🧠 Bell's Palsy House-Brackmann Grading Simulator

Grade I — Normal Facial Function

Both sides move equally; the reference point for every other grade.

• I: HB Grade (Normal function)
• 100%: Forehead movement (full symmetric wrinkling)
• 100%: Eye closure (complete, effortless)
• 100%: Mouth symmetry (no drift at rest)

What normal looks like

Baseline symmetry across forehead, eyes, and mouth at rest and motion.

Why baseline matters

Every grade above compares movement loss against this reference.

Grade II — Mild Dysfunction

Slight weakness noticeable up close; symmetry preserved at rest.

• II: HB Grade (Mild dysfunction)
• ~75%: Forehead movement (slightly reduced)
• ~95%: Eye closure (complete with effort)
• ~90%: Mouth symmetry (minor asymmetry on motion)

Subtle early signs

Close inspection reveals slight forehead and mouth weakness only.

Clinical exam cues

Synkinesis, if present, is minimal or absent at this stage.

Grade III–IV — Moderate Dysfunction

Obvious weakness and noticeable asymmetry, but not disfiguring.

• III–IV: HB Grade (Moderate dysfunction)
• ~35%: Forehead movement (slight to no movement)
• ~65%: Eye closure (incomplete closure)
• ~55%: Mouth symmetry (asymmetric with effort)

Incomplete eye closure

Lagophthalmos appears; protective blink reflex is compromised.

Functional impact

Noticeable but not disfiguring asymmetry; synkinesis may appear.

Grade V — Severe Dysfunction

Barely perceptible motion; asymmetry now visible even at rest.

• V: HB Grade (Severe dysfunction)
• ~10%: Forehead movement (barely perceptible)
• ~25%: Eye closure (largely incomplete)
• ~20%: Mouth symmetry (marked asymmetry at rest)

Rest asymmetry

Drooping is visible without any attempted facial movement.

Treatment urgency

Higher grades push earlier steroid and eye-care intervention.

Grade VI — Total Paralysis

No facial movement at all; grading guides prognosis and urgency.

• VI: HB Grade (Total paralysis)
• 0%: Forehead movement (no movement)
• 0%: Eye closure (no closure, exposure risk)
• 0%: Mouth symmetry (complete flaccidity)

Complete flaccid paralysis

No tone or movement on the affected side, any expression.

Prognosis and monitoring

Higher grade, longer duration — closer follow-up is warranted.

Early treatment matters more as House-Brackmann grade rises.