Open AccessBite force and its relation to jaw shape in domestic dogs
Author(s) -
Colline Brassard,
Marilaine Merlin,
Claude Guintard,
Élodie Monchâtre-Leroy,
J Barrat,
Nathalie Bausmayer,
Stéphane Bausmayer,
Adrien Bausmayer,
Michel Beyer,
André Varlet,
Céline Houssin,
Cécile Callou,
Raphaël Cornette,
Anthony Herrel
Publication year - 2020
Publication title -
journal of experimental biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.367
H-Index - 185
eISSN - 1477-9145
pISSN - 0022-0949
DOI - 10.1242/jeb.224352
Subject(s) - bite force quotient , molar , mandible (arthropod mouthpart) , orthodontics , biomechanics , biting , mandibular canine , dentistry , anatomy , medicine , biology , zoology , ecology , genus
Previous studies based on two-dimensional methods have suggested that the great morphological variability of cranial shape in domestic dogs has impacted bite performance. Here we use a three-dimensional biomechanical model based on dissection data to estimate the bite force of 47 dogs of various breeds at several bite points and gape angles. In vivo bite forces for three Belgian Shepherd dogs were used to validate our model. We then used three-dimensional geometric morphometrics to investigate the drivers of bite force variation and to describe the relations between the overall shape of the jaws and bite force. The model output shows that bite force is rather variable in dogs and that dogs bite harder on the molar teeth and at lower gape angles. Half of the bite force is determined by the temporal muscle. Bite force also increased with size, and brachycephalic dogs showed higher bite forces for their size than mesocephalic dogs. We obtained significant covariations between the shape of the upper or lower jaw and absolute or scaled bite force. Our results demonstrate that domestication has not resulted in a disruption of the functional links in the jaw system in dogs and that mandible shape is a good predictor of bite force.