Last factor could be the night grinding habit of a person that tends to wears off the joints.
Here are the options of treatment or alleviation of TMJ disorder.
Temporary relief of the pain can be done by hot compress on the sides of the face where the TMJ lies.
The most popular treatment is the occlusal splint where the dentist take a measurement of your teeth
and get the proper relationship of the upper and lower jaw (centric jaw relation).
This is the most effective treatment so far.
The ultimate treatment is to get your teeth, jaw and muscles in harmony with each other by getting the teeth and jaw in centric relation.