Orofacial pain refers to pain associated with the hard and soft tissues of the head, face and neck. Pain in this region can originate from several sources and there are several categories of orofacial pain disorders:
- Pain of muscle and joint origin (TMDs)
- Pain of nerve origin
- Pain of tooth origin and other intraoral disorders
- Cervical Spine Disorders
Pain of Nerve Origin
Pain of nerve origin is called neuropathic pain. Neuropathic pain disorders, specifically conditions affecting the head and neck, are a set of conditions which result either from illness, disorder or an injury to the nervous system. Injury to the nerves of the central or peripheral nervous system can cause pain signals to be sent to the brain, which can result in a chronic pain condition referred to as neuropathic pain.
Neuropathic pain may manifest itself as continuous or episodic. Neuropathic orofacial pain refers to those symptoms that primarily affect a patient’s mouth and facial area.
Episodic neuropathic pain
This type of pain is described as quick, sharp, shooting, shock-like, debilitating pain and sometimes burning sensation. The pain follows the distribution of the affected nerve. One of the most diagnosed and well known episodic neuropathic pains is trigeminal neuralgia (TN). There are other episodic neuropathic conditions that are much less common such as: glossopharyngeal neuralgia, geniculate neuralgia, superior laryngeal neuralgia, nervous intermedius neuralgia and occipital neuralgia.
Trigeminal Neuralgia is characterized by sudden, usually unilateral, severe electrical like stabbing episodes of pain, followed by total remission of symptoms. Attacks usually last from a fraction of a second to several minutes. Causes of TN include: nerve compression, tumors, multiple sclerosis and physical injury. TN is commonly brought on by non-noxious stimuli (i.e., washing or touching the face, wind on the face, talking, brushing teeth, etc.) and can also occur spontaneously.
Continuous neuropathic pain
This type of pain is described most often as a dull, persistent and burning type of pain. The pain is usually ongoing and unremitting, yet the intensity can show patterns of fluctuation from mild to severe. One of the most common and well known continuous forms of neuropathic pain is PPSN (painful peripheral sensory neuropathy), formerly known as atypical odontalgia. It is also known as phantom tooth pain and mimics the sensation of a toothache without an identifiable pain source. Damage to the nerves in the jaw may result from dental procedures including tooth extraction, local anesthetic injections and improper implant placement, leading to the onset of a chronic pain condition. Suspected causes are: psychological, neurovascular, or interruption or destruction (i.e., being cut or compressed) of the nerves. Other continuous neuropathic conditions are: Bell’s palsy, Herpes zoster, Postherpetic neuralgia, Burning mouth syndrome and Complex regional pain syndrome.
Diagnosis of neuropathic pain
The most important diagnostic step is for a doctor to take a complete medical history and description of the symptoms and perform a thorough physical exam. In addition, doctor may order any necessary tests or scans (i.e., magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), dental x-rays, or nerve blocks. Some neuralgias are often diagnosed by eliminating other serious medical problems, and ruling out other possible causes.
Treatment of neuropathic pain
A number of treatments have been found to be effective in managing neuropathies. A combination of treatments and therapies is often found most effective in managing orofacial neuropathic pain symptoms, such as: patient education, behavior modification, medication management and sometimes surgical procedures.
Headaches can be divided into two groups: primary and secondary headaches. Each disorder may have effective treatments that differ from the others, thus the management is significantly influenced by a correct diagnosis. The single most important thing is to identify the symptoms correctly, including the quality, intensity, frequency, and accompanying signs of the headache complaint. This is most effectively identified by the history given by the patient during the initial visit, thus it is crucial that these things are clearly defined during that appointment.
The questions you may be asked:
- Where is the headache located?
- Describe the type of pain?
- What is the severity of the pain on a scale of 1 to 10?
- When did you first experience this type of headache?
- How long does the pain last?
- How often do headaches occur?
- Have you noticed a trigger, such as situations, food, activities or medicines preempting the headache?
- What symptoms occur along with the headache, such as sensitivity to light, sounds, or smells?
- Are the headaches accompanied with nausea, or vomiting?
- Does anyone else in your family have headaches?
- Do you experience headaches that feel differently, or do you have more than one type of headaches?
Due to the interaction and convergence that occurs in the head and neck nervous system the pain
patterns may overlap with other entities such as TMD, as well as present concurrently with each other. Treatment is directed at any and all conditions diagnosed thus multi-disciplinary approaches are the most effective involving orofacial pain specialists, neurologists, primary care doctors, pain management doctors, physical therapists, and other medical specialties as required.
Primary headache disorders
Primary headaches are entities unto themselves and are diagnosed by their symptoms. There are four primary types of headaches: migraines, tension-type headaches, cluster headaches, and “other” primary headaches. The two most common primary headache disorders are migraine and tension-type headache.
Migraine is a complex neurobiological disorder that has been recognized since ancient times. The exact underlying cause of migraines is unknown. Research indicates that genetic factors play a role in who develops migraine headaches. People who suffer from migraine have different neurobiological response to various stimuli that act as triggers. Commonly reported triggers are light, sounds, smells, stress, hunger, dehydration, lack of sleep and fatigue. Hormone levels are also a factor, and migraine headaches are three times more common among women than men.
Migraine headache is a neurovascular disorder of the brain, involving responses across several aspects that include blood vessels, nerves, and soft tissues in the head and neck. This headache can occur from once in a lifetime to daily. The main characteristics of migraine headache are: duration of 4-72 hours, severe pain which is usually throbbing and often unilateral, severe in intensity, and associated with nausea, sensitivity to light, sound, and exacerbation with head movement. However many patients may not suffer from all these entities, which can sometimes lead to a delay in a proper diagnosis. It does seem to occur often in patients with TMDs (temporaomandibular disorders), and treatment of TMD together with migraine headache treatment shows reduced frequency of migraine headaches.
Tension-type headache is the most common headache pain. It is most commonly bilateral, feels like tightening and pressing sensation and it is mild to moderate in intensity. It is non-pulsating, not associated with nausea and not aggravated by head or neck movement. There is an episodic form that occurs infrequently, and a chronic form that occurs more frequently ( at least every other day).
It is usually located in temples, forehead, behind eyes and back of the neck. It does seem to occur often in patients with TMDs (temporomandibular disorders), and treatment of TMD has demonstrated improvement in pain levels and reduced frequency of headaches for patients with tension-type headaches.
Secondary headache disorders
Secondary headaches are due to an underlying condition and are classified by their causes. In diagnosing a headache patient, a physical or neurological examination need to be conducted to find signs of an underlying cause, such as:
- Trouble with balance
- Vision abnormalities
- High blood pressure
- Fatigue or muscle weakness
- Injuries or head trauma
- Vascular malformation
- Intracranial hemorrhage
Intraoral Pain Disorders
Intraoral (inside the mouth) pain potentially has many sources. The most common source of intraoral pain is from teeth. Some other sources for intraoral pain include bone around the teeth, mucogingival tissues, salivary glands, and tongue.
The pain coming from teeth is called pulpal pain. It comes from the nerves of the teeth. The most likely causes are large cavities, fractured teeth and infected teeth.
Periodontal pain is the pain coming from the periodontal ligament (ligament that binds the tooth to the bone) or alveolar bone (bone in which the tooth root is attached).
Mucogingival pain is the pain coming from gingiva (gums) around the teeth and from the tissues lining the inside of the cheeks, palate, floor of the mouth and under the tongue. Pain to these areas may be a result of bacterial, viral or fungal infection, trauma to the tissues of tumors.
The examples are: bacterial infection of the gingiva such as aphthous ulceration (canker sores), viral infections such as herpes simplex viral vesicles in the mouth, fungal infections such as candidiasis or oral thrush. The most common intraoral cancer is squamous cell carcinoma.
Cervical Spine Disorders
Cervical spine disorders are associated with neck pain and include: neck pain (Cervicalgia) , osteoarthritis of the neck (Cervical Osteoarthritis), persistent contractions of the certain neck muscles (Cervical Dystonia) and Headaches related to problems or dysfunction of the cervical spine (Cervicogenic headaches).