Me and my sister in law were talking about dreams and a dream came up that we both have had and still have every now and then... In my dream I'm not really sure what I'm doing but I bite down and all my teeth shatter... like completely break... all of them. I usual wake up checking if my teeth are still there. I know quite a few people have this dream but the meanings that I've read give a variety of meanings. I would really just like to know a specific answer on why this dream occurs.

Have a look at this thread, dating from some 8 months ago:

https://www.askmehelpdesk.com/mental-emotional-health/dream-interpretation-teeth-49047.html

I heard you have that dream when someone you know is going to pass away or get sick. But that's just what uve been told