Video Evaluation of Chewing Efficiency in Elderly Complete Denture Wearers

Objectives: Chewing efficiency may affect nutritional state in the elderly. Many elderly patients are complete denture wearers and many present cognitive problems. Those two factors make evaluation of mastication difficult with experimental methods such as kinematics or electromyography (EMG). Video recording analysis could be a simple way to routinely assess chewing parameters in people with and without disabilities. This technique has been validated in people with Down's syndrome but not in complete dentures wearers. This study aims to validate several parameters of video evaluation against EMG (considered as a gold standard). Methods: 12 complete denture wearers chewed four model foods differing in hardness. Sessions were videotaped and EMG recordings were registered. Masticatory time, number of masticatory cycles and cleaning duration were recorded simultaneously from video and EMG. Two investigators independently analysed the videos twice, in random order. Results: Evaluation of criterion validity: a positive correlation video/EMG was found for the parameters “chewing time” (0.89, Pearson) and “number of chewing cycles” (0.94, Spearman), and no statistical difference was found between these two EMG and video variables (t-test). Inter and intra-rater reliability gave a positive intra class coefficient (ICC) for duration of mastication [0.86 -0.98], number of chewing cycles [0.90-0.97] and for cleaning time [0.90-0.98]. The discriminatory ability was studied using ANOVA (P=0,01), the variation was significant in masticatory duration (F=10), number of masticatory cycles (F=10) and cleaning duration (F=4). Conclusion: This study confirms the possibility of using video as an alternative to EMG in evaluation of chewing efficiency in elderly complete denture wearers. Video may be an assessment tool in prosthetic rehabilitation and also helps in choosing the type of food (solid, semi-liquid and liquid) to administer to dependent persons, in particular those suffering from dementia.