[Research into actual conditions and preventive care in periodontal disease. Relationship between questionnaire results and periodontal disease in youth].

The purpose of this study was to determine the prevalence of periodontal disease and the relationship between the results of questionnaire concerning periodontal disease and the actual periodontal condition in youth. The examination was carried out in three parts. In the first part, a questionnaire was conducted on 3,886 junior and senior high school students (12 to 18 years of age) living in Kawagoe, Japan. The questionnaire was composed by of items concerning habits of oral hygiene, periodontal symptoms, understanding of periodontal disease and history of diagnosis by dentist of periodontal disease. Secondary, mass intraoral examination was carried out on all objects. The examination covered gingival inflammation, periodontal probing depth, calculus, dental plaque, dental caries and malalignment. Lastly, we examined the relationship between the results of periodontal examination and questionnaire with the original periodontal classification. The following results were obtained: 1. As an example of items in questionnaire, 83.1% brushed their teeth more than two times daily. The understanding of oral hygiene concerning dental caries was improved, but concerning periodontal disease was still poor. 2. The symptom most frequently reported was gingival bleeding during tooth brushing (18.4%). 3. The percentage of persons with periodontal disease (moderate gingival inflammation and periodontal pocket 4 mm or deeper) was of the highest frequency at 13 years old. The proportion of males increased with the advanced state of periodontal disease. 4. A significant correlation was found (chi 2-test: alpha less than 0.001) between advanced state of periodontal disease and a decrease in tooth brushing time per day. 5. A significant correlation was found between the advance of periodontal disease and gingival bleeding on tooth brushing (chi 2-test: alpha less than 0.001). Similarly, a correlation was found between the advance of periodontal disease and gingival swelling (chi 2-test: alpha less than 0.001). 6. A significant correlation was found (chi 2-test: alpha less than 0.001) between the advance of periodontal disease and aggravation of condition of dental plaque, calculus, dental caries and malalignment.