Are there differences between partial and total periodontal examination of the mouth?

Background: Diagnosis of periodontal disease for epidemiologic survey is difficult due to complexity of periodontal exam. The aim of this study was  to compare data from a full-mouth examination and a partial-mouth examination, observing the agreement between both methods of presenting the Community Periodontal Index (CPI). Methods and Findings: The population comprised of male and female subjects, aged 18 years and over, attending public health centers in the city of Recife, Brazil. A total of 505 patients participated in this study. Each participant completed a form and underwent periodontal examination. Firstly, for each tooth present one of the periodontal conditions was determined: periodontal health, gingival bleeding, dental calculus, shallow periodontal pockets and deep periodontal pockets, according to CPI. Finally, partial data (10 index teeth) was recorded derived from the total version of CPI. Bivariate analysis of frequencies and means was performed. Mc Nemar test was used to calculate the level of statistical significance of the association tested. There are significant statistical differences between partial and full-mouth examination (p<0.001). According to gender, men classified as score 1 presented the same prevalence in both methods; partial recording overestimated 0.2% of women classified as score 1; percentile difference among men was higher for subjects classified as score 0. Among subjects with at least one tooth with deep periodontal pocket, percentile difference between different approaches was higher among elders (60 years and over). Conclusions: Considering the variable age, the smaller amount of lost information refers to periodontal pockets in individuals aged 18 to 30 years of age. In older individuals classified as periodontally healthy and with gingival bleeding no loss of information was observed. Partial examination of the mouth underestimated the presence of periodontal pockets and overestimated the presence of calculus and bleeding. A high concordance between the partial and total examination was observed