reliability and validity. Methods The self-administered questionnaire was completed by 646 Japanese older people. The draft version of the scale consisted of 35 items that were generated to measure the three dimensions of personal beliefs in tooth brushing, observing own oral health status and oral function. We carried out a principal components factor analysis with promax rotation, and investigated the scale's internal consistency and construct validity. Results The final version of the scale consisted of three dimensions measured with 20 items. Cronbach's alpha of the GSEOH total scale was 0.924. There were significant differences (P

Objectives A cross-sectional study was carried out to investigate the determinants of self-rated oral health among community-dwelling older people in Japan. Methods The participants were 897 (357 men and 540 women) aged 65 years and over who participated in a comprehensive geriatric health examination, which included an oral examination, a face-to-face interview assessing cognitive function, questionnaires regarding depressive symptoms and functional capacity, and a medical examination. The oral examination measured indices of oral health status: number of present teeth, number of functional teeth, occlusal force and amount of resting saliva. Multiple logistic regression analyses were carried out to determine the factors associated with poor self-rated oral health. Results The mean age of the participants was 73.5 ± 5.0 years. The prevalence of poor and rather poor self-rated oral health was 11.5% and 29.5%, respectively. Multiple logistic regression analyses showed that the number of present teeth (odds ratio [OR] 0.97, 95% confidence intervals [CI] 0.95–0.99), difficulty in mastication (OR 3.20, CI 2.18–4.70), presence of xerostomia (OR 1.43, CI 1.02–2.01), total score on the MoCA-J (OR 1.06, CI 1.01–1.11), and reduction in frequency of leaving the house (OR 1.64, CI 1.12–2.41) were significantly associated with poor self-rated oral health. Conclusions The present results suggested that self-rated oral health was a significant factor in oral health status as well as overall well-being among community-dwelling older Japanese people. Geriatr Gerontol Int 2015; 15: 755–761.

Objective This study investigated the prevalence and factors associated with xerostomia and hyposalivation among community-dwelling older people. Background Xerostomia and hyposalivation are common symptoms in the older population. Materials and methods This study included with 894 community-dwelling, Japanese older people (355 men, 539 women; age 65–84 years) who participated in a comprehensive geriatric health examination, which included questionnaires and interviews regarding medical history, medications, Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-IC), depressive condition. The Zung Self-Rating Depression Scale (SDS) was used to evaluate depression. Resting salivary flow rate was evaluated by the modified cotton roll method. Results In this study, 34.8% of the participants (mean age, 73.5 ± 5.0 years) complained about xerostomia, while the prevalence of hyposalivation was 11.5%. Multiple regression analysis revealed hypnotics use [odds ratio (OR) = 1.71, 95% confidence interval (CI) = 1.13–2.61], SDS (OR = 1.05, CI = 1.04–1.07) and TMIG-IC total points (OR = 0.87, CI = 0.76–0.99) to be significantly associated with xerostomia. In contrast, female gender (OR = 2.59, CI = 1.55–4.31) and the use of agents affecting digestive organs (OR = 1.78, CI = 1.11–2.86) were associated with hyposalivation. Conclusion Our findings showed that the prevalence of xerostomia and hyposalivation were approximately 1 in 3 and 1 in 10 respectively. The factors associated with psychological factors and high-level functional competence, while hyposalivation was associated with medications and gender, as well as systemic and/or metabolic differences. It is important to consider these multidimensional factors associated with xerostomia and hyposalivation.

A facilities-group system designed to provide clinical training at dental clinics was developed after postgraduate clinical training became mandatory for dentists in Japan in 2006. As a result, there has been a steady increase in the number of dental clinics collaborating with dental school hospitals under this program. A larger number of dental clinics have also been designated as single-system facilities, program management facilities or collaborating facilities. However, it remains to be determined whether this increase in the number of dental clinics designated as clinical training facilities has led to an increase in the amount of training offered. Therefore, the purpose of this study was to investigate trends in the percentage of postgraduate dental trainees at dental clinics between fiscal years 2006 and 2010. The results showed no significant correlation among (1) the percentage of dental clinics designated as single-system collaborating facilities, (2) the percentage of training programs at dental clinics, and (3) the proportion of training program recruitment offers by dental clinics compared to the total number of recruits. These findings showed that increasing the number of collaborating dental clinics did not lead to an increase in the amount of clinical training at dental clinics. The findings also suggest that increasing the number of single-system or program management dental clinics is important in promoting clinical training at dental clinics.

Postgraduate clinical training for dentists has been mandatory in Japan since 2006. Hirata et al. reported that the geographic distribution of postgraduate dental trainees by prefecture in 2006 was worse than that of practicing dentists. This suggests that the postgraduate clinical training system could intensify the problem of distribution of dentists. In this study, therefore, we reviewed the geographic distribution of postgraduate dental trainees and practicing dentists between 2006 and 2010 in detail by city, ward, town and village by using the Lorenz curve and Gini coefficient. The results showed that while there was no significant worsening of geographic distribution of postgraduate dental trainees, the distribution of practicing dentists continued to deteriorate. A number of reasons may explain these findings: the clinical training system is based on a one-year employment contract, and dentists subsequently relocate as driven by the market; and geographic distribution among cities, towns and villages has worsened as a result of the merger of municipalities. The geographic distribution of practicing dentists is expected to deteriorate further if the number of dentists takes a downward turn in the future. Therefore, it is necessary to continuously review the distribution of postgraduate dental trainees.

Self-efficacy is considered to be an important factor influencing behavior change; however, there are no existing tools to measure self-efficacy in the context of oral health among older adults. The purpose of the present study was to develop the Geriatric Self-Efficacy Scale for Oral Health (GSEOH) for use with older adults, and to evaluate its reliability and validity.The self-administered questionnaire was completed by 646 Japanese older people. The draft version of the scale consisted of 35 items that were generated to measure the three dimensions of personal beliefs in tooth brushing, observing own oral health status and oral function. We carried out a principal components factor analysis with promax rotation, and investigated the scale's internal consistency and construct validity.The final version of the scale consisted of three dimensions measured with 20 items. Cronbach's alpha of the GSEOH total scale was 0.924. There were significant differences (P 0.05) in total scores on the GSEOH for the change process of oral health behavior, and in relation to self-rated oral health.We developed the GSEOH, with three factors and 20 items, and confirmed its reliability and validity. More studies are necessary to investigate the cross-cultural validity and reliability with larger samples from other countries. Geriatr Gerontol Int 2017; 17: 1406-1411.

Aim: Mastication is an important function to maintain, not only for oral health, but also for quality of life. An easy-to-use method to evaluate the chewing ability of elderly people in any environment is necessary. Few studies have discussed the effectiveness of the masseter muscle by palpation. The purpose of this study was to clarify the availability of masseter muscle tension assessment methods by investigating its relationship with oral health status, and comparing it with other methods of assessing chewing ability. Methods: This cross-sectional study was carried out with 547 community-dwelling elderly subjects (246 men and 301 women; mean age 73.8 ± 6.2 years) who participated in a comprehensive annual geriatric health examination in 2010 at Kusatsu, Gunma, Japan. Chewing ability was evaluated by masseter muscle tension palpation, differences of masseter muscle thickness, occlusal force, self-reported chewing ability, and the number of remaining and functional teeth. Masseter muscle thickness was measured by ultrasonography. Results: Masseter muscle thickness and occlusal force showed significant differences between males and females. The strength of masseter muscle tension palpation was significantly associated with men's occlusal force, masseter muscle thickness, the number of remaining and functional teeth, and self-reported chewing ability (P

A cross-sectional study was carried out to investigate the determinants of self-rated oral health among community-dwelling older people in Japan.The participants were 897 (357 men and 540 women) aged 65 years and over who participated in a comprehensive geriatric health examination, which included an oral examination, a face-to-face interview assessing cognitive function, questionnaires regarding depressive symptoms and functional capacity, and a medical examination. The oral examination measured indices of oral health status: number of present teeth, number of functional teeth, occlusal force and amount of resting saliva. Multiple logistic regression analyses were carried out to determine the factors associated with poor self-rated oral health.The mean age of the participants was 73.5 ± 5.0 years. The prevalence of poor and rather poor self-rated oral health was 11.5% and 29.5%, respectively. Multiple logistic regression analyses showed that the number of present teeth (odds ratio [OR] 0.97, 95% confidence intervals [CI] 0.95-0.99), difficulty in mastication (OR 3.20, CI 2.18-4.70), presence of xerostomia (OR 1.43, CI 1.02-2.01), total score on the MoCA-J (OR 1.06, CI 1.01-1.11), and reduction in frequency of leaving the house (OR 1.64, CI 1.12-2.41) were significantly associated with poor self-rated oral health.The present results suggested that self-rated oral health was a significant factor in oral health status as well as overall well-being among community-dwelling older Japanese people.

The purpose of the present study was to evaluate the changes in oral health and function through an oral health educational program for the independent older people with xerostomia.Community-dwelling older people with xerostomia aged over 65 years who participated in a preliminary comprehensive health survey in 2011 were recruited for the educational program. A total of 47 participants were randomly assigned into two groups, the intervention group (n = 26) and the control group (n = 21). The intervention group attended a 90-min oral health education program every 2 weeks for 3 months. The program consisted of oral hygiene instruction, facial and tongue muscle exercise, and salivary gland massage. The control group was provided only general information about oral health. The assessments of oral function, such as oral diadochokinesis of articulation, swallowing, taste threshold and salivary flow rate, were carried out before and after 3 months with or without intervention.A total of 38 participants (21 of intervention group and 17 of control group) completed the study protocol. In the intervention group, resting salivation significantly improved after the program. The second and third cumulated Repetitive Saliva Swallowing Test times significantly improved in the intervention group. The threshold for bitterness significantly lowered in the intervention group, whereas the sour threshold significantly heightened in the control group after 3 months (P 0.05).The present study suggests that the educational program targeting oral function improvement is effective among the independent older population.

Rat osteocalcin was subjected to proteolysis by cathepsins B and L at acid pH in vitro. Short fragments of fewer than 8 amino acids were liberated from both the NH2- and COOH-termini of the molecule, but the midportion, composed of antiparallel α-helical domains, was resistant to proteolysis. Intact rat osteocalcin bound 10 Ca2+/mol protein at pH 7.5 and the binding decreased to half that amount at pH 5.0, while the midportion fragment (Ala8-Lys43) bound 4–5 Ca2+/mol protein at both pH 5.0 and 7.5. When COOH-terminal-truncated rat osteocalcin (Tyr1-Lys43) was prepared with lysyl-endopeptidase, it showed nearly the same Ca2+ binding as that of the intact molecule. Our results suggest that proteolytic processing of the terminal sequence of osteocalcin alters its intrinsic Ca2+-binding capacity and that its NH2-terminal sequence is probably involved.

Faculty of Dentistry, Tokyo Medical and Dental University first introduced New Curriculum of Behavioral Dentistry in Japan. This curriculum has been established in consideration of the current social environments and dental clinical practice in our country, in addition to reference to Curriculum Guidelines in the USA. When students' impressions and assessments on the courses were researched and analyzed, the majority were found to be satisfied with this curriculum although several problems to be solved were also presented at the same time, such as timing of derivering lectures.

A polyclonal antibody against rat osteocalcin propeptide (anti-pro-OC) has been prepared and used in immunohistochemical studies to demonstrate cells expressing osteocalcin (OC). With the anti-pro-OC antibody, predominant immunoreaction was observed in cuboidal osteoblasts along the bone formation surface, and in odontoblasts and cementoblasts of the tooth. The appearance of pro-OC antigenicity was well consistent with the expression of OC mRNA in the cells as demonstrated by in situ hybridization. Matrices around these cells showed no apparent pro-OC antigenicity, which contrasted remarkably with the immunoreaction with an antibody against the N-terminal sequence of mature rat OC (anti-OC-N). Although the anti-OC-N antibody positively reacted with OC-producing cells, the intensity of the immunoreaction was much weaker than that obtained with the anti-pro-OC antibody. Furthermore, we examined the appearance of pro-OC antigenicity in maxillary alveolar bone during experimental tooth movement in rats. When the maxillary first molar was moved to the mesial direction with a closed coil spring, the bone remodeling phase in the distal alveolar bone surface changed from dominantly resorptive to formative. After the application of orthodontic force, pro-OC-positive osteoblasts appeared on the distal alveolar bone surface (tension side), according to the appearance of alkaline phosphatase activity on the bone surface. Thus, the use of the anti-pro-OC antibody is a practical means to demonstrate cells actively expressing OC and could be an alternative to in situ hybridization.

This study analysed the perceptions of dental clinical attire among patients, dentists and dental students at the Dental Hospital, Tokyo Medical and Dental University using factor analysis to investigate what kinds of factors would underlie the perceptions and would guide evaluation of wearing items of dentist. The subjects comprised 146 patients, 97 dentists, and 81 students of the Dental Hospital. Using a five-point Likert scale, the subjects were asked to score their preferences for 35 items that might be worn by a dentist in the clinic. These scores were analysed using factor analysis and seven factors were extracted. The factors were classified into three categories; the first was a traditional factor representing the public self of dentists, next was casual factors representing the private self of individual dentists, and the other was practical factors. Using MANOVA and univariate ANOVA, differences in perceptions among the subjects were found for factors of casual items while that for traditional items not (P0.05). Thus, clinical attire would be evaluated from the viewpoint of interplay between public self and private self of the clinician as well as practical aspects. The variation in perceptions would be influenced by wearers' gender and observers' age.

These effects of polychlorinated biphenyl (PCB) were examined by light and electron microscopy and biochemical analysis of lysosomal enzyme activities. Several experimental protocols with dosage schedules of either 0.2, 2.0, or 20 mg/kg of PCB were used. Typical histological changes were observed in mice given 2 mg/kg of PCB in a single injection. There were no remarkable changes until 4 days after PCB administration; marked cytoplasmic vacuolation was observed in parotid acinar cells at 7 days. The activities of lysosomal enzymes increased after the PCB injection and their maximum values appeared consistently at 4 days after the treatment; the increases were threefold for acid phosphatase, twofold for β-glucuronidase, threefold for cathepsin D, fivefold for cathepsin H and twofold for cathepsin L. As vacuolation was preceded by a large increase in lysosomal enzyme activities and the vacuoles co-localized with lysosomes, it is suggested that an increase in these activities induced by PCB may be closely related to the development of vacuolation in the parotid acinar cells as a subacute effect of PCB.

Mastication is an important function to maintain, not only for oral health, but also for quality of life. An easy-to-use method to evaluate the chewing ability of elderly people in any environment is necessary. Few studies have discussed the effectiveness of the masseter muscle by palpation. The purpose of this study was to clarify the availability of masseter muscle tension assessment methods by investigating its relationship with oral health status, and comparing it with other methods of assessing chewing ability.This cross-sectional study was carried out with 547 community-dwelling elderly subjects (246 men and 301 women; mean age 73.8 ± 6.2 years) who participated in a comprehensive annual geriatric health examination in 2010 at Kusatsu, Gunma, Japan. Chewing ability was evaluated by masseter muscle tension palpation, differences of masseter muscle thickness, occlusal force, self-reported chewing ability, and the number of remaining and functional teeth. Masseter muscle thickness was measured by ultrasonography.Masseter muscle thickness and occlusal force showed significant differences between males and females. The strength of masseter muscle tension palpation was significantly associated with men's occlusal force, masseter muscle thickness, the number of remaining and functional teeth, and self-reported chewing ability (P0.05). Female participants showed a significant association with occlusal force, masseter muscle thickness, the number of remaining teeth, and self-reported chewing ability and results of palpation (P0.05).These results showed that the palpation of masseter muscle tension is a reliable and easy-to-use method to evaluate the chewing ability of elderly people.

カテプシンDとEは, 主要な細胞内アスパラギン酸プロテアーゼである。本研究は, 両酵素の細胞内での活性調節機構を検索する目的で, 動物種や組織などの由来を異にする酵素を用いて, ATPや他のヌクレオチドによる酵素活性の上昇について比較, 検討を行った。ウシおよびラットカテプシンDは, ATPや他のヌクレオチド存在下では, ウシ血清アルブミンを基質としたときに顕著な酵素活性の上昇が認められ, AMP-PCP存在下でも酵素活性の上昇が認められた。ウシヘモグロビンや合成基質を用いたときは, アルブミンほどの酵素活性の上昇は認められなかった。一方, ヒト赤血球およびラット脾臓カテプシンEは, ヘモグロビンを基質としたときのみ, ATPや他のヌクレオチド存在下にて酵素活性の上昇が認められた。さらに, ATPは, カテプシンEの熱安定性を顕著に上昇させ, 酵素分子を安定化することが明らかとなった。

The purpose of the present study was to determine the levels of osteocalcin, a bone specific matrix protein, in gingival crevicular fluid (GCF) from periodontal disease patients and to investigate the relationship between GCF osteocalcin levels and clinical parameters. Nineteen initial visit patients, 5 patients with gingivitis and 14 patients with adult periodontitis, participated in this study. The clinical parameters including probing depth, attachment level, gingival index, and tooth mobility were recorded following careful sampling of GCF with a filter paper strip harvested for 3 minutes. Osteocalcin adsorbed on a strip was extracted in a plastic tube containing 150 microliters of 10 mM sodium phosphate buffer (pH 6.5). GCF osteocalcin was determined by a newly-developed, high sensitive enzyme immunoassay which could recognize the N-terminal 20 residue peptide. In gingivitis patients, no significant amounts of osteocalcin were detected. In periodontitis patients, on the other hand, osteocalcin levels were detected, ranging between 0 and 540 pg/tube and positively correlated with these clinical parameters (P < 0.01). Moreover, in several sites in GI = 3 group, extremely higher levels of GCF osteocalcin were detected. These results strongly suggest that in addition to the presence of GCF osteocalcin the levels of osteocalcin may reflect the degree of the periodontal inflammation at the sampled sites.

We investigated differences in the depth of hypoxia produced by apneic events of the same duration (30 seconds) amongst patients with different degrees of OSAS according to their AIs (apnea indices). The relationship between apnea duration (seconds) and fall in oxygen saturation (%) was evaluated by means of a linear regression analysis. The fall induced by a 30-second apnea event was designated as the "oxygen desaturation value 30" (ODV30). We analyzed the polysomnographic recordings of 122 OSAS patients who showed significant correlations (p0.01) between apnea duration and subsequent fall in oxygen saturation and calculated their respective ODV30. We evaluated the influence of AI and BMI on ODV30 by multi-comparison and found out that standardized partial regression coefficients of BMI and AI were 0.578 and 0.148, respectively (multi-regression analysis, SPSS). BMI was proved to be more influential on ODV30 than AI was. On the other hand, the ODV30 of mild, moderate and severe OSAS patients was 8.84 +/- 2.62% (Mean +/- S.D.), 8.25 +/- 2.45% and 10.59 +/- 3.32%, respectively. Our study shows that fall in oxygen saturation is particularly extensive in severe OSAS patients and that fall in oxygen saturation is deepened as obesity increases. We think ODV30 is a useful variable for evaluating OSAS.

The mechanical properties of dentin are changed after bleaching, although the effects of the bleaching conditions on the tensile strength of dentin have not been determined. In the current study, a tensile test of bovine dentin was conducted after bleaching and the effects of the bleaching conditions were investigated, including the number of bleaching times, the location where the bleaching agent was applied, and the kind of illumination. The weight of organic content in dentin before and after application of the agent was also measured. The results showed that the tensile strengths did not change after three times office bleaching procedure, and the location where the bleaching agent was applied, the kind of bleaching agent and the kind of illumination did not have influence on the tensile strength. On the other hand, organic component in dentin significantly decreased after application of the agent (p0.05). Since the bleaching agent would potentially affect tensile strength with deterioration of collagen matrix, the frequency of bleaching treatment should be minimized in clinical use.

Postgraduate clinical training for dentists in Japan became mandatory in April 2006. Mandatory postgraduate clinical training for physicians has been criticized as having accelerated the imbalance in distribution of physicians. This suggests the danger that the same phenomenon might occur in distribution of dentists. It is also necessary to investigate the geographic distribution of dental trainees and practicing dentists in Japan. In this study, the number of dental trainees enrolled in each clinical training program and number that had actually received clinical training at each facility were compared by prefecture. The results suggest that disparities in the number of dental trainees among prefectures are being compensated for by movement across prefectural borders under the clinical training facilities-group system. Postgraduate dental trainees, however, showed a significantly greater imbalance in geographic distribution than practicing dentists. Continuation of the postgraduate clinical training for dentists under the existing system may accelerate this imbalance in distribution of dentists. To prevent this, practical measures should be taken in accordance with the coming review of the system, based on research regarding changes in geographic distribution of dental trainees.

Abnormal occlusal sensation induced by wearing oral appliance (OA) was assessed in this study.Twelve non-apneic healthy subjects with normal dental occlusion were used in this study. The 12 subjects slept wearing OAs at night. Occlusal sensation, biting force, occlusal contact area and muscle fatigue were evaluated every 15 minutes during 4 hours after removals of worn OAs when they waked up on the following morning. Same procedures were repeated on the same subjects after the sleep without OAs on the other day.The differences of occlusal sensation was statistically significant up to 75 minutes after removal of OAs (p0.05). The difference of biting force was statistically significant immediately after removal of OAs (p0.05). There were statistically significant correlations (p0.05) between occlusal sensation and biting force in 9 of 12 subjects. Two of 12 subjects showed significant correlations (p0.05) between occlusal sensation and muscle fatigue. Only one of 12 subjects showed significant correlation (p0.05) between biting force and muscle fatigue.Abnormal occlusal sensation is probably elicited by non-physiological displacement of TMJs, nonphysiological extension of the chewing muscles and/or continuous compression toward the periodontal membranes by using OAs for hours at night.

OBJECTIVE Objective Structured Clinical Examination (OSCE) is widely used to assess the core competency of dental residents. However, the educative effect of feedback in OSCE has not been fully examined. Therefore, we investigated the educative effect of formative feedback in a medical interview station. METHODS The subjects were 51 residents in the clinical training course of our dental hospital. After completing the medical interview station, residents were individually given formative feedback by evaluators and standardized patients. Two months later, residents were asked to fill in a questionnaire about the contents of feedback and self-rating mental strain level during OSCE. Videotaped performance and feedback were reviewed by investigators to check the answers to the questionnaire. RESULTS Evaluators provided an average of 3.1 feedback items, and standardized patients provided an average of 1.6 feedback items for each resident. However, each resident remembered an average of 1.3 feedback items from evaluators and 0.9 from standardized patients. The lower the score of residents in the medical interview station, the more feedback items were given to residents. A significant negative correlation was found between the score of evaluators and self-rating mental strain level (Spearman rho = -0.326, p = 0.019). CONCLUSION For effective feedback, evaluators or standardized patients should focus on 2 to 3 items of essential points in OSCE. Repetition of feedback using videotaped performance may be useful to improve communication skills for medical interview.

The toxicity of phenol, parachlorophenol, camphorated phenol, camphorated parachlorophenol, and camphor was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay on established rat dental pulp cells (RPC-C2A). RPC-C2A cells at the confluent stage were incubated for 24 h in an experimental medium containing each compound at different concentrations. All tested drugs showed cytotoxicity in the MTT assay in a concentration-dependent manner. It is believed that camphor is a vehicle, and it reduces the toxicity of phenol and parachlorophenol. However, camphor itself showed cytotoxicity, and the addition of camphor increased the toxicity of phenol and parachlorophenol, reconfirming the cytotoxicity of these classical antiseptics.

The aim of the present study was to clarify the difference between the imagination of patients and the reality in regard to the location, the form and the size of the cavity in case of cavity preparation for dental restoration. Firstly, we manufactured the dummy dentition for simulated cavity preparation and the operator intra-orally prepared a cavity on the dummy dentition in subject to confirm its validity. Then, 5 operators intra-orally prepared prescribed cavities at the both sides of maxillary first molars on the dummy dentition in every one of 5 subjects with masking. We compared the location, the form and the area of these prepared cavities with those imagined by subjects, respectively. In 58% of cases, the subjects could accurately recognize the location of prepared teeth. And 34% of cases also determined the Class of cavity form. The imagined area was larger than the actual area and the difference was statistically significant (p0.001). These results suggested that the perception of the patients regarding the location and the form of the prepared cavity was inaccurate during cavity preparation and patients tended to overestimate amounts of removed tooth substance.

In chemo-mechanical caries removal procedures, chloramines are typically used for chemical softening of carious dentin. However, the specific effect of chloramines to be compared to sodium hypochlorite has not been sufficiently clarified. In present study, the effect of chloramines used in the Carisolv-system on carious dentin mechanical properties and morphology were investigated, using Vickers hardness test and scanning electron microscopy (SEM). Sections of permanent teeth with dentin caries were treated with chloramines, prepared by mixing amino acids (glutamic acid, lysine, and leucine) with sodium hypochlorite or with sodium hypochlorite alone or with purified water. There was a tendency that the application of the sodium hypochlorite solution softened the sound dentin and/or inner layer of carious dentin more than the application of the chloramines solution did. In SEM observations, the application of chloramines resulted in opening dentinal tubules in the outer layer of carious dentin: Occluded dentinal tubules were seen after sodium hypochlorite application. There is a possibility that the amino acids in the Carisolv-system decrease the aggressive effect of sodium hypochlorite on sound dentin and/or inner layer of carious dentin and also would enhance the disrupting effect on degenerated collagen in carious dentin outer layer.

In order to investigate the morphological characteristics of Japanese patients with obstructive sleep apnea (OSA) and basis for selection of an oral appliance (OA) therapy, the craniofacial skeleton, soft tissue and upper airway were analyzed on lateral cephalograms from 103 patients with OSA and 98 control subjects. At first, the 103 OSA patients were divided into two groups according to their body mass index (BMI). The results were the following: Micrognathia was a major risk factor of Japanese OSA patients instead of obesity; the narrowing in the hypopharynx was observed due to the inferior-located hyoid bone, especially in the obese group, an enlarged tongue and sticking of fatty-tissue to upper airway wall were observed in addition. Secondly, the 103 OSA patients were treated by OA, and were classified according to the reduction ratio of AHI (rAHI) again. The results suggested that the patients group which showed rAHIor = 50% had a balanced relationship between the maxilla and mandible. These findings proved that the morphological characteristics specific to Japanese patients with OSA and patients who were allowed to accept the OA therapy were exist.

The effect of local administration of osteocalcin (OC) on experimental tooth movement was examined in the rat. The maxillary first molar was first moved mesially with an initial tipping force of 30 g with a closed-coil spring anchored to the incisor for 10 days (n = 48). Three experimental groups (n = 8) were injected with purified rat OC at doses of 0.1, 1, and 10 micrograms, respectively. The injection into the palatal bifurcation site of the first molar was repeated daily. The control groups (n = 8) were injected with rat serum albumin (10 micrograms), phosphate buffered saline (PBS), or were not injected. Tooth movement was evaluated daily by measuring the inter-cuspal distance between the first and the second molars on a precise plaster model. The cumulative tooth movement (mm) in the 1-microgram OC-injected groups was significantly more than that in all of the control groups on day 9. The rate of tooth movement (mm/day) showed periodical elevation, with high values on days 1, 4, 7, and 9. Acceleration of tooth movement by OC was significant in the early experimental period. Subsequently, acceleration of early tooth movement by OC was histologically evaluated (n = 40). Each of four animals from the control (PBS, n = 20) and the experimental (1 microgram OC, n = 20) groups was killed daily up to 5 days. A significantly larger number of osteoclasts accumulated on the mesial alveolar bone surface in the 1-microgram OC-injected group on day 3 than that observed in control group. These results suggest that administration of OC accelerates orthodontic tooth movement due to enhancement of osteoclastogenesis on the pressure side, primarily in the early experimental period.

The purpose of this paper is to present an outline of student's practice of interviewing simulated patients at behavioral science in dentistry. This practice was initiated as part of a newly introduced behavioral science course at our school of dentistry, to enable students to acquire communication skills, comprehensive understanding, and a proper attitude vis-à-vis patients. Students as well as instructors involved in the practice evaluated it as highly relevant for clinical education. It is concluded that the development of such practices in dental education is a prerequisite for training students to dentists oriented toward patient-centered dental practice.

The release of serotonin (5-hydroxytryptamine, 5-HT) in the dorsal hippocampus was measured using an in vivo microdialysis method in rats subjected to the Vogel type conflict test. The conflict situation significantly increased 5-HT release in the dorsal hippocampus. Midazolam (0.75 and 1.5 mg/kg i.p.) suppressed the dosage-dependently this increased 5-HT release, an inhibition closely associated with the attenuation of conflict behavior. These findings suggest that the activation of serotonergic neuronal activity in the dorsal hippocampus is linked to mediation of anxiety-related behavior.

The relationship between the morphological changes and vitamin A content during the development of acute toxicity induced by polychlorinated biphenyl (PCB) in mouse parotid glands was investigated. PCB was administered intraperitoneally at a single dose of 2 mg/kg. Ultrastructural studies revealed remarkable morphological changes in the rough endoplasmic reticulum, nucleus, Golgi apparatus and the secretory granules at 7 days after the administration of PCB. The activities of adenosine monophosphatase (AMPase) and alkaline phosphatase were increased 1 day after PCB administration. Then the activity of NADPH-cytochrome c reductase increased 4 days after PCB administration. Subsequently, the vitamin A content of the parotid glands significantly decreased at 7 days compared with the control. These sequential changes in enzyme activities implied that the decrease of vitamin A content in the parotid glands may be partly due to catabolism of vitamin A by increased activities of microsomal enzymes induced by PCB. In conclusion, it is suggested that PCB also induces drug metabolizing enzymes in the parotid gland cells and that the acute toxicity of PCB on this tissue may occur, at least partly, through the reduction of vitamin A not only by the secondary effect from liver impairment but also by the locally accelerated catabolism of vitamin A in the mouse parotid gland.

We investigated the effect of microtubule inhibitors on the amelogenesis in rat incisor enamel at the maturation stage by the glyoxal bis (2-hydroxyanil) (GBHA) staining method. Several red stripes stained with GBHA appeared on the maturation enamel surface of control rats. Colchicine injection (1.3 mg/kg, s.c.) disarranged the GBHA staining stripes and increased the staining area. The ratio of the GBHA staining area to the maturation enamel surface was about 25% in the control, but this value increased about 60% at 8 and 24 hr after the colchicine injection. Lumicolchicine, which does not have the ability to disrupt microtubules, did not cause any significant changes in the enamel surface. The incorporation of 45Ca to the maturation enamel was also reduced by colchicine. Since the hypocalcemic action of microtubule inhibitors may be related to the change of the enamel surface, other drugs, sodium salicylate and sodium fluoride, that have a hypocalcemic action were tested. The staining pattern was not altered by these drugs. Therefore, the hypocalcemic action was independent of the changes of the GBHA staining pattern. These results indicated that the disruption of microtubules in the ameloblasts inhibited calcium movement in the maturation enamel, resulting in the disarrangement of the GBHA staining pattern.

The enamel of the continuous growing incisors of adult rats is characterized by the presence of a orange-yellow pigmentation, which is caused by the content of large amounts of iron. Hi stochemical studies and electron microprobe analysis have shown that iron-containing pigment is also identified within the rat incisor ameloblasts during the enamel maturation stage [1–4]. Autoradiographic studies using 55Fe have demonstrated that the iron is incorporated from papillary layer to the ameloblasts and accumulated during the progress of maturation stage, and finally secreted onto the completely mineralized enamel surface at the end of maturation[5–7]. It is thought that iron is transported as the form of transferrin in the blood plasma and stored as the form of either ferritin or hemosiderin within the cells.

The quantitative effect of vinblastine, colchicine and lumicolchicine on the rate of dentine formation was determined by chronologically-labelling dentine with the lead salt of EDTA, before and after the intravenous administration of the test drug. Colchicine and vinblastine produced a dose-dependent inhibition of dentine formation. Lumicolchicine had no adverse effect. Although the log dose-response lines of colchicine and vinblastine were parallel, the effect of vinblastine was more potent. The relative potency ratio of vinblastine to colchicine was 1.25–1.70. These results suggest that both colchicine and vinblastine may act at the same site, i.e. microtubules, thereby inhibiting the secretion of new dentine matrix.

The purpose of this study was to investigate the level of oral health awareness, and to explore the needs for home care workers to provide oral health care for disabled elderly. We conducted a questionnaire survey at two home-help service centers and a social welfare council. Subjects for this investigation were 63 home care workers. The results were as follows: 1. Ninety-six percent of home care workers thought it was necessary to provide oral health care for disabled elderly, but only 11 percent of them put oral care into practice on a daily basis. 2. From the results of a cause and effect diagram, necessities of oral care were summarized as six major causes: 1) Disabled elderly are often unable to brush their teeth, 2) The oral hygiene level may affect physical condition, 3) Disabled elderly should be protected from oral diseases, 4) Disabled elderly should have their mouths kept clean, 5) Eating and swallowing may become increasingly difficult, 6) Disabled elderly should take in adequate nutrition. 3. Sixty-eight percent of home care workers took part in a training course of nursing care including oral care. 4. Home care workers, dentists, dental hygienists, and nurses taught oral health care to home care workers. 5. From the results of a cause and effect diagram, there were three major items that home care workers want to know: 1) denture management, 2) the routine of oral care, 3) infection control. 6. Home care workers recognized that oral care should be provided by family members of disabled elderly or home care workers.