口套

例句：

1. 1. He wore a mouth guard to protect his injured tooth.
   他戴了一个牙套来保护他的受伤牙齿。
2. 2. The dentist advised him to wear a mouth guard before the procedure.
   牙医建议他在手术前戴上牙套。
3. 3. The athlete used a mouth guard during the race to prevent injury.
   运动员在比赛中使用了口套以防止受伤。