Associations between school-based fluoride mouth-rinse program, medical-dental expense subsidy policy, and children's oral health in Japan: an ecological study.

BACKGROUND: Dental caries are a common non-communicable disease among children. As a public health measure at the prefectural level, school-based fluoride mouth-rinse (S-FMR) program, medical/dental expense subsidy policies, and other factors may reduce the incidence of dental caries and tooth loss. Prefectures focusing on promoting oral health policies may promote both, but the interaction effect of implementing both subsidy policies and S-FMR at the prefectural level on caries prevention has not yet been examined. METHODS: We conducted an ecological study using two-wave panel data, prefecture-level aggregated data in Japan for 2016 and 2018. Coefficient and 95% confidence intervals (CI) were calculated for the dependent variables for oral health using mixed-effects linear regression analysis adjusted for possible confounders. Two dependent variables were used; the standardized claim ratio (SCR) of deciduous tooth extraction and 12-year-olds' decayed, missing, or filled permanent teeth (DMFT). Four independent variables were S-FMR, the SCR of dental sealants, prefectural income per person, and subsidy policy in three models: co-payment until children enter elementary school (n = 23), no co-payment until children enter elementary school (n = 7), and co-payment continuing beyond elementary school (n = 17). The effects of six interaction terms, each representing a unique pairing from the four independent variables, were individually calculated. RESULTS: S-FMR was negatively associated with the SCR of deciduous tooth extractions and DMFT (coefficient = -0.11, 95% CI -0.20; -0.01 and coefficient = -0.003, 95% CI -0.005; -0.001, respectively). No co-payment until children enter elementary school was positively associated with the SCR of deciduous tooth extraction compared to co-payment until children enter elementary school(coefficient = 11.42, 95% CI 3.29; 19.55). SCR of dental sealants was positively associated with the SCR of deciduous tooth extractions (coefficient = 0.12, 95% CI 0.06; 0.19) but negatively associated with DMFT (coefficient = -0.001, 95% CI -0.003; -0.0001). Per capita prefectural income was positively associated with the SCR of deciduous tooth extractions(coefficient = 0.01, 95% CI 0.001; 0.02). No interaction was found between S-FMR and the subsidy policy at both outcomes. CONCLUSION: High S-FMR utilization and no co-payment until children enter elementary school were associated with fewer deciduous tooth extractions. Also, S-FMR and dental sealant were associated with decreased DMFT.

Regular dental check-up status and related factors among Thai residents in Japan.

The objectives of this online study were to determine the status of regular dental check-ups among Thai nationals living in Japan and to identify barriers to regular dental check-ups by comparing them with general health check-ups. We conducted the online survey twice, in 2021 and 2022, among Thai nationals aged 18 years and older living in Japan via social networking services by an organization that supports Thai nationals living in Japan. Respondents between the ages of 30 and 59 were included in this study. Independent factors included gender, age, length of stay in Japan, family economic status, confidence in Japanese and stay for work purposes. Dependent factors were regular dental check-ups and general health check-ups in the past year. Chi-square tests and multiple logistic regression analyses were used for analysis. 56.6% of respondents had regular dental check-ups. The adjusted odds ratio for the proportion of people with regular dental check-ups was significantly higher for those with high economic status, 2.15 (1.06-4.33), compared with those with low economic status. It was also significantly higher 1.88 (1.10-3.21) for those with confidence in the Japanese language compared with those without. The study suggested the need for Japanese language support in addition to financial support for dental health prevention programs for foreigners living in Japan.

Urban-rural differences in the prevalence of having a family dentist and their association with income inequality among Japanese individuals: a cross-sectional study.

BACKGROUND: Few reported studies evaluate the status of those who have a family dentist (FD) by regional differences and the socioeconomic factors associated with this status. This study aimed to assess the prevalence of having an FD among Japanese individuals across three samples of municipality type: urban, intermediate, and rural areas, and determine the factors associated with having an FD. METHODS: This was a cross-sectional study involving a web-based survey. In total, 2,429 participants (comprising men and women aged 20-69 years) were randomly selected from among the registrants of a web research company: 811 urban residents, 812 intermediate residents, and 806 rural residents. In each area, we categorized the participants into those who had an FD (FD group) and those who did not (non-FD group). A multivariate modified Poisson regression analysis was used to determine the factors associated with the FD group as compared to the non-FD group. RESULTS: The proportion of the FD group was lowest in rural areas (42.3%), followed by intermediate (48.6%) and urban areas (49.7%). The regression analysis revealed a statistically significant tendency between associated factors in the two groups; that is, the higher the household income, the more likely that the family belonged to the FD group (prevalence ratio (95%CI), JPY 4-6 million: 1.43 (1.00-2.03), JPY ≥ 8 million: 1.72 (1.21-2.44)). CONCLUSIONS: Rural areas have the lowest proportion of people with an FD among the three areas, and income inequality is associated with having an FD. Thus, when planning policies to encourage individuals to have an FD to manage their oral health, it is necessary to consider regional differences.

The complete mitochondrial genome of the sand bubbler crab Scopimera globosa and its phylogenetic position.

The mitochondrial genome has become commonly used for the molecular phylogenetic analysis of animals. Most phylogenetic studies on brachyurans using mitogenome sequences have indicated the paraphyly of superfamilies Grapsoidea and Ocypodoidea but taxon sampling remains limited. The phylogenetic position of Scopimera has been tested in several previous studies using nuclear and/or mitochondrial DNA sequences, but the phylogenetic relationship within the family remains to be resolved. We newly sequenced the complete mitochondrial genome of the sand bubbler crab Scopimera globosa (Ocypodoidea: Dotillidae). Scopimera globosa was clustered with Ilyoplax despite the morphological similarity between Scopimera and Dotilla. The mitochondrial gene order of S. globosa was unique, whereas that of other genera in the family was the same. These results suggest that phylogenetic analysis based on mitogenome sequences and gene order comparison would provide a more robust phylogeny of Dotillidae.

Oral cleaning habits and the copy number of periodontal bacteria in pregnant women and its correlation with birth outcomes: an epidemiological study in Mibilizi, Rwanda.

BACKGROUND: Since 1996, many studies have reported that periodontal disease during pregnancy may be a risk factor for preterm birth and low birth weight; however, in Africa, periodontal disease is considered a non-high-priority disease. In addition, there are few dental facilities in rural Rwanda; thus, the oral condition of pregnant women has not been investigated. The objective of this study was to assess the tooth brushing habits of pregnant women in rural Rwanda and evaluate whether periodontal bacteria in the oral cavity of pregnant women are related to birth outcomes or oral cleaning habits. METHODS: A questionnaire survey and saliva collection were conducted for pregnant women in the catchment area population of Mibilizi Hospital located in the western part of Rwanda. Real-time PCR was performed to quantitatively detect total bacteria and 4 species of periodontal bacteria. The relationship of the copy number of each bacterium and birth outcomes or oral cleaning habits was statistically analyzed. RESULTS: Among the participants, high copy numbers of total bacteria, Tannerella forsythia, and Treponema denticola were correlated with lower birth weight (p = 0.0032, 0.0212, 0.0288, respectively). The sex ratio at birth was higher in women who had high copy numbers of Porphyromonas gingivalis and T. denticola during pregnancy (p = 0.0268, 0.0043). Furthermore, regarding the correlation between oral cleaning habits and the amount of bacteria, the more frequently teeth were brushed, the lower the level of P. gingivalis (p = 0.0061); the more frequently the brush was replaced, the lower the levels of P. gingivalis and T. forsythia (p = 0.0153, 0.0029). CONCLUSIONS: This study suggested that improving tooth brushing habits may reduce the risk of periodontal disease among pregnant women in rural Rwanda. It also indicated that the amount of bacteria is associated with various birth outcomes according to the bacterial species. Both access to dental clinics and the oral cleaning habits of pregnant women should be important considerations in efforts to alleviate reproductive-related outcomes in rural Africa.

Periodontal disease is known to cause many complications. For instance, pregnant women with periodontal disease are at increased risk of preterm birth and delivering low-birth-weight infants. However, the importance of oral care during pregnancy is not an important consideration in rural Africa, where preterm birth rates and low-birth-weight rates are particularly high. Moreover, even the oral hygiene status of pregnant women has not been assessed in such areas. In this study, we focused on the amount of periodontal bacteria that cause periodontal disease and investigated the relationship between the amount of bacteria and birth outcomes. Our findings indicate that tooth brushing guidance for pregnant women and improved access to dental clinics in rural Africa may contribute to reduced rates of preterm birth and low birth weight.

[Dental care behavior and related factors during the COVID-19 state of emergency in Japan].

Objectives　In response to the spread of SARS-CoV-2, a state of emergency was declared in Japan on April 7, 2020, and in the same month, Japan's Ministry of Health, Labor, and Welfare informed dentists of the need to postpone non-emergency dental care. The purpose of this study was to identify the patients who refrained from dental care during the state of emergency in April 2020, and to clarify their personal characteristics.Methods　A total of 1,335 patients who visited 28 dental clinics in Saitama in September 2020 completed survey questionnaires; of these, 1,227 valid responses were received. Among those who sought dental care under the state of emergency, those who did not visit a dental clinic comprised the "refrained group" and those who visited the dental clinics comprised the "visited group".Results　Multivariate logistic regression analysis showed that the odds ratios for the "refrained group" were 1.69 (95%Cl: 1.12-2.55) for females, 2.91 (95%Cl: 1.88-4.49) for those younger than 65 years, 1.71 (95%Cl: 1.04-2.82) for those that visited the dental clinic less than once a month, and 7.12 (95%Cl: 4.56-11.11) for those who did not have an appointment during the state of emergency.Conclusion　In conclusion, 35% of patients in this study refrained from visiting the dental clinic during the state of emergency. The related factors for refraining from dental care were being females, middle-aged (<65 years), visiting the dental clinic less than once a month, and not having an appointment during the COVID-19 state of emergency.

Relationship between career education experience among final-year dental hygiene students and their perspective towards work and profession: A nationwide survey in dental hygiene schools of Japan.

OBJECTIVES: This study aimed to clarify the relationship between the experience of receiving career education among final-year dental hygiene students and their views regarding their work and profession, as part of research on the working style of dental hygienists. METHODS: An anonymous, self-administered survey was sent by post to all the 162 dental hygienist schools in Japan with dental hygiene students in their final year in November 2019. The main questions were regarding student attributes, career aspirations, their perspective on work and profession and whether or not they received career education at a dental hygienist training school. Analysis was conducted by cross-tabulation and logistic regression. RESULTS: Completed questionnaires were sent to us by 150 schools (response rate 92.6%), with a response from 6,270 students. The students who had received career education had significantly higher awareness and plans for the profession and a positive attitude towards the work (p < 0.01). Following adjustment for age, sex, educational attainment, length of the course of study and timing of class the results shows that there was a significant relation between the experience of the career education with having future plans (odds ratio = 2.11, 95% confidence interval = 1.88-2.38, p < 0.01). CONCLUSIONS: It was observed that the experience of receiving career education just before graduating from dental hygienist school was related to an increased positive attitude of the students towards their work and profession. Further long-term investigations are necessary to evaluate the effects of career education among dental hygiene students and their attitude towards their profession.

The Relationship between Dental Findings and Tongue Pressure: A Survey of 745 Community-Dwelling Adults and Elderly Persons in Japan.

INTRODUCTION: Reduced tongue pressure is one of the causes of dysphagia. The purpose of this study was to investigate the relationship between dental findings and tongue pressure, and whether prosthetic treatment prevents reduced tongue pressure. METHODS: This was a cross-sectional study. Participants were 745 community-dwelling adults and elderly persons in the Goto Islands in Nagasaki, who underwent a health checkup for residents in 2015 and 2016. Data were collected on gender; age; grip strength; hemoglobin; Creatinine (Cr); glycated hemoglobin (HbA1c); history of stroke; smoking, drinking, exercise, and walking habits; number of teeth; wearing of removable dentures; functional units of natural teeth (n-FTUs), fixed prostheses (nif-FTUs), and removable dentures (t-FTUs); and tongue pressure. The associations between each variable and tongue pressure were examined using multiple regression analysis. Next, those with 3 or fewer n-FTUs were selected, and differences in tongue pressure were compared between those with 3 or fewer nif-FTUs and those with 4 or more nif-FTUs, using a propensity score matching method. RESULTS: Male gender, weak grip strength, low HbA1c, no drinking, and a low number of teeth were independent factors significantly associated with lower tongue pressure. Among participants with 3 or fewer n-FTUs, the 43 with 4 or more nif-FTUs showed significantly higher tongue pressure than the 43 with 3 or fewer nif-FTUs after propensity score matching, although the number of t-FTUs was not associated with tongue pressure. DISCUSSION/CONCLUSION: Tooth loss was significantly associated with lower tongue pressure. It was suggested that fixed prosthesis treatment might prevent the reduction of tongue pressure, but removable dentures did not have such an effect.

Perceived general health in relation to oral health status in a rural Kenyan elderly population.

BACKGROUND: This study aimed to determine the present oral health status of the rural Kenyan elderly population and to investigate whether oral health status is associated with the perceived general health. METHODS: A total of 131 individuals aged 65 years and over in Mbita Constituency, Homa Bay County in Kenya were randomly selected and visited at home. The home visit study, which was conducted from 2014 to 2016, included oral examination by a dentist and administration of a self-reporting questionnaire. The number of teeth present and functional tooth unit (FTU) points were calculated using the dental chart. Perceived general health, subjective masticatory ability, and self-reported periodontal symptoms were collected using a questionnaire sheet. Fisher's exact test and nonparametric test were used to determine the difference in percentage and means. The odds ratio of good general health based on the participants' masticatory satisfaction was calculated by logistic analysis. RESULTS: Satisfactory mastication was dependent on the number of teeth present, FTU points, and self-reported "gum bleeding" and "tooth mobility". Furthermore, satisfactory mastication was associated with perceived general health status independent of sex and age. The adjusted odds ratio of good perceived general health was 2.29 (95% confidence interval 1.05-4.99) for participants who had the subjective masticatory ability. CONCLUSION: Among the Kenyan elderly population, satisfactory mastication was related to the number of teeth present, FTU points, and self-reported periodontal symptoms. Furthermore, satisfactory mastication was associated with perceived general health status independently.

Association between high psychological distress and poor oral health-related quality of life (OHQoL) in Japanese community-dwelling people: the Nagasaki Islands Study.

BACKGROUND: We investigated the association between psychological distress and oral health status/oral health-related quality of life (OHQoL) in Japanese community-dwelling people. METHODS: We conducted a cross-sectional study using data from the Nagasaki Islands Study. A total of 1183 (455 men and 728 women) has been analyzed in this study. Psychological distress was measured using the Kessler Psychological Distress Scale (K6). Oral health status was measured by dental examination. The OHQoL was measured using the General Oral Health Assessment Index (GOHAI). We defined the total score of ≥5 points on the K6 as high psychological distress (high-K6 group). RESULTS: The multiple linear regression analysis to identify the GOHAI showed that gender, K6, the total number of teeth, the number of dental caries, and visiting a dental clinic within the past 6 months significantly associated with the GOHAI. Among all of these variables, high-K6 (≥ 5) was a substantial contributing factor of the GOHAI (ß = - 0.23, 95% Cl - 2.31 to -1.41, p < 0.0001). CONCLUSIONS: It is likely that the individual with high psychological distress was strongly related to poor OHQoL even in the general population.

Association between number of pairs of opposing posterior teeth, metabolic syndrome, and obesity.

We investigated the relationship between the number of pairs of posterior teeth and metabolic syndrome (MetS), abdominal obesity (AO), and obesity, among Japanese adults. In 2005, 2,807 Japanese adults aged 25-74 years participated in the Survey of Dental Diseases and the National Health and Nutrition Survey. Based on the survey data, BMI, AO (JAS) determined by the Japan Atherosclerosis Society, AO (IDF) by the International Diabetes Federation, and MetS were assessed. Total functional tooth units (t-FTUs) were scored with pairs of opposing posterior teeth, including artificial teeth. Subjects were divided into three categories of chewing ability based on the score of t-FTUs: Poor (if score ≤ 9), Good (if score = 10-11), and Complete (if score = 12). The relationships between chewing ability and BMI ≥ 25, BMI ≥ 30, AO (JAS), AO (IDF), and MetS were tested using univariate and multivariate logistic regression analysis. The chewing ability was significantly associated with MetS, AO, and obesity in the univariate and multivariate logistic regression analysis. Adjusted OR of "Poor" compared to "Complete" were 1.51 (95% confidence interval (CI), 1.24-1.84) for BMI ≥ 25, 2.10 (95% CI 1.40-3.14) for BMI ≥ 30, 1.31 (95% CI 1.07-1.61) for AO (JAS), 1.40 (95% CI 1.15-1.70) for AO (IDF), and 1.34 (95% CI 1.04-1.72) for MetS. All were statistically significant. Preventing tooth loss and maintaining pairs of good chewing ability may be important factors in preventing MetS, AO, and obesity.

Association between human T cell leukemia virus type-1 (HTLV-1) infection and advanced periodontitis in relation to atherosclerosis among elderly Japanese: a cross-sectional study.

BACKGROUND: Human T cell leukemia virus type-1 (HTLV-1) stimulates inflammation activity. Our previous study revealed a positive association between asymptomatic HTLV-1 infection and advanced periodontitis among elderly Japanese individuals with low levels of hematopoietic activity (reflected by reticulocyte levels). Since low hematopoietic activity has been correlated with low-grade inflammation and low-grade inflammation is associated with atherosclerosis, the status of atherosclerosis could, in turn, determine the nature of this association. METHODS: To this end, a cross-sectional study of 907 elderly Japanese individuals (aged 60-99 years), who had participated in dental health check-up during the period 2016-2018, was conducted. Advanced periodontitis was defined as periodontal pocket ≥ 6.0 mm. RESULTS: Among the study population, 295 (32.5%) were found to have atherosclerosis defined as a carotid intima-media thickness (CIMT) of ≥ 1.1 mm. HTLV-1 infection was positively associated with advanced periodontitis in participants with atherosclerosis, but no significant associations were observed among the participants without atherosclerosis. The known risk factors' (including reticulocyte and CIMT) adjusted odds ratio (OR) and 95% confidence interval (CI) of advanced periodontitis were OR 2.01 and 95% CI 1.06-3.81 for participants with atherosclerosis and OR 0.61 and 95% CI 0.34-1.12 for participants without atherosclerosis. CONCLUSION: This study found a significant association between HTLV-1 infection and advanced periodontitis among elderly Japanese with atherosclerosis. However, this association is absent in individuals without atherosclerosis, suggesting that atherosclerosis might act as a determinant in the association between HTLV-1 infection and advanced periodontitis among elderly Japanese.

Association between human T cell leukemia virus 1 (HTLV-1) infection and advanced periodontitis in relation to hematopoietic activity among elderly participants: a cross-sectional study.

BACKGROUND: We reported that human T cell leukemia virus 1 (HTLV-1) infection is positively associated with atherosclerosis. Recent evidence has revealed a close association of periodontitis with atherosclerosis, endothelial dysfunction, and disruption of the microcirculation. However, the association between HTLV-1 and advanced periodontitis has not been investigated to date. Since hematopoietic activity is closely linked to endothelial maintenance activity and is known to decline with age, we hypothesized that the state of hematopoietic activity influenced the association between HTLV-1 and advanced periodontitis in elderly participants. METHODS: A cross-sectional study was performed including 822 elderly participants aged 60-99 years who participated in a dental health check-up. Advanced periodontitis was defined as a periodontal pocket ≥ 6.0 mm. Participants were classified as having low or high hematopoietic activity according to the median values of reticulocytes. RESULTS: HTLV-1 infection was positively related to advanced periodontitis among participants with lower hematopoietic activity (lower reticulocyte count), but not among participants with higher hematopoietic activity (higher reticulocyte count). The adjusted odds ratio (95% confidence interval) considering potential confounding factors was 1.92 (1.05-3.49) for participants with a lower reticulocyte count and 0.69 (0.35-1.36) for participants with a higher reticulocyte count. CONCLUSIONS: Among elderly participants, the association between HTLV-1 infection and advanced periodontitis is influenced by hematopoietic activity. Since hematopoietic activity is associated with endothelial maintenance, these findings provide an efficient tool for clarifying the underlying mechanism of the progression of periodontitis among elderly participants.

What do eye movements tell us about patients with neurological disorders? - An introduction to saccade recording in the clinical setting.

Non-invasive and readily implemented in the clinical setting, eye movement studies have been conducted extensively not only in healthy human subjects but also in patients with neurological disorders. The purpose of saccade studies is to "read out" the pathophysiology underlying neurological disorders from the saccade records, referring to known primate physiology. In the current review, we provide an overview of studies in which we attempted to elucidate the patterns of saccade abnormalities in over 250 patients with neurological disorders, including cerebellar ataxia and brainstem pathology due to neurodegenerative disorders, and what they tell about the pathophysiology of patients with neurological disorders. We also discuss how interventions, such as deep brain stimulation, affect saccade performance and provide further insights into the workings of the oculomotor system in humans. Finally, we argue that it is important to understand the functional significance and behavioral correlate of saccade abnormalities in daily life, which could require eye tracking methodologies to be performed in settings similar to daily life.

Visual scanning area is abnormally enlarged in hereditary pure cerebellar ataxia.

The aim of paper was to investigate abnormalities in visual scanning using an eye-tracking device with patients with spinocerebellar ataxia type 6 (SCA6) and SCA31, pure cerebellar types of spinocerebellar degeneration. Nineteen SCA patients (12 patients with SCA6 and 7 patients with SCA31) and 19 normal subjects in total participated in the study. While the subjects viewed images of varying complexity for later recall, we compared the visual scanning parameters between SCA patients and normal subjects. SCA patients had lower image recall scores. The scanned area in SCA patients was consistently larger than that in normal subjects. The amplitude of saccades was slightly larger in SCA patients than that in normal subjects, although it did not statistically differ between the two groups and correlated significantly with the scanned area in most images in SCA patients. The instability ratio of fixation, reflecting gaze-evoked nystagmus and downbeat nystagmus, was higher in SCA patients than that in normal subjects. Since SCA patients showed low scores despite wide visual scanning, the scanned area is considered to be abnormally enlarged. The larger scanned area in SCA patients was supposed mainly to result from the slightly larger saccade amplitude. Additionally, SCA patients showed prominent fixation disturbances probably due to gaze-evoked nystagmus and downbeat nystagmus. Consequently, SCA patients suffer from recognizing various objects in daily life, probably due to the impaired saccade control and impaired fixation.

[Investigation of a Novel Intravenous Catheter "Safe Wing Cath"].

BACKGROUND: A Safe Wing Cath (SWC) is a novel intravenous catheter which has a unique needlestick injury safety mechanism. METHODS: We investigated the success rate of intravenous catheterization using SWC by questionnaire. Anesthesiologists were recruited who had no previous experience of using SWC. Two or three consecutive trials were subjected for investigation. RESULTS: During four months in 2012, 8 anesthesiologists were asked to do the job 23 times. The success rate was 62.5% at first use by each anesthesiologist 87.5% at second use, and 100% at third use. CONCLUSIONS: Experienced anesthesiologists can learn the technique of SWC on its second or third use.

Age- and sex-related oculomotor manifestation of dopamine deficiency in Segawa disease.

OBJECTIVE: To investigate the oculomotor manifestations of Segawa disease (SD), considered to represent mild dopamine deficiency and discuss their pathophysiological basis. METHODS: We recorded visually- (VGS) and memory-guided saccade (MGS) tasks in 31 SD patients and 153 age-matched control subjects to study how basal ganglia (BG) dysfunction in SD evolves with age for male and female subjects. RESULTS: SD patients were impaired in initiating MGS, showing longer latencies with occasional failure. Patients showed impaired ability to suppress reflexive saccades; saccades to cues presented in MGS were more frequent and showed a shorter latency than in control subjects. These findings were more prominent in male patients, particularly between 13 and 25 years. Additionally, male patients showed larger delay in MGS latency in trials preceded by saccades to cue than those unpreceded. CONCLUSIONS: The findings can be explained by a dysfunction of the BG-direct pathway impinging on superior colliculus (SC) due to dopamine deficiency. The disturbed inhibitory control of saccades may be explained by increased SC responsivity to visual stimuli. SIGNIFICANCE: Oculomotor abnormalities in SD can be explained by dysfunction of the BG inhibitory pathways reaching SC, with a delayed maturation in male SD patients, consistent with previous pathological/physiological studies.

Chewing number is related to incremental increases in body weight from 20 years of age in Japanese middle-aged adults.

BACKGROUND: Eating habits are associated with both current obesity and incremental increases in body weight from young adulthood, but no study has focused on chewing number during meals among community residents. OBJECTIVE: This study focused on the relationship between chewing number and incremental increases in body weight from 20 years of age. METHODS: A total of 93 persons aged 35-61 years participated. The subjects were asked to set the device and record their chewing number during each meal on a particular day. They were also asked whether their body weight had increased by 10 kg or more since they were 20 years old. RESULTS: The body weight of 28 subjects (30%) had increased more than 10 kg since the age of 20 years. Total chewing number showed a relationship with such body weight increases. The odds ratio of weight increments of more than 10 kg for the lowest tertile group was 4.6 [95% confidence interval (CI), 1.3-16.2] relative to the highest tertile group (Model 1). The odds ratio of weight increments for the lowest tertile group increased to 6.3 (95% CI, 1.6-25.4) in Model 2 and to 9.1 (95% CI, 1.7-49.8) in Model 3. CONCLUSION: Although this study was limited because it did not consider all risk factors, categorical chewing number was related independently to body weight increments of more than 10 kg from 20 years of age.

Abnormal saccade profiles in hereditary spinocerebellar degeneration reveal cerebellar contribution to visually guided saccades.

OBJECTIVE: To study how the pathophysiology underlying hereditary spinocerebellar degeneration (spinocerebellar ataxia; SCA) with pure cerebellar manifestation evolves with disease progression using saccade recordings. METHODS: We recorded visually- (VGS) and memory-guided saccade (MGS) task performance in a homogeneous population of 20 genetically proven SCA patients (12 SCA6 and eight SCA31 patients) and 19 normal controls. RESULTS: For VGS but not MGS, saccade latency and amplitude were increased and more variable than those in normal subjects, which correlated with cerebellar symptom severity assessed using the International Cooperative Ataxia Rating Scale (ICARS). Parameters with significant correlations with cerebellar symptoms showed an aggravation after disease stage progression (ICARS > 50). The saccade velocity profile exhibited shortened acceleration and prolonged deceleration, which also correlated with disease progression. The main sequence relationship between saccade amplitude and peak velocity as well as saccade inhibitory control were preserved. CONCLUSIONS: The cerebellum may be involved in initiating VGS, which was aggravated acutely during disease stage progression. Dysfunction associated with disease progression occurs mainly in the cerebellum and brainstem interaction but may also eventually involve cortical saccade processing. SIGNIFICANCE: Saccade recording can reveal cerebellar pathophysiology underlying SCA with disease progression.