Relationship between remaining teeth and self-rated chewing ability among population aged 45 years or older in Kaohsiung City, Taiwan.

The purposes of this study were to (1) examine the relationship between the number of various types of healthy remaining natural teeth at different sites and self-rated chewing ability and (2) evaluate the relationship between the number of functional tooth units (FTUs), comprising functional natural teeth (FNT) or fixed prostheses, and self-rated chewing ability. A sample of 296 adults (122 men and 174 women), aged 45 years or older (average age, 56.6±9.7), were recruited from seven dental clinics in Kaohsiung City. Dental information on the number and status of remaining teeth was obtained through examination by trained and calibrated dentists. Self-assessment of chewing ability (masticatory score) was evaluated with a self-administered questionnaire. Results showed that increased age is associated with a greater likelihood of difficulty in chewing. To avoid chewing difficulty, at least 24.7 FNT, 13.3 posterior-FNT, 8.1 units of natural tooth-FTUs, or 9.6 units of fixed tooth-FTUs must remain. Age and the number of healthy remaining teeth, including natural teeth and fixed prostheses, are key factors in chewing ability. Given that aging is unavoidable, the preservation of healthy remaining teeth plays a relatively important role in the maintenance of chewing ability among middle-aged and elderly people.