Video tracking-based Mandibular Movement Kinematic Analysis in patients with nasopharyngeal carcinoma

Abstract

Abstract Objective Patients with dysphagia due to nasopharyngeal carcinoma (NPC) after radiotherapy often have chewing difficulty. Kinematic analysis of mandibular movements may provide clinically useful information for the chewing function. However, current kinematic device costs limited clinical application, and specialized software is required for control and data processing. This study aimed to mandibular kinematics parameter recognition using a self-developed Nswallow 2D motion capture software. To investigate whether differences in kinematic data of mandibular movements during mastication can be used as an indicator of masticatory dysfunction in NPC patients, and the relationship with mastication efficiency. Method Thirty-three patients with early-stage NPC after radiotherapy and thirty-five healthy controls were recruited. The self-developed Nswallow 2D motion capture software was used to automatically mark and capture the facial parts of the participants. We tracked jaw kinematic during chewing, and analyzed the characteristics of kinematic data of mandibular movements during chewing tasks. Meanwhile, the masticatory efficiency using two-color chewing gum was analyzed by the Viewgum software. Result Significant differences were observed in the mastication time (Total Masticatory Time (NPC:12.349 ± 2.428; HC:8.742 ± 1.349) & Chewing Sequence Duration (NPC:636.573 ± 85.432; HC:543.646 ± 65.9388)), speed of mandibular motion (Maximum Speed (NPC:23.740(17.775,25.906); HC:28.800(24.643,38.800) & Average Speed (NPC:11.844(10.395,13.285); HC:18.169(15.790,21.435)), and Mandibular Motion Amplitude (NPC:7.159(5.887,7.869); HC:8.478(7.291;11.020)) between two groups (P < 0.000). Logistic regression analysis and receiver operating characteristic curve analyses were performed based on the above data as explanatory variables. Among them, the average chewing speed exhibited the highest area under the ROC curve, the odds ratio was 3.629, the cutoff value was 14.28, with a sensitivity of 90.91%, a specificity of 80.00%, and an area under the curve of 0.9255. The masticatory efficiency in the NPC group significantly decreased compared to the healthy control group (P < 0.000). Linear regression analysis showed that average chewing speed negatively affects masticatory efficiency. Conclusion The Nswallow 2D motion capture software represents an easy-to-use and affordable system that can be utilized to assess masticatory function in patients with NPC. In addition, the average speed of chewing is a highly sensitive kinematic indicator for evaluating mastication efficiency.