ABOP Orofacial Pain key terms

A specialized peripheral sensory neuron that detects tissue-damaging or potentially damaging stimuli and transmits that information toward the central nervous system. Most are finely myelinated or unmyelinated nerve endings.

Pain arising from activation of nociceptors by actual or threatened tissue damage, such as pulpal inflammation or joint overload. It is typically described as aching or pressure-like and usually responds to standard analgesics.

Pain caused by a lesion or disease of the somatosensory nervous system, such as nerve injury after surgery or a demyelinating process. It often includes burning, electric-shock qualities and sensory changes.

Pain arising from altered nociception despite no clear evidence of actual or threatened tissue damage or of a lesion of the somatosensory system. It often coexists with widespread sensitivity and psychosocial distress.

Reduced threshold and increased responsiveness of nociceptors at the site of injury, driven by inflammatory mediators such as prostaglandins and bradykinin. It underlies primary hyperalgesia and tenderness around the damaged tissue.

Increased excitability and synaptic efficacy of neurons in the central nervous system after intense or repeated nociceptive input. It produces spread of tenderness, secondary hyperalgesia, and amplification of pain beyond the original site.

Pain evoked by a stimulus that does not normally produce pain, such as light touch on the face. It signals altered sensory processing and is common in neuropathic and central sensitization states.

An increased pain response to a stimulus that is normally painful. It can occur at the injured site through peripheral mechanisms or in surrounding tissue through central mechanisms.

Pain perceived at a location distant from the tissue that generated it, often because converging afferent neurons project to overlapping central targets. Common in temporomandibular and cervical muscle disorders.

The sensory ganglion of the fifth cranial nerve, containing cell bodies of primary afferents that supply the face, oral cavity, and much of the intracranial dura. It lies in a cavity near the skull base.

The region of the caudal brainstem and upper cervical spinal cord where trigeminal and upper cervical afferents converge on shared second-order neurons. It explains referral between head, face, and neck.

The paired synovial joint between the mandibular condyle, the articular disc, and the temporal bone. It permits rotation and translation and is a common source of orofacial pain.

A biconcave fibrocartilaginous structure that separates the temporomandibular joint into upper and lower compartments and moves with the condyle during jaw opening.

Abnormal position of the temporomandibular joint disc relative to the condyle, commonly anterior. It may reduce on opening with a click or persist with limited opening.

A grating or crunching sound and sensation felt on joint movement, reflecting roughened articular surfaces. In the temporomandibular joint it suggests degenerative change rather than disc displacement.

Pain arising from muscle and its surrounding fascia, often with regional tenderness and trigger points. In the masticatory system it is the most common temporomandibular disorder presentation.

A hyperirritable spot within a taut band of skeletal muscle that is tender to compression and may produce local or referred pain. It can also cause restricted movement and autonomic signs.

Repetitive jaw muscle activity characterized by clenching or grinding of the teeth, occurring during sleep or wakefulness. It can contribute to muscle pain and tooth wear but is not itself a disorder.

Rhythmic masticatory muscle activity during sleep, often occurring in bursts associated with arousals. It is distinguished from daytime clenching and may coexist with sleep-disordered breathing.

A monitored sleep study recording brain activity, eye movements, muscle tone, breathing, and oxygenation. It is the reference standard for diagnosing sleep disorders relevant to orofacial pain.

Repeated collapse of the upper airway during sleep causing reduced or absent airflow, oxygen desaturation, and arousals. It is associated with snoring, daytime sleepiness, and morning headache.

A recurrent primary headache disorder with attacks lasting hours, often unilateral and pulsating, accompanied by nausea or sensitivity to light and sound. Some attacks include transient neurologic aura.

Transient focal neurologic symptoms, typically visual, that precede or accompany a migraine attack and usually resolve within an hour. It reflects cortical spreading depression rather than ischemia.

A slowly propagating wave of neuronal depolarization and depressed activity across the cortex. It is thought to generate migraine aura and to activate trigeminal afferents.

A primary headache with pressing, band-like pain of mild to moderate intensity and little nausea or disability. Peripheral and central muscle mechanisms are both implicated.

A primary trigeminal autonomic headache with severe unilateral orbital or temporal pain and ipsilateral autonomic signs such as tearing and nasal congestion. Attacks are short and recur in clusters.

A group of primary headaches characterized by unilateral trigeminal pain with prominent ipsilateral cranial autonomic features. Cluster headache and paroxysmal hemicrania belong to this group.

A disorder of the fifth cranial nerve producing brief, electric-shock-like unilateral facial pain triggered by light touch, chewing, or cold. It may be classical with vascular compression or secondary to another cause.

Pain caused by injury to a trigeminal nerve branch, such as during extraction or implant placement, with pain persisting beyond expected healing. It may include sensory loss, tingling, or burning.

An intraoral burning or dysesthetic sensation recurring daily for months without a clinically evident cause. It is often idiopathic and associated with taste change and psychological distress.

Dull, poorly localized facial pain present daily for most of the day over months, without clinical findings to explain it. It is a diagnosis of exclusion among persistent facial pain disorders.

A standardized, validated system combining clinical examination and questionnaire items to classify temporomandibular disorders into pain-related and intra-articular groups for research and practice.

A radiographic technique producing three-dimensional images of hard tissues at relatively low radiation dose. It is useful for assessing the temporomandibular joint and bony pathology.

An imaging method using magnetic fields to depict soft tissues without ionizing radiation. It is the preferred study for evaluating the temporomandibular joint disc and surrounding structures.

A set of standardized psychophysical tests measuring detection and pain thresholds to calibrated stimuli. It can demonstrate sensory gain or loss and support neuropathic pain assessment.

A serotonin receptor agonist that relieves migraine by constricting cranial vessels and inhibiting trigeminal peptide release. It is most effective early in an attack and is contraindicated in some vascular disease.

An anticonvulsant that stabilizes neuronal membranes and is first-line therapy for trigeminal neuralgia. It requires monitoring for adverse effects including blood dyscrasias and hyponatremia.

A secondary headache worsened by frequent use of acute headache medication, improving after withdrawal. It is a risk in patients taking analgesics or triptans on many days per month.

A structured psychological treatment targeting unhelpful thoughts and behaviors that maintain pain and disability. It is used alongside self-management to improve coping and function in persistent orofacial pain.

A maladaptive cognitive pattern of magnifying the threat and seriousness of pain and feeling unable to cope. It predicts greater pain-related disability and can be addressed in psychological treatment.

A behavioral approach in which a patient gradually confronts feared movements or activities in planned steps. It reduces avoidance and disability in persistent pain without provoking sustained flare.