Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Bite Force”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources

Estimating human incisal bite forces from the electromyogram/bite-force function.

This study used the electromyogram (EMG)/force-function curve as a means of estimating functional bite forces. Surface EMG recordings were made for the masseter and anterior temporalis muscles bilaterally in ten adults while incisal bite forces were measured using a force transducer embedded in custom-made hydroplastic bite blocks. Measurements were made for mouth openings of 15 and 30 mm. Each subject was first instructed to develop a maximum level of bite force, and then to develop bite-force levels that corresponded to decreasing percentages of his or her maximum, from 90 to 10%, in 10% decrements. After the force measurements had been made, each subject was instructed to incise various food substances. The power-density spectrum and r.m.s. power level were calculated for each sample. Maximum bite-force levels varied considerably among the 10 subjects, ranging from a minimum of 2.5 kg to a maximum of 40 kg. For the subjects as a whole, estimated bite forces for the different types of food ranged from 3.0 to 5.5 kg. This range was independent of the subjects' maximum bite-force levels. Thus, bite forces exerted to incise different foods probably depend more on the food than on the individual's bite capabilities. There was variability within this range, although, as expected, bite forces were least for chocolate and greatest for apple and toffee.

Adult↗

[Measurement of biting force of normal teeth at different ages].

The biting force value of normal teeth of 770 human subjects were measured by electric resistance strain gnathodynamometer. 365 were males, and 405 females. Their ages ranged from 13 to 49. The results showed that the biting force value of males is larger than that of the females (P < 0.01). In the males, the biting force value of those aged 13-16 gradually increased with age, and the maximal biting force values of incisor, bicuspid, and first molar of all the males were 43.3kg, 99.11kg, and 120.66kg respectively.

Adolescent↗

Bite force displayed during assessment of hardness in various texture contexts.

The relationship between mastication pattern, mechanical properties of the food bolus and texture perception are not fully understood, though the mastication process is known to adjust to different textural properties of foods. This study investigated the role of the bite force as one major aspect in hardness assessment of materials exhibiting simple mechanical properties over a wide hardness range. Elastic, plastic and brittle materials (silicone elastomers, waxes and pharmaceutical tablets, respectively) were tested. The rheological characteristics of these products were measured. For each product, one to four differential thresholds were determined at different points on a hardness scale by 10 individuals free of dental pathology. Bite forces were recorded by placing a small intraoral load cell under each sample. To assess the influence of the nature of the applied force, bites were made either directly on to the sample or on a metal disc placed between the teeth and the sample. As the individuals had to break the brittle products to perceive any hardness difference, bite forces were very closely correlated with the hardness of the products (r = 0.99). For plastic products, bite forces again correlated with the hardness (r = 0.96), even though individuals could stop biting at any time during the plastic deformation. Hardness perception of brittle and plastic products depends directly on sensory information about the bite force. However, hardness assessment of elastic products was obtained under constant bite force; here, the resulting deformation may provide sensory information about hardness.

Adult↗

Lack of correlation between mouth-breathing and bite force.

The correlation between mouth-breathing and bite force was studied in 81 children, 7 to 16 years old. Mouth-breathing was diagnosed on the basis of the subject history, the rhinomanometrically determined nasal airflow and the size of the airway measured on the profile cephalogram. The maximum bite force was measured at the first molars. In addition, the facial morphology was analysed on profile cephalograms. Both mouth-breathing and bite force were associated with the facial morphology but there was no association between mouth-breathing and bite force. It was concluded that the long-face morphology characteristic of mouth-breathing children is not due to weak masticatory muscles.

Adolescent↗

[An effect of the clenching speed on the method of calculating the biting force of patients by using electromyography].

The recovery of the masticatory function in patients with dentures was assessed by several indices such as masticatory efficiency, maximal biting force and electromyographic analysis. We have attempted to develop a new method of calculating the biting force of edentulous patients by using electromyography. The method has almost been established, but, depending on the clenching speed, there is a certain difference between the estimates obtained from this method and the biting force obtained from a force transducer. The purpose of this study is to clarify the effect of the clenching speed on the method of calculating the biting force by using electromyography. In 9 healthy subjects with normal dentitions, biting force and electromyograms were recorded simultaneously under 3 different clenching speed conditions. After the recording, the relation between the biting force and integrated electromyography was compared thoroughly. The effect of the clenching speed on the method of calculating the biting force by using electromyography was also investigated. The following results and conclusions were obtained: 1. At a slow clenching speed, a linear relation between the biting force and integrated electromyography was found. 2. At a medium clenching speed, the relation showed a slightly upward curvature as the biting force was increased and a slightly downward curvature as it was decreased. 3. At a fast clenching speed, the relation between the biting force and integrated electromyography showed an upward curvature as the biting force was increased, and a downward curvature as it was decreased. 4. At the slow and medium clenching speeds the estimates obtained from this method approximated the biting forces obtained from a force transducer. 5. At the fast clenching speed, the tendency was found that the estimates obtained from this method were higher than the biting force obtained from a force transducer. 6. When realizing this tendency, the method of calculating the biting force by using electromyography can be said to be clinically effective.

Bite Force↗

The accelerative component of EMG in bite force development in man.

Masseter EMG and bite force recordings were made from six subjects. Multiple regression analysis was performed and an equation produced relating EMG and bite force in SI units. Evidence is presented for a component of masseter EMG which can be related to the acceleration of bite force during onset of a clench.

Bite Force↗

Bite force discrimination by individuals with complete dentures.

The purpose of this study was to determine whether differences existed in interincisor bite force discrimination between a group of subjects wearing complete dentures and a group of dentate individuals. It was hypothesized that biting force is monitored at least in part by the sensory mechanism within the PDL and that the absence of the PDL would result in reduced bite force discrimination. A specially designed strain gauge scale was constructed for the measurement of bite force. Bite force discrimination was assessed at three different standards including 500, 1000, and 3000 gm. Data analysis revealed that, overall, bite force discrimination was not significantly different for the two groups. However, at the lightest standard of 500 gm, the dentate group performed significantly better (p less than .05) than the denture wearers. It is concluded that the sensory system within the PDL plays a role in monitoring bite force discrimination.

Adult↗

Maximum bite force, muscle efficiency and mechanical advantage in children with vertical growth patterns.

This study correlated maximum bite force and masticatory muscle electromyography (EMG) activity with craniofacial morphology and mechanical advantage of children with vertical growth patterns. From lateral cephalograms of 30 females and 17 males (9.3 +/- 3.6 years of age), 13 morphological and eight biomechanical measurements were recorded. Two maximum bite forces and 12 submaximal bite forces along with their associated EMG muscle activity were recorded at the right mandibular first molar. Muscle efficiency was evaluated using the relationship between bite forces and EMG activity levels. There were no significant sex differences (P > 0.05) for any of the morphological, functional or biomechanical variables. Factor analyses reduced: (1) the 13 morphological variables to four factors explaining 82.8 per cent of the morphological variance; (2) six functional variables to two factors explaining 68.8 per cent of the functional variance; and (3) 11 biomechanical variables to three factors explaining 90.9 per cent of the biomechanical variance. The vertical size factor was negatively correlated with the muscle efficiency factor (r = -0.39; P = 0.006) and positively correlated with the moment arm factor (r = 0.67; P < 0.001). The morphological divergence factor was negatively correlated with the bite force factor (r = -0.34; P = 0.019) and the mechanical advantage factor (r = -0.32; P = 0.028). The muscle efficiency factor (functional) was negatively correlated with the moment arm factor (r = -0.33; P = 0.023). It is concluded that: (1) independent of chronological age, children with larger faces have larger moment arms and require less muscle activity to attain any given force, and (2) greater hyperdivergence is related to poorer mechanical advantage and lower maximum bite force. These data support the relationships between bite force, muscle strength and morphology in children, similar to those reported for adults.

Adolescent↗

Bite force in pre-orthodontic children with unilateral crossbite.

In the present study bite force was examined in pre-orthodontic children with unilateral posterior crossbite and compared with an age- and sex-matched control group. The sample comprised 52 children aged 7-13 years, 26 pre-orthodontic children with unilateral posterior crossbite (crossbite group), and 26 children with neutral occlusion (control group). Unilateral bite force was measured at the first molar by means of a pressure transducer. Furthermore, symptoms and signs of temporomandibular disorders (TMD) and number of teeth in contact in the intercuspal position (ICP) were recorded. In both groups, the maximum bite force increased significantly with age and with increasing stages of dental eruption, but the bite force in both sexes did not differ significantly. There were no significant differences in bite force between sides, but this was significantly smaller in the crossbite group than in the controls (P < 0.001). Regression analysis showed that stage of dental eruption (P < 0.001), number of teeth in occlusal contact (P < 0.01), and unilateral crossbite (P < 0.001) were the only variables significantly correlated with bite force. The number of teeth in contact was significantly smaller in the crossbite group than in the controls (P < 0.05) and the frequency of muscle tenderness was significantly higher in the crossbite group than in the controls (P < 0.05). These results suggest that differences in the muscle function associated with unilateral crossbite lead to a significantly smaller bite force in the crossbite group compared with controls and this difference did not diminish with age and development. These findings indicate that early treatment of unilateral posterior crossbite is advisable to optimize conditions for function.

Adolescent↗

[Effects of bite force loss on the expression of IL-6 mRNA in rat periodontium].

OBJECTIVE: The aim of this study is to evaluate the expression of IL-6 mRNA in rat periodontal cells under normal bite force and without bite force, and to explain periodontal remodeling from the molecular level. METHODS: Animal models with normal bite force and without bite force were established by using Wistar rats. In situ hybridization technique was applied to detect changes of IL-6 mRNA expression in rat periodontal tissue. RESULTS: Without bite force, the expression level of IL-6 mRNA increased significantly in periodontal cells. CONCLUSION: This study initially investigates the molecular mechanism of periodontal remodeling, and suggests that the histological morphology may be closely related to the mechanical stimulation.

Animals↗

Maximal bite forces in healthy young adults as predicted by surface electromyography.

OBJECTIVES: To assess the repeatability of maximal bite force estimates as obtained by submaximal electromyographic-force relationships performed simultaneously and symmetrically in both sides of the mouth. The protocol could be used in a clinical context to obtain indicative values for the occlusal loads to be resisted by the prosthetic reconstructions. METHODS: Ten young healthy subjects performed; (1) a maximum voluntary clench (MVC) directly on their occlusal surfaces; (2) four simultaneous recording of submaximal bite forces (98, 196, 304 and 392 N on two transducers positioned on the left and right first mandibular molars) and surface EMG potentials of the masseter and temporalis anterior muscles. The actual force peak value was recorded. For each subject, a linear regression was run between the simultaneous bite force and EMG submaximal values recorded in the four tests. Using the EMG potentials obtained during the MVC tests, the best fitting line was used to estimate a maximum bite force. Two independent recordings were made by each subject (2 week interval) and analyzed by correlation analysis, paired Student's t-test, and Dahlberg statistic. RESULTS: Significant linear relationships were found between bite force and EMG potentials (p<0.01). The two series of indirect estimates of maximal bite force were correlated (r=0.626) without systematic differences (Student's t, p>0.01). Dahlberg statistic was 115.37 N (approximately 36% of the total variance of the group). CONCLUSIONS: Simultaneously recorded submaximal bite forces and surface EMG potentials of mandibular elevator muscles had a linear relationship. The estimates of maximum bite force were repeatable on a short-term basis (2 weeks). The method limited the disadvantages of bite force recordings, and it could be used to obtain indicative values for the occlusal loads to be resisted by the prosthetic reconstructions.

Adult↗

[An evaluation of the biting force, the body composition and the amount of masticatory action in young females].

UNLABELLED: The purposes of this study were to investigate factors related to maximum biting force and to understand the characteristics of physical properties of daily ingested foods in young females. One hundred and forty subjects aged 18-23, with Angle 1 class occlusion, had not suffered from periodontitis, and had not been treated for preparation of tooth crown of first molars. Body height and weight were measured, and percentage of body fat, fat mass (FM) and lean body mass (LBM) were estimated, using the impedance analyzer. The maximum biting force was measured by the press sensation method. According to the formula on the basis of our new version of Yanagisawa's food classification, the mean value of the amount of masticatory action for one day was calculated. Subjects were divided into the normal biting force and the low biting force groups with -1SD of the maximum biting force, in order to compare body composition and backgrounds in sports activities between these two groups. Multiple linear regression analysis was carried out, employing maximum biting force (kg.f) as a dependent variable, and having a background in sports activities, FM, LBM, the number of missing teeth, the number of dental caries and the amount of masticatory action for one day as independent variables. Results were as in the following: 1) The proportion of subjects who had a background in sports activities in the low biting force group were less than that in the normal biting force group (p < 0.01). 2) Having a background in sports activities and LBM were positively correlated to maximum biting force (p < 0.01), while the amount of masticatory action for one day was not. 3) All subjects, especially those in the low biting force group seldom had food requiring the highest amount of masticatory action. CONCLUSION: Having a background in sports activities and LBM are positively correlated with the maximum biting force, while the amount of masticatory action for one day was not correlated positively nor negatively in young females.

Adolescent↗

Occlusal perception and bite force in young subjects with and without dental fillings.

Interocclusal thickness discrimination (occlusal perception) and bite force was investigated in 29 young adults (16-18 years old). Thirteen individuals had intact dentitions (group I), whereas 16 individuals had minor restorations in posterior teeth (group C). Bite force was tested during 'gentle biting', 'biting as when chewing', and 'maximal clenching'. Endurance tests and bite force discrimination tests were also performed. The best occlusal perception was found in the incisor region in both groups, whereas the occlusal perception was somewhat smaller in the canine and premolar regions. Fifty-four per cent of the subjects in group I and 81% in group C reached certain perceptiveness at the 9-micron level. There were no statistically significant differences between test locations or groups, however. Group I had a significantly greater bite force in the incisor region during gentle biting than group C. The maximal bite force was on an average 532 N in group I and 516 N in group C. In the endurance tests, group I could withstand the muscle fatigue longer than group C, but the difference was not statistically significant. In the bite force discrimination test both groups showed a similar pattern. Group I showed a closer correlation than group C between recordings in a test of stepwise increase of force and a randomized test of five force levels. Both groups appeared functionally normal in the masticatory system and reacted similarly in the physiologic experiments.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

The effect of altering the vertical dimension of occlusion on biting force.

The effect of altering the vertical dimension of occlusion (VDO) on the biting force was studied in six men and seven women. The biting force was registered with a newly designed gnathodynamometer that uses two strain gauges cemented on its surfaces and a Wheatstone bridge connected to a chart recorder. Biting force was measured for each subject at the following three positions of vertical dimension: position 1, VD < VDO; position 2, VD = VDO; and position 3, VD > VDO. The recorded force at these positions was statistically different for all of the subjects. All subjects exerted significantly greater biting force when VD > VDO Men exerted greater biting forces than women, but this difference was not statistically significant.

Analysis of Variance↗

Bite force determination in adolescents with and without temporomandibular dysfunction.

The aims of this study were to compare bite force in adolescents with and without temporomandibular dysfunction (TMD), and to investigate the influence of gender, age, height and weight on bite force magnitude. The TMD was evaluated using a self-report questionnaire and the Craniomandibular Index, which has two subscales, the Dysfunction Index and the Palpation Index. Subjects with lower and upper extremity values were used to integrate the control (Group I -n = 20) and TMD (Group II -n = 20) groups, respectively. In addition, the TMD group should have at least one subjective symptom. Bite force was determined with a transducer, which consisted of a pressurized rubber tube connected to a sensor element (MPX 5700 - Motorola SPS, Austin, TX, USA). Analysis of covariance, Pearson's coefficient, Mann-Whitney and t-tests were applied to analyse the data. The results showed that Group II presented smaller values for bite force than Group I and boys had greater values than girls in Group II (P < 0.05). Bite force values were significantly smaller for girls between groups (P < 0.05), whereas for boys there was no statistical difference. Weak positive correlation between bite force and weight, height and age (P > 0.05) and significant negative correlation between bite force and Palpation and Craniomandibular Indexes (P < 0.05) were found. It was concluded that decreased bite force was correlated with TMD in girls, primarily with muscle tenderness.

Adolescent↗

Bite forces with mandibular implant-retained overdentures.

Sensitivity or pain of the mucoperiosteum covering the mandibular edentulous ridge is often thought to limit bite forces in complete-denture wearers. Therefore, bite forces with mandibular implant-retained overdentures may depend on the degree of implant support. This study analyzed the effects of different degrees of support for the mandibular denture on bite forces measured four years after denture treatment as part of a randomized controlled clinical trial. All subjects had received new maxillary dentures and (1) mainly implant-borne overdentures on a transmandibular implant (TMI), (2) mucosa-borne overdentures on two cylindric permucosal IMZ implants, or (3) new conventional dentures in the mandible. Fifty-three women and 15 men (mean age, 59.1 yrs; range, 41 to 77) participated in this trial. Both unilateral and bilateral bite forces were recorded at different positions with a miniature strain gauge transducer and a mechanical bite fork, respectively. The subjects were asked to bite at three force levels. Results indicated that women had significantly lower maximum bite forces than men. Persons with mandibular implant-retained overdentures had significantly higher unilateral and bilateral maximum bite forces than complete-denture wearers. However, bite forces did not differ between the mainly implant-borne (TMI) and mucosa-implant-borne (IMZ) implant systems. Therefore, it appears that differences in support for the mandibular overdenture by dental implants are not reflected in bite force capabilities.

Adult↗

Bite forces after open or closed treatment of mandibular condylar process fractures.

PURPOSE: This study compared maximum voluntary bite forces in patients who received either open or closed treatment for fractures of the mandibular condylar process. PATIENTS AND METHODS: One hundred fifty-five patients (127 male, 28 female) with unilateral fractures of the mandibular condylar process (91 treated closed and 64 treated open) were included in this study. Maximum voluntary bite forces were measured at 6 weeks, 6 months, and 1, 2, and 3 years after fracture. At each trial, unilateral maximum voluntary bite force was measured at 4 different tooth positions bilaterally using a standard transducer. Electromyography (EMG) of the masseter muscles was also recorded during the bite force measurements, and ratios of the working/balancing side EMG were calculated. Analysis of the data was performed using standard statistical methods. RESULTS: The only significant difference between the 2 samples was in the level of fractures on the condylar process. No patients treated open had fractures of the "head" of the condylar process, whereas there were 11 in the group treated closed. No differences were observed in maximum voluntary bite forces between the 2 treatment groups at any time period, or were there correlations between bite force magnitude and location of the fracture, displacement of the fracture, or any other variable studied. Both groups showed a significant recovery of maximum bite force from the 6-week to the 6-month testing session. For both groups, working/balancing EMG ratios were significantly greater when subjects were biting on the side opposite the fracture. When biting on that side, the working/balancing EMG ratios were higher in the closed treatment group, but the difference did not reach significance. CONCLUSIONS: Maximum voluntary bite forces in patients treated for mandibular condylar process fractures do not differ significantly when treatment is open or closed. Neuromuscular adaptations to the fractured mandibular condylar process occur in both groups.

Adolescent↗

A study of bite force, part 1: Relationship to various physical characteristics.

A new device for measuring and recording bilateral bite force in the molar/premolar region has been developed. Because this new device is elastic and conforms to the occlusal surfaces of the teeth, and because the sensing element is relatively comfortable, it is believed that experimental subjects are less reluctant to register true maximal forces than in earlier studies. Potential correlations of maximum bite force to gender, age, weight, body type, stature, previous history of orthodontic treatment, presence of TMJ symptoms (jaw motion limitation, clicking with pain, or joint pain), or missing teeth were studied in a sample of 142 dental students. The mean maximum bite force of the sample was found to be 738 N, with a standard deviation of 209 N. The mean maximum bite force as related to gender was found to be statistically significant, while the correlation coefficients for age, weight, stature, and body type were found to be low. Even so, all data scatterplots exhibited relatively positive relationships. Correlations of maximum bite force to an earlier history of orthodontic treatment or to the absence of teeth were not found. Subjects reporting TMJ symptoms did not exhibit a significantly different maximum bite force than subjects without symptoms.

Adult↗