Clarification of Quantitative Intraoral Circumstances with the Community Periodontal Index of Treatment Needs Data using Covariance Structure Analysis

Introduction: Although the severity of periodontal disease is evaluated by various indices, the susceptibility is different among tooth types in the same dentition. Community Periodontal Index of Treatment Needs (CPITN) is a frequently used periodontal index and hierarchically assessed in each six-divided positions. Numerous factors related to periodontal disease determine this deviation of severity among tooth sites but is difficult to be identified precisely. While Covariance Structure Analysis (CSA) defines these unmeasurable factors as latent variables and is able to examine the association about a theoretical model between latent variables and measurable variables. Aim: To assess the difference in susceptibility to periodontal disease and tooth loss among tooth positions evaluated by CPITN score using CSA. Materials and Methods: In this cross-sectional study, the values of CPITN and the number of remaining teeth of 891 Japanese patients were used as measured variables. The factor related to periodontal disease progression was defined as a latent variable "Intraoral Circumstances". Then, a simple one-way flow is described and the quantitative associations were estimated by CSA between the Intraoral Circumstances and the values of sextants evaluated by CPITN and between the CPITN values of sextants and the number of remaining teeth. Results: Values showing the quantitative, individual and detailed relationship of risk factor among sextants in the oral cavity are obtained. The molar teeth are susceptible to periodontal disease and the periodontal progression into upper anterior region is related to a small number of remaining teeth. The indicators used to evaluate the goodness of fit of the estimation exhibit that the applied model is acceptable. Conclusion: The precise differences among six positions are quantitatively estimated finally. The obtained results are statistically and epidemiologically able to determine the difference of the susceptibility and the effect on the number of remaining teeth among six positions.