The second learning objective of this course is to identify manifestations of diseased periodontium. The first step in identifying disease manifestations is to understand periodontal disease epidemiology and the degree to which its manifestations have been measured.
Periodontitis occurs frequently in the U.S. adult population. The exact prevalence of the disease in the U.S. and worldwide has been estimated to affect 20% of the adult population, but has not been definitively determined because studies lack a consistent definition of the disease and a consistent methodology. A large U.S. 1990 study by Brown et al of 15,132 subjects aged 18-64 years provides an insight into the epidemiology of periodontal diseases. It reported that 4-6 mm pockets were found in 13.4% of subjects, or 0.6 sites/subject and 1.3% of sites assessed. The same study reported pockets of 7 mm or greater were found far less frequently, in 0.6% of subjects, or 0.01 sites/subject and 0.03% of sites assessed. Additionally, the study reported that attachment loss greater or equal to 3 mm was found in 44% of subjects, increasing with age and affecting an average of 3.4 sites/subject. Attachment loss greater or equal to 5 mm was found in 13% of subjects, increasing with age and affecting an average of 0.7 sites/subject.3 Because periodontal disease is relatively widespread, clinicians routinely see its manifestations.
Disease severity ranges along a continuum of stage 1 to stage 4, and grading is determined to predict whether disease progression is slow, moderate, or rapid. Periodontitis often affects different areas of the mouth to different degrees. It is usually progressive, characterized by bursts of disease progression followed by periods where the disease is more quiescent. If left untreated, tooth loss may result due to the progressive nature of the disease. Clearly the goal is to attain and/or preserve oral tissue health with appropriate therapies. Success can be measured directly by preserving the dentition and periodontium, which includes the gingiva, periodontal ligament, root cementum and alveolar bone. Surrogate markers of success in measuring periodontal health include maintaining clinical attachment levels and reducing or eliminating pocket depths, inflammation, infection and bleeding on probing. Probing pocket depth (PPD) is a measurement of the distance between the gingival margin and the base of the probable crevice. Clinical attachment loss (CAL) is a measurement of the distance between the cemento-enamel junction (CEJ) and the base of the probable crevice or pocket. Furcation involvement may range from 1st degree, where horizontal loss of support is less than 1/3 of the width of the tooth, to 3rd degree, where there is a horizontal loss of support from one side of the furcation through to the other side. Mobility can range from degree 1 (0.2-1 mm horizontal crown motion), to degree 2 (greater than 1 mm horizontal crown motion), to degree 3 (horizontal and vertical crown motion).
The Gingival Index, published by Löe in 1967, scores a 0 for no visible signs of inflammation, a 1 for slight change in color and texture, a 2 for noticeable inflammation and bleeding upon probing and a 3 for overt inflammation and spontaneous bleeding. The Plaque Index, published by Silness & Löe in 1964, scores plaque deposits on a 0-3 scale where 0 indicates that plaque is absent, 1 indicates plaque detected by gingival marginal probing, 2 indicates visible plaque and 3 indicates abundant plaque.
It is important to keep in mind that some of these measures are markers of past disease and do not reliably predict future disease progression. The presence or absence of inflammation have been clinically assessed by gingival redness, suppuration, bleeding on probing (BOP), measurements of gingival temperature and gingival crevicular fluid (GCF) and supragingival plaque. Further measures of success include maintaining and improving periodontal comfort, esthetics and function.