Overview of orofacial pain for dentists

Pain is ‘an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage’¹ . Pain is a subjective experience influenced by both sensory inputs received by the brain (eg in response to inflammation) and the brain’s interpretation of these inputs in the context of other available information. For example, a patient’s pain experience may be influenced by their coping strategies, previous experiences with pain and pain relief, and their confidence in the clinician’s ability to diagnose and manage their condition.

Orofacial pain has many causes, only some of which are dental. If the patient’s pain is not of dental origin, refer them for medical assessment. If the patient’s pain is of dental origin, assess the type of pain (nociceptive, neuropathic or nociplastic) and its duration (acute or chronic), because these factors affect the optimal treatment strategy.

Nociceptive pain arises from activation of nociceptors (receptors in skin and deep tissues that are sensitive to potentially noxious stimuli) due to threatened or actual tissue damage (eg inflammation in irreversible pulpitis).

Neuropathic pain arises from injury or disease of the somatosensory nervous system. It is often described as a burning or tingling sensation. Oral neuropathic pain is not uncommon. It can be difficult to diagnose, and investigation by a dental specialist (eg oral medicine specialist, oral surgeon, oral and maxillofacial surgeon) may be required.

Nociplastic pain is a diagnosis of exclusion; it is considered when nociceptive and neuropathic pain have been ruled out. In nociplastic pain states, central sensitisation is the key contributor, rather than ongoing pathology.

Pain managed by dentists is usually acute dental pain. Such pain:

• is usually nociceptive
• usually resolves rapidly with appropriate dental treatment, but may require short-term use of analgesics
• serves a protective biological function—it alerts the body to a potential threat, prevents the body from further harm, and can teach the body to avoid similar harm in the future.

Chronic pain (also referred to as persistent pain) may be associated with ongoing pathology; however, often the originating pathology is no longer evident and pain persists because of lasting changes within the nervous system. Such pain:

• may be nociceptive, neuropathic, nociplastic or mixed
• can be difficult to diagnose because there may not be any obvious pathology
• may result in anxiety, fear, depression, loss of sleep and impaired social functioning; these factors may also affect a patient’s pain experience
• requires a sociopsychobiological (biopsychosocial) approach to assessment and management; see General principles of chronic pain management. Analgesics have a limited role.

Causes of chronic orofacial pain include temporomandibular disorders and burning mouth syndrome.

If a patient with chronic orofacial pain presents with dental pain, determine whether the pain is a symptom of their chronic pain condition or associated with a dental pathology. Do not undertake dental treatment unless a dental pathology is confirmed to be causing the pain.