Key points are not available for this paper at this time.
THE paucity of reliable epidemiological data1 concerning periodontal dis-ease has been discussed by several commentators.2 3 Although field surveys of gingivitis prevalence have been carried out using the P. M. A. index of Massler and Schour,4-10 studies dealing with more advanced stages of tissue destruction have generally been based upon collections of case histories, with all of the drawbacks inherent in such data,1 and have ordinarily been limited to estimates of the qualitative presence or absence of disease without regard to its severity,12 or of quantitative bone loss as determined by radiographs alone, without reference to clinical appearance.13 14 A committee of the University of Michigan Periodontal Workshop stated that the lack of valid indexes for determining the prevalence and epidemiological characteristics of periodontal diseases has hindered seriously the development of more effective preventive and treatment procedures for these diseases. 1 The Council on Dental Health of the American Dental Association commented that, The prevalence of the disease has not been measured, largely because of inadequate measuring devices.5
A.L. Russell (Fri,) studied this question.