|The clinician treating orofacial pain patients should inquire about symptoms in other areas of the body to exclude systemic disease as an etiology.|
|On occasion, head and facial pain may be a symptom of a serious underlying disease.|
Although head or facial pain frequently arises from teeth or other masticatory structures, it can originate from any of the tissues or organs in the head and neck as well as from systemic disease. If orofacial pain or headache is associated with a serious or life-threatening illness, timely recognition and referral to a physician are crucial. In cases where the cause of head or facial pain is not readily apparent, nonmasticatory, extracranial, and systemic pain sources should be considered in the differential diagnosis. This chapter briefly summarizes these pain sources based on the current classification format of the International Headache Society (IHS)1 and provides lists of associated disorders and symptoms for easy reference. Because this chapter is merely an overview of extracranial and systemic diseases, treatment guidelines are not provided. For further information, the reader is referred to other chapters in the text or to standard medical references.
Cranial bones (IHS 11.1)
Most lesions that affect the bones of the skull are not painful.2 However, some lesions of the skull can cause pain, which is received by nociceptors located in the underlying periosteum. Lesions of the skull most likely to produce pain are those that are rapidly expansile, aggressively osteoclastic, or have an inflammatory component.3 Included among this group of lesions are osteomyelitis, multiple myeloma, sickle cell disease, Paget’s disease, osteope-trosis, eosinophilic granuloma, Langerhans cell histiocytosis, osteoblastoma, and metastatic tumors.4–8
Eyes (IHS 11.3.x)
Patients with eye pain most often have obvious ocular signs accompanying the pain, making diagnosis relatively easy in such cases. However, occasionally headache or facial pain can originate in the eyes without obvious ocular signs, thus making diagnosis more difficult.
Ocular pain may be either primary or referred (Box 10-1). Primary pain arises from the ophthalmic division of the trigeminal nerve, although the maxillary division supplies most of the lower eyelid through its infraorbital branch.9 The retina and the optic nerve are not capable of nociception; however, the cornea, conjunctiva, iris, extraocular muscles, dural sheath of the optic nerve, and periorbital area are supplied with pain-sensing nociceptors. Pain may be perceived as originating in the orbit by stimulation of the optic nerve at any point along its path from the face to the cortex. Possible stimuli include intracranial tumors, tumors of the orbit or paranasal sinuses, cavernous sinus inflammation, and carotid aneurysms.10 Facial, cervical, and pericranial muscles are common sources of pain referred to the orbit or periorbital areas.11
|Box 10-1 Head and facial pain arising from the eyes|
Glaucoma (IHS 11.3.1)
Convergence disorders (heterophoria or heterotropia) (IHS 11.3.3)
Ocular inflammation (IHS 11.3.4)
Superior orbital fissure syndrome
Ocular pain associated with inflammation is often accompanied by photophobia and conjunctival injection. Pain with eye movement can be due to optic neuritis or anterior sinusitis. Refractive errors are unlikely to be the cause of eye pain or headache. Although headache is often accompanied by ocular or periorbital pain, in the absence of ocular or periocular findings, it should be assumed that the pain is not due to a primary ocular disorder, and further testing should be performed.10
Metastatic tumors to the orbit may present with diplopia (48%), pain (42%), and visual loss (30%) as the most common symptoms. Breast carcinoma (29%), melanoma (20%), and prostate cancer (13%) are the most common cancers that metastasize to the orbit. Orbital infarctions secondary to sickle cell disease cause acute periorbital pain, proptosis, ophthalmoplegia, and visual impairment.12–14
Ears (IHS 11.4)
About 50% of earaches are due to structural lesions of the external or middle ear.15 The remainder are cases of referred pain, arising from disorders such as toothache, temporomandibular disorders (TMDs), pharyngeal or laryngeal disorders, and cervical disorders.16,17 Sensory innervations of the ear are supplied by numerous nerves, including branches of the fifth, seventh, ninth, and tenth cranial nerves, in addition to branches of the second and third cervical nerves. Thus, pain originating in the regions that supply these numerous nerve branches may be perceived as pain in or around the ears.
Otalgia from primary disorders of the ear can originate in the auricle, external ear canal, tympanic membrane, or middle ear (Box 10-2) and may be accompanied by other symptoms such as vertigo, deafness, or tinnitus.18 The common causes of primary otalgia include otitis media, otitis externa, presence of a foreign body, and barotrauma.19
|Box 10-2 Head and facial pain arising from the ears|
Cholesteatoma (IHS 11.4)
Ramsey Hunt syndrome
Nasal-paranasal sinus complex
The nasal cavity is surrounded by the paranasal sinuses, which include the maxillary, ethmoid, frontal, and sphenoid sinuses. Sensory innervations of the nasal-paranasal sinus complex are supplied by the first and second divisions of the trigeminal nerve.15 Normal function of the sinuses is dependent on ciliary action that actively transports mucus and debris to the openings, or ostia, to allow drainage into the middle meatus of the nasal cavity. If the ostia become blocked due to inflammation or obstruction, fluid and bacteria accumulate, leading to signs and symptoms of sinusitis.
Acute rhinosinusitis is typically sudden in onset, lasts up to 4 weeks, and resolves with antibiotic treatment. Chronic rhinosinusitis lasts longer than 12 weeks. The symptoms of acute or chronic rhinosinusitis commonly include nasal obstruction, nasal congestion, nasal discharge, nasal purulence, postnasal drip, facial pressure and pain, alteration in the sense of smell, cough, fever, halitosis, fatigue, dental pain, pharyngitis, otalgia, and headache.20
It is noteworthy that in a study of the symptoms of acute sinusitis,21 maxillary toothache was highly specific (93%), but only 11% of patients with sinusitis actually had pain from the tooth. Headache had a sensitivity of 68% but a specificity of only 30%. Sinus headache is a nonspecific term and is often confused with migraine and tension-type headache because of similarity in location of the headache. Most of the patients who believe they have a sinus headache actually have migraine (with sinus symptoms). Other sinus-related conditions that are often considered to induce headache are not sufficiently validated as causes of headache. These include deviation of the nasal septum, hypertrophy of turbinates, atrophy of sinus membranes, and mucosal contact.22,23
The location of pain experienced may often provide clues as to which of the sinuses is primarily involved. For example, maxillary sinusitis may cause infraorbital or cheek discomfort, ethmoidal rhinosinusitis may cause tenderness over the lacrimal region, frontal sinusitis characteristically causes pain in the forehead over the orbits, and pain due to sphenoidal sinusitis radiates to the occiput and vertex areas.24 Box 10-3 lists painful disorders of the nasal-paranasal sinus complex.
|Box 10-3 Head and facial pain arising from the nasal-paranasal sinus complex|
Rhinosinusitis (IHS 11.5)
Acute or chronic sinusitis (IHS 11.5)
There are three pairs of major salivary glands: the parotid, the submandibular, and the sublingual glands. The sensory nerves to the parotid gland are supplied by the auriculotemporal branch of the trigeminal nerve, while the secretory fibers are derived from the glosso-pharyngeal nerve but transported via the auriculotemporal nerve. Both the submandibular and the sublingual glands derive their sensory nerve supply from the lingual nerve, while the secretory fibers are derived from the chorda tympani.25 Pain originating in the salivary glands is typically inflammatory, infectious, traumatic, or neoplastic in origin. Common salivary gland disorders that are accompanied by pain include sialadenitis, sialolithiasis, epidemic parotitis, and tumors. Usually, diagnosis of salivary gland pain is not difficult because of the accompanying signs or symptoms.25 For example, in salivary gland duct blockage or infection, the patient often presents with moderate to severe pain with eating in conjunction with swelling and tenderness of the affected gland. Purulent exudate associated with fever and malaise may also occur.
The throat, or pharynx, is divided into the nasopharynx, oropharynx, and hypopharynx. The sensory supply to the pharyngeal tissues is via branches of the glossopharyngeal and vagus nerves.26 Because of the significant overlap of innervations to these structures, throat pain is often poorly localized and pain referral to the ear is common.18 Painful disorders of the throat can be developmental, infectious, inflammatory, neuropathic, or neoplastic in origin.27 Box 10-4 lists the most common painful throat disorders.
|Box 10-4 Head and facial pain arising from the nasal-paranasal sinus complex|
Allergic rhinitis with postnasal drip
Chronic mouth breathing
Muscle tension dysphonia
Vocal cord granuloma
Granulomatous diseases (rheumatoid arthritis, gout)
Nonstreptococcal bacterial pharyngotonsillitis
Deep space neck infection (retropharyngeal/parapharyngeal space infection)
Oromandibular dystonia is an uncommon motor disorder that may contribute to orofacial pain. It is one form of focal dystonia that affects the orofacial region and involves the jaw-opening muscles (lateral pterygoids and anterior di-gastrics), tongue muscles, facial muscles (especially orbicularis oris and buccinator), and platysma. Dystonia is characterized by an involuntary, repetitive, sustained muscle contraction. The sustained contraction results in an abnormal posturing of facial structures and subsequent pain.28,29
Multiple sclerosis (MS) is an inflammatory autoimmune disease characterized by demyelinat-ing lesions and plaques within the central nervous system (CNS). The modal time of onset of MS symptoms is during the third to fourth decade of life, with the average age of onset at 30 years, which is younger than that of trigeminal neuralgia (TN), with an average age of onset at 50 years.30 In patients with MS, TN occurs at approximately 20 times more often than in the general population31 and is usually due to lesions in the intrapontine trigeminal tract or root entry zone.32 Up to 31% of TN is bilateral in patients with MS, a rate much higher than that in patients without MS.29 Treatment of TN pain in MS patients is similar to treatment of TN in patients without MS (see chapter 6).
Lyme disease is a multisystem infection caused by the tick-borne spirochete Borrelia burgdorferi. The systemic dissemination of spirochetes from the site of the tick bite may result in a characteristic red rash called erythema migrans. The systemic infection primarily involves three extracutaneous organ systems: (1) the heart, most commonly causing otherwise unexplained conduction block; (2) the joints, causing arthralgias; and, typically much later in infection, (3) the nervous system. Only 10% to 15% of patients develop symptomatic nervous system involvement, which may present as cranial neuropathy, painful radiculopathy, or lymphocytic meningitis.33 The most common manifestation of nervous system infection in both Europe and the United States is cranial nerve involvement, most often facial nerve palsy, which is reported in 5% to 8% of early-stage, untreated patients. The disorder itself is indistinguishable from Bell’s palsy, except that in Lyme disease it can be bilateral in up to 20% to 25% of affected individuals. Although 80% of Lyme disease–associated cranial nerve palsies affect the facial nerve, other nerves can be involved. Involvement of nerves to the extraocular muscles (III, IV, VI) can cause diplopia; involvement of the fifth nerve can cause hypoesthesia or pain; and seventh nerve involvement can result in hearing changes or vertigo.34
A recent international consensus position paper defined bruxism as follows: “A repetitive jaw-muscle activity characterized by clenching or grinding of the teeth and/or by bracing or thrusting of the mandible. Bruxism has two distinct circadian manifestations: it can occur during sleep (indicated as sleep bruxism) or during wakefulness (indicated as awake bruxism).”35
Awake bruxism is a distinctive entity to sleep bruxism and is characterized by tooth clenching during waking hours. It may be viewed as a response to stress or anxiety and affects 20% of the population.33,36 The prevalence of sleep bruxism is estimated by subjective sleep grinding noises during sleep and is reported to be 5% to 8% in adults, 10% to 20% in children, and 3% in the elderly.37–40 Risk factors for sleep bruxism include smoking,41 caffeine,42 illicit drugs,43 and anxiety.44,45 Patients with sleep bruxism may present with numerous clinical features based on self-report, partner report, and clinical observations (Box 10-5).
|Box 10-5 Clinical features of sleep bruxism*|
|Self-report from patient or sleep partner|
|Sleep partner complains of grinding noise (occasionally tapping noise with oromandibular myoclonus)|
|Waking in the morning|
Jaw muscle discomfort/fatigue
Temporal headache of short duration
Difficulty in jaw opening, jaw stiffness, temporomandibular joint noise Tooth hypersensitivity to cold stimuli (eg, food, drink, or air)
|Tooth wear, fracture, and/or cervical defects
|Masseter muscle hypertrophy during voluntary clenching (bilateral)
Jaw muscle tenderness (masseter, temporalis) and temporomandibular joint pain
|Dental restoration failure or fracture (eg, crown, denture, inlay, implant)
Tongue biting (observed in oromandibular myoclonus)
|*Adapted from Kato and Lavigne46 with permission.|
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