Intraoral (inside the mouth) pain potentially has many sources. Any of the numerous structures within the oral cavity can elicit pain, and therefore, any evaluation for pain in the head, face or jaw should include an exam of the oral cavity. An orofacial pain specialist must work closely with other dentists when assessing causes for intraoral pain. The muscles, nerves, blood vessels, TMJ, TMJ disc, tendons and other structures of the face, jaws, head and neck have the potential to refer pain into the oral cavity. Also, structures within the oral cavity have the potential to refer pain outside of the mouth. All areas must be evaluated to arrive at an accurate diagnosis. See the “Chronic Pain” section for a definition of referred pain.
The most common source of orofacial pain is from intraoral structures. Some common sources for intraoral pain include the teeth, teeth nerves, bone around the teeth, mucogingival tissues (gums, soft tissues of cheeks, palate, under the tongue), salivary glands, and tongue.
Common disorders associated with these various structures:
Pulpal pain – this is pain from the nerve of the teeth. The most likely causes are large cavities, fractured teeth and infected/abscessed teeth.
Periodontal pain – pain from the periodontal ligament (ligament that binds the tooth to the bone) or alveolar bone (bone in which the tooth root is attached). The causes can be bacterial infections causing abscessing of these tissues or trauma to these tissues.
Mucogingival pain – mucogingival pertains to the tissue lining the inside of the cheeks and palate, covering of the floor of the mouth under the tongue, and the gingiva (gums) around the teeth. Pain to these areas may be a result of bacterial infection of the gingiva, aphthous ulceration (canker sores), herpes simplex viral vesicles in the mouth, candidiasis (an oral fungal infection), trauma to the tissues, mucogingival cancer, or burning mouth syndrome (BMS). BMS may cause a generalized burning sensation to the mucogingival tissues in the mouth and the tongue.
Xerostomia – excessive dry mouth that may lead to pain. The possible causes includes an extensive list, which are too numerous to list in this context. An individual with undiagnosed xerostomia may need a comprehensive examination by an oral medicine specialist.
Glossal pain – pain of the tongue. Burning mouth syndrome (as listed above), infections of the tongue and trauma are common sources of glossal pain. Benign migratory glossitis is another condition of the tongue that may cause pain or burning. It is benign, as listed in the name, and is of an unknown cause, but results in discolored, smooth patches on the tongue that tend to move around over time (“migrate”). These areas may be tender or painful when eating spicy food.