I have a large white circle on the side of the back part of my tongue, and just had my wisdom teeth removed, what could it be from?

Evaluation Needed: The cause of a white circle on the side of your tongue could be many things. It could be your tongue rubbing against something like your bone or fragment or partial or restoration. Differential diagnosis could also include thrush but oral cancer is also another diagnosis to rule out. It's important that you get this looked at to have a definitive diagnosis.

Geographic tongue: White circles are quite common on tongues and is called "geographic tongue" because it can make your tongue look like a map. See your dentist who can confirm this or further evaluate it.

Variant of normal : Dr. Jarvis is right. Most likely geographic tongue. Could also be a chemical burn (cinnamon, aspirin, hot pepper) , a viral/bacterial infection (std like syphillis) or inflammatory lesion like an aphthous ulcer (canker sore). See your dentist for diagnosis.