I had braces on my teeth, and my face impacted the steering wheel. It caused my upper right
lip to split.
Scar tissue developed leaving me with what appeared to be a permanent fat lip. About a year and half ago, I had cosmetic surgery to eliminate this. For the first six months, it looked great. You could hardly notice that anything had ever happened to my lip. After the first six months, the scar tissue started to show again, and has developed since then.