Markkanen H, Rajala M, Paunio I
Community Dent Oral Epidemiol. 1979 Apr;7(2):96-100. doi: 10.1111/j.1600-0528.1979.tb01193.x.
Occurrence of periodontal disease was investigated in an industrial population by a modified Peridontal Treatment Need System (PTNS). The study comprised an initial clinical examination and a follow-up examination of 165 persons 1 year later. The reproducibility of the modified PTNS was satisfactory; in a subsample studied twice the weighted kappa with its 99% confidence limits was 0.80 +/- 0.18. Only 3% of the dentulous subjects had no treatment need because of gingival or periodontal disease in the first clinical examination, in spite of the low mean age (33.2 years) of the population. The periodontium of the maxillary teeth was significantly (P less than 0.001) than that in the mandibular teeth, but there were no significant differences between right and left side of jaws. During the 1-year follow-up period the periodontal condition of 23% of subjects improved, whereas in 9% it deteriorated.
