Influence of functional dentition on satisfaction with oral health and impacts on daily performance among Brazilian adults: a population-based cross-sectional study

Background: Dental esthetics, chewing and speech should be preserved in a dentition denominated functional and are closely related to satisfaction with oral health (SOH), impacts caused by oral problems and have a possible association with Oral Health-Related Quality of Life. Thus, the purpose of the present study was to investigate the influence of different concepts of functional dentition (FD) on both SOH and impacts on daily performance (IDP) among Brazilian adults. Methods: A cross-sectional study was conducted with 9564 adults (35-44 years). SOH and IDP were evaluated using the Oral Impacts on Daily Performance (OIDP) questionnaire. FD was considered based on four different definitions: I-classification of the World Health Organization (FDWHO = >= 20 teeth); II-well-distributed teeth (WDT = >= 10 teeth in each arch); III-classified by esthetics and occlusion (FDClass5 = sequential presence of one tooth in each arch, >= 10 teeth in each arch, 12 anterior teeth, >= three posterior occluding pairs [POPs] of premolars and >= one POP molar bilaterally); and IV-classified by esthetics, occlusion and periodontal status (FDClass6 = FDClass5 plus all sextants with CPI <= 3 and/or CAL <= 1). The proportion of adults satisfied with oral health and without overall impact (OIDP = 0) was calculated for each definition of FD. Multiple Poisson regression models were adjusted by demographic-socioeconomic characteristics, self-reported oral problems and the use of dental services for each dependent variable. Results: When FDClass5 and FDClass6 were considered a greater proportion of adults reported being satisfied (52.1 and 53.1%, respectively) and have OIDP = 0 (52.4 and 53.3, respectively). In the multiple models, SOH was associated with FDClass5 (RP = 1.21) and FDClass6 (RP = 1.24) and OIDP = 0 was associated with WDT (RP = 1.14) and FDClass6 (RP = 1.21). Conclusions: The greater influence of WDT, FDClass5 and FDClass6 on aspects related to quality of life in comparison to FDWHO demonstrates the need for the establishment of a broader definition of FD that encompasses subjective aspects.