I have jaw pain / tmj, but have tightness and sometimes pain that radiates to my cheeks and chin. why does it radiate to these other areas?

Radiating tmj pain: pain associated with TMJ often is associated with the muscles and ligaments that connect to the joint this may lead to pain or soreness in the cheeks, temple, neck or ear

Referred pain: TMJ disorder is a dysfunction that causes pain throughout the face. Trigger points can refer pain to other areas, causing a headache, neck pain, earache, or even toothache.

Referred Pain: The TMj often involves surrounding muscles, ligaments and nerves and can have widespread associated symptoms.