Orofacial Pain

Orofacial pain is a term used by specialists to describe a conglomeration of conditions associated with discomfort in the mouth, jaws or face. Patients are often surprised to learn about the diverse causes of orofacial pain. The most common pain in the mouth is dental pain. The most common pain in the face is muscle pain. When an obvious cause is not present, pains are generally classified as: neuropathic pains (related to nerves, such as a neuralgia), neurovascular pains (related to nerves and blood vessels, such as a migraine) and musculoskeletal pains (related to muscle and joints, such as TMJ and neck problems). The following information summarizes these types of disorders, their origins and symptoms.

NEUROPATHIC PAIN

What is neuropathic pain?

Neuropathic pain refers to pains originating in the central (brain and spinal cord) or peripheral (nerve fibers) nervous system. Most of us are familiar with an injured body part sending signals along a healthy nerve to tell us that the body part hurts. In neuropathic pain, the problem lies within the nerve itself, telling us that a healthy body part hurts. Therefore, it can be very frustrating for a patient experiencing severe pain while everything appears to be healthy. Neuropathic pains are often accompanied by complaints of burning, stinging or shocking sensations, and sometimes mechanical complaints, such as intense squeezing or pulling.

What is trigeminal neuralgia?

Neuralgia refers to pain along the distribution of a nerve. Trigeminal neuralgia is a unique type of nerve pain with specific characteristics. The facial pain is characterized by spontaneous, brief episodes of electric shock-like pains limited to the distribution of the involved branch of the nerve. Pain may be triggered by light touch in a " trigger zone" usually along the same nerve distribution as the pain. It may also occur spontaneously. The paroxysms (volleys) of pain usually last from seconds to minutes.

The trigeminal nerve is the major sensory nerve to the face and head. It has three branches and the pain may be in one or more branches of the nerve. Most often the pain is on one side of the face only. The International Headache Society's diagnostic criteria are listed below.

IHS Diagnostic Criteria for Trigeminal Neuralgia

A. At least three attacks of unilateral facial pain fulfilling criteria B and C
B. Occurring in one or more divisions of the trigeminal nerve, with no radiation beyond the trigeminal distribution
C. Pain has at least three of the following four characteristics:

  1. recurring in paroxysmal attacks lasting from a fraction of a second to 2 minutes
  2. severe intensity
  3. electric shock-like, shooting, stabbing or sharp in quality
  4. precipitated by innocuous stimuli to the affected side of the face

D. No clinically evident neurological deficit
E. Not better accounted for by another ICHD-3 diagnosis.

Are there other types of neualgias?

Many neuralgias exist and may be named for the involved nerve such as glossopharyngeal neuralgia (one of the sensory nerves of the tongue) or occipital neuralgia (a sensory nerve at the base of the skull). Very important to note is that two forms of neuralgias exist: paroxysmal and continuous. Paroxysmal neuralgias are intense, often electric, pains that come in volleys. An example of a paroxysmal neuralgia is trigeminal neuralgia, which is described above.

Continuous neuralgias never subside and are often described as constant burning and aching, sometimes with episodic shooting pains. An example of a continuous neuralgia may follow shingles and is called post herpetic neuralgia. Continuous neuralgias may be extremely difficult to diagnose and treat, as many causes can be responsible for the nerve dysfunction. In contrast to paroxysmal neuralgias, continuous neuralgias in the head and face may affect both sides of the head and face. Characteristic of continuous neuralgias is that the site of pain often involves a larger area than the distribution of the involved nerve. Frequently patients complain of extreme sensitivity to touch or temperature, and their pain may be much worse than one would expect from an obvious injury.

I have a neuralgia that did not respond to medication.

Sometimes different medications must be evaluated. Continuous neuralgias may respond to different medications than those prescribed for paroxysmal neuralgias. Sometimes a procedure is needed to treat the problem and special pain medications may be the best approach.

What is a continuous neuralgia?

Instead of coming in volleys, this type of neuropathic pain is constant and is often accompanied by symptoms of burning, pressure, squeezing and/or pulling. In addition, continuous neuralgias may not follow the path of a nerve and the pain may cross the midline to the other side.

NEUROVASCULAR PAINS

What are primary headaches?

Primary headaches are headaches that have no other known cause for the pain such as fever, trauma or tumor. 

What is a migraine?

Migraine is a specific type of headache often described as a "sick headache" because it is accompanied by nausea and sometimes vomiting as well as the need to lie down. The headaches usually last from 4 to 72 hours. Many people also report sensitivity to both light and sound with a migraine headache. Some patients (approximately 15%) experience an aura before the headache that often presents as flashing or moving lights. Auras last 20-30 minutes and may also present with frightening symptoms such as numbness or even speech problems.

IHS Diagnostic criteria (migraine without aura)

A. At least five attacks fulfilling criteria B–D
B. Headache attacks lasting 4-72 hours (untreated or unsuccessfully treated)
C. Headache has at least two of the following four characteristics:

  1. unilateral location
  2. pulsating quality
  3. moderate or severe pain intensity
  4. aggravation by or causing avoidance of routine physical activity (e.g. walking or climbing stairs)

D. During headache at least one of the following:

  1. nausea and/or vomiting
  2. photophobia and phonophobia

E. Not better accounted for by another ICHD-3 diagnosis.

IHS Diagnostic criteria (migraine with aura)

A.  At least two attacks fulfilling criteria B and C
B. One or more of the following fully reversible aura symptoms:

  1. visual
  2. sensory
  3. speech and/or language
  4. motor
  5. brainstem
  6. retinal

C. At least two of the following four characteristics:

  1. at least one aura symptom spreads gradually over 5 minutes, and/or two or more symptoms occur in succession
  2. each individual aura symptom lasts 5-60 minutes
  3. at least one aura symptom is unilateral
  4. the aura is accompanied, or followed within 60 minutes, by headache not better accounted for by another ICHD-3 diagnosis.

Are there other types of headaches?

Many types of headaches exist and vary according to the cause, such as illness, trauma or tumor. Aside from migraines, there are two other forms of primary headaches (no other cause for the headache): cluster headache and tension-type (TTH) headache.

What is a cluster headache?

A cluster headache is a neurovascular headache like migraine but has very different characteristics. Cluster headaches are an example of the trigeminal (name of the sensory nerve of the face) autonomic (accompanied by symptoms from the involuntary nervous system) cephalalgia (headache). While cluster headaches generally affect men and have attacks lasting 15-180 minutes, other similar trigeminal autonomic cephalalgias may primarily affect women. The forms that affect women are generally more frequent (up to 30 attacks in a day) and of shorter duration (2-15 minutes), and often are referred to as indomethacin-responsive headaches because the medication indomethacin is very effective. A cluster headache is a one-sided pain so intense that sufferers often cry and pace because the pain is too severe to lie still. This behavior is very different from that of migraine patients where the patient wants to lie still. Cluster headaches usually occur in closely packed groups (clusters) with periods of remission between clusters. The autonomic symptoms that accompany a cluster headache may include unilateral red eye, smaller pupil of the eye, nasal stuffiness and/or clear drainage, drooping eyelid and even sweating on one side of the forehead. During cluster episodes, alcohol should be totally avoided as it is a major trigger. Nausea and vomiting are not associated symptoms. Cluster headache may be episodic or chronic.

What Is tension-type Headache (TTH) and is it psychological?

Tension-type headache is the most common headache, affecting up to 70% of the population. Although some TTH headaches may be intense, they are usually mild to moderate and lack migraine characteristics such as throbbing, vomiting and sensitivity to both light and sound. TTH is often described as a hatband or squeezing and pressing pain. The name tension-type does not mean that emotional stress is the cause but describes the type of headache one would expect from muscle tension. In fact, one form of TTH has no muscle tenderness at all on examination. If a person is prone to headaches, stress may be a trigger and increase the frequency.

What is a rebound or medication overuse headache?

When certain prescription and over-the-counter medications are used too frequently, headaches may worsen and increase in frequency requiring increased dosing of medication. Eventually these patients have a constant headache unless increased doses of medication are used. The headaches are often described as a dull, moderate pain – without medication – that worsens within 4-6 hours if the patient tries to wean off the medication. Even caffeine can cause caffeine withdrawal in certain patients. We must remember that caffeine is also present in soft drinks, chocolate and many over-the-counter pills.

MUSCULOSKELETAL PAINS

Are TMJ and TMD the same?

These terms are often used interchangeably but are different. TMD stands for Temporomandibular Disorders which includes all disorders of the jaw muscle, jaw joint or both. The cause of these disorders may be due to jaw-joint disease, inflammation, structural alterations, muscle disorders, infection, developmental problems or even a fracture of the jaw bone. The term TMJ refers to the Temporomandibular Joint. This term is often incorrectly used to describe disorders of the temporomandibular joint and associated structures. The TMJ is the joint between the lower jaw, or mandible, and the temporal bone of the skull.

Are TMDs treated with an intra-oral appliance?

Studies have shown that certain types of TMD may improve with the use of an intraoral appliance. These devices are thought to decrease the load or force placed on the jaw joints and muscles when worn. Although many different forms of appliances are available with claims of success, most will have similar therapeutic values. An accurate diagnosis along with an appropriate and multi-disciplined approach to therapy is the key for success of any treatment approach. No two individuals are the same so treatment should be individualized for each patient.

I have had several TMJ surgeries and my pain is worse. Should I consider another surgery?

Surgery should only be considered after more conservative therapies have failed to resolve the primary problem. Surgery should never be considered as the primary means of resolving pain. Surgery is considered when a specific diagnosis is known that cannot be adequately treated without surgery. For example, a tumor in the joint would require surgery. When multiple surgeries have been performed without benefit or with the symptoms increasing, a re-evaluation is critical. Patients may have had more than one reason for their pain or the diagnosis may have changed. Sometimes, because of poorly understood reasons, neuropathic pain is the cause, and this problem often worsens with additional surgery. In this situation, changes in the peripheral or central nerves are continuously sending signals that pain is located in a healthy area (see neuralgia).

What Are myofascial pain and fibromyalgia and are they the same?

Although myofascial pain and fibromyalgia share some common characteristics, these two musculoskeletal conditions are different. The following comparison may be helpful in understanding that either or both conditions may be present:

  • Myofascial pain is a regional (one or two areas) muscle disorder. Fibromyalgia is a generalized condition, characterized by aching especially in the weight-bearing muscles.
  • Myofascial pain is characterized by trigger points, which are localized areas that when pressed will cause pain to be felt in a different location. Fibromyalgia also is accompanied by localized areas of reproducible pain upon pressure that are called tender points, but these points usually do not cause referred pain when pressed.
  • Myofascial pain occurs equally in men and women. Fibromyalgia occurs primarily in women.
  • Myofascial pain usually begins with a specific muscle problem such as a strain, overuse or trauma. Fibromyalgia begins insidiously and develops as a generalized pain.
  • Patients with myofascial pain often complain of one-sided pain whereas fibromyalgia patients have symmetrical pain on both sides of their bodies.
  • Pain from myofascial pain can be traced to specific trigger points whereas the pain of fibromyalgia may have no identifiable origin.
  • Treatment for myofascial pain generally is specific local therapy. Treatment for fibromyalgia requires a more comprehensive approach that may include nutritional therapy, sleep evaluation and therapy, physical therapy and more.
  • Myofascial pain is usually diagnosed by physical findings.
  • While there are specific diagnostic measures for fibromyalgia, it is most often diagnosed by a lack of any obvious physical findings such as tissue injury or disease