Towards a patient-specific model of facial skin

Complex surgical procedures on the face, such as jaw reconstruction, frequently result in problematic scars that may be aesthetically upsetting for the patient or can interfere with chewing or swallowing. An accurate facial computer model of a patient’s face could allow surgeons to test different surgical incision pattern designs before surgery to determine which design is likely to result in the best outcome. A computer model of a patient’s face must take into account the complex properties of facial skin, such as the variability of stretch depending on direction. This requires experimental data from tests on a real human face; however, there is little data available at present about the stiffness of facial skin and soft tissues. The goal of Dr. Cormac Flynn’s research is to determine how the complex properties of facial skin affect our chewing and swallowing actions and how facial scars interfere with these functions. He aims to develop a computer model of the face with the most accurate representation of facial skin possible. To do this, he will use a biomedical device to determine the stiffness and thickness of skin and soft tissue below the skin surface of volunteers. His second task will be to use a small robotic device to apply small forces to a volunteer’s face and measure how much the skin surface deforms. The force will be applied to a number of points on the face in succession to provide a rich set of data that will be used to develop the skin model. Dr. Flynn will determine appropriate computer models to represent the skin and underlying soft tissue and apply his data from the first two experiments to set the parameters. Finally, he will merge the face model with an existing computer model of the jaw and tongue developed at UBC. The ability of the resulting model to simulate chewing and swallowing will be compared with existing computer models. This research will provide crucial knowledge about how facial skin and the underlying soft tissues influence chewing and swallowing, and will be used in the development of a computer model that surgeons can use to improve both reconstructive surgery outcomes and quality of life for patients.