Masticatory biomechanics of red and grey squirrels (Sciurus vulgaris and Sciurus carolinensis) modelled with multibody dynamics analysis

Cox, Philip G.; Watson, Peter J.

Abstract

The process of feeding in mammals is achieved by moving the mandible relative to the cranium to bring the teeth into and out of occlusion. This process is especially complex in rodents which have a highly specialized configuration of jaw adductor muscles. Here, we used the computational technique of multi-body dynamics analysis (MDA) to model feeding in the red (Sciurus vulgaris) and grey squirrel (Sciurus carolinensis) and determine the relative contribution of each jaw-closing muscle in the generation of bite forces. The MDA model simulated incisor biting at different gapes. A series of 'virtual ablation experiments' were performed at each gape, whereby the activation of each bilateral pair of muscles was set to zero. The maximum bite force was found to increase at wider gapes. As predicted, the superficial and anterior deep masseter were the largest contributors to bite force, but the temporalis had only a small contribution. Further analysis indicated that the temporalis may play a more important role in jaw stabilization than in the generation of bite force. This study demonstrated the ability of MDA to elucidate details of red and grey squirrel feeding biomechanics providing a complement to data gathered via in vivo experimentation.

Citation

Cox, P. G., & Watson, P. J. (2023). Masticatory biomechanics of red and grey squirrels (Sciurus vulgaris and Sciurus carolinensis) modelled with multibody dynamics analysis. Royal Society Open Science, 10(2), Article 220587. https://doi.org/10.1098/rsos.220587

• Journal Article Type: Article
• Acceptance Date: Jan 26, 2023
• Online Publication Date: Feb 15, 2023
• Publication Date: 2023-02
• Deposit Date: Feb 16, 2023
• Publicly Available Date: Feb 16, 2023
• Journal: Royal Society Open Science
• Electronic ISSN: 2054-5703
• Publisher: The Royal Society
• Peer Reviewed: Peer Reviewed
• Volume: 10
• Issue: 2
• Article Number: 220587
• DOI: https://doi.org/10.1098/rsos.220587
• Keywords: Grey squirrel; Bite force; Skull; Multi-body dynamics analysis; Masticatory muscles; Red squirrel
• Public URL: https://hull-repository.worktribe.com/output/4201179