Epidemiology and Etiology of Periodontal Disease

Periodontitis is a chronic disease of the hard and soft tissue supporting the teeth caused by bacterial plaque resulting in progressive destruction of the periodontal ligament and alveolar bone.30,31 The disease typically has a slow to moderate rate of disease progression, but periods of accelerated attachment loss may be associated with local and/or systemic factors.32-34 The disease is classified as mild (1-2 mm of clinical attachment loss), moderate (3-4 mm of clinical attachment loss), or severe (≥5 mm clinical attachment loss).35,36 The prevalence of periodontitis has been estimated to be over 47% of U.S. adults, or 64.7 million individuals.37 Of those individuals, 8.7% showed mild disease, 30.0% demonstrated moderate disease, and 8.5% had severe chronic periodontitis.37 Risk indicators for periodontitis include male gender, Hispanic ethnicity, cigarette smoking, uncontrolled diabetes mellitus, and lower socioeconomic status.38 Prevalence of periodontitis varied two-fold between the lowest and the highest levels of socioeconomic status.39

Disease progression of periodontitis has been categorized into subpopulations demonstrating rapid progression (10-15% of disease cases), moderate progression (80% of disease cases), and mild/no progression (5-10% of disease cases).32,40,41 The similar prevalence of disease and disease progression in treated and untreated populations,42 suggests that host factors may play the larger role in disease progression after bacterial initiation.43-48