And removal is called for in cases where fluid collects around a wisdom tooth that is partly or fully below the gum.

VOA: special.2011.08.10

It's providing a means of deciding where the gum has decayed.

提供了决定牙周炎在哪恶化的手段。

耶鲁公开课 - 死亡课程节选

Let's say that you know that a specific chewing gum makes your breath bad.

假设你知道有一种口香糖会让你有不好闻的口气。

I've been 课堂 - SpeakingMax英语口语达人