Periodontal diseases may occur at any age after eruption of teeth, affecting the permanent as well as the primary dentition. However, the disease is most common during adulthood and old age. Genetics is now recognized as the major etiologic factor. In addition to the most prevalent chronic type of these diseases, there is also an aggressive type. Periodontal diseases have also been associated with major systemic problems such as cardiovascular disorders and premature births. Our projects focus on genetics susceptibility to aggressive periodontitis.