Aggressive periodontitis describes a type of periodontal disease and includes two of the seven classifications of periodontitis as defined by the 1999 classification system:[1]
LAP is localised to first molar or incisor interproximal attachment loss, whereas GAP is the interproximal attachment loss affecting at least three permanent teeth other than incisors and first molar.[2] The prevalence of LAP is less than 1% and that of GAP is 0.13%.[2] Approximately 0.1% of white Caucasians[3] (with 0.1% in northern and in central Europe, 0.5% in southern Europe, and 0.1-0.2% in North America[2]) and 2.6% of black Africans may have LAP.[3] Estimates of the disease prevalence are 1-5% in the African population and in groups of African descent, 2.6% in African-Americans, 0.5-1.0% in Hispanics in North America, 0.3-2.0% in South America, and 0.2-1.0% in Asia.[2] On the other hand, in Asia, the prevalence rate of 1.2% for LAP and 0.6% for GAP in Baghdad and Iran population, and 0.47% in Japanese population.[2]
Therefore, the prevalence of LAP varies considerably between continents, and differences in race or ethnicity seem to be a major contributing factor.[2]
Aggressive periodontitis is much less common than chronic periodontitis and generally affects younger patients than does the chronic form.[4][5] Around 1 in every 1000 patients experience more rapid loss of attachment.[6] Males seem to be at higher risk of GAP than females[2]
The localized and generalized forms are not merely different in extent; they differ in etiology and pathogenesis.