Mouth almoat locks wwn i start to tey to say something

Mouth almoat locks wwn i start to tey to say something I (M20) have had this problem for years where ill go to say something but ill open my mouth and it kind of locks in place when its open and i cant get anything out and ive noticed i dont breath or i quit breathing on accident for a second when my mouth gets locked it usualy only lasts a couple of seconds but i was wondering if anyone has had this problem and i was wondering if anyone has found a way to stop this from happening. I would appriciate any advice