我需要戴牙套来矫正牙齿。

I need to wear ___braces to straighten my teeth.

矫正器用来移动牙齿，保持器用来固定牙齿。

___Braces move the teeth, and a ___retainer keeps them in place.

他的裤子有点松，所以他拉紧了背带。

His pants were a bit loose, so he tightened his ___braces.

医生建议他戴牙套来矫正牙齿。

The dentist suggested he wear ___braces to straighten his teeth.