The long term objectives are to observe, document and analyze oral disease in heterosexual intravenous drug users. This subproject will focus on the oral disease epidemiology of a cross-sectional sample of HIV+ and HIV-IVDUs from the Methadone Maintenance Treatment Program at BIMC> The specific aims are: 1) to determine the prevalence of oral lesions in HIV+ IVDUs compared to HIV- IVDUs; 2) to determine the prevalence of necrotizing periodontitis and atypical gingivitis (HIV- associated periodontitis and HIV-associated gingivitis) in HIV+ IVDUs: 3) to determine the prevalence of acute necrotizing ulcerative gingivitis (ANUG) in HIV+ compared to HIV- IVDUs; 4) to compare probing pocket depth and attachment loss in HIV+ and HIV- IVDUs; 5) to determine the caries prevalence in HIV+ compared to HIV- IVDUs; 6) to determine the relationship between oral lesions and T4 cell levels and T4/T8 ratios in the sample. Health relatedness: Heterosexual intravenous drug users are rapidly becoming a predominant HIV infected population. Preliminary studies indicate the HIV associated oral diseases are prevalent among IVDUs, in addition to rampant decay and advanced periodontal disease. It is hypothesized that HIV virus may be transmitted through breaks in the periodontal tissues and through exposed pulps of teeth with rampant decay. Because it has been reported that many IVDUs smoke "crack cocaine" which can lead to unprotected oral sex, this may be another route of transmission and possible infectivity. This study will provide considerable data on oral aspects of HIV infection in a major population infected with the virus.