What a public health planner wants from a periodontal assessment

Despite certain shortcomings, the assessment of caries using the DMF system of scoring is relatively simple, reproducible and provides some indication of treatment needs and the success of the treatment measures provided. No such index is yet in existence which will give similar information about the much more complicated disease processes involved in periodontal disease. Early attempts to introduce suitable indices included the PI index PMA and OHI indices with their modifications. These indices have performed best in assessing disease status but gave little or no information about treatment needs, treatment achievement or failure. WHO attempted to simplify the indices so that they could be scored on a present or absent basis, but clinical trials revealed the impossibility of maintaining comparability even on this level. Subsequent refinement of the procedure has produced improvements in the system including the recording of five categories of treatment needs, namely special oral hygiene instruction, prophylaxis and oral hygiene, instruction, periodontal therapy without extraction of teeth and periodontal therapy with extraction of some or all teeth. The system is described in the second edition of the WHO manual on Oral Health Surveys. There is still need for epidemiologists to further refine the criteria of periodontal disease and to identify the significance of the various signs of gingival and periodontal pathology.