The purpose of this study was to assess the prevalence and distribution of dental caries and periodontal disease in Taiwanese high school students aged 15–18. A total of 1069 Taiwanese students participated in a cross-sectional nationwide dental survey. By using a stratified method based on the National Health Insurance administration regions, 24 high schools were randomly sampled in different areas of Taiwan. The participants were examined with dental mirrors and community periodontal index (CPI) probes without using radiographs, to measure dental caries and periodontal status. Demographic information and other relevant risk indicators for the two diseases were gathered via a self-report questionnaire. In this study population, the weighted mean decayed, missing and filled teeth (DMFT) scores for ages 15 to 18 were 5.2, 6.1, 6.1, and 5.7. The weighted mean decayed, missing and filled surfaces (DMFS) scores were 9.0, 12.0, 13.1, and 11.2 at ages 15, 16, 17, and 18, respectively. Additionally, 88.2% of the subjects had periodontal disease, with calculus as the most prevalent type. Moreover, 5.2% of these students showed loss of attachment. There was no significant association between dental caries and periodontal disease. Dental caries and periodontal disease were prevalent among Taiwanese high school students in this national dental survey.

There are few published studies that report the prevalence of intraoral anomalies for young children. The purpose of this study was to investigate the prevalence and distribution of several congenital oral and paraoral anomalies in Taiwanese children under age six. Twenty‐five cities and townships were randomly sampled in different areas of Taiwan using the stratified method. These cities and townships represent cross‐sectional samples of geographic locations and socioeconomic levels. A total of 981 Taiwanese children under age six were examined with dental mirrors and explorers as part of the national dental survey. The results of this survey indicated an 11.31% prevalence of geographic tongue. This number is higher than that reported in studies previously performed in different countries. The occurrence of double teeth in primary dentition was found to be 2.14%. Ankyloglossia had a frequency of 1.22%, and primary talon cusp a frequency of 0.61%. Seven (0.71%) children exhibited fissured tongues. Thirteen (1.33%) cases of hypodontia were found. These values were different from those reported in several other countries, which may be attributed to differences in the ethnic and racial composition of the population studied.