Chewing Behavior Research Articles

A meta-analysis and meta-regression of the impact of particle size, level, source and preservation method of forages on chewing behavior and ruminal fermentation in dairy cows

A meta-analysis of the impact of forage particle size (FPS) on chewing activity, rumen pH and volatile fatty acids (VFA) in dairy cattle was conducted following a search of the literature. A meta-regression was conducted to test the additional effect of forage level, source and preservation method on the heterogeneity of the results of FPS on the same target variables. A total of 42 papers and 86 trials with the change of FPS in the diet of dairy cattle were identified. Decreasing of FPS in the diet from an average of 10.0±4.9–6.7±4.11mm lowered eating (P<0.01), rumination (P<0.01), and total chewing time (P<0.01) by 19, 28, and 44min/d, respectively. A similar effect and heterogeneity were observed for all these variables when expressed as min per kg of DMI. Meta-regression analysis revealed forage level as an important source for this heterogeneity. Accordingly, this analysis indicated that eating time (P=0.04) and total chewing time (P<0.01) per kg of DMI decreased with lowering FPS in high level of dietary forage inclusion (>500g/kg forage). Forage preservation method was another source of variation accounting for high heterogeneity in the results of FPS in which eating (P=0.03), rumination (P=0.01), and total chewing (P=0.02) activity decreased only in silage-based diets but not in hay-based diets. Total VFA concentration (P<0.01) and butyrate proportion (P=0.03) increased by 25 and 9%, respectively, with decreasing of FPS. Forage level also was an important source of the variability in which rumen pH dropped (P<0.01) with decreasing of FPS only in low level of forage feeding. In contrast, VFA concentration (P=0.02) and propionate proportion (P<0.01) increased with decreasing FPS in high level of forage inclusion. As result, the A:P ratio lowered (P=0.04) with decreasing of FPS in high level of forage feeding. Moreover, rumen pH decreased (P<0.01) with decreasing of FPS in silage-based diet, but acetate proportion increased (P<0.01) with decreasing FPS in hay-based diet, resulting in greater (P<0.01) A:P ratio with decreasing FPS in hay-based diet. In conclusion, the study confirms enhancing effects of feeding long FPS on chewing activity and ruminal fermentation; however, these effects were strongly modulated by forage level and preservation method of forages, with decreasing FPS being more influential in high level of forage inclusion and in hay-based diets.

Assessment of the differences in masticatory behavior between male and female adolescents

Chewing behavior may show sex differences; thus, the present study aimed to compare the masticatory aspects and the prediction of masticatory performance between male and female adolescents. Ninety-one healthy subjects (47 girls, 44 boys), caries-free and aged 14–17years, were included. Masticatory performance and maximal bite force were evaluated using a color-changeable chewing gum and digital gnathodynamometer, respectively. Masticatory behavior was assessed by the subjective aspect of the quality of the masticatory function (validated questionnaire) and the Orofacial Myofunctional Evaluation with Scores expanded (OMES-e) was used to determine chewing time, frequency of chewing cycles and other aspects. Salivary flow rate was also assessed. The physical examination involved measurements of facial morphometry, body weight, height, skeletal muscle mass, and dental/occlusal evaluations. It was observed that boys showed larger facial dimensions, higher bite force and chewing frequency and better masticatory performance than girls. They also showed shorter chewing time, fewer chewing cycles and lower score for OMES-e (that is, more changes in orofacial myofunctional aspects). Bite force showed a weak correlation with skeletal muscle mass only in boys (r=0.3035; p=0.0451). The masticatory performance was dependent on the bite force in boys (Adj R2=19.2%; Power=84.1%); among girls, masticatory performance was dependent on the frequency of chewing cycles and masticatory behavior (subjective aspect) (Adj R2=34.1%; Power=96.1%). The findings support the existence of sex differences in many masticatory aspects of function and behavior, hence the importance of considering sex differences when evaluating masticatory function and myofunctional therapy outcomes among young subjects.

Influence of texture, taste and/or flavour modifications on chewing behaviour of food gels

Influence of texture, taste and/or flavour modifications on chewing behaviour of food gels

Dental-macrowear and diet of Tigara foragers from Point Hope, northern Alaska.

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.

Relationships of Image Texture Properties with Chewing Activity and Mechanical Properties during Mastication of Bread

Abstract The objective of this study was to investigate the relationships of image texture properties with chewing behaviors, and mechanical properties during mastication of bread. Gray-level gradient co-occurrence matrix (GGCM) was used to process the images of boluses. The chewing behaviors were recorded by electromyography (EMG), and the mechanical properties were measured by texture analyzer. The results showed that among the texture features, the inverse difference moment (IDMGGCM) was selected as the main parameter to describe the decomposition of boluses. IDMGGCM was positively related to the weight gain (r = 0.865, p &lt; 0.01), negatively correlated with hardness (r = –0.835, p &lt;0.01) and EMG activity per cycle (r = –0.767, p &lt; 0.01). GGCM is an effective texture analysis method that could correctly identify 70.1–80.8 % of food bolus images to the corresponding chewing cycles. This study provided a new clue for texture analysis of bread bolus images and offered data revealing the bolus property changes during the mastication of bread.

Influencia del tipo de masticación sobre la memoria y el aprendizaje espacial en ratones albinos de la cepa BALB/c

IntroductionSince the relationship between chewing and cognitive functions has not been fully elucidated, this study aimed to determine the impact of chewing behaviour on spatial learning and memory in albino male BALB/c mice. MethodsTwenty mice aged 8 weeks were divided into 2 equal groups. The regular chewing group was fed with uncrushed grains (the same diet given to all 20 mice since they were weaned) and the limited chewing group was fed with crushed grains. At 16 weeks of age, the mice were evaluated over 5 days, including a 4-day acquisition phase prior to a probe test of spatial learning and memory in the Morris water maze on the fifth day. ResultsA comparison of the regular chewing group and the limited chewing group found no significant differences in either the acquisition phase or the probe test. However, there were significant differences in the acquisition phase for just the regular chewing group when comparing results from the first day to those from the other 3 days. ConclusionsThe results suggest that regular chewing affects spatial learning and memory since mice in the regular chewing group decreased their times to find the hidden platform during the acquisition phase.

Effects of Food Education Program to Improve Oral Function, Chewing Ability and Chewing Behavior, toward Preschool Children

Effects of Food Education Program to Improve Oral Function, Chewing Ability and Chewing Behavior, toward Preschool Children

Effects of an Education Program to Improve Chewing Ability and Chewing Behavior among Preschool Children

Effects of an Education Program to Improve Chewing Ability and Chewing Behavior among Preschool Children

Suitability of feeding and chewing time for estimation of feed intake in dairy cows

Monitoring of feeding and rumination behaviour can provide useful information for dairy herd management. The feeding behaviour of dairy cows can be recorded by different techniques, such as video cameras, weighing troughs or chewing sensors. Among feeding characteristics, individual feed intake of cows is of utmost interest, but as weighing troughs have high space and cost requirements they are used primarily in research studies. The objective of the present study was to evaluate whether records on feeding time or chewing activity or a combination of both contain enough information to estimate feed intake with sufficient accuracy. Feed intake and feeding time per cow were recorded by means of weighing troughs. Concurrently, chewing activity of seven cows was recorded by MSR-ART pressure sensors during five to eight measuring days per cow. Feeding and chewing behaviour were evaluated in time slots (1 min) and additionally assigned to feeding bouts for further analysis. The 1 min time slots were classified into feeding/no feeding or chewing/no chewing by the two systems, and agreement was found in 92.2% of the records. On average, cows spent 270±39 min/day at the feeding troughs and chewed 262±48 min/day. The average fresh matter intake (FMI) was 49.6±5.1 kg/day. Feed intake was divided into 9.7 bouts/day during which cows fed in average 27.8±21.7 min/bout and chewed 27.0±23.1 min/bout. The correlation between FMI and feeding time was r=0.891 and between FMI and chewing time r=0.780 overall cows. Hence, both systems delivered suitable information for estimating feed intake.

Digestibility of NDF and its effect on the level of rumen fermentation of carbohydrates

DOI: 10.15414/afz.2015.18.04.110–113 Received 14. July 2015 ǀ Accepted 12. October 2015 ǀ Available online 7. December 2015 The objective of this study, was to determinate the effects of digestibility of NDF of TMR on rumen fermentation characteristics and nutrient digestion, dairy cows were fed total mixed ration (TMR). We are measured NDF digestibility of TMR using in situ methods.Digestibility of NDF of TMR in our experiment range 26.8 to 48.2%. Digestibility of NDF of TMR did not alter VFA production but had effects on A/P ratio and production of acetate and propionate. Our results indicate that TMR with more dNDF may provide more favourable condition for nutrient digestion both in the rumen and in the total tract of dairy cows. Keywords : rumen, fermentation, NDF, volatile fatty acids, digestibility of NDF References ALLEN, M. S., BRADFORD, B. J. and OBA, M. (2009) BOARD-INVITED REVIEW: The hepatic oxidation theory of the control of feed intake and its application to ruminants. In J. Anim. Sci., vol. 87, no. 10, pp. 3317–3334. doi:http://dx.doi.org/10.2527/jas.2009-1779 BEEVER, D. E. and MOULD, F. L. (2000) Forage evaluation for efficient ruminant livestock production. In: D. I. Givens et al. (eds.) Forage Evaluation in Ruminant Nutrition. Wallington: CAB International. HOFFMAN, P.C. and SHAVER, R.D. (2009) UW-Feed Grain Evaluation System Marshfield Soil and Forage Analysis Laboratory. [Online] Available at: http://www.uwex.edu/ces/dairynutrition/documents/ WisconsinFGES.pdf. [Accessed? 2015-06-04]. HUTJENS, M. F. (2002) Is your TMR as good as it can be? In Hoard´s Dairyman, vol. 147, no. 18, pp. 698. CHUMPAWADEE, S. and PIMPA, O. (2009) Effect of fodder tree as fiber sources in total mixed ration on feed intake, nutrient digestibility, chewing behaviour and ruminal fermentation in beef cattle. In J. Anim. And Vet. Adv, vol. 8, no. 7, pp. 1279:1284. doi: http://dx.doi.org/2009.1279.1284 KOLVER, E. S. and DE VETH, M. J. (2002) Prediction of ruminal pH from pasture based diets. In J. Dairy Sci., vol. 85, no. 5, pp. 1255–1266. doi:http://dx.doi.org/10.3168/jds.S0022-0302 (02)74190-8 LINN, J.G. et al. (1989) Feeding the dairy herd. Madison: North Central Regional Extension. LOPEZ, S., J. DIJKSTRA, and FRANCE, J. (2000) Prediction of energy supply in ruminants, with emphasis on forages. In: D. I. Givens, E. Owens, R. F. E., Axford, and H. M. Omed, (eds.) Forage Evaluation in Ruminant Nutrition. Wallingford: CAB International, pp. 63-94. NRC (2001) Nutrient requirements of dairy cattle: Nutrient requirements of domestic animals. 7th revised edition. Washington: National Reserach Council. OBA, M. and ALLEN, M. S. (1999) Evaluation of the importance of the digestibility of neutral detergent fiber from forage: effects on dry matter intake and milk yield of dairy cows. In J. Dairy Sci., vol. 82, no. 3, pp. 589-596. doi:http://dx.doi.org/10.3168/jds.S0022-0302(99)75271-9 OBA, M. and ALLEN, M. S. (2000) Effects of brown midrib 3 mutation in corn silage on productivity of dairy cows fed two concentrations of dietary neutral detergent fiber: 3. Digestibility and microbial efficiency. In J. Dairy Sci., vol. 83, no. 6, pp. 1342–1349. doi: http://dx.doi.org/10.3168/jds.S0022-0302(00)75001-6 ORSKOV, E.R. and MCDONALD, I. (1979) The estimation of protein degradability in the rumen from incubation measurements weighed according to rate of passage. In J. Agric. Sci., vol. 92, no. 3, pp. 499-503. doi:http://dx.doi.org/10.1017/S0021859600063048 VARGA G.A. (2006) In vivo digestibility of forage. In: Proc. Tri-State dairy nutrition conference, Fort Wayne. Columbus: The Ohio State University, pp 95-106. VOELKER LINTON., J. A. and ALLEN, M. S. (2009) Nutrient demand interacts with forage family to affect N digestion and utilization responses in dairy cows. In J. Dairy Sci., vol. 92, no. 4, pp.1594-1602. doi:http://dx.doi.org/10.3168/jds.2008-1327

Chewed out: an experimental link between food material properties and repetitive loading of the masticatory apparatus in mammals.

Using a model organism (rabbits) that resembles a number of mammalian herbivores in key aspects of its chewing behaviors, we examined how variation in dietary mechanical properties affects food breakdown during mastication. Such data have implications for understanding phenotypic variation in the mammalian feeding apparatus, particularly with respect to linking jaw form to diet-induced repetitive loading. Results indicate that chewing frequency (chews/s) is independent of food properties, whereas chewing investment (chews/g) and chewing duration(s), which are proportional to repetitive loading of the jaws, are positively related to food stiffness and toughness. In comparisons of displacement-limited and stress-limited fragmentation indices, which respectively characterize the intraoral breakdown of tough and stiff foods, increases in chewing investment and duration are linked solely to stiffness. This suggests that stiffer foods engender higher peak loads and increased cyclical loading. Our findings challenge conventional wisdom by demonstrating that toughness does not, by itself, underlie increases in cyclical loading and loading duration. Instead, tough foods may be associated with such jaw-loading patterns because they must be processed in greater volumes owing to their lower nutritive quality and for longer periods of time to increase oral exposure to salivary chemicals.

Fur chewing and other abnormal repetitive behaviors in chinchillas (Chinchilla lanigera), under commercial fur-farming conditions

Abstract Fur chewing is a behavioral disorder frequently reported in chinchillas kept for fur-farming purposes. Rodents kept in barren cages usually develop some form of abnormal repetitive behavior, which can indicate a past or present welfare problem. Fur chewing may not be the only form of abnormal repetitive behavior present but is the one reported because of its direct repercussion on fur production. The aim of this study was to describe the frequency of occurrence of fur chewing and the distribution of time dedicated to it in chinchillas diagnosed as presenting this behavior. A secondary aim was to determine the presentation of other abnormal repetitive behaviors. Ten chinchillas, 5 fur chewers and 5 controls, were video recorded for 24 hours with an infrared camera. Behavioral analysis was done with The Observer XT from Noldus (The Netherlands). Focal sampling and continual recording were used, the 24-hour time budget was calculated, and abnormal repetitive behaviors were analyzed in terms of time dedication and frequency of presentation. A paired t test was used to compare differences in the amount of nocturnal versus daytime abnormal behavior. When normality was not met, a 2-sample t test and randomization test were used to compare data between treatments. No differences were observed between the time budgets of fur-chewing and control chinchillas, and all individuals exhibited more than one abnormal repetitive behavior. The amount of time devoted to abnormal repetitive behaviors was significantly higher during night in both groups and reached its lowest level between 13:00 and 17:00 hours. Fur chewing is not the only abnormal repetitive behavior developed by chinchillas in fur-farming systems, although it is the only one reported by the producer. The presence of bar chewing, cage scratching, and backflipping should also be welfare concerns. The higher presentation of abnormal repetitive behaviors at night may be associated with the lack of recognition by the producer, especially because these abnormal behaviors do not result in direct product loss as does fur chewing.

Effects of food diameter on bite size per mouthful and chewing behavior

Obesity is well known to be associated with a wide variety of illnesses, and is an increasing problem not only in developed countries but also in developing countries. It is well known that large bite size contributes to excess energy intake and obesity, whereas an increased number of chews before swallowing the food bolus is associated with suppression of obesity. However, the effect of food diameter on bite size per mouthful and on chewing behavior remains poorly understood. Here, we examined the effects of food diameter on bite size and chewing behavior using a masticatory counter during the mastication of stick-type biscuits having the same length (10 cm) and ingredients, but with four different diameters (3.0, 3.5, 4.0, and 8.0 mm). Bite length and bite weight per mouthful were similar among the 3.0, 3.5, and 4.0 mm groups. However, bite length in the 8.0 mm group was significantly smaller, whereas bite weight was significantly greater than in the 3.0/3.5 mm groups. Further, the number of chews gradually increased, whereas the number of chews per bite weight gradually decreased, with an increase of biscuit diameter. These results indicate that a smaller biscuit diameter is associated with a smaller bite weight per mouthful and a greater number of chews per bite weight. This is the first report to quantity the effect of food diameter on bite weight per mouthful and on chewing behavior; these results should be helpful in the design of effective, safe, and low-cost behavioral modification therapy to combat obesity.

Changes in jaw muscle activity and the physical properties of foods with different textures during chewing behaviors

This study aimed to investigate how the activity of the masseter (Mas) and suprahyoid (Hyoid) muscles is influenced by the physical properties of food, how changes in the rheological properties of food differ between different foods during the process of food reduction, and how different salivary flow rates affect bolus-making capability during masticatory behavior in healthy humans. Ten healthy adults participated in this study. Electromyographic (EMG) recordings were obtained from the Mas and Hyoid muscles, and 15g of steamed rice and rice cake was prepared as test foods. In the ingestion test, the subjects were asked to eat each food in their usual manner. The chewing duration, number of chewing cycles before the first swallow, Mas and Hyoid EMG activity, and chewing cycle time were compared between the foods. Total chewing duration was divided into three substages: early, middle, and late; chewing cycle time and EMG activity per chewing cycle of each substage were compared between the foods and among the substages. In the spitting test, the rheological properties of the bolus at the end of each substage were compared between the foods and among the substages. Finally, stimulated salivary flow rates were measured and the relationships between salivary flow rate and chewing duration, EMG activity, and changes in physical food characteristics were investigated. There were significant differences in total chewing duration and the number of chewing cycles, but not in chewing cycle time, between the foods, which had similar hardness values. The EMG activity levels of the Mas and Hyoid per chewing cycle for the rice cake were significantly greater than for the steamed rice throughout the recording periods. While Mas activity did not change among the substages during chewing, Hyoid EMG activity decreased as chewing progressed. Chewing cycle time also gradually decreased as chewing progressed. The hardness of both foods initially increased, then gradually decreased back to baseline. The adhesiveness of the rice cake initially increased, and did not fall throughout the recording period; the adhesiveness of the steamed rice did not significantly change. Cohesiveness barely changed in either of the two foods during chewing, but was significantly greater for the rice cake than for the steamed rice. Finally, a correlation between the stimulated salivary flow rate and chewing performance was evident only in a change in Mas EMG activity. The current results demonstrate that the activities of the Mas and Hyoid muscles changed as chewing progressed, and were affected by hardness, adhesiveness, and cohesiveness. Salivary flow rate may affect the changes in Mas activity during the process of bolus formation.

Oral Processing of Mixtures of Food Particles

AbstractWe investigated the chewing behavior and fragment size outcome in oral processing of mixtures of food particles. Experiments were conducted with colored gel particles to distinguish particles before and after chewing. Twelve subjects were asked to chew different sized gel particles and expectorate the bolus just before swallowing to measure their fragment size distributions. Chin movement was video‐recorded to measure chewing time and frequency. The results showed that the fragment size of ready‐to‐swallow bolus was affected by the food particle size and the presence of other particles of different sizes. When subjects chewed single‐sized gel particles, smaller particles were chewed less – with the result that they were swallowed more intact. In a mixture of two sizes, larger particles were preferentially selected for chewing so that the smaller particles were chewed significantly less than when chewed on their own, allowing them to be swallowed even more intact.Practical ApplicationsThere is a growing interest from food manufacturers in understanding the oral processes during eating and to apply this to new product development. Although the limits of food particle size and size combination effects still need to be tested within a variety of food products, there may be potential to use these chewing behaviors to influence the fragment size of a swallowed bolus for controlled digestion rate or to minimize adverse sensory effects of healthy food products (e.g., low‐fat, low‐sugar, low‐salt, with added health‐promoting functional ingredients). For instance, it may be possible to minimize the unpleasant taste/odor of phytonutrients by incorporating them into smaller particles in the mix so that they can be swallowed with minimal chewing. On the other hand, it may be possible to maximize sweet/salty tastes by adding sugar/salt to large particles that are more actively chewed. Further studies are necessary to test the feasibility of this concept.

Basic small ruminant nutrition

The objective of this presentation is to provide an overview of fundamental nutrient requirements and basic feeding practices for sheep and goats in an effort to improve the practitioner's ability to address related concerns from small ruminant clientele. Many principles of ruminant nutrition as applied to dairy or beef cattle can be extrapolated to sheep and goats, but they should not just be considered "little cows”. Feeding behavior of sheep and goats is classified as intermediate browsers compared to the bulk roughage grazing cow. Feed selection and chewing behavior will alter how feeds are processed in the rumen. Additionally, with their smaller size compared to cattle there will be differences in rate of passage influencing rumen dynamics. Equally, sheep and goats are not equivalent, as feeding sheep are more grazers compared to browsing by goats. Sheep and goats also have some significant nutrient requirement differences, especially related to copper, thus products formulated to meet the needs of both species should be scrutinized. The feeding management focus will be on key nutritional principles addressing the role of forage quality on animal health and performance and need for proper mineral and vitamin supplementation. Having an understanding of basic sheep and goat feeding practices can provide an opportunity to offer additional services to new or ongoing small ruminant clients.

Technical note: An in vitro study of dental microwear formation using the BITE Master II chewing machine.

Dental microwear has been used for decades to reconstruct the diets of fossil hominins and bioarchaeological populations. The basic theory has been that hard-brittle foods (e.g., nuts, bone) require crushing and leave pits as they are pressed between opposing cheek-tooth surfaces, whereas soft-tough foods (e.g., grass blades, meat) require shearing and leave scratches as they are dragged along opposing surfaces that slide past one another. However, recent studies have called into question the efficacy of microwear as an indicator of diet. One issue has been the limited number of in vitro studies providing empirical evidence for associations between microwear pattern and chewing behavior. We here describe a new study using a chewing simulator, the BITE Master II, to examine the effects of angle of approach between opposing teeth and food consistency on microwear surface texture. Results indicate that opposing teeth that approach one another: 1) perpendicular to the occlusal plane (crushing) result in pits; 2) parallel to the occlusal plane (shearing) result in striations in the direction of movement; and 3) oblique to the occlusal plane (45°) result in both striations and pits. Results further suggest that different food types and abrasive loads affect the propensity to accumulate microwear features independent of feature shapes.

Peripheral and central control of swallowing initiation in healthy humans

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 gum freely. We delivered 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 from differences 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.

55~84세 한국 성인의 현존치아수와 구강기능의 관계

본 연구는 2007~2009년 제4기 국민건강영양조사 자료를 분석하여 만 55~84세 한국인의 현존치아수와 인구사회경제적 요인, 주관적 건강수준, 그리고 구강기능 요인간의 관련성을 파악하고자 하는 목적으로 수행되었으며, 그 결과 성별과 교육수준, 부정구강진료여부, 주관적 건강 및 구강 건강상태, 씹기와 말하기 행동이 현존치아수와 관련된 변수임을 확인하였다. 인구사회경제적 요인 중, 성별에 따른 결과에서는 남성이 여성에 비해 현존치아수가 1.12개 적었으며(p<0.001), 교육수준이 높을수록 현존치아수가 많았다. 부정치과진료시술 유무와 현존치아수의 분석 결과에서는 부정치과진료 경험자가 비경험자보다 2.43개 적은 치아를 가지고 있었다(p<0.001). 주관적 건강 및 구강건강상태는 현존치아수에서 유의한 차이를 보였다. 구강기능 요인과 현존치아수의 관계에서 씹기 행동과 구강기능간의 유의한 차이를 확인하였고, 특히 말하기 행동은 불편함의 정도가 높다고 응답한 그룹일수록 현존치아수가 통계적으로 확연하게 감소하였다(p<0.001). 이러한 결과를 통해 구강기능 중에서 씹기보다는 말하기가 현존치아수와 더 밀접한 관련성을 가진다는 사실을 확인할 수 있었다. 따라서 본 연구의 결과는 만 55~84세 한국인의 구강건강 및 구강기능 향상을 위한 기초자료로 활용될 수 있을 것이다. The purpose of this study is to analyze the factors of oral function associated with number of present teeth (NT) in Korean elderly adults. The research was designed as cross-sectional study using the data of the 4th Korea National Health and Nutritional Examination Survey, and the samples were selected by stratified clusters sampling. The subjects aged 55 to 84 years were 4,780 that joined the oral examination survey and questionnaires. The respective variables reflecting socioeconomic status, subjective health status and oral function factor were analyzed and their distributional differences were confirmed by complex sampling logistic regression analysis. Multivariable liner regression models considering covariates were applied to explain the associations between the number of present teeth and other variables. Gender, educated level, illegal dental treatment, self-rated oral health and oral functional factors, including chewing behavior and speaking behavior, were associated with the number of present teeth (p<0.05). Subjects with better self-rated oral health had more NT than those with worse. Subjects with worse speaking behaviors had less NT than those with better. Interventions aiming to enhance oral health in elderly adults should consider socioeconomic, demographic, and oral functional factors.

Characterization of pica and chewing behaviors in privately owned cats: a case-control study.

The aim of this study was to characterize pica behavior in cats. Cat owners were recruited to participate in a questionnaire survey on pica behavior exhibited by their cats. Emphasis was put on the type of item ingested. Questions on early history and environment, as well as general health and gastrointestinal signs, were asked. Owners of healthy cats not showing pica were also recruited into a control group. Associations between variables and groups were statistically tested. Pica was directed most commonly at shoelaces or threads, followed by plastic, fabric, other items, rubber, paper or cardboard and wood. Some cats ingested specific items but only chewed others. A significant positive association was found between sucking and ingesting fabric (P = 0.002). Ad libitum feeding was significantly lower in the pica group than the control group (P = 0.01). Prevalence of self-sucking behavior was significantly higher in the pica group than the control group (P = 0.001). Cats with pica vomited significantly more often than control cats (P = 0.01). Pica, the ingestion of inedible items, does not seem to be the consequence of a suboptimal environment or early weaning. Cats with pica were less commonly fed ad libitum than healthy cats. As frequently reported, pica and vomiting were related, but the causative association is not well established and thus warrants further investigation.