Periodontitis was associated with mesial concavity of the maxillary first premolar: a cross-sectional study.

The association between the anatomical features of teeth and the pathogenesis of periodontitis is well-documented. This study aimed to evaluate the influence of the mesial concavity of the maxillary first premolar on periodontal clinical indices and alveolar bone resorption rates. Employing a cross-sectional design, in 226 patients with periodontitis, we used cone beam computed tomography(CBCT) to examine the mesial concavity and alveolar bone resorption of 343 maxillary first premolar. Periodontal clinical indicators recorded by periodontal probing in the mesial of the maxillary first premolar in patients with periodontitis. Our findings indicate that the presence of mesial concavity at the cemento-enamel junction of the maxillary first premolar was not significantly influenced by either tooth position or patient sex (p > 0.05). Nonetheless, the mesial concavity at the cemento-enamel junction of the maxillary first premolar was found to exacerbate alveolar bone resorption and the inflammatory condition (p < 0.05). We infer that the mesial concavity at the cemento-enamel junction of the maxillary first premolar may contribute to localized alveolar bone loss and accelerate the progression of periodontal disease.

Impact of an Information Leaflet on Knowledge of Hepatocellular Carcinoma and Hepatitis B among Chinese Youth.

BACKGROUND: To assess the effect of an information leaflet on the level of Chinese youth's knowledge about hepatitis B and hepatocellular carcinoma (HCC), the most common type of primary liver cancer (PLC). MATERIALS AND METHODS: A total of 500 students, from two universities in the Chaoshan area of China, were randomly divided into an intervention group of 280 participants and a control group of 220. Baseline knowledge of HCC and hepatitis B was evaluated by questionnaire interview. Subsequently, only the intervention group was given an information leaflet of HCC and hepatitis B. Three months later, the two groups were contacted for a second interview. Changes in knowledge from baseline of HCC and hepatitis B were compared between the two groups. RESULTS: There was no statistically significant difference in mean PRE-questionnaire scores between the intervention and control groups. However, the mean POST-questionnaire score was significantly higher in the intervention group after the intervention. The leaflet had the greatest effect on the participants' questionnaire score, and raised their level of knowledge about HCC and hepatitis B. CONCLUSIONS: The information leaflet intervention is significantly effective in improving the knowledge of HCC and hepatitis B among the youth.