How does TMJ cause headaches and other facial pain?

Misalignment of the jaw and disorder in the joints causes the symptoms of TMD in two ways:

• First, around the temporomandibular (TMJ) joint itself are nerves and blood vessels that lead to other areas of the head and neck. When the TMJs and jaw are misaligned, it creates excessive pressure on these nerves and blood vessels and pain is perceived as coming from where they eventually lead to (i.e. head, neck, shoulder, etc…) This is what confuses most of those that suffer because the problem isn't in the actual area of the pain. This is the same mechanism by which a problem in the joints of your spine can lead to numbness or pain in other regions of the body such as your hands or feet.
  
  
• Secondly, TMD can cause these symptoms by disrupting the balance of the muscles associated with the jaw and skull. The jaw has a precise optimal position for creating balance and harmony in the muscles that attach to it. If this balance is disrupted, as is the case in TMD, these muscles become irritated and overly active eventually leading to muscle fatigue and spasms. Muscles that are excessively fatigued and spasming can be very painful and lead to the cascade of physiological problems and symptoms discussed earlier.

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  What is TMJ Dysfunction (TMD)?
  
  The term “TMJ Dysfunction” describes an imbalance in the relationship of the jaw to the skull. This imbalance causes two problems for those that suffer from it. First, it leads to improper alignment of the Temporomandibular Joints (TMJs) which connect these two bones. Secondly, it creates disharmony in the muscles which attach to the bones. The cascade of painful symptoms that arise solely from these two problems is staggering to most people. Although most times the pain is not actually in the TMJs themselves, you can feel your own by pressing your fingers just in front of your ears and opening and closing your mouth.