The wisdom on the top never came out

So there was no extraction.

You said: 如果上麵的已經拔了，下麵這個沒用，但很難清理到，容易出蛀牙，我會把它拔了。

What do you mean "下麵這個沒用，..."  ?

I really appreciate your response, as I am so nervous about this wisdom tooth.  If I had an extraction before, I probably would not have been so nervous.