Aggressive periodontitis describes a type of periodontal disease and includes two of the seven classifications of periodontitis as defined by the 1999 classification system:
Localized aggressive periodontitis (LAP)
Generalized aggressive periodontitis (GAP)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. The prevalence of LAP is less than 1% and that of GAP is 0.13%. Approximately 0.1% of white Caucasians (with 0.1% in northern and in central Europe, 0.5% in southern Europe, and 0.1-0.2% in North America) and 2.6% of black Africans may have LAP. 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. 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.Therefore, the prevalence of LAP varies considerably between continents, and differences in race or ethnicity seem to be a major contributing factor.Aggressive periodontitis is much less common than chronic periodontitis and generally affects younger patients than does the chronic form. [2][3] Around 1 in every 1000 patients experience more rapid loss of attachment. Males seem to be at higher risk of GAP than femalesThe localized and generalized forms are not merely different in extent; they differ in etiology and pathogenesis.
Etiology
Microbiology
Of the microflora characterised in aggressive periodontitis, approximately 65-75% of bacteria are Gram-negative bacilli, with few spirochaetes or motile rods present. Aggressive periodontitis is often characterised by a rapid loss of periodontal attachment associated with highly pathogenic bacteria and an impaired immune response. Various studies have associated Aggregatibacter actinomycetemcomitans, formerly known as Actinobacillus actinomycetemcomitans, with aggressive periodontitis. An early study dating back to 1983 explains its prevalence and documents its role in localised aggressive periodontitis.Virulence factors are the attributes of microorganisms that enable it to colonise a particular niche in its host, overcome the host defences and initiate a disease process. Fives Taylor et al. (2000) have categorised the virulence factors of Aggregatibacter actinomycetemcomitans as follows. Samaranayake notes the evidence for the specific involvement of Aggregatibacter actinomycetemcomitans includes: an increased incidence of it found in subgingival plaque obtained from lesional sites, high level of its antibody which tends to fall following successful treatment, its possession of a wide range of potentially pathogenic products and its elimination with concordant disease regression, following treatment with successful periodontal therapy and adjunctive tetracycline.Porphyromonas gingivalis is a Gram-negative anaerobe associated with the pathogenicity of periodontal disease, and aggressive periodontitis is no exception. Greater numbers of both Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans were found in active, destructive periodontal lesions in comparison to non-active sites.Capnocytophaga spp are implicated as prime periodontal pathogens, especially in localised aggressive periodontitis.