Tic Evaluation The patients or their parents completed the form of Tic Symptom Self-Report (TSSR)1 based on the disease state of TS in a week before each hospital visit. The TSSR, which has the advantage of evaluating the time course of the disease, consists of motor and phonic tic scores (from 0 to 60, with higher scores indicating more severe disease states). We compared the scores before and while wearing the splint and calculated the reduction rates (%) of tic scores (Fig. 1, Supporting Fig. 2, Supporting Table 3). To make more objective assessment of splint-induced changes in TS-related tics, we counted the actual number of motor tics for 3 minutes before and during splint application in 8 patients (No. 9-13, 15, 19, and 22) whose videos were stored in our hospital (Supporting Fig. 1). The data were statistically analyzed using the Wilcoxon signed-rank test or Spearman's rank correlation coefficient.