My guess is teeth also. Like Sauzo said, feel around and press down on the bumps gently. If you feel anything pointy-ish or hard then you've probably found teeth. Fortunately, the times I've been tagged I was able to just keep still and take the bite. Unfotunately, human nature tells your body to pull away, which actually makes the injury worse for the snake and the keeper. Anyway, my guess is teeth, and from what I've read they will often work themselves out.
