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Background: Eating rate is a modifiable risk factor for obesity and efficient methods to objectively characterise an individual's oral processing behaviours could help better identify people at risk of increased energy consumption. Many previous approaches to characterise oral processing and eating rate have relied on specialised equipment or wearable devices that are time consuming, expensive or require expertise to administer. The current trial used video-coding of the consumption of a standardised test food (the ‘carrot test’) to measure oral processing. Objective: We sought (i) to test whether self-reported eating rate (SRER) is predictive of food oral processing derived from coded eating behaviours captured in the laboratory with a standardised test food, and (ii) to test whether differences in SRER are predictive of oral processing behaviours, eating rate and intake of a test meal. Methods: Two hundred and fifty-three volunteers (86 male and 167 female, mean age 39.5 ± 13.6 years, mean BMI 22.2 ± 3.4 kg/m2) provided their SRER and anthropometric measurements of height, weight and dual-energy X-ray absorptiometry (DEXA) percentage fat mass. Participants were also video recorded eating a fixed 50 g portion of carrot and an ad libitum lunch meal of fried rice. Average eating rate (g/min), bite size (g) and number of chews per bite for the carrot and lunch were derived through behavioural coding of the videos. Energy intake (kcal) was recorded at lunch and a later afternoon snack. Results: Faster SRER significantly predicted faster eating rate, larger bite size and more chews per bite observed during intake of the carrot (ß = −0.26–0.21, p ≤ 0.001) and the lunch (ß = −0.26–0.35, p ≤ 0.014). SRER did not significantly predict intake at lunch or during the afternoon snack (ß = 0.05–0.07, p ≥ 0.265). Participants’ oral processing of the carrot significantly predicted oral processing of the lunch (ß = −0.25–0.40, p ≤ 0.047) and faster eating rate of the carrot signifi

Objectives: The aim of this study was to examine effects of the observation of video-recorded chewing in a daily setting on mixing ability, cognition, activities of daily living, depressive symptoms and quality of life of older adults with dementia. Methods: A clustered randomised controlled trial was carried out with residents from 14 residential care facilities. n = 56 participants' data were analysed. An experimental group watched videos of people chewing, displayed on tablet-PCs during lunch, while a control group watched videos of nature and buildings. This was scheduled to take place 5 days a week for 12 weeks. A two-colour chewing gum test was used to measure mixing ability, neuropsychological tests for cognition and questionnaires for the other outcomes. Effects were examined via hierarchical linear mixed model analyses for T1–T3 (i.e. pre-, halfway and post-intervention). When a significant interaction effect was found, T4 (follow-up) was also included. Results: The experimental (n = 27) and control (n = 28) groups differed on a few variables at baseline. A significant Time*Group interaction effect was found for the Mini-Mental State Examination only (b = 1.18, t(48.35) = 2.53, p =.015), in favour of the experimental group. A significant effect was also found, albeit smaller, when T4 was included. Conclusion: One potential reason for the intervention effect on cognition is activation of specific brain areas. Some challenges associated with conducting this intervention in a daily setting are presented. Further research is required before a well-considered decision can be made regarding any potential implementation. Trial Registration: Number: NTR5124. Date of registration: 30 March 2015, retrospectively registered (during participant inclusion).

Introduction. Acute stress is related to the energetic release of catecholamines, cytokines, and cortisol, which trigger pain perception. Chewing stimulates serotonergic neurons, these neurons modulate the neural pathways of pain; however, the relationship between these variables is still in the process of understanding. Objective. To determine the effect of acute stress and chewing stimulus on pain. Methods. an experiment that was developed in the Faculty of Medicine of the UNMSM. 40 eight-week-old male Balb/c mice were randomly assigned into 5 equal groups. A: week 1 without any stimulus and week 2 chewing stimulus + stress. B: week 1 without any stimulus and week 2 stress. C: week 1 stress and week 2 without any stimulus. D: week 1 masticatory stimulus + stress and week 2 without any stimulus. E: control, without any stimulus. Pain was assessed in the 5 groups at 7 and 14 days using the tail-withdrawal time test before thermal stimulation. Results. The ANOVA test was used for the intergroup evaluation, finding no significant difference. Using the t student test for related samples, the intragroup evaluation was made, where a significant difference was found between 7 vs. 14 days, both in group A (p=0.029) and in group C (p=0.03). Conclusion. The effect of acute stress on pain perception was decreased by chewing stimulus in Balb/c mice., Introducción. El estrés agudo se relaciona con la enérgica liberación de catecolaminas, citoquinas y cortisol, las cuales afectan la percepción dolorosa. La masticación estimula neuronas serotoninérgicas, dichas neuronas modulan a las vías neurales del dolor; sin embargo, la relación entre dichas variables aún está en proceso de entendimiento. Objetivo. Determinar el efecto del estrés agudo y del estímulo masticatorio sobre el dolor. Métodos. Experimento que se desarrolló en el bioterio de la Facultad de Medicina de la UNMSM. 40 ratones Balb/c machos de 8 semanas de edad. Los ratones fueron asignados aleatoriamente en 5 grupos iguales. A: semana 1 sin ningún estímulo y semana 2 estimulo masticatorio + estrés. B: semana 1 sin ningún estímulo y semana 2 estrés. C: semana 1 estrés y semana 2 sin ningún estímulo. D: semana 1 estímulo masticatorio + estrés y semana 2 sin ningún estímulo. E: control, sin ningún estimulo. El dolor se evaluó en los 5 grupos a los 7 y 14 días mediante la prueba de tiempo de retirada de la cola ante estímulo térmico. Resultados. Se empleó la prueba de ANOVA para la evaluación intergrupo, no hallándose diferencia significativa. Mediante la prueba de t student para muestras relacionadas se hizo la evaluación intragrupo donde se encontró diferencia significativa entre los 7 vs los 14 días tanto en el grupo A (p=0,029) como en el grupo C (p=0,03). Conclusión. El efecto del estrés agudo sobre la percepción dolorosa fue disminuida por el estímulo masticatorio en ratones Balb/c

The purpose of this study was to explore the influence of simple jaw opening and closing task of chewing movements on the activities of the prefrontal cortex (PFC) from the viewpoint of stress reduction. We measured cerebral blood flow (CBF) in the PFC during a block-tapping task of the jaw in healthy participants. Eleven young healthy individuals with normal dentition (7 males and 4 females, mean age 28.0 ± 3.7 years) volunteered for this study. CBF was measured using a wearable, functional near-infrared spectroscopy device. Measurements were taken using the central incisors and first molars at interocclusal distances of 5 and 10 mm. The participants were asked to bite a hard/soft block. CBF in all conditions showed limited variability or decreasing trend compared to resting state before the task. The main effect was observed for interocclusal distance (p = 0.008), and there were no significant differences for measurement area of the PFC, tooth type, and material type. An interaction was found between tooth type and material type. In conclusion, these results suggest that simple and rhythmical chewing motion has an effect of reducing CBF in the PFC and resting the PFC, which is an especially notable aspect of periodontal sensory information in the molar.

The purpose of this study was to explore the influence of simple jaw opening and closing task of chewing movements on the activities of the prefrontal cortex (PFC) from the viewpoint of stress reduction. We measured cerebral blood flow (CBF) in the PFC during a block-tapping task of the jaw in healthy participants. Eleven young healthy individuals with normal dentition (7 males and 4 females, mean age 28.0 ± 3.7 years) volunteered for this study. CBF was measured using a wearable, functional near-infrared spectroscopy device. Measurements were taken using the central incisors and first molars at interocclusal distances of 5 and 10 mm. The participants were asked to bite a hard/soft block. CBF in all conditions showed limited variability or decreasing trend compared to resting state before the task. The main effect was observed for interocclusal distance (p = 0.008), and there were no significant differences for measurement area of the PFC, tooth type, and material type. An interaction was found between tooth type and material type. In conclusion, these results suggest that simple and rhythmical chewing motion has an effect of reducing CBF in the PFC and resting the PFC, which is an especially notable aspect of periodontal sensory information in the molar.

Fecal particle size provides important information on the feeding and digestion of herbivores. Understanding the effects of the potential proximate determinants on fecal particle size helps us interpret this widely used measurement. In folivores, previous studies found that diet composition, dietary toughness, and age–sex-related factors, such as body size and tooth wear, influenced fecal particle size. However, the role of these factors remains unknown in frugivorous and omnivorous primates. This study aims to clarify how age–sex class and diet influence fecal particle size in omnivorous Japanese macaques in Yakushima. We expected that their variable diet and differences among age–sex classes would cause variations in fecal particle size. We simultaneously documented Japanese macaques' diet, dietary toughness, and fecal particle size in the lowland area of Yakushima in the period from March 2018 to April 2019. Unexpectedly, fecal particle size showed limited differences across months and no difference among age–sex classes. Dietary toughness showed no effects on fecal particle size, while the consumption of fruits showed only a marginally significant negative effect. Our data indicate that the results of chewing were not affected by dietary toughness in our study subjects, while age–sex classes showed no difference in food comminution. This lack of variation might derive from a diet with low dietary toughness. We also found that the physical structure of preferred foods played an important role in fecal particle size variations. These results suggest that food comminution is less variable in frugivorous and omnivorous primates compared to highly specialized species (e.g., geladas). Factors other than what we examined in this study, such as food physical structure and chewing behavior, should also be taken into consideration.

Different from other sensory information, oral-sensory information can be received in different ways (chewing, swallowing, and drinking). The way of receiving gustatory information and the experience of consumption have been neglected by previous studies and literatures. This research examines that chewing (vs. swallowing) food activates people’s low mental construal, may help consumers focus on the current moment and appreciates the experience of eating. Study 1 and Study 2 focused on the main effect of discovering the relationship between chewing and mental construal levels by using behavioral identification form and goal focus form. The result shows that chewing can activate people’s concrete thinking, which may help them to pay attention to be the present moment and accepting any thoughts or feelings. Study 3 and Study 4 investigated the calcium supplement market in terms of chewable supplements and swallowable supplements. The result shows chewable supplements indicate a higher desire to purchase the supplements. These findings may explain the popularity of chewable and crunchy food in the market.

Different from other sensory information, oral-sensory information can be received in different ways (chewing, swallowing, and drinking). The way of receiving gustatory information and the experience of consumption have been neglected by previous studies and literatures. This research examines that chewing (vs. swallowing) food activates people’s low mental construal, may help consumers focus on the current moment and appreciates the experience of eating. Study 1 and Study 2 focused on the main effect of discovering the relationship between chewing and mental construal levels by using behavioral identification form and goal focus form. The result shows that chewing can activate people’s concrete thinking, which may help them to pay attention to be the present moment and accepting any thoughts or feelings. Study 3 and Study 4 investigated the calcium supplement market in terms of chewable supplements and swallowable supplements. The result shows chewable supplements indicate a higher desire to purchase the supplements. These findings may explain the popularity of chewable and crunchy food in the market.

Addition of particles to foods, such as fruit pieces to dairy products or vegetable pieces to soup, is a convenient approach to alter nutritional composition, appearance, perception and acceptance. The aim of this study was to investigate the effect of addition of peach gel particles to yogurt on oral behavior, sensory perception and liking of consumers differing in age. One homogeneous yogurt and seven yogurts with peach gel particles were prepared. The added peach gel particles varied in size, fracture stress, or concentration. Oral behavior of n = 62 healthy Dutch, young adults (21 ± 2 years) and n = 62 healthy Dutch elderly (70 ± 5 years) participants was characterized by video recordings. Yogurts’ sensory properties and liking were scored on nine-point scales. Elderly consumed yogurts with higher number of chews and longer consumption time leading to lower eating rate than young adults. Addition of particles, regardless of characteristics, increased number of chews, consumption time, and decreased eating rate up to 60% for both consumer groups, with an average decrement of 110 g/min for young and of 63 g/min for elderly consumers. With increasing peach gel hardness and concentration, the number of chews and consumption time increased while eating rate decreased. Peach gel particle size did not affect oral behavior. Sensory perception of yogurts with added peach gel particles was similar for healthy young adult and healthy elderly. Only small differences in sensory perception were observed between the young adults and elderly for flavor attributes, crumbliness, juiciness, and perceived particle size. Similarly, minor differences in liking of a few yogurts with peach pieces were observed between both consumer groups. Thus, healthy ageing seems to affect sensory perception of semi-solid foods to a limited extent only. We conclude that changes in food texture by addition of particles can be used as a strategy to steer eating rate and potentially impact food intake

This scientific article shows the results of the research project “Characterization of food intake and swallowing of the elderly in a geriatric center of the city of Cali, during the 2018-2019 period”. The characteristics of food intake and swallowing in older adults of a geriatric hospital were identified. Based on the multiple causes of alteration in the processes of food intake and swallowing that older adults present in their evolutionary process that involves the aging of the human being, influenced by numerous conditioning factors, intrinsic such as genetic, state of health and other extrinsic ones such as habits in general, which can therefore generate consequences not only of malnutrition but also of alterations in the process of intake, respiratory disturbances and even death. The research followed a quantitative approach, its type was descriptive and transversal (Rios Ramírez, 2017). For this research there were three groups evaluated: patients with neurological disorders 29 people with 36%, patients with sensory disorders 28 people with 35% and patients without any diagnosis 23 people with 29%. In relation to the process of food intake and swallowing it was found that there is adapted chewing, in the neurological group, with 8 people (22%). Weak suction in 12 people of the neurological group, (29%) was found. Regarding the swallowing process, based on the classification of the FOIS scale, at level 5, 1 woman from the neurological group (4%) and at level 6, 7 women from the neurological group (26%). As a conclusion, it was found that in the population evaluated there are more alterations in the process of food intake in the male group of adults with neurological alteration (100%) than in females (79%). The most compromised structure was the teeth, since edentulism prevails, dentures that were poorly adapted were usually evident and 70% of the population does not use dental prostheses, Este artículo reporta los hallazgos del proyecto “Caracterización de ingesta de alimentos y la deglución de los adultos mayores en un centro geriátrico de la ciudad de Cali, entre 2018-2019”. Se identifican las características de la ingesta de alimentos y deglución en adultos mayores. A raíz de las alteraciones que se presentan en el envejecimiento y que se influencian por factores condicionantes, intrínsecos como los genéticos, estado de salud y otros extrínsecos como los hábitos en general, se puede presentar malnutrición y alteraciones en el proceso de la ingesta, alteraciones respiratorias e inclusive la muerte. El estudio es de tipo cuantitativo, descriptivo y transversal (Rios Ramírez, 2017). Para este estudio se evalúan tres grupos: pacientes con alteraciones neurológicas 29 personas (36%), pacientes con alteraciones sensoriales 28 personas (35%) y pacientes sin ningún diagnóstico 23 personas (29%). Con relación al proceso de ingesta de alimentos y deglución se encontró que hay masticación adaptada, en el grupo neurológico, con 8 personas (22%). Succión débil en 12 personas del grupo neurológicos, (29%). Respecto al proceso de deglución, en la clasificación de la escala de FOIS, en el nivel 5, 1 mujer del grupo neurológico (4%) y en el nivel 6, 7 mujeres del grupo neurológico (26%). Se concluye que en la población evaluada hay más alteraciones en el proceso de la ingesta de alimentos en el grupo de los adultos con alteración neurológica (100%) y de género femenino (79%). La estructura más comprometida fueron los dientes, ya que prevalece el edentulismo, la prótesis dental mal adaptada y el 70% de la población no hace uso de prótesis dental.

This scientific article shows the results of the research project “Characterization of food intake and swallowing of the elderly in a geriatric center of the city of Cali, during the 2018-2019 period”. The characteristics of food intake and swallowing in older adults of a geriatric hospital were identified. Based on the multiple causes of alteration in the processes of food intake and swallowing that older adults present in their evolutionary process that involves the aging of the human being, influenced by numerous conditioning factors, intrinsic such as genetic, state of health and other extrinsic ones such as habits in general, which can therefore generate consequences not only of malnutrition but also of alterations in the process of intake, respiratory disturbances and even death. The research followed a quantitative approach, its type was descriptive and transversal (Rios Ramírez, 2017). For this research there were three groups evaluated: patients with neurological disorders 29 people with 36%, patients with sensory disorders 28 people with 35% and patients without any diagnosis 23 people with 29%. In relation to the process of food intake and swallowing it was found that there is adapted chewing, in the neurological group, with 8 people (22%). Weak suction in 12 people of the neurological group, (29%) was found. Regarding the swallowing process, based on the classification of the FOIS scale, at level 5, 1 woman from the neurological group (4%) and at level 6, 7 women from the neurological group (26%). As a conclusion, it was found that in the population evaluated there are more alterations in the process of food intake in the male group of adults with neurological alteration (100%) than in females (79%). The most compromised structure was the teeth, since edentulism prevails, dentures that were poorly adapted were usually evident and 70% of the population does not use dental prostheses, Este artículo reporta los hallazgos del proyecto “Caracterización de ingesta de alimentos y la deglución de los adultos mayores en un centro geriátrico de la ciudad de Cali, entre 2018-2019”. Se identifican las características de la ingesta de alimentos y deglución en adultos mayores. A raíz de las alteraciones que se presentan en el envejecimiento y que se influencian por factores condicionantes, intrínsecos como los genéticos, estado de salud y otros extrínsecos como los hábitos en general, se puede presentar malnutrición y alteraciones en el proceso de la ingesta, alteraciones respiratorias e inclusive la muerte. El estudio es de tipo cuantitativo, descriptivo y transversal (Rios Ramírez, 2017). Para este estudio se evalúan tres grupos: pacientes con alteraciones neurológicas 29 personas (36%), pacientes con alteraciones sensoriales 28 personas (35%) y pacientes sin ningún diagnóstico 23 personas (29%). Con relación al proceso de ingesta de alimentos y deglución se encontró que hay masticación adaptada, en el grupo neurológico, con 8 personas (22%). Succión débil en 12 personas del grupo neurológicos, (29%). Respecto al proceso de deglución, en la clasificación de la escala de FOIS, en el nivel 5, 1 mujer del grupo neurológico (4%) y en el nivel 6, 7 mujeres del grupo neurológico (26%). Se concluye que en la población evaluada hay más alteraciones en el proceso de la ingesta de alimentos en el grupo de los adultos con alteración neurológica (100%) y de género femenino (79%). La estructura más comprometida fueron los dientes, ya que prevalece el edentulismo, la prótesis dental mal adaptada y el 70% de la población no hace uso de prótesis dental.

A questionnaire survey was conducted to investigate eating behavior and the subjective symptoms of oral frailty, and to examine the relationship between them. A total of 744 subjects with ages over 65 years were included. The questionnaire comprised 18 question items indicating eating behavior and seven question items indicating oral frailty. All items were assessed according to 4 grades on a scale of 1 (not applicable) to 4 (applicable). The total score of oral frailty gradually increased with age. Regarding the scores for “eating recognition” and “eating habits”, no changes were observed, however the scores for “eating action” demonstrated a decreasing tendency with age and the scores of ≥ 85 years age group was significantly lower than the 65–69, 70–74, and 75–79 years age groups. As a result of multiple regression analysis, among the significant independent variable, the scores of “I do not chew foods well” under the category of “eating action” showed the highest standard partial regression coefficients for dependent variable of symptoms of oral frailty. The significant association was found between the eating behavior and subjective symptoms of oral frailty, and this study suggests that the good chewing habit might be an important criterion for the prevention of oral frailty.

Objectives: To study, whether there are associations between chewing side preference and other lateralities, whether there is a genetic origin for preferred chewing side (PCS), relations to sex, birth order and orthodontic treatment. Materials and Methods: The study included 113 twin pairs, 57 pairs monozygotic, 47 pairs same sex dizygotic and 9 pairs of opposite sex. The lateralities of preferred chewing side, footedness and eyedness were assessed by functional tests and handedness was checked by asking. Results: Right-handed, -footed and -eyed as separated groups, and true-right sided (combined), were evenly distributed by preferred chewing side. By contrast, left-handed, -footed, -eyed and non-right sided used more left or both sides when chewing. Birth order affected preferred chewing side among monozygotic: the first-born twin was more likely to have the preferred chewing side on the non-right, whereas second-born twins used right side. Gender, zygosity and orthodontic treatment were not statistically significant factors. Limitations: Examination of chewing sidedness could have been done in several different ways to provide a definite result. Sample size of opposite sex twins was very small. Conclusions: Preferred chewing side generally seemed to follow the side where other lateralities occur; however, monozygotic twins seemed to be more receptive to it. True-right sided were more evenly distributed than non-right sided by the preferred chewing side.

Aim: The aim of this cohort study was to evaluate the perceptions of adolescents regarding pain levels and chewing impairment throughout the first 12 months of orthodontic treatment with fixed appliances. Methods: A total of 120 adolescents aged 11 and 12 years undergoing orthodontic treatment at the Faculty of Dentistry of the Federal University of Minas Gerais participated in this study. Malocclusion was evaluated by means of the Dental Aesthetic Index. Pain level and degree of chewing impairment were evaluated by means of two questions selected from the short form of the Child Perceptions Questionnaire (CPQ11-14). Each question had five response options with the following scoring system: never (0), once or twice (1), sometimes (2), often (3) and every day/almost every day (4). Both questions were answered by the adolescents at four different times: before fixed appliances’ placement (T1), one month after banding and fixed appliances’ bonding (T2), four months after banding and fixed appliances’ bonding (T3), and 12 months after banding and fixed appliances’ bonding (T4). Results: The mean age of adolescents was 11.39 (±0.68). Significant differences were observed for pain levels (p=0.038) and chewing impairment (p=0.020) over the study period. Pain levels at T1 were significantly lower than at T2 (p=0.038) and T4 (p=0.020). Chewing impairment at T1 was significant lower than at T2 (p<0.001), T3 (p=0.014) and T4 (p=0.005). Conclusion: Adolescents undergoing orthodontic treatment with fixed appliances present an increase in pain levels and in chewing impairment.

学位の種類: 博士（歯学）. 報告番号: 甲第4154号. 学位記番号: 新大院博（歯）甲第352号. 学位授与年月日: 平成28年3月23日, Physiology & Behavior, 2016, 155, 250-259, Clinically, reclining posture has been reported to reduce risk of aspiration. However, during involuntary swallow in reclining posture, changes in orofacial and pharyngeal movement before and during pharyngeal swallow should be considered. Further, the mechanisms underlying the effect of body posture on involuntary swallowremain unclear. The aimof the present studywas to determine the effect of body posture on activity patterns of the suprahyoid muscles and on patterns of bolus transport during a natural involuntary swallow. Thirteen healthy male adults participated in a water infusion test and a chewing test. In the water infusion test, thickened water was delivered into the pharynx at a very slowrate until the first involuntary swallowwas evoked. In the chewing test, subjectswere asked to eat 10 g of gruel rice. In both tests, the recordingwas performed at four body postures between upright and supine positions. Results showed that reclining changed the location of the bolus head at the start of swallow and prolonged onset latency of the swallowing initiation. Muscle burst duration and whiteout time measured by videoendoscopy significantly increased with body reclining and prolongation of the falling time. In the chewing test, reclining changed the location of the bolus head at the start of swallow, and the frequency of bolus residue after the first swallowincreased. Duration and area of EMGburst and whiteout time significantly increased with body reclining. These data suggest that body reclining may result in prolongation of pharyngeal swallow during involuntary swallow., 博士（歯学）, 新潟大学

学位の種類: 博士（歯学）. 報告番号: 甲第4162号. 学位記番号: 新大院博（歯）甲第360号. 学位授与年月日: 平成28年3月23日, Physiology & Behavior, 2015, 151, 404-411, We investigated (1) how peripheral inputs might assist central inputs in the control of voluntary evoked swallowing, (2) inter-individual variation in involuntary and voluntary swallowing initiation, and (3) whether natural chewing behavior affects the initiation of involuntary swallowing in healthy humans. Eleven participants completed a repetitive saliva swallowing test (RSST), chewing test (CHEW), and rest period (REST). In RSST, participants repetitively swallowed as quickly as possible. In CHEW, subjects chewed gumfreely. Wedelivered pharyngeal electrical stimulation (PEStim) to the laryngopharynx and compared the number of swallows that occurred with and without PEStim. PEStim significantly increased the number of voluntary evoked swallows in RSST, as well as the number of swallows in CHEW and REST trials, although this facilitatory effect was larger in REST trials. We found a positive correlation between the number of swallows at RSST without PEStim and that at REST with PEStim within individuals. Additionally, we found a significant positive correlation between the number of swallows at RSST with PEStim and the sum of that at RSST without PEStim and at REST with PES. Based on the current results, we suggest that (1) peripheral inputs within a certain range appear to facilitate the central inputs that control voluntary swallowing, (2) inter-individual variations in swallowing initiation may arise fromdifferences in the excitability of the common neural network in the lower brainstem, and (3) during chewing, food reduction in the oral cavity is prioritized, such that the neural network associated with chewing may regulate swallowing initiation., 博士（歯学）, 新潟大学

Ethnographic studies indicate that Eskimo foragers are characterized by well-defined sexual division of labor and extensive use of anterior teeth as a tool, resulting in higher degrees of wear. However, little is known about the intra- population variation in molar-macrowear rates and dietary implications. Here, percentages of dentin exposure (PDE) were recorded on first mandibular molars among Tigara foragers from Point Hope (Alaska) and attempt to correlate age and sex variation in wear patterns. We found that no overall sex-related differences in PDE exist and suggest that molars did not take a part in para-masticatory or cultural practices. Strong correlation with increasing age was found as expected but males wore their teeth at higher rates than females related to masticatory demands during growth. Our findings suggest that individual variation in molar-macrowear must be attributed to biomechanics of chewing and cultural behavior rather than sexual variation in food acquisition.

Gilthead sea bream (Sparus aurata) usually chew their feed before swallowing it. Under rearing condition, this feeding behaviour generates significant feed waste in the form of pellet fragments. The study aimed to experimentally quantify feed losses by chewing considering fish weight and the feed pellet size. Gilthead sea bream with a body weight of 28–1019 g were fed with differently sized pellets (2–8 mm) from a commercial aquafeed gamma. Feed wastes were collected and data were used to create a model able to estimate the waste derived from this particular feeding behaviour. The results pointed to a substantial feed loss, which increased proportionally with fish size as the pellets are larger. Simulations for a complete ongrowing cycle carried out following the aquafeed manufacturer's recommendations with regard to pellet size revealed that feed wastes by chewing represent 8% of the feed delivered. Alternative feeding regimes based on the use of smaller pellets would lead to a significant reduction in losses (up to 50%) through chewing. Improving the feeding strategy would help to minimize waste output, increasing gilthead sea bream aquaculture sustainability. Statement of relevance: This study deals with the wastes generated by chewing in the ongrowing of gilthead seabream of different body weight fed with different pellet sizes. This is the only work modelling the losses by chewing phenomenon, also suggesting alternative feeding regimes to improve environmental sustainability of the aquaculture process.

Ethnographic studies indicate that Eskimo foragers are characterized by well-defined sexual division of labor and extensive use of anterior teeth as a tool, resulting in higher degrees of wear. However, little is known about the intra- population variation in molar-macrowear rates and dietary implications. Here, percentages of dentin exposure (PDE) were recorded on first mandibular molars among Tigara foragers from Point Hope (Alaska) and attempt to correlate age and sex variation in wear patterns. We found that no overall sex-related differences in PDE exist and suggest that molars did not take a part in para-masticatory or cultural practices. Strong correlation with increasing age was found as expected but males wore their teeth at higher rates than females related to masticatory demands during growth. Our findings suggest that individual variation in molar-macrowear must be attributed to biomechanics of chewing and cultural behavior rather than sexual variation in food acquisition.

Gilthead sea bream (Sparus aurata) usually chew their feed before swallowing it. Under rearing condition, this feeding behaviour generates significant feed waste in the form of pellet fragments. The study aimed to experimentally quantify feed losses by chewing considering fish weight and the feed pellet size. Gilthead sea bream with a body weight of 28–1019 g were fed with differently sized pellets (2–8 mm) from a commercial aquafeed gamma. Feed wastes were collected and data were used to create a model able to estimate the waste derived from this particular feeding behaviour. The results pointed to a substantial feed loss, which increased proportionally with fish size as the pellets are larger. Simulations for a complete ongrowing cycle carried out following the aquafeed manufacturer's recommendations with regard to pellet size revealed that feed wastes by chewing represent 8% of the feed delivered. Alternative feeding regimes based on the use of smaller pellets would lead to a significant reduction in losses (up to 50%) through chewing. Improving the feeding strategy would help to minimize waste output, increasing gilthead sea bream aquaculture sustainability. Statement of relevance: This study deals with the wastes generated by chewing in the ongrowing of gilthead seabream of different body weight fed with different pellet sizes. This is the only work modelling the losses by chewing phenomenon, also suggesting alternative feeding regimes to improve environmental sustainability of the aquaculture process.

Recent developments in the field of sensory science have indicated that texture preference plays a vital role in overall consumer acceptance and liking of food products. Several studies have tried to substantiate these claims, one of which involves the use of so-called mouth behavior theory. Jeltema et al. proposed that consumers can be segmented into one of four groups based on their oral behavior and texture preferences (chewers, crunchers, suckers and smooshers). Gaining knowledge of the mechanisms that drive consumer preferences for food textures can potentially assist in developing products that a more appealing to consumers. The current thesis investigates the relationship between food texture preference and oral mouth behavior in Danish and Chinese consumers in terms of liking of yoghurt products. Preliminary research conducted by the project donor, Arla Foods amba, indicated that Danish and Chinese consumers have different preferences for yoghurt textures. The aim of the present thesis was to ascertain whether differences existed in texture preferences between Danish and Chinese consumers and the possible explanation by differences in preferred mouth behavior. A secondary objective was to investigate whether differences in texture preferences between mouth behavior groups could be explained in terms of oral physiology. In collaboration with the Department of Odontology at the University of Copenhagen, electromyography was utilized to highlight key differences between mouth behavior segments. The third and final goal was to develop a questionnaire capable of segmenting consumers in any national market into the four mouth behavior groups. This would enable product developers to gain a better understanding of the predominant texture preferences of consumers in a given market. A consumer study was conducted in which Danish and Chinese consumers, presently residing in Denmark, were tasked with evaluating five yoghurt products of varying texture properties and pro

Recent developments in the field of sensory science have indicated that texture preference plays a vital role in overall consumer acceptance and liking of food products. Several studies have tried to substantiate these claims, one of which involves the use of so-called mouth behavior theory. Jeltema et al. proposed that consumers can be segmented into one of four groups based on their oral behavior and texture preferences (chewers, crunchers, suckers and smooshers). Gaining knowledge of the mechanisms that drive consumer preferences for food textures can potentially assist in developing products that a more appealing to consumers. The current thesis investigates the relationship between food texture preference and oral mouth behavior in Danish and Chinese consumers in terms of liking of yoghurt products. Preliminary research conducted by the project donor, Arla Foods amba, indicated that Danish and Chinese consumers have different preferences for yoghurt textures. The aim of the present thesis was to ascertain whether differences existed in texture preferences between Danish and Chinese consumers and the possible explanation by differences in preferred mouth behavior. A secondary objective was to investigate whether differences in texture preferences between mouth behavior groups could be explained in terms of oral physiology. In collaboration with the Department of Odontology at the University of Copenhagen, electromyography was utilized to highlight key differences between mouth behavior segments. The third and final goal was to develop a questionnaire capable of segmenting consumers in any national market into the four mouth behavior groups. This would enable product developers to gain a better understanding of the predominant texture preferences of consumers in a given market. A consumer study was conducted in which Danish and Chinese consumers, presently residing in Denmark, were tasked with evaluating five yoghurt products of varying texture properties and pro

Background and aims: There is an important role of the neck sensory motor system in control of body posture and balance, and it is reasonable to believe that the jaw sensory motor system can directly and indirectly influence the modulation of the postural control system. The purpose of this study was to evaluate possible effects of dynamic jaw position while chewing on the postural control system. Materials and methods: We compared the mean center of gravity (COG) velocity during quite standing on a foam surface with eyes closed during three test conditions: (i) with resting jaw position, (ii) with open jaw position, and (iii) while chewing standard bolus of chewing gum. One hundred and sixteen normal healthy male subjects (average age 31.56 +/- 8.51 years; height 170.86 +/- 7.26 cm) were recruited for the study. Their COG velocity (deg/s) was measured using the NeuroCom (R) Balance Master Version 8.5.0 (Clackamas, OR, USA). Statistical analysis: Data was tested by the Friedman test. Results and conclusions. The results show that COG velocity decreased significantly while chewing in comparison to both open and resting jaw position (p < 0.0001). Our finding corroborates previous studies and suggests that the jaw sensory motor system can modulate postural control mechanisms. Gum chewing activity can enhance the postural stability during upright standing on an unstable surface and in the absence of visual input in healthy young adults. Our results should be taken into consideration in treatment and rehabilitation planning for patients with postural instability.

The objective of this study was to evaluate the correlations between nutrient intake and ingestive behavior of steers Holstein x Zebu in the rearing on Brachiaria brizantha 'Marandu', during the rainy season. We used 22 steers averaging seven months of age and mean initial body weight of 164,09±12,13 kg, distributed in a completely randomized design with two types of supplement and eleven repetitions per supplementation and managed in a rotational grazing area of 6,5 ha Pearson linear correlations between the behavioral variables and the digesti- bility of the nutrients were studied. The correlation coefficients were tested by the t test. The rumination time was positively correlated with the digestibility of nutrients. Feeding time at the trough positively correlated with the digestibility of dry matter (DM), organic matter (ODM), crude protein (CP) and ether extract. Positive correlation was observed between total chewing time and digestibility of nutrients. The number of periods of idle and rumination showed positive correlations with the digestibility of nutrients and the number of feeding periods in the trough correlated positively with the digestibility coeficient of CP. Bite rate and the number of bites per day correlated positively with the digestibility of nutrients. Positive correlation was observed between the num- ber of chews per day and digestibility of DM, OM and total carbohydrates (CT). Positive correlations were observed between the efficiencies of feeding and rumination of dry matter and neutral detergent fiber with digestibility coefficient of nutrients studied. The nutrient digestibility has a direct influence over the behavioral expressions of animals studied., Objetivou-se com esse estudo avaliar as corre- lações existentes entre o consumo de nutrientes e o comportamento ingestivo de novilhos mestiços 1⁄2 Holandês x Zebu na fase de recria em pastagem de Brachiaria brizantha 'Marandu', no período das águas. Foram utilizados 22 novilhos com média de sete meses de idade e peso corporal médio inicial de 164,09±12,13 kg, distribuídos em delineamento inteiramente casualizado, com dois tipos de suple- mento e onze repetições por tipo de suplementação e manejados em pastejo rotacionado numa área de 6,5 ha. Efetuou-se a análise de correlação linear de Pearson entre as variáveis comportamentais estudadas e os coeficientes de digestibilidade dos nutrientes encontrados. Os coeficientes de corre- lação foram testados por meio do teste t. O tempo de ruminação apresentou correlação positiva com o coeficiente de digestibilidade dos nutrientes. O tempo de alimentação no cocho correlacionou po- sitivamente com o coeficiente de digestibilidade da matéria seca (MS), matéria orgânica (MO), proteína bruta (PB) e extrato etéreo (EE). Correlação positiva foi observada entre o tempo de mastigação total e o coeficiente de digestibilidade dos nutrientes. O número de períodos de ócio e ruminação apre- sentaram correlações positivas com o coeficiente de digestibilidade dos nutrientes e o numero de períodos de alimentação no cocho correlacionou positivamente com o coeficiente de digestibilidade da PB. A taxa de bocados e o número de bocados por dia correlacionaram-se positivamente com o coeficiente de digestibilidade dos nutrientes. Correlação positiva foi observada entre o número de mastigações merícicas por dia e o coeficiente de digestibilidade da MS, MO e carboidratos totais (CT). Correlações positivas foram observadas entre as eficiências de alimentação e ruminação da matéria seca e da fibra em detergente neutro com o coeficiente de digestibilidade dos nutrientes estudados. A digestibilidade dos nutrientes exerce influência direta sobre as expres

The objective of this study was to evaluate the correlations between nutrient intake and ingestive behavior of steers Holstein x Zebu in the rearing on Brachiaria brizantha 'Marandu', during the rainy season. We used 22 steers averaging seven months of age and mean initial body weight of 164,09±12,13 kg, distributed in a completely randomized design with two types of supplement and eleven repetitions per supplementation and managed in a rotational grazing area of 6,5 ha Pearson linear correlations between the behavioral variables and the digesti- bility of the nutrients were studied. The correlation coefficients were tested by the t test. The rumination time was positively correlated with the digestibility of nutrients. Feeding time at the trough positively correlated with the digestibility of dry matter (DM), organic matter (ODM), crude protein (CP) and ether extract. Positive correlation was observed between total chewing time and digestibility of nutrients. The number of periods of idle and rumination showed positive correlations with the digestibility of nutrients and the number of feeding periods in the trough correlated positively with the digestibility coeficient of CP. Bite rate and the number of bites per day correlated positively with the digestibility of nutrients. Positive correlation was observed between the num- ber of chews per day and digestibility of DM, OM and total carbohydrates (CT). Positive correlations were observed between the efficiencies of feeding and rumination of dry matter and neutral detergent fiber with digestibility coefficient of nutrients studied. The nutrient digestibility has a direct influence over the behavioral expressions of animals studied., Objetivou-se com esse estudo avaliar as corre- lações existentes entre o consumo de nutrientes e o comportamento ingestivo de novilhos mestiços 1⁄2 Holandês x Zebu na fase de recria em pastagem de Brachiaria brizantha 'Marandu', no período das águas. Foram utilizados 22 novilhos com média de sete meses de idade e peso corporal médio inicial de 164,09±12,13 kg, distribuídos em delineamento inteiramente casualizado, com dois tipos de suple- mento e onze repetições por tipo de suplementação e manejados em pastejo rotacionado numa área de 6,5 ha. Efetuou-se a análise de correlação linear de Pearson entre as variáveis comportamentais estudadas e os coeficientes de digestibilidade dos nutrientes encontrados. Os coeficientes de corre- lação foram testados por meio do teste t. O tempo de ruminação apresentou correlação positiva com o coeficiente de digestibilidade dos nutrientes. O tempo de alimentação no cocho correlacionou po- sitivamente com o coeficiente de digestibilidade da matéria seca (MS), matéria orgânica (MO), proteína bruta (PB) e extrato etéreo (EE). Correlação positiva foi observada entre o tempo de mastigação total e o coeficiente de digestibilidade dos nutrientes. O número de períodos de ócio e ruminação apre- sentaram correlações positivas com o coeficiente de digestibilidade dos nutrientes e o numero de períodos de alimentação no cocho correlacionou positivamente com o coeficiente de digestibilidade da PB. A taxa de bocados e o número de bocados por dia correlacionaram-se positivamente com o coeficiente de digestibilidade dos nutrientes. Correlação positiva foi observada entre o número de mastigações merícicas por dia e o coeficiente de digestibilidade da MS, MO e carboidratos totais (CT). Correlações positivas foram observadas entre as eficiências de alimentação e ruminação da matéria seca e da fibra em detergente neutro com o coeficiente de digestibilidade dos nutrientes estudados. A digestibilidade dos nutrientes exerce influência direta sobre as expres

The aim of this study was to examine the effect of chewing efforts on sensory and pain thresholds of the orofacial skin of symptom-free subjects. Fourteen healthy volunteers were recruited. Using a stair-case method, the tactile detection threshold (TDT) and the filament-prick pain detection threshold (FPT) on the cheek skin (CS) and the skin overlying the palm side of the thenar skin (TS) were measured before and after chewing gum for 5 min (Time 1: T1) and keeping the jaw relaxed for 5 min (Time 2: T2) as a control. Both for the test and control situation, the TDT was higher in all measurement sites after 5 min. As for the FPT, the reactions between T1 and T2 were quite opposite: the FPT increased and/or remained stable in T1, while, it decreased at all sites in T2. There were significant session effects (T1-T2) on the FPT at the left CS (P < 0.01), right CS (P < 0.05) and TS (P < 0.05). The increase of TDT after chewing/no chewing could be due to habituation, while the decrease of FPT observed in the control situation might be due to sensitization, respectively. This potential sensitization, however, was not observed after chewing efforts. Further studies are needed to clarify the modulating effect of masticatory function on the trigeminal sensory system., Archives of Oral Biology, 57(9), pp.1251-1255; 2012

V diplomové práci byly sledovány nutriční a senzorické parametry masa hlemýždě zahradního /Helix Pomatia/ a to ze zemí Česká republika, Polsko, Maďarsko a Litva. U vzorků hlemýžďů z výše uvedených zemí byl analyzován obsah tuku, vody, dusíkatých látek, aminokyselin, pigment, dále bylo zjišťováno pH a vaznost masa. Vzorky hlemýžďů byly podrobeny senzorické analýze. Hodnoceny byly deskriptory: pružnost, tvrdost, žvýkatelnost, gumovitost, šťavnatost, barva a vzhled., The master thesis was based on nutritional and sensory characteristics of garden snail meat /Helix pomatia/ from nature of these countries - Czech Republic, Poland, Hungary and Lithuania. In the samples of snails meat were analyzed content of fat, water, proteins, amino acid, pigment and pH, water-holding kapacity as well. Meat samples of snails were evaluated by sensory analysis, with these descriptors: flexibility, hardness, chewing, gumminess, juiciness, colour and meat appearance., Ústav biochemie a analýzy potravin, obhájeno

Objective. The present study aimed to elucidate possible physiological mechanisms behind impaired endurance during chewing as previously reported in WAD. We tested the hypothesis of a stronger autonomic reaction in WAD than in healthy subjects in response to dynamic loading of the jaw-neck motor system. Design. Cardiovascular reactivity, muscle fatigue indicies of EMG, and perceptions of fatigue, exhaustion and pain were assessed during standardised chewing. Twenty-one WAD subjects and a gender/age matched control group participated. Baseline recordings were followed by two sessions of alternating unilateral chewing of a bolus of gum with each session followed by a rest period. Results. More than half of the WAD subjects terminated the test prematurely due to exhaustion and pain. In line with our hypothesis the chewing evoked an increased autonomic response in WAD exhibited as a higher increase in heart rate as compared to controls. Furthermore, we saw consistently higher values of arterial blood pressure for WAD than for controls across all stages of the experiment. Masseter EMG did not indicate muscle fatigue nor were there group differences in amplitude and mean power frequency. Pain in the WAD group increased during the first session and remained increased, whereas no pain was reported for the controls. Conclusion. More intense response to chewing in WAD might indicate pronounced vulnerability to dynamic loading of the jaw-neck motor system with increased autonomic reactivity to the test. Premature termination and autonomic involvement without EMG signs of muscle fatigue may indicate central mechanisms behind insufficient endurance during chewing.

In this study crispness assessment in different dry-crisp foods were evaluated. Roasted almonds with different degrees of roasting and two different types of extruded snacks, wheat crusts and cheese balls, at different water activities were used as samples. Crispness behaviour was characterised by using coupled sound-texture measurements and by sensory evaluation with the use of a consumer panel. Instrumental texture measurements were made using compression and penetration tests. While in the almond samples the compression test discriminated better than the penetration test among the samples, in both kinds of snacks the compression with the tooth-like probe proved to be as good as penetration tests to assess crispy characteristics. Consumers evaluated the samples by chewing with the back molars or by biting with the incisive teeth. The results obtained in sensory evaluation were similar to instrumental results. Consumers were able to better discriminate between the almond samples by chewing than by biting but in the snacks samples the ratings both by biting and chewing modalities were very similar and showing the same discrimination level. These findings could have useful applications: for panel training, at the time of naming attributes and defining how they are evaluated; also, to obtain the most of sensory-consumer correlations, having in mind that the "ease of breakdown" in the mouth is proved to contribute to the relative preferences among narrow texture ranges within products.

Previous studies in animals and humans show anatomic and physiological connections between the trigeminal and cervical regions. This investigation tested the hypothesis of a functional integration between the human jaw and neck motor systems in rhythmic jaw activities. By means of a wireless optoelectronic 3-D movement recording system, spatiotemporal characteristics of mandibular and head-neck movements were studied during rhythmic jaw opening-closing and chewing tasks, in healthy and in individuals with pain and dysfunction in the jaw and neck region following neck trauma, Whiplash-associated Disorders (WAD). As a basis, a methodological study evaluated the applicability of skin and teeth attached reflex markers fixed to the lower jaw and to the head in optoelectronic recording of chewing movements. The results showed concomitant and coordinated mandibular and head movements during rhythmic jaw tasks. The start of the head movement generally preceded the start of the mandibular movement. For chewing, larger size and harder texture of bolus were associated with larger head extension and larger amplitude of both mandibular and head movements. Immobilization of the head by mechanical fixation deranged jaw motor behaviour with regard to speed and amplitude of mandibular movements. Even with head fixation, muscle activity was present in neck muscles during activities. Compared to healthy subjects, WAD individuals showed smaller amplitudes and disturbed coordination of mandibular and head movements. Furthermore, a dynamic load test showed a reduced endurance during chewing in the WAD group. In conclusion, the results suggest that optimal jaw function requires free unrestricted head-neck movements and support the hypothesis of a close functional relationship between the jaw and the neck regions in rhythmic jaw activities. A new concept for human jaw function is proposed, in which "functional jaw movements" are the result of activation of jaw as well as neck muscles, lead

Previous studies in animals and humans show anatomic and physiological connections between the trigeminal and cervical regions. This investigation tested the hypothesis of a functional integration between the human jaw and neck motor systems in rhythmic jaw activities. By means of a wireless optoelectronic 3-D movement recording system, spatiotemporal characteristics of mandibular and head-neck movements were studied during rhythmic jaw opening-closing and chewing tasks, in healthy and in individuals with pain and dysfunction in the jaw and neck region following neck trauma, Whiplash-associated Disorders (WAD). As a basis, a methodological study evaluated the applicability of skin and teeth attached reflex markers fixed to the lower jaw and to the head in optoelectronic recording of chewing movements. The results showed concomitant and coordinated mandibular and head movements during rhythmic jaw tasks. The start of the head movement generally preceded the start of the mandibular movement. For chewing, larger size and harder texture of bolus were associated with larger head extension and larger amplitude of both mandibular and head movements. Immobilization of the head by mechanical fixation deranged jaw motor behaviour with regard to speed and amplitude of mandibular movements. Even with head fixation, muscle activity was present in neck muscles during activities. Compared to healthy subjects, WAD individuals showed smaller amplitudes and disturbed coordination of mandibular and head movements. Furthermore, a dynamic load test showed a reduced endurance during chewing in the WAD group. In conclusion, the results suggest that optimal jaw function requires free unrestricted head-neck movements and support the hypothesis of a close functional relationship between the jaw and the neck regions in rhythmic jaw activities. A new concept for human jaw function is proposed, in which "functional jaw movements" are the result of activation of jaw as well as neck muscles, lead

Coordinated mandibular and head-neck movements during jaw opening-closing activities suggest a close functional linkage between the jaw and the neck regions. The present study investigated whether size and texture of bolus can influene head-neck behaviour during chewing. Using an optoelectronic 3-D recording technique, we analyzed concomitant mandibular and head-neck movements in 12 healthy adults chewing small (3 g) and large (9 g) boluses of chewing gum and Optosil®. The main finding was a head extension during chewing, the amount of which was related mainly to bolus size. Furthermore, each chewing cycle was accompanied not only by mandibular movements, but also by head extension-flexion movements. Larger head movement amplitudes were correlated with larger size and, to some extent, also with harder texture of the bolus. The results suggest that head-neck behaviour during chewing is modulated in response to changes in jaw sensory-motor input.

We have previously shown an association between neck injury and disturbed jaw function. This stydy tested the hypothesis of a relationship between neck injury and impaired endurance during chewing. Fifty patients with whiplash-associated disorders (WAD) were compared with 50 temporomandibular disorders (TMD) patients and 50 healthy subjects. Endurance was evaluated during unilateral chewing of gum for 5 min when participants reported fatigue and pain. Whereas all healthy subjects completed the task, ¼ of the TMD and a majority of the WAD patients discontinued the task. A majority of the WAD patients also reported fatigue and pain. These findings suggest an association between neck injury and reduced functional capacity of the jaw motor system. From the results, we propose that routine examination of WAD patients should include jaw function and that an endurance test as described in this study could also be a useful tool for non-dental professionals.

Previous studies in animals and humans show anatomic and physiological connections between the trigeminal and cervical regions. This investigation tested the hypothesis of a functional integration between the human jaw and neck motor systems in rhythmic jaw activities. By means of a wireless optoelectronic 3-D movement recording system, spatiotemporal characteristics of mandibular and head-neck movements were studied during rhythmic jaw opening-closing and chewing tasks, in healthy and in individuals with pain and dysfunction in the jaw and neck region following neck trauma, Whiplash-associated Disorders (WAD). As a basis, a methodological study evaluated the applicability of skin and teeth attached reflex markers fixed to the lower jaw and to the head in optoelectronic recording of chewing movements. The results showed concomitant and coordinated mandibular and head movements during rhythmic jaw tasks. The start of the head movement generally preceded the start of the mandibular movement. For chewing, larger size and harder texture of bolus were associated with larger head extension and larger amplitude of both mandibular and head movements. Immobilization of the head by mechanical fixation deranged jaw motor behaviour with regard to speed and amplitude of mandibular movements. Even with head fixation, muscle activity was present in neck muscles during activities. Compared to healthy subjects, WAD individuals showed smaller amplitudes and disturbed coordination of mandibular and head movements. Furthermore, a dynamic load test showed a reduced endurance during chewing in the WAD group. In conclusion, the results suggest that optimal jaw function requires free unrestricted head-neck movements and support the hypothesis of a close functional relationship between the jaw and the neck regions in rhythmic jaw activities. A new concept for human jaw function is proposed, in which "functional jaw movements" are the result of activation of jaw as well as neck muscles, lead

Previous studies in animals and humans show anatomic and physiological connections between the trigeminal and cervical regions. This investigation tested the hypothesis of a functional integration between the human jaw and neck motor systems in rhythmic jaw activities. By means of a wireless optoelectronic 3-D movement recording system, spatiotemporal characteristics of mandibular and head-neck movements were studied during rhythmic jaw opening-closing and chewing tasks, in healthy and in individuals with pain and dysfunction in the jaw and neck region following neck trauma, Whiplash-associated Disorders (W AD). As a basis, a methodological study evaluated the applicability of skin and teeth attached reflex markers fixed to the lower jaw and to the head in optoelectronic recording of chewing movements. The results showed concomitant and coordinated mandibular and head movements during rhythmic jaw tasks. The start of the head movement generally preceded the start of the mandibular movement. For chewing, larger size and harder texture of bolus were associated with larger head extension and larger amplitude of both mandibular and head movements. Immobilization of the head by mechanical fixation deranged jaw motor behaviour with regard to speed and amplitude of mandibular movements. Even with head fixation, muscle activity was present in neck muscles during activities. Compared to healthy subjects, WAD individuals show ed smaller amplitudes and disturbed coordination of mandibular and head movements. Furthermore, a dynamic load test showed a reduced endurance during chewing in the W AD group. In conclusion, the results suggest that optimal jaw function requires free unrestricted head-neck movements and support the hypothesis of a close functional relationship between the jaw and the neck regions in rhythmic jaw activities. A new concept for human jaw function is proposed, in which "functional jaw movements" are the result of activation of jaw as weil as neck muscles, l

Previous studies in animals and humans show anatomic and physiological connections between the trigeminal and cervical regions. This investigation tested the hypothesis of a functional integration between the human jaw and neck motor systems in rhythmic jaw activities. By means of a wireless optoelectronic 3-D movement recording system, spatiotemporal characteristics of mandibular and head-neck movements were studied during rhythmic jaw opening-closing and chewing tasks, in healthy and in individuals with pain and dysfunction in the jaw and neck region following neck trauma, Whiplash-associated Disorders (WAD). As a basis, a methodological study evaluated the applicability of skin and teeth attached reflex markers fixed to the lower jaw and to the head in optoelectronic recording of chewing movements. The results showed concomitant and coordinated mandibular and head movements during rhythmic jaw tasks. The start of the head movement generally preceded the start of the mandibular movement. For chewing, larger size and harder texture of bolus were associated with larger head extension and larger amplitude of both mandibular and head movements. Immobilization of the head by mechanical fixation deranged jaw motor behaviour with regard to speed and amplitude of mandibular movements. Even with head fixation, muscle activity was present in neck muscles during activities. Compared to healthy subjects, WAD individuals showed smaller amplitudes and disturbed coordination of mandibular and head movements. Furthermore, a dynamic load test showed a reduced endurance during chewing in the WAD group. In conclusion, the results suggest that optimal jaw function requires free unrestricted head-neck movements and support the hypothesis of a close functional relationship between the jaw and the neck regions in rhythmic jaw activities. A new concept for human jaw function is proposed, in which "functional jaw movements" are the result of activation of jaw as well as neck muscles, lead

Previous studies in animals and humans show anatomic and physiological connections between the trigeminal and cervical regions. This investigation tested the hypothesis of a functional integration between the human jaw and neck motor systems in rhythmic jaw activities. By means of a wireless optoelectronic 3-D movement recording system, spatiotemporal characteristics of mandibular and head-neck movements were studied during rhythmic jaw opening-closing and chewing tasks, in healthy and in individuals with pain and dysfunction in the jaw and neck region following neck trauma, Whiplash-associated Disorders (WAD). As a basis, a methodological study evaluated the applicability of skin and teeth attached reflex markers fixed to the lower jaw and to the head in optoelectronic recording of chewing movements. The results showed concomitant and coordinated mandibular and head movements during rhythmic jaw tasks. The start of the head movement generally preceded the start of the mandibular movement. For chewing, larger size and harder texture of bolus were associated with larger head extension and larger amplitude of both mandibular and head movements. Immobilization of the head by mechanical fixation deranged jaw motor behaviour with regard to speed and amplitude of mandibular movements. Even with head fixation, muscle activity was present in neck muscles during activities. Compared to healthy subjects, WAD individuals showed smaller amplitudes and disturbed coordination of mandibular and head movements. Furthermore, a dynamic load test showed a reduced endurance during chewing in the WAD group. In conclusion, the results suggest that optimal jaw function requires free unrestricted head-neck movements and support the hypothesis of a close functional relationship between the jaw and the neck regions in rhythmic jaw activities. A new concept for human jaw function is proposed, in which "functional jaw movements" are the result of activation of jaw as well as neck muscles, lead

Many fish species have evolved feeding mechanisms and behaviours enabling them to feed on specific prey. However, such mechanisms may not be optimal for feeding on commercial-pelleted diets in aquaculture. Gilthead sea bream chew and occasionally eject pellets or parts of pellets from the mouth when feeding on commercial diets. This may result in an increase in nutritional waste from the intensive culture of this species. In this study we examined the prevalence of this food processing behaviour in two sizes of sea bream, feeding on three types of natural prey items in comparison to a commercial pellet, to give an insight into the circumstances in which excess chewing and ejection of food items from the mouth occurred. These included two hard-textured food items (commercial pellet and hard-shelled prey) and two soft-textured food items (larvae and small crustacean). Both sizes of sea bream frequently consumed the soft-textured food types, however large sea bream also frequently consumed hard-textured pellets. Hard-textured food required longer handling times and elicited more chewing and the ejection of food items from the mouth. These results suggest that future investigations on the food processing behaviour and consequent waste when fed commercial diets differing in texture could give an insight into improving diets and feeding efficiency for intensively cultivated gilthead sea bream.

This report is a compilation of references and abstracts of all research on tobacco in India from 1985 to 2003. Studies are organised by subject matter, and within each sub-topic, are arranged by year of publication with most recent studies listed first, and for studies published in the same year, alphabetically by author’s last name. The studies include tobacco use surveys, studies on tobacco-related mortality, tobacco-related diseases both cancerous and non-cancerous, according to body system and site, and other health problems associated with tobacco use and environmental tobacco smoke. Other topics include the toxicity of tobacco products, educational interventions and the psychology of tobacco use, tobacco control measures and policies, reports on tobacco advertising and sponsorship and research into the tobacco health hazards faced by tobacco workers. It also includes studies on tobacco employment, tobacco growing and technology, and the economics of tobacco. The following databases were searched: Pub Med, Medline, and J-Gate (a new Indian database). The keywords used for the searches were ‘(Tobacco OR smoking) AND India’, as well as names of diseases known from international research findings to be associated with tobacco, ‘AND India’. In some cases, reports were excluded if they were duplicative, or the methodology or findings were unclear.

This report is a compilation of references and abstracts of all research on tobacco in India from 1985 to 2003. Studies are organised by subject matter, and within each sub-topic, are arranged by year of publication with most recent studies listed first, and for studies published in the same year, alphabetically by author’s last name. The studies include tobacco use surveys, studies on tobacco-related mortality, tobacco-related diseases both cancerous and non-cancerous, according to body system and site, and other health problems associated with tobacco use and environmental tobacco smoke. Other topics include the toxicity of tobacco products, educational interventions and the psychology of tobacco use, tobacco control measures and policies, reports on tobacco advertising and sponsorship and research into the tobacco health hazards faced by tobacco workers. It also includes studies on tobacco employment, tobacco growing and technology, and the economics of tobacco. The following databases were searched: Pub Med, Medline, and J-Gate (a new Indian database). The keywords used for the searches were ‘(Tobacco OR smoking) AND India’, as well as names of diseases known from international research findings to be associated with tobacco, ‘AND India’. In some cases, reports were excluded if they were duplicative, or the methodology or findings were unclear.