Bite force quotient

About: Bite force quotient is a research topic. Over the lifetime, 1221 publications have been published within this topic receiving 42262 citations. The topic is also known as: BFQ.

Biting and Chewing in Overdentures, Full Dentures, and Natural Dentitions

Abstract: It has been suggested that the provision of dental implants can improve the oral function of subjects with severely resorbed mandibles, possibly restoring function to the level experienced by satisfied wearers of conventional complete dentures. Nevertheless, a quantitative comparison has never been made and can be drawn from the literature only with difficulty, since studies differ greatly in methodology. To make such a comparison, we measured bite force and chewing efficiency by using identical methods in subjects with overdentures, complete full dentures, and natural dentitions. Our results indicated that bite forces achieved with overdentures on dental implants were between those achieved with artificial and natural dentitions. Chewing efficiency was significantly greater than that of subjects with full dentures (low mandible), but was still lower than that of subjects with full dentures (high mandible) and overdentures on bare roots. Differences in the height of the mandible revealed significant differences in chewing efficiency between the two full-denture groups. Furthermore, subjects with a shortened dental arch exerted bite forces similar to those of subjects with a complete-natural dentition, but their chewing efficiency was limited due to the reduced occlusal area. For all groups combined, a significant correlation was found between maximum bite force and chewing efficiency. Nearly half of the variation in chewing efficiency was explained by bite force alone.

Bite force and state of dentition

Abstract: The maximal bite force and the strength of the finger-thumb grip of 125 Skolt Lapps, aged 15 to 65, was measured with a specially devised apparatus The bite force was measured with the biting fork placed between the first molars and between the incisors, respectively The finger-thumb grip was measured by letting the subject press the prongs of the fork between the thumb and forefinger of each hand as hard as possible The range of inter-individual variation of the maximal bite force and finger-thumb grip was great The mean values were higher for the males than for the females In the males the maximal bite force thus measured in the molar region was 39 kg (382 N) and 18 kg (176 N) in the incisor region The corresponding values for the females were 22 kg (216 N) and 11 kg (108 N) The finger-thumb grip strength for males was, on the average, 10 kg (98 N); that of the females, 7 KG (69 N) The average difference in bite force between the men and the women was larger in the group with natural teeth than in the one with complete dentures The values found for the bite force decreased with increasing age, especially for the females Most of this reduction with increasing age was probably due to the age-dependent deterioration of the dentition In both sexes the bite force was notably smaller among the denture wearers than among the dentate persons The number of natural teeth varied closely with the bite force, ie the greater number of natural teeth the greater the bite force

Sexual dimorphism of head size in Gallotia galloti: testing the niche divergence hypothesis by functional analyses

Abstract: 1. Two often cited hypotheses explaining sexual head size dimorphism in lizards are: sexual selection acting on structures important in intrasexual competition, and reduction of intersexual competition through food niche separation. 2. In this study some implicit assumptions of the latter hypothesis were tested, namely that an increase in gape distance and bite force should accompany the observed increase in head size. These assumptions are tested by recording bite forces, in vivo, for lizards of the species Gallotia galloti. In this species, male lizards have significantly larger heads than female conspecifics of similar snout–vent length. 3. Additionally, the average force needed to crush several potential prey species was determined experimentally and compared with the bite force data. This comparison clearly illustrates that animals of both sexes can bite much harder than required for most insect food items, which does not support the niche divergence hypothesis. The apparent ‘excess’ bite force in both sexes might be related to the partially herbivorous diet of the animals. 4. To unravel the origin of differences between sexes in bite capacity, the crushing phase of biting was modelled. The results of this model show different strategies in allocation of muscle tissue between both sexes. The origin of this difference is discussed and a possible evolutionary pathway of the development of the sexual dimorphism in the species is provided.

The Functional Significance of Primate Mandibular Form

Abstract: A stress analysis of the primate mandible suggests that vertically deep jaws in the molar region are usually an adaptation to counter increased sagittal bending stress about the balancing-side mandibular corpus during unilateral mastication. This increased bending stress about the balancing side is caused by an increase in the amount of balancing-side muscle force. Furthermore, this increased muscle force will also cause an increase in dorso-ventral shear stress along the mandibular symphysis. Since increased symphyseal stress can be countered by symphyseal fusion and as increased bending stress can be countered by a deeper jaw, deep jaws and symphyseal fusion are often part of the same functional pattern. In some primates (e.g., Cercocebus albigena), deep jaws are an adaptation to counter bending in the sagittal plane during powerful incisor biting, rather than during unilateral mastication. The stress analysis of the primate mandible also suggests that jaws which are transversely thick in the molar region are an adaptation to counter increased torsion about the long axis of the working-side mandibular corpus during unilateral mastication. Increased torsion of the mandibular corpus can be caused by an increase in masticatory muscle force, an increase in the transverse component of the postcanine bite force and/or an increase in premolar use during mastication. Patterns of masticatory muscle force were estimated for galagos and macaques, demonstrating that the ratio of working-side muscle force to balancing-side muscle force is approximately 1.5:1 in macaques and 3.5:1 in galagos during unilateral isometric molar biting. These data support the hypothesis that mandibular symphyseal fusion is an adaptative response to maximize unilateral molar bite force by utilizing a greater percentage of balancing-side muscle force.