Oral physiological characteristics among Chinese subjects in the eastern region of China

With an increasing number of elderly in China, it becomes imperative to establish a comprehensive understanding of their physiological capabilities and investigate fundamental mechanisms underpinning the discrepancies between Chinese individuals and other ethnical groups, which will facilitate government policymaking, design and development of special food products.

In this study, 100 healthy Chinese subjects in the eastern region of China (22-89 years old) were recruited with full consent, then divided into young adult, middle-aged and elderly groups. Subjects' maximum biting force (MBF), maximum tongue pressure (MTP), maximum oral volume (MOV), and saliva flow rate were recorded. Unstimulated (US) and stimulated (SS) saliva were collected. Subjects were then objectively clustered into 3 different levels of oral processing capability. A total of 10 young subjects from two different clusters were selected for chewing efficiency (CE) determination.

With increased age, there is a decline in subject's dental status, MBF and MTP. Gender affects greatly on MOV; males have larger MOV. No significant effects on SS and US flow rate were found with age and gender. The finding of a similar CE and differences in overall capability in relevant physiological variables (MBF and MOV in young adults) suggest that the degree of CE is not determined by a total capability of various oral physiological variables. In contrast, the findings suggest that CE will be non-impaired as long as each of the relevant physiological variables (i.e. dental status, MBF) operates at a supra-threshold level.