Facial paralysis: a patient guide to causes and treatment options
A facial paralysis diagnosis raises a lot of questions: why it happened, whether it will improve, and what can be done in the meantime. This guide summarizes, in general terms, the most common causes and the range of treatment options.
Most common causes
The most common cause is Bell’s palsy, which is idiopathic (no identifiable cause) and likely related to viral inflammation of the facial nerve. Other causes include trauma, tumors affecting the facial nerve or its pathway, and after-effects of skull-base or parotid gland surgery.
When does it recover on its own?
Most cases of Bell’s palsy improve spontaneously within weeks to months with medical treatment (corticosteroids, eye protection). The prognosis depends on the initial severity and how quickly treatment begins after symptoms appear.
When to consider surgery
Surgical treatment is considered when, after a reasonable time window, there are no signs of recovery, when the underlying cause justifies it from the outset (for example, a severed nerve), or when lasting effects remain that impair function — such as eyelid closure — or facial symmetry.
How the degree of impairment is measured
Validated grading scales are used to objectively track severity and treatment progress. The House-Brackmann scale classifies paralysis into six grades, from normal function to total paralysis, based on symmetry at rest and movement of the forehead, eyes and mouth. The Sunnybrook scale is more detailed: it scores from 0 to 100, combining resting symmetry, the range of voluntary movement across five expressions, and the degree of synkinesis (associated involuntary movements). Using the same scale consistently at every visit allows a patient’s progress to be compared objectively, beyond visual impression alone.
The role of botulinum toxin
Besides surgery, botulinum toxin type A has a well-established role in managing facial paralysis. Injected in low doses into the overactive muscles of the healthy side, or into synkinetic muscles on the affected side, it helps reduce hypercontraction and improve symmetry both at rest and while smiling. Because its effect is reversible and temporary (3-6 months), it also serves as a tool ahead of surgery: it lets the patient experience an approximation of the outcome of a future surgical reanimation before deciding whether to take that step.
The approach to facial paralysis is tailored to each case, combining static and dynamic reanimation techniques when needed.
Related specialty: Facial Paralysis
References
- 1.House JW, Brackmann DE. Facial nerve grading system. Otolaryngol Head Neck Surg. 1985;93(2):146-147.
- 2.Ross BG, Fradet G, Nedzelski JM. Development of a sensitive clinical facial grading system. Otolaryngol Head Neck Surg. 1996;114(3):380-386.
- 3.Renga M, D’Emilio R, Salti G, et al. Facial Paralysis Treatment and Facial Symmetrization with Botulinum Neurotoxin: A Narrative Review with Illustrative Clinical Cases. Toxins. 2026;18(6):253.
- 4.Baumann A, Ewers R. Application of temporalis muscle and fascia transfer in facial reanimation. En: Biglioli F, editor. Facial Palsy: Techniques for Reanimation of the Paralyzed Face. Cham: Springer; 2021.
About the author
Dr. Pablo Vaquero is an attending Oral and Maxillofacial Surgeon at Vall d’Hebron University Hospital (Barcelona) and a surgeon at the Instituto Maxilofacial at Centro Médico Teknon. Trained in Hong Kong, Buenos Aires and Charité Berlin, he is Spain’s National Trainee Representative to the EACMFS and the author of scientific publications and the Lifting Surgery chapter of the SECOM CyC reference manual.