Genetic considerations of risk in human periodontal disease.

Increasingly, evidence suggests that underlying host susceptibility factors play a significant role in periodontitis in high-risk patients and that this risk may be partly under genetic control. Support for a heritable component to periodontitis risk comes from the consistent association of periodontitis with certain monogenic traits, as well as from formal genetic studies of both twins and early onset periodontitis. It is significant that not all genetic predispositions to periodontitis involve defects of the immune system. Structural or developmental defects in collagen, cementum, and epithelium also appear to be significant risk factors for periodontitis. Dissection of a genetic model system for periodontitis may prove valuable in fully understanding disease pathogenesis in periodontitis, particularly for understanding the role of host susceptibility factors.