Background: There is growing international interest in identifying the effects of ageing on oral health and on appropriate strategies for managing oral disorders. The Japanese Society of Gerodontology (JSG), as the official representative of researchers and clinicians interested in geriatric dentistry in Japan, makes several recommendations on the concept of “oral hypofunction.”Aims: This study proposes diagnostic criteria and management strategies to reduce the risk of oral hypofunction among older people.Conceptual Framework: We define oral hypofunction as a presentation of 7 oral signs or symptoms: oral uncleanness; oral dryness; decline in occlusal force; decline in motor function of tongue and lips; decline in tongue pressure; decline in chewing function; and decline in swallowing function. The criteria of each symptom were determined based on the data of previous studies, and oral hypofunction was diagnosed if the criteria for 3 or more signs or symptoms were met.Conclusions: We recommend that more evidence should be gathered from clinical studies and trials to clarify our diagnostic criteria and management strategies.

Oral function declines in older individuals due to disease and age-related changes, making them vulnerable to oral and physical frailty. Therefore, it is important to manage the decline in oral function in older outpatients. Oral hypofunction is diagnosed by seven tests related to oral function, oral hygiene, oral moisture, occlusal force, oral diadochokinesis, tongue pressure, masticatory function, and swallowing function. However, sex or age were not factored into the current reference values of these tests. We included subjects attending the dental hospital clinic for maintenance, and recorded and analyzed oral hypofunction and the factors associated with its diagnosis. Of the 134 outpatients (53 males and 81 females, mean age 75.2 ± 11.2 years), 63% were diagnosed with oral hypofunction. Oral hypofunction prevalence increased significantly with age, and significant variations were observed in all tests. Furthermore, oral hygiene and swallowing function were not associated with oral hypofunction diagnosis. All examined factors decreased with increasing age, even after adjusting sex, except for oral hygiene and moisture. Occlusal force and masticatory function were higher in men after adjusting age. This study suggested that older outpatients were likely to be diagnosed with oral hypofunction, and that the test reference value and their selection for oral hypofunction should be reconsidered.