Undergraduate dental students' perceptions of head and neck anatomy teaching in Australia.

INTRODUCTION: Most Australian universities have abbreviated the anatomy curriculum and modified its mode of delivery. This study examines dental student perceptions of different methods of head and neck anatomy teaching with respect to the adequacy of allocated time and the relative meaningfulness of the teaching methods. METHODS: All second-year students in the School of Dentistry and Health Sciences at Charles Sturt University (CSU) were invited to complete a matrix-grid questionnaire. Participants were asked to score four methods of teaching (lectures, study of prosected materials, tutorials and quizzes) using a 5-point Likert scale. The questionnaire included questions about the time adequacy for anatomy lectures, tutorials and laboratory study, and the potential value of learning anatomy through the study of prosected materials. SPSS (Version 21.0) was used to analyse the data, and statistical significance was set at 0.05. RESULTS: Seventy-two students (79.5%) responded to the survey. Overall, learning anatomy through the study of prosected materials was the single highest scored method, followed by lectures, tutorials and quizzes. Graduate entrants felt that not enough time was devoted to learning anatomy through the study of prosected materials, compared with school leavers (89.4% and 10.6%, respectively), having one extra session of learning in the anatomy laboratory (71.4% and 28.6%, respectively) and adding dissection (75.0% and 25.0%, respectively) would be helpful. CONCLUSION: This study demonstrates that dental students perceive the study of prosected materials in the wet laboratory as the most valuable method of learning anatomy, but an extended anatomy curriculum would be even more effective and appreciated.

Effect of experimental anterior temporalis muscle pain on jaw movements.

To test the hypotheses that experimental noxious stimulation of the anterior temporalis muscle results in significant decreases in jaw movement amplitude and velocity, and there are significant correlations between scores of mood or pain-related cognitions and amplitude and velocity. The jaw movements of 14 asymptomatic participants were recorded during standardised open/close jaw movements and free and standardised chewing tasks. Tonic infusion of hypertonic saline into the right anterior temporalis muscle maintained pain intensity between 40 and 60 mm on a 100-mm visual analogue scale. Tasks were performed in a single session in the following sequence: baseline condition, test 1 condition (during hypertonic or isotonic saline infusion), test 2 condition (during saline infusion) (10-min rest between conditions). Participants completed the Depression, Anxiety and Stress Scale (DASS-21) and the Pain Catastrophizing Scale (PCS). Amplitude and velocity of opening and closing were compared between conditions with a repeated-measures analysis of variance (anova), and Spearman's rank correlation coefficient explored correlations; statistical significance: P < 0·05. For any of the three tasks, there were no significant differences in kinematic variables between any condition and no significant correlations between DASS-21 or PCS scores and kinematic variables during hypertonic saline infusion. The absence of a significant reduction in velocity or amplitude of open/close or chewing jaw movements during experimental temporalis muscle pain is not consistent with the Pain Adaptation Model proposing decreases in kinematic measures in pain. The lack of significant correlations between psychological variables and measures of jaw movement may reflect the low scores reported by our study sample.

Endometrial Thickness as a Predictor of Endometrial Malignancy among the Women Presenting with Abnormal Uterine Bleeding.

Abnormal uterine bleeding (AUB) is the most common and frequent presenting complaint in Gynaecology in all age group especially in perimenopausal and postmenopausal women. The spectrum of AUB in women of our country includes a wide varieties of organic pathology. The objective of this study was to assess the role of endometrial thickness as a predictor of endometrial malignancy among the women presenting with AUB. This cross-sectional descriptive type of observational study was conducted among 122 women of perimenopausal (40-50 years) and 87 women of postmenopausal (>50 years) age group presenting with AUB in the Obstetrics and Gynaecology department of Mymensingh Medical College Hospital, Bangladesh from February 2020 to August 2021. These patients were subjected to a detailed history and meticulous general, systemic and local examination. The relevant investigations like Transvaginal Sonography (TVS) followed by endometrial biopsy by dilatation and curettage were done in all study participants. Most of the women were in the age group 41-45 years in perimenopause and 51-55 years in postmenopause. Mean±SD was 45.8±4.1 years in perimenopause and 56.3±6.4 years in postmenopause. There was statistical significance in developing endometrial malignancy regarding risk factors of nulliparity, Hypertention (HTN), Diabetes mellitus (DM) and hormone intake between perimenopause and postmenopause. Endometrial thickness was measured in perimenopause and postmenopause. Mean±SD of Endometrial thickness (ET) in perimenopause and postmenopause was 11.3±4.4mm and 7.2±6.3mm with statistical significance (p<0.001). Sensitivity, specificity, Positive predictive value (PPV), Negative predictive value (NPV) and accuracy of TVS were 85.5%, 67.4%, 81.2%, 73.8% and 78.7% in perimenopause and 85.9%, 20%, 89%, 75% & 83.9% in postmenopause. Cut off limit of ET in detection of endometrial malignancy was 18.5mm with sensitivity 74.8% and specificity 63.6% in perimenopause and 12.2mm with sensitivity 81.0% and specificity 65.8% in postmenopausal women. Women with AUB, endometrial malignancy should be suspected when endometrial thickness on TVS >18.5mm and >12.2mm in perimenopause and postmenopausal age group respectively. TVS has high sensitivity in detection of endometrial malignancy both in perimenopausal and postmenopausal women with AUB and TVS is a reliable, noninvasive method.

Indication and Post-operative Complication of Primary Caesarean Section in Multiparous Women in A Tertiary Level Hospital.

The spectrum of indications for primary caesarean section changes with advancing parity. As parity advances more cesarean section are done for maternal rather than fetal indications. The objective of this study was to determine the indications and complications of caesarean section in multiparous women with history of previous vaginal delivery. This cross-sectional descriptive observational study was conducted in Mymensingh Medical College Hospital from January 2019 to June 2019 among 100 purposively selected multiparous women who underwent primary caesarean section. A well-designed, semi-structured questionnaire was used to collect data by face-to-face interview, clinical examinations and laboratory investigations. Data analysis was conducted in SPSS 20.0 version. Majority (74.0%) of the women in this study were in the age group 21-30 years with mean age of 26.3±5.76 years. Majority of the patients were of second gravida (42.0%) followed by third gravida (33.0%). The highest gravida in this study was 6th. Most of the patients were of para 1(44.0%). Highest para in this study was para 5. The most common indication of caesarean section in this study was foetal distress (26.0%). The next common indications were cephalo-pelvic disproportion (22.0%), antepartum haemorrhage (13.0%), mal-presentaion or mal-position (16.0%). Other causes were PROM (8.0%), prolonged labour (6.0%), cord prolapse (2.0%), post-dated pregnancy (4.0%), severe pre-eclampsia (2.0%) and secondary subfertility (1.0%). There was no case of maternal mortality in this study but 15 mothers suffered from various post-operative complications like wound infection (4.0%), UTI (4.0%), puerperal pyrexia (3.0%), postpartum haemorrhage (3.0%) and paralytic ileus (1.0%). Among the babies delivered 97 were live births. Among the 97 live births 11(11.34%) were preterm babies. Among the babies delivered majority (85.0%) was with good APGAR score (7-10). In conclusion it can say that a multiparous women in labour requires the same attention as that of primigravida. A parous women needs good obstetric care to improve maternal and neonatal outcome and still keeping caesarean section to a lower rate.

Analysis of Socio Demographic Risk Factors of Cervical Intraepithelial Neoplasia at Colposcopic Clinic in Mymensingh Medical College Hospital.

Cervical intraepithelial neoplasia (CIN) is a pre-malignant lesion of the cervix of uterus. Several risk factors increased the risk of developing CIN. Purpose of this study was to evaluate the socio-demographic risk factors related to CIN at our setting. This Cross sectional observational study was performed at Colposcopic clinic of Mymensingh Medical College Hospital (MMCH), Mymensingh, Bangladesh from 9th November 2017 to 8th May 2018. Overall demographic features of 50 patients of precancerous cervical lesion show that, most of the patients belonged to the age group 30-39 years (46.0%), mean age was 32.7±10.3 years. Maximum numbers of respondents came from rural area (58.0%), followed by urban area (42.0%). Among them house wife- 46.0%, daily worker- 30.0% and illiterate 36.0%, primary level of education 32.6%. Among the patients the poor class 46.0% and 58.0% of the respondents were married at age ≤19 year. Among the respondents, (26.0%) were conceived their first child 1 month after their marriage and 54.0% of the women within 12 months of marriage. In this study multipara were (62.0%). Oral contraceptive pill was taken by (42.0%) of patients. The association of risk factors revealed that betel or tobacco chewing present in 28.0% cases; history of menstrual regulation (MR), dilatation, evacuation and curettage (DE&C), miscarriage were in 26.0% cases, family history of cancer were in 16.0% cases and multiple sexual exposure was in 10.0% cases. Women develop pre-malignant cervical lesions require early treatment. It is recommended that provision of proper health care support, early detection of CIN and proper management, can reduce the fatal outcome of the disease.

Development of temporomandibular disorder symptoms: a 3-year cohort study of university students.

The aims of this study were to examine the incidence of temporomandibular disorders (TMDs) over a 3-year period and to evaluate the risk of self-reported TMDs among university students in Japan. The study population comprised 2374 university students examined at the start of their undergraduate course and 492 students re-examined after 3 years using questionnaires on symptoms of TMD and experiences of jaw injury, stress, orthodontic treatment and parafunctional habits. Cumulative incidence (%) and relative risks were calculated overall. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to determine the degree of risks of these variables for symptoms of TMDs using logistic regression. Results of logistic regression analysis showed that male subjects with experience of jaw injury had a 3·54 (CI=1·45-8·68, P<0·01)-fold higher risk of temporomandibular joint (TMJ) pain than that for those who did not. Female subjects who reported experiencing stress and bruxism had 10·56 (CI=1·28-87·54, P<0·05)- and 5·00 (CI=1·21-20·71, P<0·05)-fold higher risks of TMJ sound, respectively, than the risk for female subjects who had not experienced stress or bruxism. The results indicated that experiences of jaw injury, stress and bruxism were significantly associated with increased risks of development of TMJ disorders in a 3-year cohort.

"Screen and Treat" Approach among VIA Positive Women during Cervical Cancer Screening Program: Experience at Low Resource Setting.

Cancer of the uterine cervix is one of the leading causes of mortality and morbidity among women in poor countries. It is the most common reproductive cancer among women in Bangladesh and most women are diagnosed at advanced stage when appropriate treatment is not possible. But this cancer is preventable through proper screening and simultaneous treatment of premalignant lesions. The same day "Screen and Treat" approach is an endeavour to reach the goal especially at low resource settings. Ablation of precancerous lesions by thermo-coagulation is a promising mode of complete cure as this method is easy to apply, effective and relatively cheaper than other procedures. To avoid the issue of overtreatment, an intermediate approach- colposcopy can be used. Aim of this study was to diagnose premalignant lesions of cervix during screening procedure and to treat the lesions by thermo-coagulation at the same sitting. This prospective study was carried out at Upzilla Health Complex (UHC), Rangunia, from 3rd February 2018 to 6th February 2018 in a campaign of cervical cancer screening program by visual inspection of cervix with 5.00% acetic acid (VIA). About 1000 women attending the outpatient department were enrolled in this study by consecutive sampling technique according to inclusion and exclusion criteria. Informed consent was taken after explaining the screening method, thermo-coagulation procedure and follow up schedule. VIA was found positive in 22 cases. Colposcopy was done in VIA positive cases by Gynocular colposcope. Punch biopsy was taken when colposcopy revealed positive in 12 women. Then thermo-coagulation was done. Histopathology report revealed, CIN1 (cervical intraepithelial neoplasia 1)- in 6 cases (50.00%); CIN 2 (cervical intraepithelial neoplasia 2)- in 01 case (8.33%); Chronic cervicitis with squamous metaplasia- in 05 cases (41.67%). Sensitivity and specificity of colposcopy was calculated considering colposcopy directed biopsy as gold standard, which was 100.00% and 75.00% respectively in CIN-1. While in CIN-2 it was 100.00% and 95.20% respectively. VIA is an effective screening tool for cancer cervix. Main advantage is the "screen and treat" approach can be attempted for at risk women in low resource setting by thermo-coagulation which is accepted by women while guaranteeing satisfactory cure rates. Thus, reduces loss to follow-up and have an impact on cervical cancer control.

Relationship between folic acid intake and gingival health in non-smoking adults in Japan.

OBJECTIVE: To assess the relationship between dietary intake of folate and gingival bleeding in non-smoking adults in Japan. MATERIALS AND METHODS: Data were obtained from residents who participated in the regional nutrition survey and survey of dental diseases conducted by the administrative office of northernmost prefecture of Japan. Dietitians visited households to collect data on dietary intake. Clinical parameters, including Community Periodontal Index (CPI) and bleeding on probing (BOP), were examined in community centers. Information on smoking habit was obtained from the interview. Then the data from 497 non-smoking adults with 20 teeth or more, aged 18 years or older, were analyzed. The relationship between dietary intake of folic acid and gingival bleeding status was estimated using multivariate analysis. RESULTS: Pearson's correlation coefficient showed a significant negative correlation between dietary folate level and bleeding on probing. The negative association between folate level and bleeding on probing remained statistically significant in multiple regression analysis (standardized beta = -0.204, P < 0.001). However, no significant association was found between CPI scores and folate intake level. CONCLUSIONS: The results suggest that dietary intake of folic acid, an important indicator of gingival bleeding in adults, may provide an important clinical target for intervention to promote gingival health.

Effect of Expectation on Pain Processing: A Psychophysics and Functional MRI Analysis.

Pain is a complex phenomenon that is highly modifiable by expectation. Whilst the intensity of incoming noxious information plays a key role in the intensity of perceived pain, this intensity can be profoundly shaped by an individual's expectations. Modern brain imaging investigations have begun to detail the brain regions responsible for placebo and nocebo related changes in pain, but less is known about the neural basis of stimulus-expectancy changes in pain processing. In this functional magnetic resonance imaging study, we administered two separate protocols of the same noxious thermal stimuli to 24 healthy subjects. However, different expectations were elicited by different explanations to subjects prior to each protocol. During one protocol, pain intensities were matched to expectation and in the other protocol they were not. Pain intensity was measured continuously via a manually operated computerized visual analogue scale. When individuals expected the stimulus intensity to remain constant, but in reality it was surreptitiously increased or decreased, pain intensity ratings were significantly lower than when expectation and pain intensities were matched. When the stimulus intensities did not match expectations, various areas in the brain such as the amygdala, anterior cingulate cortex (ACC), dorsolateral prefrontal cortex (dlPFC), and the midbrain periaqueductal gray matter (PAG) displayed significantly different patterns of activity compared to instances when stimulus intensity and pain expectations were matched. These results show that stimulus-expectancy manipulation of pain intensity alters activity in both higher brain and brainstem centers which are known to modulate pain under various conditions.

Relationships between patient characteristics and reasons for tooth extraction in Japan.

OBJECTIVES: The purpose of this study was to examine the relationships between patient characteristics and reasons for extraction of permanent teeth. METHODS: 5131 dentists were selected from the list of the membership directory of the Japan Dental Association by systematic random selection. The dentists were asked to record the reason for each extraction of permanent teeth during a period from February 1 to 7, 2005. Reasons for tooth extraction were assigned to five groups: caries, fracture of teeth weakened by caries or endodontics, periodontal diseases, orthodontics and other reasons. We used cross tabulation and multiple logistic regression analysis to estimate the relationships between patient characteristics and reasons for tooth extraction. RESULTS: 2001 dentists (response rate of 39.0%) returned the forms, and complete information on 7333 patients was obtained. A total of 3,196 (43.6%) patients underwent tooth extraction due to caries and its sequela, and 2721 (37.1%) patients underwent tooth extraction due to periodontal disease. Multiple logistic regression analysis showed that denture wearers were more likely to undergo tooth extraction due to periodontal disease in all age groups (p < 0.05). Males tended to undergo tooth extraction due to periodontal disease than did females in all age groups (p < 0.05) except for age group 30-49. Subjects with 19 or less teeth were more likely to undergo tooth extraction due to periodontal disease in the age groups 30-49 (p < 0.001) and 50-69 (p < 0.001). In the age group of 50 years or older, female (p<0.01) and the possession of 20 or more natural teeth (p < 0.05) were related to caries extraction. However, there was no clear relationship between caries extraction and patient characteristics under 50 years old. CONCLUSION: There was a significant relationship between denture wearing and periodontal extraction. In the middle aged population, patients with 19 or less teeth lost their teeth mainly due to periodontal disease.

Disruption of default mode network dynamics in acute and chronic pain states.

It has been proposed that pain competes with other attention-demanding stimuli for cognitive resources, and many chronic pain patients display significant attention and mental flexibility deficits. These alterations may result from disruptions in the functioning of the default mode network (DMN) which plays a critical role in attention, memory, prospection and self-processing, and recent investigations have found alterations in DMN function in multiple chronic pain conditions. Whilst it has been proposed that these DMN alterations are a characteristic of pain that is chronic in nature, we recently reported altered oscillatory activity in the DMN during an acute, 5  minute noxious stimulus in healthy control subjects. We therefore hypothesize that altered DMN activity patterns will not be restricted to those in chronic pain but instead will also occur in healthy individuals during tonic noxious stimuli. We used functional magnetic resonance imaging to measure resting state infra-slow oscillatory activity and functional connectivity in patients with chronic orofacial pain at rest and in healthy controls during a 20-minute tonic pain stimulus. We found decreases in oscillatory activity in key regions of the DMN in patients with chronic pain, as well as in healthy controls during tonic pain in addition to changes in functional connectivity between the posterior cingulate cortex and areas of the DMN in both groups. The results show that similar alterations in DMN function occur in healthy individuals during acute noxious stimuli as well as in individuals with chronic pain. These DMN changes may reflect the presence of pain per se and may underlie alterations in attentional processes that occur in the presence of pain.

Association between experience of stressful life events and muscle-related temporomandibular disorders in patients seeking free treatment in a dental hospital.

OBJECTIVES: Psychological factors are known to play an important role in the etiology and maintenance of temporomandibular disorders. Since there have been very few studies on this issue in Asian countries, the study was aimed to investigate the relationship between various stressful life events and temporomandibular disorders in patients seeking free treatment in a Dental Hospital, Bangladesh. MATERIALS AND METHODS: Five hundred and twenty Bangladeshi adults (370 males and 150 females; mean age, 30.9 +/- 8.2 years) participated in this study. The subjects were given a questionnaire to evaluate their stress status in the last 12 months. The Research Diagnostic Criteria for TMD (RDC/TMD) was used as TMD diagnostic system by three standardized examiners. Two hundred and thirty-six patients were RDC/TMD-defined TMD-positive and were subsequently classified into 7 groups: group I, myofacial pain only; group II, disk displacement only; group III, joint pain only; group IV, myofacial pain and disc displacement; group V, myofacial pain and joint pain; group VI, disc displacement and joint pain; and group VII, myofacial pain, disk displacement and joint pain. Two hundred and eighty-four subjects were RDC/TMD-defined TMD-negative subjects (controls). Adjusted odds ratios were calculated by multiple logistic regression analysis. RESULTS: Logistic regression analysis revealed that patients diagnosed with myofacial pain (group I) and a combination of myofacial and joint pain (group V) had significantly higher levels of financial and job stress than did the controls. Self-health-related stress and stress related to a spouse or deaths of a relative were also identified as predisposing factors for myofacial pain (group I). CONCLUSION: This study suggests that myofacial pain is more common in individuals with various types of psychological stress. When treating patients with facial pain, dentists should consider the possible presence of psychological factors.

The effects of catastrophizing on central motor activity.

BACKGROUND: Pain catastrophizing significantly affects an individual's experience of pain. High pain catastrophizing is associated with increased fear avoidance behaviours, pain intensity and disability. The aim of this investigation was to determine the effect of pain catastrophizing on ongoing brain activity and movement-evoked brain activity during acute orofacial muscle pain. METHODS: Thirty-four healthy, pain-free subjects were recruited. In 17 subjects, the effect of catastrophizing on regional brain activity was determined. In 19 subjects, functional magnetic resonance imaging was used to determine the effects of pain catastrophizing on brain activation patterns during jaw movements in the presence of ongoing pain. RESULTS: We found that in the presence of pain, catastrophizing was significantly correlated with activity in multi-sensory integrative brain regions, including the dorsolateral and medial prefrontal cortices. Importantly, this relationship did not exist when subjects were not experiencing pain. In addition, during repetitive open-close jaw movements in the presence of pain, activity in the primary motor cortex, cerebellar cortex and the trigeminal motor nucleus was positively correlated with pain catastrophizing scores. In contrast, in the dorsolateral prefrontal cortex, as pain catastrophizing scores increased, the magnitude of signal intensity change during jaw movements decreased. Again, no such relationships occurred when the individual was not in pain. CONCLUSIONS: These data show that during pain, catastrophic thinking has a significant impact on activity in motor and sensory integrative regions. Reducing negative coping strategies may be an effective means in reducing fear avoidance behaviours and the intensity of ongoing pain.

Relationship between stress factor and periodontal disease in a rural area population in Japan.

OBJECTIVES: Several studies conducted in Western countries have shown significant associations between stress factors and periodontal disease. However, there have been only a few studies conducted in Asian countries. The present study was designed to identify possible relationship between stress and periodontal disease in residents of a rural area in Japan. - MATERIAL AND METHODS: Data were collected from 1,089 adults with at least six natural teeth in a typical farming district of Japan. Subjects were asked to complete a questionnaire on daily stresses in various aspects of life. Data on gender, occupation, smoking, alcohol drinking habits, dental health behavior and systemic disease status were obtained from the questionnaires. Periodontal disease status was assessed using clinical attachment loss (CAL), and the subjects were dichotomized according to mean CAL<1.5 mm (control group) and>/=1.5 mm (diseased group). Logistic regression was applied to assess the associations between stress and other factors with periodontal disease, and odds ratios (ORs) as well as 95% confidence intervals were calculated. RESULTS: In bivariate analysis, significant relationships were found between periodontal disease and stress within 1 month (P<0.001), job stress (P<0.001), self-health-related stress (P<0.001) and family health-related stress (P<0.01). Logistic regression analysis revealed that subjects who felt job stress (OR=1.71, P<0.05) and those who felt stress due to self health (OR=1.72, P<0.05) were more prone to have periodontal disease than were those who never or only rarely felt such stress. Significant correlations were also found between periodontal disease and smoking habit, frequency of dental clinic visits and hyperlipidemia (OR=1.8, P<0.05, OR=2.0, P<0.001, OR=2.1, P<0.05, respectively). - CONCLUSION: The results suggest that stress related to self health and job might be potential risk indicators for development of periodontal diseases. Intervention measures including stress reduction may provide adjunctive approaches for preventing and treating periodontal disease.

West Nile virus in Pakistan. III. Comparative vector capability of Culex tritaeniorhynchus and eight other species of mosquitoes.

Eight species of mosquitoes from Pakistan were compared with Culex tritaeniorhynchus as experimental vectors of West Nile (WN) virus. When fed by the membrane or cotton-pledget methods on a dose of WN virus 100% infective for Cx tritaeniorhynchus, 95% and 73% of the females of Cx fuscocephala and Cx pseudovishnui became infected, respectively. Cx quinquefasciatus, Cx univittatus, Aedes albopictus, Ae. caspius, Ae. indicus and Ae. lineatopennis were all significantly less susceptible than Cx tritaeniorhynchus. In agreement with the single dose comparisons, the median per os infective dose of WN virus for Cx fuscocephala, Cx pseudovishnui and Ae. caspius was substantially greater than for Cx tritaeniorhynchus. The median parenteral infective dose for all six species tested was less than 1 SMICLD50. Both Cx tritaeniorhynchus and Cx quinquefasciatus were more susceptible to infection with WN virus when fed on viraemic chickens than when fed on defibrinated blood using cotton pledgets or membranes. After infection by intrathoracic inoculation, only Ae. indicus and Ae. lineatopennis showed a reduced ability to transmit WN virus when compared to Cx tritaeniorhynchus.

Surface composition and structure of titanium polished with aqueous slurry of ferric oxide.

Cast plates were prepared from commercial titanium. The plates were polished with a slurry of fine ferric oxide powder. The surface composition and structure were investigated by electron probe microanalysis (EPMA) and X-ray photoelectron spectroscopy (XPS). In the high pressure-polished surface, iron was non-uniformly distributed but oxygen was mostly uniformly distributed, while in a light pressure-polished surface, iron and oxygen were uniformly distributed though at lower and higher concentrations, respectively. EPMA state analysis and XPS suggested that the iron might exist as Fe2+ in the outermost surface, while it might be in a metallic state in the inner surface layer.

Masseter motor unit recruitment is altered in experimental jaw muscle pain.

Some management strategies for chronic orofacial pain are influenced by models (e.g., Vicious Cycle Theory, Pain Adaptation Model) proposing either excitation or inhibition within a painful muscle. The aim of this study was to determine if experimental painful stimulation of the masseter muscle resulted in only increases or only decreases in masseter activity. Recordings of single-motor-unit (SMU, basic functional unit of muscle) activity were made from the right masseters of 10 asymptomatic participants during biting trials at the same force level and direction under infusion into the masseter of isotonic saline (no-pain condition), and in another block of biting trials on the same day, with 5% hypertonic saline (pain condition). Of the 36 SMUs studied, 2 SMUs exhibited a significant (p < 0.05) increase, 5 a significant decrease, and 14 no significant change in firing rate during pain. Five units were present only during the no-pain block and 10 units during the pain block only. The findings suggest that, rather than only excitation or only inhibition within a painful muscle, a re-organization of activity occurs, with increases and decreases occurring within the painful muscle. This suggests the need to re-assess management strategies based on models that propose uniform effects of pain on motor activity.

Association of dietary habits with symptoms of temporomandibular disorders in Bangladeshi adolescents.

The prevalences of signs and symptoms of temporomandibular disorder (TMD) in Bangladeshi adolescents and their associations with intake of various hard food items were investigated. A group of 1200 randomly selected high school students aged 12-17 years from three communities (rural, semi-urban and urban) completed a questionnaire on dietary habits and presence of TMD symptoms and were examined clinically. In bivariate analysis, no significant relationship was observed between TMD symptoms and eating of hard foods. However, in logistic regression analysis, clicking showed a significant correlation with consumption of hard vegetable and fruits more than three times per week (P < 0.05). A statistically significant correlation was also observed between consumption of all hard food items (at least one item in each of the four categories of hard food) more than 12 times per week and pain in the temporomandibular joint (TMJ) (P < 0.05). A positive association was found between pain in the TMJ and older age (15-17 years) (P < 0.001). The prevalence of pain in the TMJ was significantly higher in males (P < 0.01). Prevalences of clicking and pain in the TMJ were significantly higher in subjects living in a rural area than in subjects living in an urban area (P < 0.01 and P < 0.01, respectively). Subjects having one or more decayed, missing and filled teeth (DMFT) showed significantly higher prevalences of clicking (P < 0.01) and restricted mouth opening (P < 0.01). The results suggest that prevalence of TMD symptoms are related to prolonged consumption of hard food items.

Acetylation phenotype status in a Bangladeshi population and its comparison with that of other Asian population data.

The objective of the present study was to determine the acetylator status of the Bangladeshi population and to compare the findings with the acetylator status of other Asian populations. The acetylator phenotype was determined in 517 unrelated healthy Bangladeshi subjects. The phenotyping procedure was done according to Price Evans' method using the NAT2 specific probe drug--sulphadimidine. The Bangladeshi population showed a bimodal distribution of fast and slow acetylators. Of a total of 517 healthy Bangladeshi, 79.5% (n=411) were fast acetylators and the rest 20.5% (n=106) were slow acetylators. The high frequency of the fast acetylators in the population of Bangladesh was comparable to other populations in East Asia. When this acetylator status was compared with other Asian data, the Asian population showed a positive correlation between the acetylator status and the geographical longitude (r=0.919; t=7.37; p>0.001; d.f.=10). The regression line of the scatter diagram showed that the frequency of acetylating capacity increasingly occurred in the populations towards eastern Asia (regression coefficient=0.54; constant=52.36). This line was termed as the Asian fast acetylator longitude (AFAL). Thus the AFAL was able to predict the acetylator status of the Asian population by the east-west geographical longitude. The AFAL could be a useful prognosticator in the disposition for the effective and safe use of numerous drugs and xenobiotic compounds in humans.