Bite Force Data Research Articles

Design and Implement Strategy of Wireless Bite Force Device.

Abnormal bite force is an important risk factor for oral and maxillofacial disorders, which is a critical dilemma that dentists face every day without effective solutions. Therefore, it is of great clinical significance to develop a wireless bite force measurement device and explore quantitative measurement methods to help find effective strategies for improving occlusal diseases. This study designed the open window carrier of a bite force detection device through 3D printing technology, and then the stress sensors were integrated and embedded into a hollow structure. The sensor system mainly consisted of a pressure signal acquisition module, a main control module, and a server terminal. A machine learning algorithm will be leveraged for bite force data processing and parameter configuration in the future. This study implemented a sensor prototype system from scratch to fully evaluate each component of the intelligent device. The experimental results showed reasonable parameter metrics for the device carrier and demonstrated the feasibility of the proposed scheme for bite force measurement. An intelligent and wireless bite force device with a stress sensor system is a promising approach to occlusal disease diagnosis and treatment.

The value of dental implant superior frontal sinus augmentation combined with orthodontic treatment

To explore the clinical value of dental implant superior frontal sinus elevation combined with orthodontic treatment. From August 2020 to August 2021, 88 patients with maxillary posterior tooth defect were enrolled. There were 44 patients in each group. The experimental group received the combined treatment of upper frontal sinus elevation and orthodontic treatment, while the control group received general prosthodontic treatment. The evaluation indexes included the total treatment time and recovery time of teeth, chewing efficiency, bite force, clinical efficacy and treatment satisfaction data. Data summary showed that the bite force of the experimental group was similar to that of the control group before treatment, and the chewing condition was consistent with the above, P > 0. 05; After different treatment intervention, the bite force of the control group was worse, the chewing condition of the experimental group was better, the effective rate and total satisfaction rate of the control group were less than the experimental group, at the same time, the total repair time of the experimental group was shorter, compared with the control group, there was a significant difference in data, P < 0. 05. The combined treatment of upper frontal sinus augmentation and orthodontics can effectively improve the masticatory efficiency and occlusal ability of patients, improve the clinical treatment effect, and shorten the total treatment and repair time of patients, with higher acceptance of clinical patients, which has an important reference value.

Bite force data suggests relationship between acrodont tooth implantation and strong bite force.

Extant and extinct reptiles exhibit numerous combinations of tooth implantation and attachment. Tooth implantation ranges from those possessing roots and lying within a socket (thecodonty), to teeth lying against the lingual wall of the jawbone (pleurodonty), to teeth without roots or sockets that are attached to the apex of the marginal jawbones (acrodonty). Attachment may be ligamentous (gomphosis) or via fusion (ankylosis). Generally speaking, adaptative reasonings are proposed as an underlying driver for evolutionary changes in some forms of tooth implantation and attachment. However, a substantiated adaptive hypothesis is lacking for the state of acrodont ankylosis that is seen in several lineages of Lepidosauria, a clade that is plesiomorphically pleurodont. The convergent evolution of acrodont ankylosis in several clades of lepidosaurs suggests a selective pressure shaped the evolution of the trait. We hypothesize that acrodont ankylosis as seen in Acrodonta and Sphenodon punctatus, is an adaptation either resulting from or allowing for a stronger bite force. We analyzed bite force data gathered from the literature to show that those taxa possessing acrodont dentition possess a stronger bite force on average than those taxa with pleurodont dentition. Dietary specialists with pleurodont dentition may also possess relatively high bite forces, though body size may also play a role in their ability to bite hard. Furthermore, our results have implications for the evolution of acrodont ankylosis and potential behaviors related to strong bite force that influenced the evolution of acrodonty within Acrodonta and Rhynchocephalia.

The ontogeny of maximum bite force in humans.

Ontogenetic changes in the human masticatory complex suggest that bite force, a key measure of chewing performance, increases throughout growth and development. Current published bite force values for humans exist for molar and incisal biting, but few studies measure bite forces across all tooth types, or measure bite force potentials in subjects of different ages. In the absence of live data, models of bite force such as the Constrained Lever Model (CLM), are employed to predict bite force at different bite points for adults, but it is unclear whether such a model can accurately predict bite force potentials for juveniles or subadults. This study compares theoretically derived bite forces and live bite force data, and places these within an ontogenetic context in humans. Specifically, we test whether (1) patterns of maximum bite force increase along the tooth row throughout ontogeny, (2) bite force patterns estimated using the CLM match patterns observed from live bite force data, and (3) changes in bite forces along the tooth row and throughout ontogeny are associated with concomitant changes in adductor muscle leverage. Our findings show that maximum bite forces increase throughout ontogeny and change along the tooth row, with the highest forces occurring at the posterior dentition. These findings adhere to the expectations under the CLM and validate the model's utility in predicting bite force values throughout development. Furthermore, adductor muscle leverage values reflect this pattern, with the greatest leverage values occurring at the posterior dentition throughout ontogeny. The CLM informs our study of mammalian chewing mechanics by providing a model of how morphological changes of the masticatory apparatus during ontogeny affect bite force distribution along the tooth row. Furthermore, the decreased bite force magnitudes observed in juveniles and subadults compared with adults suggest that differences in juvenile and subadult diets may partially be due to differences in bite force production potentials.

How can we utilize bite force data to evaluate oral function of the elderly population?

How can we utilize bite force data to evaluate oral function of the elderly population?

Skull Size and Biomechanics are Good Estimators of In Vivo Bite Force in Murid Rodents.

Rodentia is a species-rich group with diversified modes of life and diets. Although rodent skull morphology has been the focus of a voluminous literature, the functional significance of its variations has yet to be explored in live animals. Myomorphous rodents, including murids, have been suggested to represent "high-performance generalists." We measured in vivo bite force in 14 species of wild and lab-reared murid rodents of various sizes and diets to investigate potential morphofunctional differences between them. We dissected their skulls and computed a biomechanical model to estimate bite force. We first tested if our model allowed good estimation of in vivo data. Then, using morphological, in vivo and estimated bite force data in a phylogenetic context, we aimed to find the drivers of bite force differences among species. Estimated and in vivo bite forces were strongly correlated, which indicates that (a) biomechanical models allow a good estimation of real performance, and that (b) size and muscular changes (increased mass, fiber length, and PCSA) are the main drivers of bite performance differences. Myomorphous rodents, therefore, may have evolved high bite force through a combination of changes in size and musculature, which gave them a great versatility in their ability to process food. We found mixed results at the intraspecific level, with only some species displaying a good fit between estimated and in vivo measurements. We suggest that limited variation in size and muscular organization, and increased behavioral variation might decrease the precision of bite force estimates within species. Anat Rec, 301:256-266, 2018. © 2018 Wiley Periodicals, Inc.

Does pain in the masseter and anterior temporal muscles influence maximal bite force?

ObjectiveThe aim of this study was to evaluate changes in pain and muscle force, and the relationship between them, in patients with muscle pain and bruxism, prior to and after treatment. MethodsThirty women with bruxism and myofascial pain (Ia) were included in this study. Sleep bruxism diagnosis was made based on clinical diagnostic criteria, and awake bruxism diagnosis was made by patient questionnaires and the presence of tooth wear. The diagnosis of myofascial pain was established according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC-TMD). Dentulous or partially edentulous patients (rehabilitated with conventional fixed prostheses) were included in the study according to the inclusion and exclusion criteria. The pain treatment protocol included occlusal splints, patient education, and physiotherapy for 30days. Bite force was measured using a dynamometer at the central incisor and the first molar regions on both sides. The exams were performed at baseline, after 7days, and 30days after treatment. The Wilcoxon test was used to compare patient pain level response among the periods analyzed in the study. Bite force data were submitted to two-way repeated-measures ANOVA, followed by the Tukey HSD test (p<0.05). A simple regression analysis was performed to verify the relation between pain level and bite force. ResultsResults revealed that there was a statistical difference in pain level over time for both muscles and sides (p<0.01). In the molar region, the bite force exhibited significantly higher values after 30days of treatment, when compared with the baseline (p<0.001). There was a correlation between pain level and bite force only for the temporal muscle in all periods analyzed (p<0.05). There was no strong correlation in the response level points to support the association of pain and bite force. ConclusionsPain level decreased and bite force increased in the molar region after treatment. No strong correlation or dispersion in the relationship between pain levels and bite force was seen in women with myofascial pain and bruxism.

Modeling observed animal performance using the Weibull distribution.

To understand how organisms adapt, researchers must link performance and microhabitat. However, measuring performance, especially maximum performance, can sometimes be difficult. Here, we describe an improvement over previous techniques that only consider the largest observed values as maxima. Instead, we model expected performance observations via the Weibull distribution, a statistical approach that reduces the impact of rare observations. After calculating group-level weighted averages and variances by treating individuals separately to reduce pseudoreplication, our approach resulted in high statistical power despite small sample sizes. We fitted lizard adhesive performance and bite force data to the Weibull distribution and found that it closely estimated maximum performance in both cases, illustrating the generality of our approach. Using the Weibull distribution to estimate observed performance greatly improves upon previous techniques by facilitating power analyses and error estimations around robustly estimated maximum values.

An anatomy ontology for oro‐pharyngeal muscles and the logical underpinnings of comparative anatomy (338.4)

The FEED ontology is an ontology for oro‐pharyngeal muscles and behaviors (http://code.google.com/p/feedontology/). The FEED ontology is an outgrowth of the Feeding Experiments End‐User Database (FEED, http://www.feedexp.org), a multi‐species mammalian database that includes EMG, bone strain, bite force, sonomicrometry, and kinematic data collected during feeding behaviors. FEED utilizes a controlled vocabulary of terms for mammalian feeding muscles and feeding behaviors. The FEED ontology contains classes that refer to anatomical structures, behaviors, and other entities involved in feeding, each of which is given a unique identifier and an explicit definition that is interconnected to other entities by logically defined relationships. These logical definitions make explicit the semantic underpinnings of comparative anatomy. Many of the classes have been merged directly into Uberon (Mungall et al., 2012. Genome Biology, 13(1), R5), a large, multi‐species anatomy ontology. The structure enables connections and queries across the FEED and other ontologies with which it is integrated, such as GO (Gene Ontology), and MA (Mouse Anatomy), as well as to the FEED database itself, and it contributes to the growing framework of ontologies and databases for organizing and analyzing biological data across disciplines and domains.

Built to bite: cranial design and function in the wrinkle‐faced bat

AbstractOne of the major goals of evolutionary biology is to explain phenotypic diversity and understand the limits imposed by those phenotypes. The cranial morphology of the wrinkle‐faced bat Centurio senex (Family Phyllostomidae) is bizarre and enigmatic. Its extremely short and wide skull consistently emerges as an outlier in morphological studies and many researchers have speculated about its function. Here, we investigate the hypothesis that the unique skull morphology of Centurio is associated with the ability to generate high bite forces and/or high bite forces at wide gapes. We accomplish this by comparing bite force data gathered in the field and estimates of gape limitations gathered from museum specimens. We also examine the possibility that Centurio uses unique feeding behaviors that may impose unique loading regimes on the facial skeleton. We found that relative to head size, Centurio generates the strongest bites known for any fruit‐eating phyllostomid bat, but that its ability to generate high bite forces at wide gape angles is likely limited. We also propose that its exceptionally strong bite indicates the ability to consume hard food items when other resources are limited, and that these ‘resource bottlenecks’ may have imposed strong selective pressure on its skull morphology. Behavioral data indicate that Centurio exhibits a unique reliance on unilateral biting (loading) during feeding. Based on data summarizing bite force, estimates of gape ability and feeding behavior, we suggest that Centurio's exceptionally short and wide skull reflects adaptations for high bite forces and repeated unilateral loading of the facial skeleton during feeding.

Morphological correlates of bite force and diet in the skull and mandible of phyllostomid bats

Summary Bite force is an important performance measure for vertebrate and is related to a variety of ecological challenges. Phyllostomid bats present highly diversified feeding habits associated with extensive cranial shape divergence. Biomechanical models predict that the cranial shape changes are linked to dietary variation through bite force. However, the relationship of cranial shape, diet and bite force had not been explicitly tested before. Here we use a combination of geometric morphometric techniques and comparative methods to test for morphological correlates of bite force and diet in 14 phyllostomid bat species. Skull and mandible shape variation were assessed by vectors, derived from a two‐block partial least squares analysis of geometric shape and size‐independent bite forces. The relationship between bite force, skull shape and diet was assessed by phylogenetic generalized least square regressions. Most variation in the bite force data examined here (approximately 74%) was explained by size variation alone, but the shape vectors for both skull and mandible explained a significant part of the residual variation in bite force (83% and 56%, respectively), as did the dietary differences (56%). Although the first principal component of diet variation is associated with a negative correlation between insectivory and frugivory, residual bite force and cranial shape are not associated with this diet contrast. Shape and residual bite force variation in the sample were strongly associated with the second diet component, depicting an increase in nectarivory. Species with stronger bites (insectivorous and frugivorous) than expected for their sizes presented a shorter rostrum and mandible, higher skulls, and more developed muscle attachment areas. On the other hand, the characteristic cranial elongation of nectarivorous species (supporting the long tongue) is a trade‐off with bite force. These morphological correlates of bite force are similar to those observed in carnivores and non‐herbivorous marsupials, and can be related to morphological characters used in biomechanical models for bite force prediction. Our results reinforce the effectiveness of statistically integrating geometric shape variables to bite force and diet information in the investigation of patterns of cranial shape change and trophic radiation in ecologically diverse vertebrate groups.

Effects of Gape and Tooth Position on Bite Force and Skull Stress in the Dingo (Canis lupus dingo) Using a 3-Dimensional Finite Element Approach

Models of the mammalian jaw have predicted that bite force is intimately linked to jaw gape and to tooth position. Despite widespread use, few empirical studies have provided evidence to validate these models in non-human mammals and none have considered the influence of gape angle on the distribution of stress. Here using a multi-property finite element (FE) model of Canis lupus dingo, we examined the influence of gape angle and bite point on both bite force and cranial stress. Bite force data in relation to jaw gape and along the tooth row, are in broad agreement with previously reported results. However stress data showed that the skull of C. l. dingo is mechanically suited to withstand stresses at wide gapes; a result that agreed well with previously held views regarding carnivoran evolution. Stress data, combined with bite force information, suggested that there is an optimal bite angle of between 25° and 35° in C. l. dingo. The function of these rather small bite angles remains unclear.

Bite force in vertebrates: opportunities and caveats for use of a nonpareil whole-animal performance measure

Measurements of whole-organism performance traits have been useful in studies of adaptation and phenotype– environment correlations. Bite force capacities may be tightly linked to both the type and magnitude of the ecological challenges of food acquisition, mate acquisition, and antipredation in vertebrates. In the present study, we present technical details on bite meters and on measuring bite forces. The ability to take reliable measurements depends on specific features of the measuring device and on where in the mouth the bite is applied. Using both previously available and original data, we demonstrate several ecologically and evolutionarily relevant features of bite force measurements. First, maximal bite forces are repeatable among individuals across all vertebrates studied to date. Second, in ectotherms such as lizards, maximal bite forces are affected by body temperature and motivational states. Third, bite forces are strongly correlated with head size and shape. Fourth, bite forces correlate with features of prey of vertebrates. Finally, bite forces are linked to male dominance and correlated with social-display structures. Thus, bite force performance measures can be used as ‘traits’, and thus be used in integrative studies at multiple levels of organismal biology. Accordingly, bite force data will help our understanding of the functions, capacities, and evolution of jaw–cranial musculoskeletal systems. Moreover, a plethora of opportunities exist for the use of bite force measurements, and if methods are carefully applied, several levels of organismal and ecological organization can be integrated to aid our understanding of the ecology and evolution of vertebrate taxa. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 93, 709–720.

Variations in activities of human jaw muscles depend on tooth-tipping moments

Static mechanical analyses of the masticatory apparatus often assume that jaw muscle activity, as measured using electromyography (EMG), is linearly and constantly related to magnitude of bite force during biting, regardless of bite force-induced tooth-tipping moments. The objective of this study was to test the hypothesis that the relationship between EMG of the jaw muscles and bite force varies with the magnitude and sign of tooth-tipping moments. Seven healthy male subjects produced unilateral static occlusal forces at five biting positions, resulting in sequential changes from buccal (+) to lingual (−) tipping moments on the mandibular first molar. Jaw muscle activities were recorded bilaterally using surface (for temporalis and masseter muscles) and indwelling (for lateral pterygoid muscles) electrodes. Bite forces were recorded and controlled using custom devices. EMG versus bite force data were plotted and regression relationships were calculated for each subject, muscle and biting position. Linear regression analysis, analysis of variance and Bonferroni adjusted least significant difference tests were used to determine the effects of muscle, side (ipsilateral, contralateral) and biting position within subjects. It was found that the relationship between EMG and bite force for different tipping moments differed significantly within a subject and muscle. This was most common in the lateral pterygoid and temporalis muscles (all P ≤ 0.042), where slopes of the EMG:bite force relationship varied between 3:1 and >25:1. In the masseter muscle, the EMG:bite force relationship for different tipping moments differed significantly in one subject ( P < 0.008); slopes varied up to 4.6:1. In conclusion, the relationship between EMG and bite force was linear. However, the slopes of the relationship changed significantly depending on sign (+, −) and magnitude of tipping moments acting on the molars.

BITE FORCES AND EVOLUTIONARY ADAPTATIONS TO FEEDING ECOLOGY IN CARNIVORES

The Carnivora spans the largest ecological and body size diversity of any mammalian order, making it an ideal basis for studies of evolutionary ecology and functional morphology. For animals with different feeding ecologies, it may be expected that bite force represents an important evolutionary adaptation, but studies have been constrained by a lack of bite force data. In this study we present predictions of bite forces for 151 species of extant carnivores, comprising representatives from all eight families and the entire size and ecological spectrum within the order. We show that, when normalized for body size, bite forces differ significantly between the various feeding categories. At opposing extremes and independent of genealogy, consumers of tough fibrous plant material and carnivores preying on large prey both have high bite forces for their size, while bite force adjusted for body mass is low among specialized insectivores. Omnivores and carnivores preying on small prey have more moderate bite forces for their size. These findings indicate that differences in bite force represent important adaptations to and indicators of differing feeding ecologies throughout carnivoran evolution. Our results suggest that the incorporation of bite force data may assist in the construction of more robust evolutionary and palaeontological analyses of feeding ecology.

Temporomandibular joint loading generated during bilateral static bites at molars and premolars

The aim of this study was to investigate the features of the loading vectors of the temporomandibular joint (TMJ) generated during bilateral static bites at the molars and at the premolars, and to determine the major factors affecting the difference between the two loading vectors. We computed the subjects' estimated and theoretical minimum TMJ loadings under the two different bite conditions by applying the subjects' bite-force and electromyographic (EMG) data to a two-dimensional (2D) standard model of the jaw based on a rigid-body spring model of the TMJ. For a molar bite, (1) the estimated loading vector was not equal to its theoretical minimum; (2) the TMJ-loading/bite-force ratio, describing the proportion of TMJ loading, was relatively small, 0.477 on average; and (3) the estimated loading vector pointed in the direction of the central part of the articular disk's intermediate zone. For a premolar bite, on the other hand, (1) the estimated loading vector was nearly equal to its theoretical minimum; (2) the TMJ-loading/bite-force ratio was relatively large, 0.904 on average; and (3) the estimated loading vector pointed at the superior portion of the articular disk's intermediate zone. The differences between the TMJ-loading vectors for molar and premolar bites originated primarily from changes in the bite-point location.

Finite‐element analysis of biting behavior and bone stress in the facial skeletons of bats

The wide range of dietary niches filled by modern mammals is reflected in morphological diversity of the feeding apparatus. Despite volumes of data on the biomechanics of feeding, the extent to which the shape of mammal skulls reflects stresses generated by feeding is still unknown. In addition to the feeding apparatus, the skull accommodates the structural needs of the sensory systems and brain. We turned to bats as a model system for separating optimization for masticatory loads from optimization for other functions. Because the energetic cost of flight increases with body mass, it is reasonable to suggest that bats have experienced selective pressure over evolutionary time to minimize mass. Therefore, the skulls of bats are likely to be optimized to meet functional demands. We investigate the hypothesis that there is a biomechanical link between biting style and craniofacial morphology by combining biting behavior and bite force data gathered in the field with finite-element (FE) analysis. Our FE experiments compared patterns of stress in the craniofacial skeletons within and between two species of bats (Artibeus jamaicensis and Cynopterus brachyotis) under routine and atypical loading conditions. For both species, routine loading produced low stresses in most of the skull. However, the skull of Artibeus was most resistant to loads applied via its typical biting style, suggesting a mechanical link between routine loading and skull form. The same was not true of Cynopterus, where factors other than feeding appear to have had a more significant impact on craniofacial morphology.

Bite force measurement in awake rats

This report describes the implementation of bite force measurement in awake rats and software instruments (Spike 2 script programs) that quantify and analyze the bite force data. One script program employs user-defined control of threshold bite force, which allows an easy adjustment of target force prior to training the rat. Furthermore, the interactive program allows on-line control of threshold bite force at anytime during the training session. Upon detection of the bite force crossing the threshold, it automatically triggers the external water delivery system for reinforcement. Another script program detects successful biting attempts, compiles times stamps and force level for each attempted bite, and calculates the total number of bites, success rate and mean bite force per training session. Using the new methodology, we trained five adult rats to produce the bite force of 1300 g. Our results demonstrated that all rats achieved the target force with a similar time course and exhibited little variability in success rate and mean bite force. The script programs provided instant review and analyses of the captured data. These techniques simplify assessment of bite force in behaving rats.

Ontogeny of feeding function in the gray short-tailed opossumMonodelphis domestica: empirical support for the constrained model of jaw biomechanics

The constrained model of masticatory function enables specific predictions of bite force potentials in skulls of differing craniodental configurations. In this study, empirical support for the constrained model is provided using maximum voluntary bite force data along Region I and II of the jaws of gray short-tailed opossums Monodelphis domestica. Then, growth series of M. domestica are used to assess how bite force potential changes with growth by evaluating craniodental changes using longitudinal sets of dorsoventral radiographs and by assessing maximal bite force potential at the Region I-II boundary of the jaw in juveniles (aged 70-80 days) and adults. Our findings show that, while juveniles and adults alike enclose at least three molariform teeth within Region II (the area of highest bite force potential along the jaw), age-dependent elongation of the masticatory muscle resultant lever arm and narrowing of the palate relative to jaw length especially enhance the mechanical advantage of the adductor muscle resultant in adults. While maximal bite forces at the Region I-II boundary are absolutely greater in adults, these bite forces scale isometrically with body mass, which suggests that mass-specific forces exerted by jaw adductor muscles of larger (adult) opossums are disproportionately smaller than those exerted by smaller (juvenile) opossums.

Maximum Bite Force and Prey Size of Tyrannosaurus rex and Their Relationships to the Inference of Feeding Behavior

The feeding behavior of the theropod dinosaur Tyrannosaurus rex is investigated through analysis of two variables that are critical to successful predation, bite force and prey body mass, as they scale with the size of the predator. These size-related variables have important deterministic effects on the predator’s feeding strategy, through their effects on lethal capacity and choice of prey. Bite force data compiled for extant predators (crocodylians, carnivorans, chelonians and squamates) are used to establish a relationship between bite force and body mass among extant predators. These data are used to estimate the maximum potential bite force of T. rex, which is between about 183,000 and 235,000 N for a bilateral bite. The relationship between maximum prey body mass and predator body mass among the same living vertebrates is used to infer the likely maximum size of prey taken by T. rex in the Late Cretaceous. This makes it possible to arrive at a more rigorous assessment of the role of T. rex as an active predator and/or scavenger than has hitherto been possible. The results of this analysis show that adult Triceratops horridus fall well within the size range of potential prey that are predicted to be available to a solitary, predaceous T. rex. This analysis establishes boundary conditions for possible predator/prey relationships among other dinosaurs, as well as between these two taxa.