Marcus Gunn Syndrome - A Rare Neural Misdirection Phenomenon Case Report.

Rationale: This case report describes the Marcus Gunn phenomenon (MGP), an infrequent type of congenital unwanted contractions of facial muscles that occurs in 4%-6% of patients with congenital ptosis. The defining characteristic of MGP is the affected eyelid lifting in a manner similar to the opening of the mouth. Patient Concerns: It addresses a 45-year-old man who was examined in the dental clinic with a severely decayed tooth. He exhibited evidence of normal vision and synchronous movement of his lips and eyelid. Diagnosis: The conditions matched those of the autosomal dominant disorder with incomplete penetration, the MGP. The carious tooth was restored without the necessity for any surgical intervention. Treatment: The patient was given appropriate dental treatment without any surgical intervention for Marcus Gunn Syndrome. Outcome: After receiving routine fillings to treat dental caries, the patient stopped complaining of pain. Take-away Lesson: This case report reveals insight into a situation that has been speculated to be an example of neural redirection syndrome, in which impulses from the trigeminal nerve's motor unit are naturally redirected into the levator palpebrae superioris muscles of the upper eyelid and the superior pterygoid muscle.