How do age and tooth loss affect oral health impacts and quality of life? A study comparing two national samples

Age and loss of teeth can be expected to have a complex relationship with oral health-related quality of life. This study aimed to explain how age and tooth loss affect the impact of oral health on daily living using the short form, 14-item Oral Health Impact Profile (OHIP-14) on national population samples of dentate adults from the UK (1998 UK Adult Dental Health Survey) and Australia (1999 National Dental Telephone Interview Survey). After correcting for key covariables, increasing age was associated with better mean impact scores in both populations. Those aged 30-49 years in Australia showed the worst (highest) scores. In the UK, those aged under 30 showed the highest scores. In both countries, adults aged 70+ showed much better scores than the rest (P < 0.001). When corrected for age, the independent effect of tooth loss was that the worst scores were found where there were fewer than 17 natural teeth in the UK and fewer than 21 teeth in Australia. People with 25 or more teeth averaged much better scores than all other groups (P < 0.001), although there were differences in pattern between countries. When Australians were analysed by region of birth, the pattern of scores by tooth loss for British/Irish immigrants was strikingly similar to that for the UK sample. First-generation immigrants from elsewhere showed much worse overall scores and a profoundly different pattern to the Australian- and British-born groups. Age, number of teeth and cultural background are important variables influencing oral health-related quality of life.