Recent epidemiologic trends in periodontitis in the USA

The most important development in the epidemiology of periodontitis in the USA during the last decade is the result of improvements in survey methodologies and statistical modeling of periodontitis in adults. Most of these advancements have occurred as the direct outcome of work by the joint initiative known as the Periodontal Disease Surveillance Project by the Centers for Disease Control and Prevention and the American Academy of Periodontology that was established in 2006. This report summarizes some of the key findings of this important initiative and its impact on our knowledge of the epidemiology of periodontitis in US adults. This initiative first suggested new periodontitis case definitions for surveillance in 2007 and revised them slightly in 2012. This classification is now regarded as the global standard for periodontitis surveillance and is used worldwide. First, application of such a standard in reporting finally enables results from different researchers in different countries to be meaningfully compared. Second, this initiative tackled the concern that prior national surveys, which used partial-mouth periodontal examination protocols, grossly underestimated the prevalence of periodontitis of potentially more than 50%. Consequently, because previous national surveys significantly underestimated the true prevalence of periodontitis, it is not possible to extrapolate any trend in periodontitis prevalence in the USA over time. Any difference calculated may not represent any actual change in periodontitis prevalence, but rather is a consequence of using different periodontal examination protocols. Finally, the initiative addressed the gap in the need for state and local data on periodontitis prevalence. Through the direct efforts of the Centers for Disease Control and Prevention and the American Academy of Periodontology initiative, full-mouth periodontal probing at six sites around all nonthird molar teeth was included in the 6 years of National Health and Nutrition Examination Surveys from 2009-2014, yielding complete data for 10 683 dentate community-dwelling US adults aged 30 to 79 years. Applying the 2012 periodontitis case definitions to the 2009-2014 National Health and Nutrition Examination Surveys data, the periodontitis prevalence turned out to be much greater than previously estimated, namely affecting 42.2% of the population with 7.8% of people experiencing severe periodontitis. It was also discovered that only the moderate type of periodontitis is driving the increase in periodontitis prevalence with age, not the mild or the severe types whose prevalence do not increase consistently with age, but remain ~ 10%-15% in all age groups of 40 years and older. The greatest risk for having periodontitis of any type was seen in older people, in males, in minority race/ethnic groups, in poorer and less educated groups, and especially in cigarette smokers. The Centers for Disease Control and Prevention and the American Academy of Periodontology initiative reported, for the first time, the periodontitis prevalence estimated at both local and state levels, in addition to the national level. Also, this initiative developed and validated in field studies a set of eight items for self-reported periodontitis for use in direct survey estimates of periodontitis prevalence in existing state-based surveys. These items were also included in the 2009-2014 National Health and Nutrition Examination Surveys for validation against clinically determined cases of periodontitis. Another novel result of this initiative is that, for the first time, the geographic distribution of practicing periodontists in relation to the geographic distribution of people with severe periodontitis is illustrated. In summary, the precise periodontitis prevalence and distribution among subgroups in the dentate US noninstitutionalized population aged 30-79 years is better understood because of application of valid periodontitis case definitions to full-mouth periodontal examination, in combination with reliable information on demographic and health-related measures. We now can monitor the trend of periodontitis prevalence over time as well as guide public health preventive and intervention initiatives for the betterment of the health of the adult US population.