[Characteristics of certain early periodontitis: apropos of two cases].

The study of early onset periodontitis led in the last years to important improvement in the etiopathogenic knowledge of periodontitis. The clinical and microbiological analysis of 2 early onset periodontitis cases gives a better understanding of the evolution of these 2 models of periodontal lesions. Hypothesis are presented concerning the transition between localized juvenile periodontitis and rapidly advanced periodontitis.