David got braces for his lower teeth.

大卫帮下面的牙齿装了牙套。

youdao

Please move the brush downwards on the upper teeth and upwards on the lower teeth.

刷上颌时牙刷当背上挪动，刷下颌时牙刷当背下移静。

youdao

Daily before meals to relax the body, lips close, then the upper and lower teeth have quietly tapping rhythm.

每日三餐前坚持全身放松，口唇轻闭，然后上下齿有节律地悄悄叩击。

youdao

When he returns my smile, I see that he has two gold lower teeth, which light up the gloom.

NEWYORKER: Baptizing the Gun

"One of the ways you can tell that is how your upper teeth fit to the lower teeth, " Papay said.

CNN: How gunshot survivor became first to receive face transplant

Claire thought a moment, tapping her pencil against her lower teeth.

NEWYORKER: Max at Sea