In America, it has been found that severe periodontal disease is more frequent in poorer populations. Socioeconomic disadvantage at the individual and neighbourhood level is associated with severe periodontitis among African-Americans and whites, according to research conducted at the Mailman School of Public Health and reported in the American Journal of Public Health.

The study, based on a sample of people aged 45 to 64, found that low income was associated with the prevalence of severe periodontitis among whites, and both low education and income levels were associated with severe periodontitis among African-Americans. 'These associations remained significant after adjustment for age, gender, recruitment centre, and neighbourhood socioeconomic conditions,' said Luisa N. Borrell, lead author of the paper. 'Specifically, the odds of having severe periodontitis were twice as high among African Americans without a high-school diploma than among their peers with a college degree or postgraduate education. Moreover, low income African Americans and whites were at least 50% more likely to have severe periodontitis than their high-income counterparts.'

This is the first study of its kind to investigate neighbourhood effects on periodontal disease, although it had been assumed that area of residence influences a person's health behaviours. 'In the case of periodontal disease, social contexts could promote or prevent behaviours that may affect periodontal health such as smoking, regardless of individual socioeconomic status,' said Dr Borrell.