One study discovered that 43% of people with TMJ also have problems sleeping. Studies are still ongoing to fully understand the connection between these two disorders. The relationship could be that, when a person stops breathing, the natural physiological response is to push the lower jaw forward to open the airway. The continual repetition of this movement during sleep places stress on the temporomandibular joints, creating inflammation and pain. Another theory is that TMJ contributes to obstructive sleep apnea because the joint and muscular structure that controls the lower mandible is out of alignment and therefore partly responsible for airway obstruction.