Epidemiology of periodontal disease.

The epidemiological studies of the 50s and 60s have used visual diagnosis for gathering data to describe prevalence and severity of periodontal diseases within a population. Well-defined index systems were developed and loss of connective tissue attachment from a fixed landmark was established. More recently, the CPITN which had been designed to examine treatment needs in populations was also used erroneously to assess information about prevalence and severity. While data gathered on the basis of the CPITN are rather inconclusive, all the recent epidemiological surveys which used the full spectrum of clinical measurements yielded a rather low proportion of the population of industrialized countries affected by severe periodontal disease. Apparently, quite a large proportion of most populations show signs of gingivitis, but little loss of connective tissue attachment. Only a low percentage is at risk from periodontal disease progression and hence, would need advanced periodontal therapy. While epidemiological surveys used to determine signs and symptoms of inflammation and hence, treatment goals had been defined towards eliminating these symptoms, more recent decision making models for treatment planning have redefined treatment goals: the maintenance of all natural teeth in the dentition in a state of function throughout life. These proposed models are the first attempts to identify subjects at high risk from periodontal disease progression using conventional, but standardized radiography and hereby supplementing clinical data. One of these models is discussed in detail.