A study of some masticatory functions in 90-year old subjects.

A group of 35 90-year old subjects, randomly selected from the gerontologic population study in Göteborg (H-70), were examined with respect to function and dysfunction of the masticatory system. The methods included a questionnaire, clinical examination and recording of bite force endurance and maximal bite force, measured in the central incisor region. Forty percent were edentulous, 29% were partially edentulous and wore a removable denture, while the others were dentate without removable prostheses. Signs and symptoms of temporomandibular disorders were mostly mild and infrequent, except TMJ crepitation which was recorded in 69% of the subjects. Maximal bite force was in general low (mean 94 N) but showed a great individual variation (range 10 to 410 N). Bite force endurance was also very variable (mean 72 s, range 10 to 205 s). None of the 35 subjects reported poor masticatory ability, but 2 said they could not chew all kinds of food. In spite of a reduced bite force this group of 90-year olds considered their masticatory ability as good and most of them had no severe signs and symptoms of temporomandibular disorders.