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 163 records · Page 9Linked to original sources
PubMed1990

Clinical significance of bite force reproduction ability.

The objective of this study was to evaluate the clinical relevance of measurement of bite force reproduction ability. This parameter was measured at reference force levels of 2, 10, and 50 N in a group of patients with articular and nonarticular temporomandibular disorders and in a control group. The ability to reproduce the reference forces was measured at four equidistant occasions. All subjects poorly and imprecisely reproduced the reference force levels. A trend in the matches or in their imprecision could not be found (P greater than 0.05). Bite force reproduction ability did not differ between the patient group and the control group (P greater than 0.05). It was concluded that measurement of bite force reproduction ability does not provide a useful clinical assessment tool.

Adult↗
PubMed1988

A feedback method to determine the three-dimensional bite-force capabilities of the human masticatory system.

A feedback procedure is described that enables a subject to exert bite forces in certain specified directions during static contraction of the human jaw muscles. The output of a three-dimensional transducer is fed to a computer. The magnitude and direction of the resultant force are computed and visualized by a cross on the screen of the computer terminal. In a bite experiment, the subject is instructed to match this cross with a point on the screen, representing the desired bite-force direction. The procedure allows for determination of the range of possible bite-force directions and magnitudes for various locations on the dental arch and study of the concomitant recruitment patterns of the jaw muscles. Some examples of measurement are given.

Adult↗
PubMed1988

Effect of mouth opening on bite-force discrimination.

The purpose of this study was to determine whether different extents of mouth opening affect normal subjects' (N = 24; 12 women, 12 men) ability to discriminate differences in their interincisor bite force. Three mouth openings were selected including 50, 70, and 90 percent of maximum opening for each subject. Bite force was measured using a specially designed strain gauge scale which permitted subjects to monitor visually when their biting force equalled a preset resistance. Resistance forces of 500 and 1000 gm. were selected as standards. The procedure involved the use of a modified method of constant stimuli in which each subject was presented with a series of paired resistance settings, one at a time--the first resistance setting being the standard and the second resistance was the comparator. This paired-comparisons procedure was continued until the subjects' difference limen (DL) value (the threshold of discrimination between two forces) could be established. An analysis of variance yielded no significant differences in subjects' ability to discriminate bite force as a function of mouth opening.

Adult↗
PubMed1992

Masticatory muscle fatigue: endurance times and spectral changes in the electromyogram during the production of sustained bite forces.

The purpose of this experiment was to determine if the characteristics of fatigue observed in the limb muscle system are also evident in the muscles of mastication, specifically, the masseter and temporalis. Surface electrodes were placed bilaterally over the masseter and temporalis muscles of 10 adults. Each subject was instructed to maintain maximal and six levels of submaximal incisal bite forces for as long as possible. The power density spectrum of the electromyographic signals for each muscle was calculated at the onset and failure of the task. The decrease in endurance time with an increase in bite force followed a pattern similar to that in limb muscles, and each muscle was characterized by a consistent reduction in the mean power frequency of the power density spectrum and a variable change in r.m.s. power. The variability of changes in r.m.s. power (which is inconsistent with changes found in the limb muscles) was explained in terms of either changes in motor-unit firing rate or the muscle's relative contribution to the generation of bite force. The analyses also demonstrated a curvilinear relationship between bite force and r.m.s. power, but no relationship between bite force and the mean power frequency of the power density spectrum.

Adult↗
PubMed2004

Joint tenderness, jaw opening, chewing velocity, and bite force in patients with temporomandibular joint pain and matched healthy control subjects.

AIMS: To evaluate the effect of temporomandibular arthralgia on mandibular mobility, chewing, and bite force. METHODS: Twenty female patients (ages 19 to 45 years) with unilateral temporomandibular joint (TMJ) pain during chewing (49 +/- 27 mm on a 100-mm visual analog scale) and provocation, as well as TMJ tenderness, were studied. The TMJ conditions were classified as disc derangement disorders (n = 9), osteoarthritis (n = 7), and inflammatory disorders (n = 4). The patients were compared with matched healthy volunteers without orofacial pain or tenderness. Exclusion criteria were the presence of fewer than 24 teeth or malocclusion. The methods used were (1) algometric assessment of the pressure pain threshold (PPT) over the TMJ; (2) clinical recordings of maximum jaw opening; (3) computerized kinematic assessment of maximum vertical distance, velocity, and cycle duration during chewing of soft gum; and (4) measurement of unilateral molar bite force. RESULTS: The mean (+/- SD) PPT in the patients' painful side (69 +/- 20 kPa; P = .000001) was significantly lower than in the control subjects (107 +/- 22 kPa). Jaw opening was also significantly less (P = .00003) in the patients (42 +/- 9 mm) than in the controls (52 +/- 4 mm). Chewing cycle duration and maximum closing velocity were significantly different (P < or = .03) in the patients (948 +/- 185 milliseconds and 142 +/- 46 mm/s, respectively) versus the controls (765 +/- 102 milliseconds and 173 +/- 43 mm/s, respectively), and bite force was significantly lower (P = .000003) in the patients (238 +/- 99 N) than in the controls (394 +/- 80 N). Both bite force and jaw opening in patients were significantly correlated (P < or = .02) with PPT (r = 0.53 and 0.63, respectively). CONCLUSION: These systematic findings supplement results from acute pain experiments and confirm indications from unspecified patient groups that the clinical presence of long-standing TMJ pain is associated with marked functional impairment. This impairment might be a result of reflex adaptation and long-term hypoactivity of the jaw muscles.

Adult↗
PubMed1995

Effects of fatigue and chewing training on maximal bite force and endurance.

The purpose of the study was to evaluate the effects of chewing training on the strength and resistance to fatigue of the masticatory muscles. Twenty-five healthy adults were divided into an experimental group (7 men, 10 women) and a control group (4 men, 4 women). The experimental group chewed a special hard chewing gum one hour daily for 28 days. Maximal bite force and endurance were measured. The maximal bite force already showed a significant increase in the experimental group by the middle of the experimental period (p < 0.05), reached the highest values by the end of the training period (p < 0.001), and also remained at high levels 2 weeks after (p < 0.001). Subjects with weak initial maximal bite force values showed the highest increase in their strength after training (r = -0.66, p < 0.01). This type of training did not influence the endurance time during maximal clenching or the reduction in this endurance time after a dynamic fatigue test. No significant differences were found between the maximal bite force before and that after the fatigue test under either untrained or trained conditions. In the control group no significant differences were found between the recording sessions. In conclusion, 4 weeks training with a hard chewing gum seems to influence the functional capacity of the masticatory muscles and increase their strength.

Adult↗
PubMed1989

Biting forces in patients with craniomandibular disorders.

Treatment for 10 female patients having craniomandibular disorders of neuromuscular origin showed a reduction in dysfunctional symptoms and improvement in their condition. In response to treatment, a standardized recording method was used to measure alterations to bite force values. In about 60 percent of categories representing various positions in the dental arch from which maximal and submaximal biting forces were measured, there was significant variation between replicate registrations. This persisted after treatment, indicating some loss of sensory acuity for fine bite-force adjustments in these patients. Discriminatory ability for large force adjustments was not, however, observed to be affected. Bite force values showed considerable fluctuation both before and after treatment. The lack of substantial increase in force values after a reduction in muscular dysfunction with treatment appears to suggest that an inhibitory mechanism controlling jaw-closing activity and pressure persists as a protective reflex for these patients.

Adult↗
PubMed2001

[Effect of decreased bite force on the temporal and spatial expression of type I collagen mRNA in rat molar periodontal ligament].

OBJECTIVE: The aim of this study was to observe the effect of decreased bite force on type I collagen mRNA in periodontal ligament (PDL) and probe into the molecular mechanism of the change in type I collagen mRNA. METHODS: Animal models were established by extracting left maxillary molars of rats. In situ hybridization was applied. RESULTS: The results showed that under decreased bite force, the expression level of type I collagen mRNA decreased at the sixth hour (49.7 +/- 11.1) (P < 0.05), reached the nadir on the second day (23.7 +/- 8.6), began to get over on the third day (43.1 +/- 10.3), and reached a relatively high level at the second week(56.3 +/- 9.8), but it was still lower than that of the normal bite force group (91.4 +/- 16.0)(P < 0.05); the expression of type I collagen mRNA near the cementum was higher than that near the alveolar bone. CONCLUSION: These results indicate that the expression level of type I collagen mRNA is closely related to bite force.

Animals↗
PubMed1979

The effect of anteroposterior inclination of the occlusal plane on biting force.

With the experimental design of this study the following conclusions were reached. 1. Biting force during maximum clenching was the greatest when the occlusal plane was made parallel to the ala-tragus line. It decreased when the occlusal plane was inclined about 5 degrees anteriorly or about 5 degrees posteriorly. 2. The efficiency of biting force exertion during maximum clenching showed the best value when the occlusal plane was made parallel to the ala-tragus line. 3. Muscle activity during clenching at various given forces was least when the occlusal plane was made parallel to the ala-tragus line. The anteroposterior inclination of the occlusal plane tends to affect the biting force, and the method with the ala-tragus line seems to be the most reasonable for occlusal plane orientation.

Aged↗
PubMed1985

Temporomandibular joint abnormalities and bite force in a group of adults with rheumatoid arthritis.

Maximal mouth opening, translatory condylar motion (radiographically assessed) and bite force in sixteen adults with rheumatoid arthritis and radiographic temporomandibular joint abnormalities were compared with data from sixteen individuals without joint disease. Mean mouth opening in the arthritis group was reduced, but not statistically significant. Condylar translation and bite force showed significantly lower values than in the healthy individuals. Maximal mouth opening seemed to be the most uncertain parameter for the estimation of jaw function. In seven patients with a normal mouth opening (40-46 mm), both the condylar translation and the bite force were significantly impaired.

Adult↗
PubMed2002

Effect of loss of bite force on interleukin-1beta expression in rat periodontium.

OBJECTIVE: To study the expression of interleukin-1beta(IL-1beta) in the fibroblasts and osteoblasts in the periodontal ligament cells(PDLC) of normal rats and rats with loss of bite force, to explain the molecular mechanism of periodontium remodeling. METHODS: Rat models of lost bite force were established using Wistar rats. The changes in the histological morphology of the periodontium and the expression of IL-1beta in the PDLC and osteoblasts were observed in both normal rats and the rat models using HE staining and immunohistochemistry techniques. RESULTS: In rat models of lost bite force, the periodontal ligament structure appeared to be disorganized and absorption occurred in the alveolar bone. The expression level of IL-1beta in the PDLC and osteoblasts was significantly enhanced in comparison with that in the normal rats, as demonstrated by immunohistochemical study. CONCLUSION: Loss of bite force may induce structural disorganization of the periodontal ligament and absorption in the alveolar bone, and the expression level of IL-1beta in PDLC and osteoblasts show significant elevation, indicating that the changes in histological morphology is closely coordinated with the functional changes in the periodontium.

Animals↗
PubMed2005

Ontogenetic scaling of bite force in lizards and turtles.

Because selection on juvenile life-history stages is likely strong, disproportionately high levels of performance (e.g., sprint speed, endurance, etc.) might be expected. Whereas this phenomenon has been demonstrated with respect to locomotor performance, data for feeding are scarce. Here, we investigate the relationships among body dimensions, head dimensions, and bite force during growth in lizards and turtles. We also investigate whether ontogenetic changes in bite performance are related to changes in diet. Our analyses show that, for turtles, head dimensions generally increase with negative allometry. For lizards, heads scale as expected for geometrically growing systems. Bite force generally increased isometrically with carapace length in turtles but showed significant positive allometry relative to body dimensions in lizards. However, both lizards and turtles display positive allometric scaling of bite force relative to some measures of head size throughout ontogeny, suggesting (1) strong selection for increased relative bite performance with increasing head size and (2) intrinsic changes in the geometry and/or mass of the jaw adductors during growth. Whereas our data generally do not provide strong evidence of compensation for lower absolute levels of performance, they do show strong links among morphology, bite force, and diet during growth.

Animals↗
PubMed2004

Scaling of jaw muscle size and maximal bite force in finches.

Fringillids and estrildids differ in their husking performance on hard closed-shelled seeds, which are cracked before they are eaten. The time required to husk a seed is directly related to seed hardness, and husking time is therefore expected to be related to bite force as well. We investigated whether there is a significant difference in jaw muscle mass and maximal bite force between fringillids and estrildids. The analysis shows that fringillids have relatively larger jaw muscles than estrildids and are able to produce higher bite forces than estrildids of the same body size. This difference in jaw muscle mass mainly results from a difference in jaw closing muscles. Compared with other birds, the jaw muscles of both fringillids and estrildids scale strongly positively allometric with body size. Muscle fibre length scales negatively allometric with body size, which results in relatively high muscle and bite forces. Comparison with the scarce data available for other trophic groups suggests that the scaling of jaw muscle size depends on diet and that jaw muscle size in finches is an adaptation to their feeding behaviour.

Analysis of Variance↗
PubMed2002

The influence of various attachment types in mandibular implant-retained overdentures on maximum bite force and EMG.

The type of attachment that is used in oral rehabilitation by means of implant-retained mandibular overdentures may influence the retention and the stability of the denture. In this study, we examined the hypothesis that a better retention and stability of the denture improve the oral function. Eighteen edentulous subjects received 2 permucosal implants, a new denture, and, successively, 3 suprastructure modalities. Maximum bite force and electrical activity of the masseter and temporalis muscles were measured. The maximum bite force nearly doubled after treatment for each of the 3 attachments. However, the average bite force after treatment was still only two-thirds of the value obtained for dentate subjects. No large differences in maximum bite force and muscle activity were found among the 3 attachment types. Temporalis activity was significantly lower than masseter activity when subjects clenched without implant support. There was no difference in activity when subjects clenched with implant support.

Adult↗
PubMed1999

Occlusal contact area, occlusal pressure, bite force, and masticatory efficiency in patients with anterior disc displacement of the temporomandibular joint.

The occlusal contact area, occlusal pressure, bite force, and masticatory efficiency were measured in 48 patients with anterior disc displacement (ADD) of the temporomandibular joint (TMJ). The results were compared with those of 30 normal controls without TMJ dysfunction. The values of occlusal contact area, bite force, and masticatory efficiency measured in patients with ADD were significantly smaller than those measured in the controls, although there was no difference in occlusal pressure between the two groups. The results of the measurements of 22 patients with ADD with reduction were also compared with those of 26 patients with ADD without reduction. There was no difference in any measurement between these patients subgroups. The analysis of occlusal contact area, bite force, and masticatory efficiency appeared to be useful methods in documenting the fact that masticatory function was impaired in patients with ADD of the TMJ.

Adenosine Triphosphate↗
PubMed1992

Bite-force endurance in patients with temporomandibular joint osteoarthrosis and internal derangement.

The aim of this study was to investigate the potential clinical relevance of testing bite force endurance in patients with articular temporomandibular disorders. The endurance of a 50 N bite force was measured in 51 patients with painful temporomandibular joint disorders. The results were compared to those of a control group of 20 subjects. The force exerted was sustained until this task could not be continued because of intolerable pain or fatigue. The endurance test was repeated following therapy. Testing bite force endurance could be reliably carried out (paired t-test not significant, product-moment correlation coefficient 0.87). The mean endurance time in the patient group was significantly different from that of the control group (t = 7.43, df = 69, P < 0.01). The 95% confidence intervals for patients and controls did not show any overlap. No difference in endurance time between diagnostic subgroups could be detected (F = 1.30, df = 4,46, P < 0.28). Following treatment, all patients showed a significant increase of endurance time (t = 8.09, df = 50, P < 0.01) and reported a decrease in post-test pain. The mean difference between pre- and post-treatment endurance was 60s. Subjects of the control group stopped the biting effort predominantly because of muscle fatigue. By contrast, the main reason of the patients to cease the effort was TMJ pain. The results of this study indicate that the discriminatory power of the test is sufficient to justify its utility as a complementary tool in assessing the functional capacity of the masticatory system.

Adolescent↗
PubMed1997

[Research on the relation between the biting force with complete denture and compression of the mandibular denture bearing mucosa].

This experiment was designed to study the relation between the biting force and compression mucosal recovery and recovering time of the denture bearing mucosa with ten edentulous patients by the occlusometer and the photoelectric movement transducer. The results showed that the favourable threshold of biting force for denture bearing mucosa was 1.3 kg in anterior tooth region and 2.5 kg in molar region, up to 30 minutes after removal of biting force, the mucosal thickness was still 0.20 mm in anterior tooth region and 0.11 mm in molar region. According to these characteristics of the denture bearing mucosal compression and recovery, masticatory force of the complete dentures should be limited below above mentioned threshold.

Aged↗