The International Association for the Study of Pain (IASP) defines pain as “an unpleasant sensory and emotional experience which we primarily associate with tissue damage or describe in terms of such damage, or both.” This definition recognizes that pain is a perception. The nervous system mechanism for detection of stimuli that have the potential to cause tissue damage is very important for triggering behavioural process that protect against current or further tissue damage. This is done by reflex reaction and also by preemptive actions against stimuli that can lead to tissue damage such as strong mechanical forces, temperature extremes, oxygen deprivation, and exposure to certain chemicals.
The clinician who attempts to understand and manage pain needs to have a thorough appreciation for different types of pain that can be encountered which are classified as acute pain, chronic pain, primary, secondary, neuropathic and inflammatory.
Dental pains may have their origin in the dental pulps or in the periodontal structures.
Pulpal pains may be classified as acute, chronic, recurrent or mixed with periodontal elements. Periodontal pain is deep somatic pain of the musculoskeletal type. As such, it is more localized than is pulpal pain.
Nondontogenic pain can be classified as muscular, cardiac, sinus, TMJ pain, neurovascular pain and musculoskeleton pain. Pain gives a warning of tissue damage and activation of defensive mechanisms, with the aim of prevention of further damage. Knowing the pathways and mechanisms of pain, possible causes and different characters of orofacial pain, clinical examination will eventually lead to a proper diagnosis.