LOCALIZED JUVENILE PERIODONTITIS AND ACTINOBACILLUS-ACTINOMYCETEMCOMITANS IN A BRAZILIAN POPULATION

Localized juvenile periodontitis (LJP) has been used as a model for st udying periodontal disease, and its prevalence is considered to be hig her in third-world countries (0.3-8%) than in industrialized countries (0.1%). Mostly, the disease has been associated with Actinobacillus a ctinomycetemcomitans (A.a.) but lack of association has also been repo rted. The aim of this study was to identify LJP patients in geographic ally different Brazilian populations and assess the presence of A.a. i n their periodontal lesions. 7843 children, 12-19-years of age, from t he cities of Rio de Janeiro, Votorantim and Belo Horizonte were screen ed, and LJP patients were identified by strict clinical and radiograph ical criteria. A final LJP prevalence of 0.3%, with a 99% confidence i nterval between 0.16% to 0.47%, was found. The prevalence in the subpo pulations varied between 0.1-1.1% in the different areas. Subgingival bacterial samples were obtained from the oral cavity of 25 patients an d their family members. 80% of these patients, 39.5% of their family m embers, 35.3% of their parents, and 43.9% of all siblings were culture positive for A.a. All but one of the families had at least one member in addition to the patient who was culture positive for A.a. In 3 fam ilies, >1 member showed radiographic and clinical signs of LJP. 30% of non-LJP subjects coming from one of the areas with higher LJP prevale nce harbored A.a. We conclude that LJP is highly associated with A.a. in this Brazilian population.