Abstract

Background: Marcus Gunn jaw-winking syndrome (MGJWS) is a rare congenital synkinesis in which involuntary elevation of a ptotic eyelid occurs during jaw movement. Classically, it is elicited through voluntary mandibular movements such as opening the mouth or moving the jaw sideways. Unilateral choanal atresia is a congenital nasal airway obstruction that can remain undiagnosed into adulthood. The coexistence of these two entities has been poorly defined.
Case Presentation: We report an atypical case of a 19-year-old female who presented with marked, prominent, and readily visible unilateral eyelid elevation that occurred only during actual mastication. Moreover, during routine examination, there was no ptosis at rest, and the phenomenon could not be elicited when the patient was asked to open or close her mouth. Additionally, eyelid elevation was observed in cognitive distraction or daydreaming with no explicit jaw movement or food-related stimuli. Additional medical examination showed ipsilateral choanal atresia and a history of nasal obstruction with persistent nasal discharge on the same side since childhood.
Results: The clinical findings were consistent with atypical presentation of Marcus Gunn jaw-winking syndrome characterized by non-volitional triggers, absence of ptosis at rest, and association with ipsilateral choanal atresia.
Conclusion: This case demonstrates a rare case of atypical MGJWS with non-volitional triggers and mentions the rare presence of ipsilateral choanal atresia. The results suggest shared embryological or neurodevelopmental mechanisms and broaden the clinical spectrum of MGJWS.

Key words: Marcus Gunn jaw-winking, choanal atresia, synkinesis, congenital cranial dysinnervation disorders, ptosis, case report.