I think this might just mean that you have your jaw in a funny position while you sleep and it caused you to feel that way in your dream. For example, maybe while you were sleeping you had your mouth open and subconsciously wanted to close it, so in your dream you felt like something gummy was blocking your mouth.
Physical positions during sleep sometimes get acted out in dreams.
For example, I once had a dream that I had horrible back pain and couldn't turn my back around to stop the pain because I felt stuck. In reality, I couldn't wake up to adjust myself in a way that would stop my back from hurting, I must have been in a strange sleeping position for that dream to occur. It's not the first time it's happened, so I know this is the case.