Orofacial pain refers to pain or discomfort that is experienced in the mouth or face. Areas of the face include the eyes, nose, forehead, cheeks and chin. Some pain in these areas, however, could also be caused by dental pain, which originates in the teeth or jaws.

Orofacial pain may be acute (short–term) or chronic (lasting longer than three months). It may occur in different parts of the face such as teeth, periodontal tissues, salivary glands, paranasal sinuses, eyes, nose, ears, temporomandibular joints of the jaw (TMJ disorder), bones, muscles, nerves or blood vessels.

Orofacial pain may become particularly problematic for individuals because it affects a person’s ability to meet basic human needs such as eating and drinking, swallowing, smiling and communicating.

Not only can orofacial pain be a symptom of certain disorders, but it can also be an indication of an underlying disease elsewhere in the body.

Some types of orofacial pain are related to problems with nerves.  Cranial nerves are 12 pairs of nerves that emerge from the brainstem instead of the spinal cord that, among other roles, provide sensation to the mouth and face, and the cervical plexus nerves are nerves that supply sensation to the back of the head and some neck muscles.

The cranial nerves are known by name and Roman numeral. The following is a list of these nerves, along with their primary functions:

• I. Olfactory - smell
  
  
• II. Optic - vision
  
  
• III. Oculomotor – most eye movements
  
  
• IV. Trochlear – some eye movement
  
  
• V. Trigeminal – facial sensation
  
  
• VI. Abducens – some eye movement
  
  
• VII. Facial – facial expression and some sense of taste
  
  
• VIII. Acoustic (also known as the auditory or vestibulocochlear nerve) – hearing and balance
  
  
• IX. Glossopharyngeal – pharyngeal muscles and some sense of taste
  
  
• X. Vagus – parasympathetic sensation to internal organs
  
  
• XI. Spinal accessory – neck muscles
  
  
• XII. Hypoglossal – most movements of the tongue

The facial nerve is a major motor nerve that controls muscles of facial expression and supplies sensation to the scalp.  Some taste sensations and secretions of the mouth are also controlled by it.  Another major cranial nerve is the trigeminal nerve, which provides sensation to most of the face and head via three main branches. Because there is some interface between these nerves, certain types of dental pain can result in referred pain throughout the face and side of the head.  If these nerves are irritated or there is a loss of blood supply to any of the nerves, orofacial pain may result.