Investigation on masticatory muscular functionality following oral reconstruction – An inverse identification approach

• Published in: Journal of biomechanics Vol. 90; pp. 1 - 8
• Main Authors: Zheng, Keke, Liao, Zhipeng, Yoda, Nobuhiro, Fang, Jianguang, Chen, Junning, Zhang, Zhongpu, Zhong, Jingxiao, Peck, Christopher, Sasaki, Keiichi, Swain, Michael V., Li, Qing
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 11-06-2019; Elsevier Limited
• Subjects: Conflicts of interest; Correlation analysis; Electromyography; Force; In vivo methods and tests; Inverse identification; Mandibular reconstruction; Mastication; Measurement techniques; Muscle forces; Muscles; Occlusal force; Optimality criteria; Optimization techniques; Physiology; Rehabilitation; Sequential Kriging Optimization (SKO); Surgery; United States > US; Japan; Occlusal force; Sequential Kriging Optimization (SKO); Mandibular reconstruction; Muscle forces; Inverse identification; Optimality criteria
• ISSN: 0021-9290; 1873-2380
• DOI: 10.1016/j.jbiomech.2019.04.007

This study developed a new framework by correlating the clinical measurements in vivo with numerical modeling in silico at different time points for quantifying the magnitudes and directions of oral muscle forces.
[Display omitted]
The human masticatory system has received significant attention in the areas of biomechanics due to its sophisticated co-activation of a group of masticatory muscles which contribute to the fundamental oral functions. However, determination of each muscular force remains fairly challenging in vivo; the conventional data available may be inapplicable to patients who experience major oral interventions such as maxillofacial reconstruction, in which the resultant unsymmetrical anatomical structure invokes a more complex stomatognathic functioning system. Therefore, this study aimed to (1) establish an inverse identification procedure by incorporating the sequential Kriging optimization (SKO) algorithm, coupled with the patient-specific finite element analysis (FEA) in silico and occlusal force measurements at different time points over a course of rehabilitation in vivo; and (2) evaluate muscular functionality for a patient with mandibular reconstruction using a fibula free flap (FFF) procedure. The results from this study proved the hypothesis that the proposed method is of certain statistical advantage of utilizing occlusal force measurements, compared to the traditionally adopted optimality criteria approaches that are basically driven by minimizing the energy consumption of muscle systems engaged. Therefore, it is speculated that mastication may not be optimally controlled, in particular for maxillofacially reconstructed patients. For the abnormal muscular system in the patient with orofacial reconstruction, the study shows that in general, the magnitude of muscle forces fluctuates over the 28-month rehabilitation period regardless of the decreasing trend of the maximum muscular capacity. Such finding implies that the reduction of the masticatory muscle activities on the resection side might lead to non-physiological oral biomechanical responses, which can change the muscular activities for stabilizing the reconstructed mandible.