Oro-facial pain in Chiari type 1 malformation

The symptom of facial pain is one of the most common reasons for referral to a dental centre or an oral maxillofacial treatment centre. Orofacial pain is a common symptom with many causes. However, oro-facial pain is rarely the only symptom of Chiari type 1 malformation (CM1), a disease characterized by an anatomical defect at the base of the skull where the cerebellum and the spinal cord herniate through the foramen magnum into the cervical spinal canal. Approximately 20% of patients with CM1 may also experience facial hypesthesia, trigeminal or glossopharyngeal neuralgia, paralysis of the vocal cords, soft palate weakness. In the literature, proposed mechanisms to explain the trigeminal neuralgia and CM1 correlation are vascular compression at the nerve root entry zone, which could be affected by hydrocephalus or anatomic factors related to the CM1, demyelination, micro-ischemic changes and direct brainstem compression. However, further investigation on the mechanisms involved in orofacial pain in patients with CM1 is needed.