The second method is to move upper and lower teeth by archwire lingually and bucally.

二是利用上下颌的正畸弓丝移动上下牙齿向颊、舌方向；

youdao

Puffer fish of the upper and lower teeth are connected together, as if a sharp blade .

河豚的上下颌的牙齿都是连接在一起的，好像一块锋利的刀片。

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

The exact cause of teeth grinding is not known, but the most likely culprits are things like stress, sleep disorders, crooked or missing teeth and having an abnormal bite, where the upper and lower teeth do not come together normally (known as malocclusion).

CNN: What can I do about teeth grinding?