The House-Brackmann facial paralysis scale allows clinicians to assess the degree of facial paralysis a patient is experiencing by evaluating the characteristics of facial function. The scale assigns a grade from 1 to 6, which corresponds to varying levels of facial movement and symmetry, as outlined below:

- "Normal facial function in all areas" results in "Grade 1: Normal." This represents no noticeable issues with facial movement.
- "Slight weakness on close inspection; mouth: slight asymmetry, forehead: moderate to good function; eye: complete closure with minimum effort; normal symmetry and tone at rest" is classified as "Grade 2: Mild dysfunction," indicating minor issues detectable only on close observation, with overall good function.
- "Obvious but not disfiguring weakness between 2 sides, noticeable but not severe synkinesis, contracture, and/or hemifacial spasm; mouth: slightly weak with maximum effort, forehead: slight to moderate movement, eye: complete closure with effort; normal symmetry and tone at rest" translates to "Grade 3: Moderate dysfunction." This grade signifies noticeable weakness without severe disfigurement.
- "Obvious and disfiguring asymmetry; mouth: asymmetric with maximum effort, forehead: no motion, eye: incomplete closure; normal symmetry and tone at rest" is identified as "Grade 4: Moderately severe dysfunction," indicating significant weakness affecting appearance.
- "Barely perceptible motion on contraction; mouth: slight movement, forehead: no motion, eye: incomplete closure; asymmetry at rest" corresponds to "Grade 5: Severe dysfunction," where movement is very limited and asymmetry is evident even at rest.
- "Complete absence of any facial movement" is equated to "Grade 6: Complete paralysis," representing total loss of voluntary facial motion.

The House-Brackmann scale provides a standardized method for evaluating facial nerve function, ensuring clinicians can systematically assess and track the progress or improvement of facial paralysis over time. Each grade serves as a guide to determine the severity of the condition and aids in formulating treatment plans.

The House-Brackmann Facial Paralysis Scale is a clinical tool used to assess the severity of facial nerve dysfunction, specifically in patients with facial paralysis. This scale is widely used in the evaluation of patients with Bell's palsy, Ramsay Hunt syndrome, or other conditions causing facial nerve paralysis. 

The House-Brackmann scale grades facial function from I (normal) to VI (total paralysis), taking into account parameters such as symmetry at rest, voluntary movement, and synkinesis (involuntary movement). 

The clinical utility of this scale lies in its ability to provide a standardized method for assessing the degree of facial nerve damage, which can guide treatment decisions and allow for consistent tracking of patient progress over time. 

There are no specific exclusion criteria for the use of the House-Brackmann scale, but it may be less accurate in patients with partial facial nerve palsy or in those with dynamic facial asymmetry due to causes other than facial nerve dysfunction.