Temporomandibular Joint (TMJ) Disorder: This is often the most common cause of jaw pain, especially if the pain is localized to the jaw area, worsens with jaw movement, and is associated with clicking or locking of the jaw. TMJ disorders can result from various factors, including teeth grinding, jaw clenching, and misalignment of the teeth or jaw.

Dental Problems: Issues such as tooth decay, abscesses, or gum disease can cause pain that radiates to the jaw. The pain is usually localized to a specific tooth or area and may be exacerbated by temperature changes, sweet tastes, or pressure.
Sinusitis: Inflammation of the sinuses can cause pain in the face, including the jaw area, especially if the maxillary sinuses are involved. This pain is often accompanied by nasal congestion, headache, and facial pressure.
Tension Headache: Tension headaches can cause pain in the jaw and face, typically described as a band or a squeezing sensation around the forehead, and can be associated with stress or muscle tension.
Bruxism: Grinding or clenching of the teeth, often during sleep, can lead to jaw pain and stiffness, particularly in the morning.

Myocardial Infarction (Heart Attack): Although less common, jaw pain can be a symptom of a heart attack, especially in women. The pain is often described as a dull ache or pressure that may radiate to the arm, neck, or back, and is accompanied by other symptoms such as shortness of breath or nausea.
Trigeminal Neuralgia: A condition characterized by sudden, severe, shock-like pain around the eyes, lips, or nose, due to irritation of the trigeminal nerve. Jaw pain can be a part of the presentation, especially if the mandibular division of the nerve is involved.
Giant Cell Arteritis: An inflammatory condition affecting the blood vessels, which can cause jaw claudication (pain in the jaw when chewing) among other symptoms like headache, visual disturbances, and scalp tenderness.

Osteonecrosis of the Jaw: A condition characterized by the death of jawbone tissue, often associated with long-term use of bisphosphonates or other medications. It can cause severe jaw pain, especially after dental procedures.
Sarcoma or Other Jaw Tumors: Although rare, tumors of the jaw can cause pain, swelling, and changes in the jaw's shape or function.
Eagle Syndrome: A condition where an elongated styloid process or calcified stylohyoid ligament causes pain in the jaw and face, often accompanied by dysphagia or foreign body sensation in the throat.