Seeing a tmj specialist is advised
im on that same scene, apart from lock jaw and ear problem, i get this light stiff neck when i turn my head toward right. it's not that bad though but still the little abnormal pain would be around.
It sounds like an issue w/ TMJ. Make an appointment with your dentist. More than likely you will need to be fitted w/ a TMJ appliance, or a bite guard of some sort.
I have a pain in my jaw as well. Sometimes i can barely open my mouth in morning to brush my teeth. It sometimes locks and sometimes causes ear pain. My dentist has referred me to a jaw specialist in London. Still waiting for the letter.