Temporal fascia function during human growth: biomechanical modelling to predict the impact of surgical intervention
Lead Research Organisation:
University of Liverpool
Department Name: Musculoskeletal & Ageing Science
Abstract
During growth, hard and soft tissues of the skull interact to influence skull shape as bone remodels in response to mechanical loading. However, the soft tissues that generate loads are not limited to the jaw closing musculature (temporalis, masseter, and pterygoids), but also consist of complex ligaments, tendons and fascial layers. One particularly overlooked and/or understudied structure is the temporal fascia. The temporal fascia covers the entire temporalis muscle on the side of our head, aiding in jaw movement and chewing, and potentially has a suite of functions to redistribute craniofacial strain, from directing temporalis muscle force, to limiting bending of the zygomatic arch (cheek bone) and orbit induced by the force of the masseter muscle.
To date, the structure and function of the temporal fascia have only been investigated in a handful of studies, limiting our understanding of its functional significance. However, there is growing evidence from experimental studies, histology and mechanical testing, suggesting a more functionally significant role of the temporal fascia during growth and normal jaw function. Experimental work conducted in the 1960's showed distinct bone shape changes of the zygomatic arch in Cebus monkeys following permanent detachment of the temporal fascia. However, the impact of removal of the temporal fascia from the zygomatic arch during craniofacial surgery in children, a common procedure for patients with craniosynostosis, has not been investigated.
Computational biomechanical models provide a promising non-invasive method of investigating bone responses to external loads. Industries such as the automotive and aerospace engineering, have implemented computational modelling into the design pipeline, saving money with simulations instead of production. The medical and health industry have started using biomechanical models to test patient-specific implants, the outcomes of surgery, and to learn more about the loads we experience during running. It is now possible to investigate whether the removal of the temporal fascia in a patient would have a significant impact on stress distribution within the skull, and function of the jaw muscles. This is especially relevant for children who are in a key stage of craniofacial growth when jaw muscles are loaded for the first time.
As such, the primary purpose of this project is to explore the function of the temporal fascia, characterising its role during craniofacial growth and chewing, by building, analysing and validating biomechanical models of the human skull and jaw muscles. To date, the temporal fascia has never been incorporated into human computational biomechanical models (e.g., finite element analysis). This may be problematic when investigating jaw joint function and disorders (e.g., tooth grinding or bruxism), as well as temporal fascia function as mentioned above. Omitting the temporal fascia could potentially be impacting the accuracy of biomechanical models and the potential of these models for clinical uses in craniofacial, maxillary and dental surgeries, including where the impact of disruptive surgery to the temporal region is not fully understood. By building these models and exploring the function of the temporal fascia, we hope to provide insight into the impact of removing the temporal fascia during surgery, as well as its general role in normal jaw function and bone growth.
To date, the structure and function of the temporal fascia have only been investigated in a handful of studies, limiting our understanding of its functional significance. However, there is growing evidence from experimental studies, histology and mechanical testing, suggesting a more functionally significant role of the temporal fascia during growth and normal jaw function. Experimental work conducted in the 1960's showed distinct bone shape changes of the zygomatic arch in Cebus monkeys following permanent detachment of the temporal fascia. However, the impact of removal of the temporal fascia from the zygomatic arch during craniofacial surgery in children, a common procedure for patients with craniosynostosis, has not been investigated.
Computational biomechanical models provide a promising non-invasive method of investigating bone responses to external loads. Industries such as the automotive and aerospace engineering, have implemented computational modelling into the design pipeline, saving money with simulations instead of production. The medical and health industry have started using biomechanical models to test patient-specific implants, the outcomes of surgery, and to learn more about the loads we experience during running. It is now possible to investigate whether the removal of the temporal fascia in a patient would have a significant impact on stress distribution within the skull, and function of the jaw muscles. This is especially relevant for children who are in a key stage of craniofacial growth when jaw muscles are loaded for the first time.
As such, the primary purpose of this project is to explore the function of the temporal fascia, characterising its role during craniofacial growth and chewing, by building, analysing and validating biomechanical models of the human skull and jaw muscles. To date, the temporal fascia has never been incorporated into human computational biomechanical models (e.g., finite element analysis). This may be problematic when investigating jaw joint function and disorders (e.g., tooth grinding or bruxism), as well as temporal fascia function as mentioned above. Omitting the temporal fascia could potentially be impacting the accuracy of biomechanical models and the potential of these models for clinical uses in craniofacial, maxillary and dental surgeries, including where the impact of disruptive surgery to the temporal region is not fully understood. By building these models and exploring the function of the temporal fascia, we hope to provide insight into the impact of removing the temporal fascia during surgery, as well as its general role in normal jaw function and bone growth.
Technical Summary
This project will explore the functional significance of the temporal fascia through ontogenetic growth, as a contributer to bone remodelling, and as a key component in jaw muscle and temporomandibular joint (TMJ) function. Growing evidence from mechanical testing and histology have shown that the temporal fascia may have a significant role in controlling temporalis muscle force direction and bone strain distribution over the zygomatic arch and cranial vault. However, the temporal fascia is often overlooked in investigations of TMJ function and mastication, including disorders such as bruxism and during craniofacial growth. To-date, no human in silico biomechanical models have incorporated the temporal fascia, despite the growing use of in silico models in biomedical engineering, potentially impacting our understanding of jaw muscle function and TMJ disorders.
We will build, analyse and validate in silico biomechanical models of human skulls at various ages (e.g., 6 months, 2 year, 6 years, 12 years and adults), including an adult male and female. We will achieve this by combining multibody dynamics analysis (MDA) of jaw movements, and finite element analysis (FEA) of bone strain of the human skull during mastication, including the temporal fascia, and alter the loads to incorporate the temporal fascia with various material properties, and with sections attached or removed from the zygomatic arch to replicate surgical manipulation of the temporal fascia. This has implications not only for accuracy of model outputs for basic science, but also in clinical research requiring an understanding of masticatory function, and in the design of clinical surgery in humans.
We will build, analyse and validate in silico biomechanical models of human skulls at various ages (e.g., 6 months, 2 year, 6 years, 12 years and adults), including an adult male and female. We will achieve this by combining multibody dynamics analysis (MDA) of jaw movements, and finite element analysis (FEA) of bone strain of the human skull during mastication, including the temporal fascia, and alter the loads to incorporate the temporal fascia with various material properties, and with sections attached or removed from the zygomatic arch to replicate surgical manipulation of the temporal fascia. This has implications not only for accuracy of model outputs for basic science, but also in clinical research requiring an understanding of masticatory function, and in the design of clinical surgery in humans.
