Alexander Barna

1 Introduction Non-flaccid facial paralysis (NFFP) is a distressing sequela of facial nerve injury that greatly impacts facial function and quality of life [1, 2]. Facial synkinesis is a subtype of NFFP that causes involuntary facial contractions during voluntary facial movements (e.g., eye closure during speech) [3]. Aside from its impact on facial movements, facial synkinesis can also lead to social anxiety, depression, and diminished quality of life [2, 4-6].

1 Introduction Bell's palsy is the most common cause of acute facial nerve paralysis in the general population [1, 2]. It is characterized by rapid-onset unilateral facial weakness or paralysis in a lower motor neuron distribution. Affected individuals can experience devastating sequelae including oral incompetence, disfigurement, hyperacusis, facial pain and lagophthalmos with associated ocular injury [3].