Unique etiologic, demographic, and pathologic characteristics of localized aggressive periodontitis support classification as a distinct subcategory of periodontitis.

Background. Localized aggressive periodontitis (LAgP) occurs in 2% of African-American adolescents but only 0.15% of white adolescents. First molars and incisors are affected by rapid onset and progression. Methods. This nonsystematic critical review evaluated published data for LAgP and chronic periodontitis (CP), focusing on potential differences in epidemiology, microbiology, immunology, genetics, and response to therapy. Results. LAgP differs from CP by localization to incisors and first molars, early onset and rapid progression in adolescents and young adults, and a 10-fold higher prevalence in populations of African or Middle Eastern origin, often with strong familial aggregation. The bacterium Aggregatibacter actinomycetemcomitans and hyperresponsive neutrophils are frequently observed. Antibiotic and nonsurgical therapies are highly effective. Conclusions. LAgP differs in many ways from the far more common CP that affects older adults. The substantial evidence of dissimilarities summarized in this review strongly supports the classification of LAgP as a distinct form of periodontitis. Practical Implications. Classifying LAgP as a distinct subcategory of periodontitis will encourage future research and does not conflict with the newly proposed "staging and grading" system. The silent onset and rapid progression of LAgP make early diagnosis and frequent follow-up with patients essential for effective treatment.