Oral health and happiness after 3-years with causal mediation of oral functions

Overall, 45.2 % (n = 24,371) of participants were males. Mean age was 73.3 years (SD± 5.7 years) and 17.1 % (n = 9,195) became unhappy at follow-up. The incidence of unhappy participants was 24.9 % (n = 127) from those who had 0-9 teeth and no dental prosthesis declining to 15.4 % (n = 5034) from those who had ≥20 teeth. In the adjusted model and compared to the participants who had 0-9 teeth and no dental prosthesis, those with better oral health (i.e, having more teeth and used dental prosthesis) tended to have lower risk of being unhappy at follow-up (≥20 teeth RR = 0.80, 95 %CI = 0.68-0.95). The interaction analysis showed reduced risk of unhappiness for those who used a dental prosthesis. Having difficulty in speaking and chewing partially explained 4.7 %-16.3 % of the association depending on the number of remaining teeth.