If you open your mouth and there is a clickinging or poppin where your jaw hinges open. More than likely it is TMJ. There is treatment for it. You can do some mouth stretches, there is medicine, and mouth guards. It just depends on the severity. I used to notice it when I'd try to take a bite of a big cheeseburger. 🙂 My jaw would pop and sometimes be uncomfortable. If it gets bad definitely call your Dr. For help. For me, it was just something that started to happen one day. I did some stretches which really helped. For me it just subsided. It didn't totally go away, but it isn't really bothering me anymore.