Temporomandibular Joint (TMJ) Disorder: This is the most common cause of jaw pain, often related to muscle tension, jaw alignment issues, or trauma to the jaw area. Symptoms can include pain when chewing, clicking of the jaw, and limited range of motion.

Dental Problems: Issues such as cavities, abscesses, or gum disease can cause significant jaw pain. The pain may be localized to a specific tooth or more generalized.
Sinusitis: Inflammation of the sinuses can cause pain that radiates to the jaw, especially in the upper teeth and jaw area.
Tension Headache: Tension headaches can cause pain that spreads to the jaw, often due to muscle tension.
Bruxism: Grinding or clenching of the teeth can lead to jaw pain and discomfort, especially noticeable in the morning.

Myocardial Infarction (Heart Attack): Though less common, jaw pain can be a symptom of a heart attack, especially in women. It's crucial to consider this diagnosis, especially if accompanied by other symptoms like chest pain or shortness of breath.
Trigeminal Neuralgia: A chronic pain condition that affects the trigeminal nerve, which can cause intense shock-like or stabbing pain in parts of the face, including the jaw.
Osteonecrosis of the Jaw: A condition often associated with bisphosphonate use, characterized by the death of jawbone tissue, leading to pain and exposed bone.

Giant Cell Arteritis: An inflammation of the arteries that can cause jaw pain, especially when chewing, along with other symptoms like headache and visual disturbances.
Sarcoma or Other Jaw Tumors: Though rare, tumors in the jaw can cause pain and should be considered in the differential diagnosis, especially if there's an unexplained mass or persistent pain.
Eagle Syndrome: A condition caused by an elongated styloid process or calcified stylohyoid ligament, leading to sharp, stabbing pain in the jaw and face.