Why do some people lose teeth across their lifespan whereas others retain a functional dentition into very old age?

Abstract

To analyse the importance of caries, periodontitis, and medical and psychosocial factors for risk of becoming edentulous across their lifespan and to examine factors critical for retaining functional dentition into very old age. From the longitudinal population-based Octogenarian Twin study which analysed psychosocial and health variables, 357 individuals aged 82 + in 1995-1998 were collected. Information about number of teeth, decayed and filled surfaces percentage and periodontal disease experience were drawn from dental records. Reasons for and time of edentulousness were recorded. Outcome varied - depending on perspective and factors for losing or retaining teeth. Significant factors for losing teeth varied over the lifespan. Losing teeth early in life was related to lower social class; in middle age, to lower education; and in old age, to poor lifestyle factors and low social class. Caries constituted the main reason for tooth loss (about 55%). This increased substantially in the >80 year age-group (75%). Maintaining a functional dentition into old age was significantly associated with non-smoking, more education, being married and good periodontal health. It is important to apply life-span and cohort perspectives to oral health and disease. In our sample of persons born before World War I, caries was the main reason for losing all teeth, with substantially increased prevalence by age. Lifestyle factors were significant for losing and for retaining teeth. Periodontal condition had a significant influence on the likelihood of retaining functional dentition, and also when taking psychosocial variables into account.