Showing papers on "Bite force quotient published in 1991"
TL;DR: The results showed that the largest possible bite force was not always produced in a direction perpendicular to the occlusal plane, and maximal bite force in medial and posterior directions was larger than that in corresponding lateral and anterior directions.
137 citations
TL;DR: It was found that the masseter muscle in patients with ZMC fractures developed significantly less force than masseter Muscle in controls, which cast uncertainty on the role of the masseters muscle in postreduction displacement of the fractured ZMC.
83 citations
TL;DR: The purpose of this study was to investigate the effects of drug-induced local anesthesia on the generation of first molar bite force and electromyographic (EMG) activity in adults and found no statistically significant differences in bite force or integrated EMG levels between the unanesthetization and anesthetized sides.
47 citations
TL;DR: In vivo measurements of bite force and bone strain obtained in growing African green monkeys were used to study skull biology and geometry and mandate careful use of concepts about skeletal geometry based on static analysis that have not been experimentally verified with in vivo procedures.
36 citations
TL;DR: The results suggest that during development the possibility of the system to generate large bite forces is increased at the cost of a restriction in the range of jaw excursion and that a restriction takes place in therange of possible force directions that can be exerted at the molars.
Abstract: Using dissection, biometry, and two three-dimensional mechanical models, the postnatal changes of the rabbit masticatory muscles were studied by analyzing their three-dimensional orientation, their strength and fiber lengths, and certain functional consequences of these changes. The first mechanical model uses length-tension relationships of the muscles and predicts the maximum bite force as a function of mandibular position. It shows that young rabbits are able to generate large bite forces at a wider gape than adult animals and that the forces are directed more vertically. In spite of the postnatal changes the mechanical advantage of the system remains about equal. However, the muscles are reoriented so that they exert a larger degree of parallel action, suggesting a larger bite force magnitude but a smaller range of bite force directions. The second model predicts this range. It shows that during postnatal development a relative gain occurs in the possibilities for the system to exert forces directed rostrodorsally. In all other directions the capability to exert force decreases. The results suggest that during development the possibility of the system to generate large bite forces is increased at the cost of a restriction in the range of jaw excursion and that a restriction takes place in the range of possible force directions that can be exerted at the molars.
36 citations
01 Jan 1991
TL;DR: Bite area was similar at all sward heights, but decreased as grazed stratum bulk densit y increased, and bite depth and bite weight increased with pasture height and were not influenced by sward structure at a constant height.
Abstract: An upper limit to the force animals exett to sever a bite maybe important in maintaining grazing momentum. Structural strength of accessible pasture components would then determine bite dimensions and weight. Pure Perennial ryegrass turfs (surface area 0.1m2 x O.lm soil depth), were manipulated by clipping to produce 3 pasture heights (5, 10 and 15cm) x 3 sward structures (varying in leaf to pseudostem ratio and bulk density). Six sheep grazed 4 Nrfs fixed to a force plate of each height and bulk density. Mean peak bite force, bite weight, bite depth, bite area, bite volume and grazed stratum bulk density were calculated. Peak bite force increased with sward surface height but significantly so only between 10 and 15an. Sward stmcNre. had no effect except on the Scm sward treatment with the highest grazed stratumbulk density. Bite depth and bite weight increased with pasture height and were not influenced by sward structure at a constant height. Bite area was similar at all sward heights, but decreased as grazed stratum bulk densit y increased. On short swards, proximity to the ground restricted bite depth and bite weight rather than peak bite force. Low bite weights per newton bite force may constrain bite depth and weight rather than absolute peak bite force.
19 citations
31 Oct 1991
TL;DR: The acoustic myogram (AMG) was obtained from four jaw closer muscles at different levels of incisor bite force for 13 human subjects and there was a nearly linear, or slightly curvilinear, positive relation between rms EMG and bite force.
Abstract: The acoustic myogram (AMG) was obtained from four jaw closer muscles at different levels of incisor bite force for 13 human subjects AMGs and surface EMGs were obtained from anterior temporalis (bilateral) and masseter (bilateral) muscles at six levels of incisor bite force (0-30% Maximum voluntary contraction, or MVC) Each force level was maintained for 4 s; digitization occurred at 256/s There was a nearly linear, or slightly curvilinear, positive relation between rms EMG and bite force AMG amplitude (rms) increased to a maximum at a low force level and remained constant or decreased for higher forces The AMG-tension relation for a muscle may depend upon the ratio of recruitment to firing rate control of tension
4 citations
TL;DR: To analyze the influence of craniofacial morphology on the functions of stomatognathic system, dentulous subjects in the normal face group were selected and had been engaged in vertical clenching to measure the magnitude and direction of bite force as well as the EMG activity of masticatory muscles.
Abstract: To analyze the influence of craniofacial morphology on the functions of stomatognathic system, dentulous subjects in the normal face group were selected and had been engaged in vertical clenching to measure the magnitude and direction of bite force as well as the EMG activity of masticatory muscles. The correlation was studied among them.The results were as follows:1. The correlation curve of temporal muscle was hyperbolic. The correlation curves of masseter muscle and medial pterygoid muscle were linear.2. The ratio of the EMG activity of the increasing part was equal to or higher than that of the holding part at 25-100%MC.3. A significant correlation was observed between θ' and 4 angle measurements. The correlation of 13 items of the craniofacial measurements and direction of bite force was investigated with the EMG activity per 1kgf. A significant correlation was observed between the EMG activity per 1kgf and several items of craniofacial measurements.
2 citations
01 Jan 1991
1 citations
TL;DR: The purpose of this study was to explicate the mechanism of jaw movement and its control system, using bite force and EMG of the masticate muscles with a view to examine the result as an effective means of treatment.
Abstract: The purpose of this study was to explicate the mechanism of jaw movement and itscontrol system, using bite force and EMG of the masticate muscles with a view to examine theresult as an effective means of treatment. A new system of taking three-dimensional bite forcewas developed, which can take the value and direction of bite force. The description and evaluationof the new system and the result of the load test are presented.The results were as follows:1. The vertical and lateral direction (60 degree on occlusal plane) load tests revealed thatthe precision of the three-dimensional bite force measurement system was fully established.2. When using this system, it is necessary to use the jig for fixing the maxillary andmandibular clutches.3. Using an oscilloscope as the bite force feedback device was useful to instruct the level ofbite force.4. This system is very effective to measure the value and direction of bite force.
1 citations