Oral epidemiological studies in a Swedish adult population focusing on periodontal disease

Abstract: Epidemiological surveys are used for prospective planning, and retrospective control of dental health goals in relation to personnel and economic resources. <br/>The general aim of this thesis was to describe and analyze oral conditions, mainly from a periodontal perspective, in the adult population in the County of Värmland, Sweden, and to identify potential risk associations/factors. <br/><br/>Randomly selected population samples of 35-, 50-, 55-, 65- and 75-year-old subjects, stratified by urban/rural living, were examined by means of questionnaires radiographs and clinical registrations for cross-sectional analyzes. In addition a 10-year-prospective longitudinal study was performed in the 50-year-old subjects. Periodontal conditions were recorded by the use of periodontal attachment level (PAL), Community Periodontal Index of Treatment Needs (CPITN), furcation involvements and alveolar bone level (ABL) measurements. Risk analyzes included factors related to dental/oral conditions, general health, and behavioral and environmental conditions. Risk associations/factors were evaluated utilizing both bivariate and multivariate models.<br/><br/>The cross-sectional studies revealed that symptoms of caries and periodontal disease accumulated with age. Smokers compared to never-smokers and low educated compared to high educated subjects had fewer remaining teeth and a higher prevalence of both caries and periodontal disease.<br/>Periodontally healthy subjects were characterized by a high number of remaining teeth, a low number of caries lesions, a positive lifestyle, and were predominantly women. Subjects with severe periodontal disease were associated with a reduced number of remaining teeth, male gender, cigarette consumption and poor lifestyle. In 50-year-olds, the mean ABL loss over 10 years was small and only few subjects suffered severe disease progression. Tooth loss was more common in the molar than in the anterior tooth regions, while periodontal bone loss had a random distribution in the dentition. In descending order, probing pocket depth >= 4 mm, smoking, number of remaining teeth and impaired general health were risk factors for periodontal disease progression. Analysis on the tooth level disclosed no additional risk factors. Lifestyle factors, apart from smoking, had a low predictive value in the identification of subjects with stable periodontal conditions as well as subjects with progressive periodontal disease.<br/><br/>Conclusions<br/>The cross-sectional survey in this series of studies showed that the prevalence of severe periodontal disease in the examined population was low but increased by age. Furthermore, it was more likely to find advanced periodontal destruction in smokers and subjects with low education.<br/>In the longitudinal cohort study the periodontal disease progression was slow in the majority of subjects. Already established periodontal disease and smoking habits were the main risk factors for periodontal disease progression. Minimal periodontal disease progression was poorly explained by lifestyle factors.