What do we learn from the clinical and biological evaluation of the oral cavity in centenarians?

The number of centenarians is rapidly increasing worldwide and so are the studies on this segment of the population. A general consensus in the literature is that healthy longevity is an outcome of multiple factors, but the interrelationship between good oral health and healthy aging remains not fully understood. As part of the “CaT: Centenari a Trieste” study, a population-based cohort study set in Trieste, Italy, we report here the results of subjective self-reported oral health parameters and objective clinical and biological oral variables and their association with cognitive impairment in 25 centenarians enrolled in the study from September 2017 to May 2019. Oral health-related variables were recorded by means of a self-evaluation questionnaire and a comprehensive oral examination of teeth, prostheses and mucosae conducted by a trained dentist. In addition, 6-n-propylthiouracil (PROP) taste perception and salivary oxidative stress markers, specifically the Total Oxidative Status and Ferric Reducing Ability of Saliva, were measured. Finally, the oral data obtained were compared with the presence or absence of dementia in the enrolled subjects. The centenarians included in our study were generally satisfied with their oral health. Among the causes of discomfort, the most prevalent were difficulties in chewing and biting, with few subjects describing a correlation between their oral health and psycho-social issues. We evaluated possible relations of clinical and biological variables to the likelihood of being demented and did not find significant associations. We found a higher though not statistically significant mean salivary flow and antioxidant capacity of saliva in non-demented subjects. When evaluating the PROP taste perception profile, we found a higher proportion of supertasters compared with previous studies and different taste perception profiles according to dementia. Despite the relatively small number of participants, we believe that our study contributes to a better understanding of the clinical and biological profile of the oral cavity in subjects aged over 100 years, encouraging the inclusion of a comprehensive evaluation of the oral cavity in centenarian studies performed worldwide.