Relationships Between Test Results for Oral Hypofunction, Subjective Frailty Symptoms and Oral Health-Related Quality of Life of Japanese Dental Outpatients: A Multicentre, Cross-Sectional Study

Background: Oral hypofunction is the stage before oral dysfunction. The subjective symptoms of poor oral function and the decline in oral health-related quality of life (OHRQoL) that occur in the oral hypofunction stage can be missed.

Objective: This multicentre cross-sectional study was performed to examine the relationships between the test results for oral hypofunction, subjective frailty symptoms and OHRQoL of outpatients in dental clinics.

Methods: The basic characteristics and oral function test results of 637 dental clinic outpatients were evaluated. The subjective symptoms of physical and oral frailty were investigated using a questionnaire. OHRQoL was assessed using the Japanese short version of the Oral Health Impact Profile (OHIP-JP16) and OHRQoL dimension score.

Results: The overall prevalence of oral hypofunction was 37.8%, with no significant difference between men and women. No significant differences in the presence or absence of subjective symptoms of frailty and a high OHIP score were observed based on sex. However, the prevalence of oral hypofunction was significantly different among the age groups and increased with age. The subjective symptoms of frailty score, OHIP score and OHRQoL dimension score were significantly higher in patients with versus without oral hypofunction. Age, number of underlying diseases, total score for subjective symptoms of frailty, total score for OHIP and OHRQoL dimension score were significantly associated with oral hypofunction.

Conclusion: Oral hypofunction may affect the subjective symptoms of frailty and OHRQoL in older adults.