underbite

n.[医]反颌(指下颌或下门齿前突,超出上颌或上门齿)[仿 overbite]

下颌前突（指下颌骨向前突出，导致上下牙齿没有正常的覆盖对咬）

名词

1. She had to get braces to correct her underbite.
她不得不戴牙套来矫正她的下颌前突。
2. People with severe underbite may experience difficulty in biting and chewing food properly.
严重的下颌前突可能导致咬和咀嚼食物困难。