RÉSUMÉ
BACKGROUND: It is important to evaluate preoperative anxiety and prepare sedation when performing dental surgery under local anesthesia. Spielberger's State-Trait Anxiety Inventory (STAI) is useful for predicting preoperative anxiety. State anxiety is defined as a subjective feeling of nervousness. Reduction in the number of the state anxiety items (questions) will be clinically important in allowing us to predict anxiety more easily. METHODS: We analyzed the STAI responses from 1,252 patients who visited our institution to undergo dental surgery under local anesthesia. Multiple linear regression analysis was conducted for 9 groups comprising anxiety level determinations using the STAI; we then developed a coefficient of determination and a regression formula. We searched for a group satisfying the largest number of requirements for regression expression while setting any necessary conditions for accurately predicting anxiety before dental surgery under local anesthesia. RESULTS: The regression expression from the group determined as normal for preoperative state anxiety was deemed the most suitable for predicting preoperative anxiety. CONCLUSIONS: It was possible to reduce the number of items in the STAI by focusing on “Preoperative anxiety before dental surgery.”