Evidence for a trade-off between early growth and tooth wear in Svalbard reindeer

Ruminants depend on efficient physical degradation of forage through chewing to increase the surface area of the food particles presented to the microflora. Fossil evidence suggests that increased molar height is an adaptation for wear tolerance in dry ecosystems with sparse vegetation, but no study has shown selection pressure for hypsodonty in contemporary ruminants. We explored the relationships between particle size in rumen, tooth wear (scanned molar occlusal topography), age and body mass of female Svalbard reindeer living in an arctic desert at 78 degrees latitude on Svalbard. We predicted that (H1) if the rumen particle size is determined mainly by constraints due to tooth wear, and if tooth wear is mainly a function of age, average particle size in rumen should increase with age. From allometric relations it is known that larger individuals can survive on a lower-quality diet, we therefore predicted (H2) larger particle sizes with increases in (ln) body mass, irrespective of age and wear. Lastly, if there is a trade-off between growth and tooth wear in dry ecosystems (a selection pressure for hypsodonty), we predicted (H3) that teeth of heavier animals should be more worn than those of lighter animals of the same age. The proportion of small particles (<1.0 mm) decreased rapidly with increasing age (consistent with H1). Heavier females within an age class had more worn teeth (consistent with H3) than lighter ones. A close-to-isometric relationship between particle size and body mass suggested that heavier animals partly compensated for reduced tooth efficiency by chewing more. We provide the first evidence of a trade-off between fast early growth and wear (a somatic cost) of a senescence-related trait--the structure and height of the molar--in a wild ruminant inhabiting an arctic desert where selection pressure for increased tooth height is expected. This suggests that foraging conditions are more extreme than the environment in which the species originally evolved.     

Postcanine tooth size in female primates

The results of many allometric studies of postcanine tooth size in mammals have not corresponded to expectations of tooth size based on energy requirements and dental function. The purpose of this study is to investigate the relationship between postcanine occlusal surface area, body size, and the metabolic demands of pregnancy and lactation in female primates. Tooth and body sizes from 38 primate species were taken from the literature to test two hypotheses: 1) females should have relatively larger teeth than males in order to masticate additional food for the energetic costs of reproduction; 2) taxa with the largest neonatal size (a measure of average metabolic costs of pregnancy and lactation) should have females with a greater degree of relative dental enlargement. The results show that relatively large female teeth are not found consistently in primate species. Females have less occlusal surface area than expected on the basis of the male tooth and body size regression in 21% of the species, and there is no correlation between relative female tooth size and relative newborn size across higher primate taxa. The degree of female dental enlargement is most closely related to degree of sexual dimorphism in body weight. The correlation between degree of body weight dimorphism and relatively larger postcanine teeth in females than in males is 0.87 in the 38 species. Species that are monomorphic in weight tend to be monomorphic in tooth size even though females apparently require more food than males.(ABSTRACT TRUNCATED AT 250 WORDS)     

Tooth wear patterns in voles (Microtus agrestis and Clethrionomys glareolus) and efficiency of dentition in preparing food for digestion

Voles (Microtinae) are among the smallest of mammals which feed extensively on plant leaf material. They achieve higher digestive efficiencies than large ungulates, and this study considers the role that dentition may play in grinding food into small particles, so assisting efficient digestion. Bank ( Clethrionomys glareolus) and field voles ( Microtus agrestis) were found to chew their food into far smaller particles than ungulates, field voles producing smaller particle sizes than bank voles. Scanning electron micrographs showed differences in tooth wear patterns between species, and in bank voles a change in diet led to changes in tooth wear and to changes in the efficiency with which food was processed. Field voles have a pore structure on the occlusal surface of the molar teeth which could play an important role because when the teeth act antagonistically these pores could grate fragments of plant leaves into very small particles and hence enable the animals to achieve high digestive efficiencies.     

Chewing disability in older adults attributable to tooth loss and other oral conditions

doi: 10.1111/j.1741‐2358.2010.00412.x Chewing disability in older adults attributable to tooth loss and other oral conditions Background: This study evaluates associations between oral health‐related factors and chewing ability, and quantifies the risk contributed by each factor. Materials and methods: Chewing ability and information on number of teeth, dentures and dental problems over the last 12 months were collected by mailing questionnaires to a random sample of 60‐ to 71‐year‐olds from Adelaide, South Australia. Logistic regression was used to model oral status and oral symptoms as predictors of chewing disability, and to estimate the population‐attributable fraction. Results: A total of 444 persons responded (response rate = 68.8%). Among dentate subjects, 10.3% were chewing‐deficient, with chewing disability more prevalent (p < 0.05) among those with <21 teeth (26.4%), dentures (20.4%), painful aching in the mouth (25.4%), pain in the face (16.7%), broken/chipped teeth (15.6%), sensitive teeth (14.1%), loose teeth (37.1%), and sore gums (18.0%). Adjusted Odds ratios (OR) showed inadequate dentition (OR = 4.20), painful aching in the mouth (OR = 4.88), and presence of loose teeth (OR = 4.70) were associated with chewing disability (p < 0.01), and their population attributable fractions were 18.5%, 15.1% and 7.8% respectively. Conclusions: Loose teeth, number of teeth and pain in the mouth were associated with chewing disability, with an inadequate dentition and pain in the mouth contributing most to chewing disability in this population.     

Functional ecology and evolution of hominoid molar enamel thickness: Pan troglodytes schweinfurthii and Pongo pygmaeus wurmbii

The divergent molar characteristics of Pan troglodytes and Pongo pygmaeus provide an instructive paradigm for examining the adaptive form-function relationship between molar enamel thickness and food hardness. Although both species exhibit a categorical preference for ripe fruit over other food objects, the thick enamel and crenulated occlusal surface of Pongo molar teeth predict a diet that is more resistant to deformation (hard) and fracture (tough) than the diet of Pan. We confirm these predictions with behavioral observations of Pan troglodytes schweinfurthii and Pongo pygmaeus wurmbii in the wild and describe the mechanical properties of foods utilized during periods when preferred foods are scarce. Such fallback foods may have exerted a selective pressure on tooth evolution, particularly molar enamel thinness, which is interpreted as a functional adaptation to seasonal folivory and a derived character trait within the hominoid clade. The thick enamel and crenulated occlusal surface of Pongo molars is interpreted as a functional adaptation to the routine consumption of relatively tough and hard foods. We discuss the implications of these interpretations for inferring the diet of hominin species, which possessed varying degrees of thick molar enamel. These data, which are among the first reported for hominoid primates, fill an important empirical void for evaluating the mechanical plausibility of putative hominin food objects.     

Effects of dietary fracture toughness and dental wear on chewing efficiency in geladas (Theropithecus gelada)

Chewing efficiency has been associated with fitness in mammals, yet little is known about the behavioral, ecological, and morphological factors that influence chewing efficiency in wild animals. Although research has established that dental wear and food material properties independently affect chewing efficiency, few studies have addressed the interaction among these factors. We examined chewing efficiency, measured as mean fecal particle size, as a function of seasonal shifts in diet (and corresponding changes in food fracture toughness) in a single breeding population of a grazing primate, the gelada monkey, at Guassa, Ethiopia. We also measured dental topographic traits (slope, angularity, and relief index) and relative two‐ and three‐dimensional shearing crest lengths in a cross‐sectional wear series of gelada molars. Chewing efficiency decreased during the dry season, a pattern corresponding to the consumption of foods with higher fracture toughness. Older individuals experienced the most pronounced decreases in chewing efficiency between seasons, implicating dental wear as a causal factor. This pattern is consistent with our finding that dental topographic metrics and three‐dimensional relative shearing crest lengths were lowest at the last stage of wear. Integrating these lines of behavioral, ecological, and morphological evidence provides some of the first empirical support for the hypothesis that food fracture toughness and dental wear together contribute to chewing efficiency. Geladas have the highest chewing efficiencies measured thus far in primates, and may be analogous to equids in their emphasis on dental design as a means of particle size reduction in the absence of highly specialized digestive physiology. Am J Phys Anthropol 155:17–32, 2014. © 2014 Wiley Periodicals, Inc.     

Dietary adaptations in the teeth of murine rodents (Muridae): a test of biomechanical predictions

Functional dental theory predicts that tooth shape responds evolutionarily to the mechanical properties of food. Most studies of mammalian teeth have focused on qualitative measures of dental anatomy and have not formally tested how the functional components of teeth adapt in response to diet. Here we generated a series of predictions for tooth morphology based on biomechanical models of food processing. We used murine rodents (Old World rats and mice) to test these predictions for the relationship between diet and morphology and to identify a suite of functional dental characteristics that best predict diets. One hundred and five dental characteristics were extracted from images of the upper and lower tooth rows and incisors for 98 species. After accounting for phylogenetic relationships, we showed that species evolving plant‐dominated diets evolved deeper incisors, longer third molars, longer molar crests, blunter posteriorly angled cusps, and more expanded laterally oriented occlusal cusps than species adapting to animal‐dominated diets. Measures of incisor depth, crest length, cusp angle and sharpness, occlusal cusp orientation, and the lengths of third molars proved the best predictors of dietary adaptation. Accounting for evolutionary history in a phylogenetic discriminant function analysis notably improved the classification accuracy. Molar morphology is strongly correlated with diet and we suggest that these dental traits can be used to infer diet with good accuracy for both extinct and extant murine species.     

Complexity of ruminant masticatory evolution

The evolution of robust jaws, hypsodont teeth, and large chewing muscles among grazing ruminants is a quintessential example of putative morphological adaptation. However, the degree of correlated evolution (i.e., to what extent the grazer feeding apparatus represents an evolutionary module), especially of soft and hard tissues, remains poorly understood. Recent generation of large datasets and phylogenetic information has made testing hypotheses of correlated evolution possible. We, therefore, test for correlated evolution among various traits of the ruminant masticatory apparatus including tooth crown height, jaw robustness, chewing muscle size, and characters of the molar occlusal surfaces, using phylogenetic and nonphylogenetic comparative methods as well as phylogenetic evolutionary model selection. We find that the large masseter muscles of grazing ruminants evolved with the inclusion of grass in the diet, an increase in the proportion of occlusal enamel bands oriented parallel to the chewing stroke, and possibly hypsodonty. We suggest that the masseter evolved under two evolutionary regimes: i) selection for higher masticatory forces during chewing and ii) flattening of the tooth profile, which resulted in reduced tooth guidance and, thus, a requirement for more chewing muscle activity during each chewing stroke, in agreement with previous research. The linear jaw metrics (depth of the mandibular angle, mandibular angle width, and length of the superficial masseteric scar) all show correlated evolution with hypsodonty and the proportion of enamel bands oriented parallel to the chewing stroke. We suggest that changes in the shape of the mandible represent the combined effects of selection for a reorientation of the chewing stroke, so as to emphasize horizontal translation of the teeth, and accommodation of high‐crowned teeth. Our analyses show that the ruminant feeding apparatus is an evolutionary mosaic with its various components showing both correlated and independent evolution. J. Morphol. 275:1093–1102, 2014. © 2014 Wiley Periodicals, Inc.     

Helicoidal plane of dental occlusion

A helicoidal plane of postcanine occlusion has been patchily reported in many recent and fossil dentitions of man, and has been suggested as a taxonomic marker distinguishing between the dentitions of Homo and Australopithecines. The present paper describes the helicoidal plane in 19 out of 23 modern human (probably Indian) worn dentitions, in both gracile and robust Australopithecines and in extant anthropoids. It is suggested that tooth wear converts the plane of occlusion present in little-worn teeth, the Monson curve, into a helicoidal plane when 1) the diet is more abrasive, 2) the enamel is thinner and less abrasion resistant, and 3) a longer time separates the eruption of the three molar teeth in a jaw quadrant. A model demonstrates that during the power stroke of a chewing cycle the working side molars move in much the same direction whether the molar occlusal plan follows a Monson curve or a helicoidal plane. The difference is that in the former case the three molars work at the same time while in the latter case they work in sequence from anterior to posterior, thereby concentrating force on one tooth at a time. Because the occlusal plane changes during the life of individuals consuming an abrasive diet, the condition of most anthropoids and hominids, it is argued that the Monson curve has functional significance not because of its influence on occlusal relations and/or jaw movement but because the molar teeth are embedded in bone roughly perpendicular to it, a direction which resists tilting of the teeth during mastication. It is concluded that the helicoidal plane probably has little if any value as a taxonomic marker.     

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. Am J Phys Anthropol 158:769–775, 2015. © 2015 Wiley Periodicals, Inc.     

Common solutions to resolve different dietary challenges in the ruminant dentition: The functionality of bovid postcanine teeth as a masticatory unit

Plasticity of tooth shape in mammals is of great adaptive value for the efficient exploitation of specific feeding niches and is a crucial mechanism for ecological diversification. In this study, we aimed to infer chewing effectiveness from the functional shape of different postcanine teeth within bovids, the most diverse extant group of large herbivorous mammals. We consider the postcanine dentition as a masticatory unit and test for differences related to food biomechanical properties, dietary abrasiveness, and chewing dynamics. We compare functional properties of the postcanine tooth row among species with well‐known dietary strategies by integrating digitalization of high‐resolution occlusal surface 3D‐models of upper postcanine dentitions and quantification of the indentation index (D), a structural parameter representing enamel complexity. We test for differences in the occlusal shape among tooth positions in the postcanine dentition using robust, heteroscedastic tests in a one‐way analysis of variance. Our results show three distinct patterns of enamel complexity along the tooth row: (1) D is more homogeneously distributed among tooth positions; (2) D increases gradually in the mesiodistal axis along the tooth row; and (3) D increases abruptly only at the transition between premolars and molars. We interpreted these patterns as different adaptive configurations of the postcanine tooth row relating to diet. Grass‐ and fruit‐eating bovids show the same abrupt increase in enamel complexity at the transition from premolars to molars. Intermediate feeding and leaf‐browsing species show the same gradual, mesiodistal increase in complexity along the tooth row. The absolute physical dietary resistance (biomechanical properties plus abrasiveness) and its relation to mechanical constraints of the chewing stroke are the likely selective factors leading to convergence of enamel complexity patterns along the tooth row among taxa with different diets. J. Morphol. 275:328–341, 2014. © 2013 Wiley Periodicals, Inc.     

The interplay between increased tooth crown‐height and chewing efficiency,and implications for Cervidae evolution

Mammals of numerous lineages have evolved high‐crowned (hypsodont) teeth particularly during the last 20 million years. This major phenotypic change is one of the most widely studied evolutionary phenomena in a broad range of disciplines, though the mechanisms underlying its transformation remain unresolved. Here, we present the first Finite Element Analysis (FEA) to investigate the alternative hypothesis that there is a biomechanical link between increased hypsodonty and a more effective mastication in deer. Our FE experiments compared patterns of stress and strain within and between different fossil and living species under different loading conditions, and found that more hypsodont teeth are suited for restricting stresses to those areas where chewing loading occurs. This mechanical improvement is consequence of specific and pronounced variations in tooth geometry and morphology of the occlusal surface that are strongly related to crown growth in the vertical plane. We demonstrate that hypsodonty enables selenodont‐teeth to adopt a mechanically improved design that increases the pressure whilst shearing foods. As ruminants are physiologically limited by both the quantity of food consumed and the time spent in the mastication and digestion, hypsodonty is highly advantageous when feeding on mechanically resistant, tough and fibrous foods. Consequently, it allows grass‐eaters to spend less time chewing, thereby increasing the volume of food ingested and/or providing more time for digestion. This study provides a promising line of evidences in support of biomechanical effectiveness, in addition to or instead of increased wear resistance, as a factor in explaining the evolutionary origins of the hypsodont phenotype.     

Tooth morphology and other aspects of the Teso dentition

The teeth of over 5,000 Teso schoolchildren members of a Nilo-Hamitic tribe in East Africa, were examined for morphological traits. There was a significant difference between the sexes in the number of cusps on the lower first and second molars, in the prevalence of the cusp of Carabelli, and in variability and agenesis of the upper lateral incisor. The results showed that females consistently favoured tooth reduction. There was also a tendency among those possessing extra cusps on one molar to have extra cusps or other molars. Records kept of the prevalence of the tribal custom of extracting lower central incisors indicated that this practise is rapidly dying out. On another group of teeth which had been extracted from adults common variations of root morphology were noted, together with the fissure pattern of the lower molars. Measurements were made of those teeth which were unworn and were not broken down by dental decay, and the lower third molar was found to be the largest tooth of the series. Observations on the pattern of molar tooth wear showed that the buccal as well as the occlusal surface was strongly affected.     

Interspecific and intraspecific relationships between tooth size and jaw size in primates

The association between mandibular robusticity, postcanine megadontia, and canine reduction in hominins has led to speculation that large and robust jaws might be required to spatially accommodate large canine and molar teeth in hominins and other primates. If so, then variations in mandibular form that are generally regarded as biomechanical adaptations to masticatory demands might instead be incidental effects of functional requirements of tooth support. While the association between large teeth and deep, robust jaws in hominins is well known, the relationship between tooth size and jaw size has not been systematically evaluated in a comparative sample of primates. We evaluate the relationships between molar tooth size, canine tooth size, and mandibular corpus and symphyseal dimensions in a sample of adult anthropoids in interspecific (n=84 species) and intraspecific (n=36 species) contexts. For intraspecific comparisons, tooth size and jaw size are correlated, but for a majority of species this is a function of sexual size dimorphism. Interspecific comparisons lend little direct support to the hypothesis that jaw breadth directly covaries with molar tooth breadth, but they do support the hypothesis that mandibular depth is associated with canine tooth size in males. The latter observation suggests that if there is a causal association between canine size and mandibular depth, it is subject to a threshold effect. In contrast, neither corpus nor symphyseal robusticity, measured as a shape index of breadth/height, are correlated with tooth size. Our results suggest that further studies of the relationship between tooth size and corpus morphology should focus on tooth root size and corpus bony architecture, and that species-specific factors should have a strong impact on such relationships.     

Seasonal variation in molar outline of bank voles: An effect of wear?

Morphometric characters can be of use for elucidating the evolutionary history of species by providing an insight into the selective pressure related to the character of interest, and by allowing integration of fossil specimens. This potential interest of phenotypic characters, however, depends on how much other sources of variation, such as the life-history of the animal, may blur an evolutionary signal. For instance, age structure varies along the year, causing in turn various assemblages of wear stages in the teeth sampled at a given place and time. In this context, we investigated the season of trapping as potential source of variation in the size and shape of the molar occlusal surface of the bank vole, Clethrionomys glareolus.The size and shape of the occlusal surface of the third upper molar was quantified using outline analysis in 60 bank voles from Finland, trapped at the same study site in successive spring and autumn. The occlusal surface clearly differed in size and shape between the two seasons of trapping. Using 3D imaging as a visual support, we interpret this difference as the result of differential wear. The population in autumn is dominated by young specimens with unworn teeth whereas spring populations are composed of old animals with worn down molars. The range of seasonal variation in tooth size and shape appears to be of the same order of magnitude as biogeographic variation, demonstrating that differential wear may have a strong impact on biogeographic and evolutionary studies. Yet, beyond the effect of trapping season, a biogeographic signal still emerged, related to the genetic lineages evidenced in other studies. In consequence, morphometric characters such as size and shape of molar occlusal surfaces appear as valuable tracers of biogeographic differentiation, but future studies should take seasonal variations into account for more robust interpretation.     

Patterns of molar wear in hunger-gatherers and agriculturalists

Tooth wear records valuable information on diet and methods of food preparation in prehistoric populations or extinct species. In this study, samples of modern and prehistoric hunger-gatherers and agriculturalists are used to test the hypothesis that there are systematic differences in patterns of tooth wear related to major differences in subsistence and food preparation. Flatness of molar wear is compared for five groups in hunger-gatherers (N = 298) and five groups of early agriculturalists (N = 365). Hunger-gatherers are predicted to develop flatter molar wear due to the mastication of tough and fibrous foods, whereas agriculturalists should develop oblique molar wear due to an increase in the proportion of ground and prepared food in the diet. A method is presented for the quantitative measurement and analysis of flatness of molar wear. Comparisons of wear plane angle are made between teeth matched for the same stage of occlusal surface wear, thus standardizing all groups to the same rate of wear. Agriculturalists develop highly angled occlusal wear planes on the entire molar dentition. Their wear plane angles tend to exceed hunger-gatherers by about 10 degrees in advanced wear. Wear plane angles are similar within subsistence divisions despite regional differences in particular foods. This approach can be used to provide supporting evidence of change in human subsistence and to test dietary hypotheses in hominoid evolution.     

SEM analysis of tooth enamel

SEM analysis contains researches of tooth enamel surfaces of two populations. First group of samples is tooth enamel of prehistorically ancestor from Vucedol and the second group of samples is enamel of modern Croatian citizen. Even on small number of human teeth samples from cooperage site of Vucedol (3,000 BC) and today's Croatian people, we can conclude about chewing biometry of prehistorically ancestors and today's modern Croatian people, comparing interspecifically the morphology of enamel microdefects. With the interspecific comparison of morphology changes on tooth occlusal surfaces, we can connect the size and shape of abrasive particles and diet with microdefects of tooth enamel.     

The role of tooth enamel mechanical properties in primate dietary adaptation

Primate teeth adapt to the physical properties of foods in a variety of ways including changes in occlusal morphology, enamel thickness, and overall size. We conducted a comparative study of extant primates to examine whether their teeth also adapt to foods through variation in the mechanical properties of the enamel. Nanoindentation techniques were used to map profiles of elastic modulus and hardness across tooth sections from the enamel-dentin junction to the outer enamel surface in a broad sample of primates including apes, Old World monkeys, New World monkeys, and lemurs. The measured data profiles feature considerable overlap among species, indicating a high degree of commonality in mechanical properties. These results suggest that differences in the load-bearing capacity of primate molar teeth are more a function of morphology-particularly tooth size and enamel thickness-than of underlying mechanical properties.     

Muscles advance the teeth in sand dollars and other sea urchins

We demonstrate the action of the dental promoter muscles in advancing the continuously growing teeth of sand dollars and sea urchins. Teeth wear at the occlusal end, while new calcite is added to the opposite end. Dental ligaments rigidly hold teeth during chewing, but soften and reform during advancement. The source of forces that advance the teeth was unknown until our discovery of the dental promoter muscles. The muscles, which underly the tooth, attach centrally to the stereom of the pyramid of the Aristotle''s lantern (jaw) and peripherally to a membrane that covers the distal end of the tooth. The muscles shorten along an axis nearly parallel to the long axis of the tooth. We stimulated contraction by addition of acetylcholine, with increasing concentrations of acetylcholine generating higher forces. Forces exerted by this muscle are appropriate for its size and are 1000 times lower than forces exerted by interpyramidal muscles that generate chewing forces. In sand dollars, a single muscle contraction of the dental promoter muscle can account for half the mean daily advancement of the teeth.     

An investigation of dentinal fluid flow in dental pulp during food mastication: simulation of fluid–structure interaction

This study uses fluid–structure interaction (FSI) simulation to investigate the relationship between the dentinal fluid flow in the dental pulp of a tooth and the elastic modulus of masticated food particles and to investigate the effects of chewing rate on fluid flow in the dental pulp. Three-dimensional simulation models of a premolar tooth (enamel, dentine, pulp, periodontal ligament, cortical bone, and cancellous bone) and food particle were created. Food particles with elastic modulus of 2,000 and 10,000 MPa were used, respectively. The external displacement loading $(5\,\upmu \hbox {m})$ was gradually directed to the food particle surface for 1 and 0.1 s, respectively, to simulate the chewing of food particles. The displacement and stress on tooth structure and fluid flow in the dental pulp were selected as evaluation indices. The results show that masticating food with a high elastic modulus results in high stress and deformation in the tooth structure, causing faster dentinal fluid flow in the pulp in comparison with that obtained with soft food. In addition, fast chewing of hard food particles can induce faster fluid flow in the pulp, which may result in dental pain. FSI analysis is shown to be a useful tool for investigating dental biomechanics during food mastication. FSI simulation can be used to predict intrapulpal fluid flow in dental pulp; this information may provide the clinician with important concept in dental biomechanics during food mastication.