I had conquered my jaw and lip biting years ago with orthodontia and full mouth braces in my early 50's. Misaligned teeth are said to be the cause of jaw and lip biting.
But after AN surgery I learned all over again about the importance of knowing how your tongue, lips, and jaws are moving when you eat. I had a bad time in the first three our four months post op with lip biting. I had minimal visble facial issues, but the numbness on my tongue was a real nuisance to deal with. I had the greatest difficulty with bread and rolls. In addition to being hard to chew up and biting my lip, I suffered from dry mouth and needed extra water to get dry foods down. My dentist gave me some tips.
So, if you are having any of these problems try cutting or tearing larger foods, and chase with liquids. For the pesky lip bite pain I rinsed with warm salt water. Alcohol and peroxide based mouth washes aggravated my taste buds and numb tongue. Use a very soft tooth brush, often. This too will pass.