Could TMJ cause ear fullness / pressure sensations? If so, is there anything I can do when feeling the pressure to relieve it and confirm tmj? Thanks!

Treat TMJ. If the TMJ is causing the ear symptoms, the best way to get rid of the ear symptoms is to treat the TMJ. Any dentist can be a TMJ expert with the proper training and experience. Most commonly, oral surgeons, prosthodontists, and orofacial pain specialists. Ask your MD, your dentist and your dental society for referrals.
Definitely yes. Can caused by tmj/tmd. Temporo-mandibular disorder is the second most frequent cause of orofacial pain after dental pain. Tmd can be divided into disorders related to the muscles of mastication and those emanating from the tmj. Earache and is a common symptom due to the close location to tmj. Proper diagnosis is the key for the successful treatment. Rec.: orofacial pain practitioner for a consult.