Dr. Clara Yu

Happy Father’s Day to the best daddy ever!

Paradoxical masseter muscle hypertrophy (PMMH) 1-2 weeks after Botox to masseters.

Why it happens

1. Partial denervation
• Botox weakens some fibers, but not all
• Remaining fibers overcompensate → hypertrophy

2. Uneven injection pattern
• Deep vs superficial imbalance
• Missed posterior or inferior fibers

3. Dose too low for muscle size
• Common in strong bruxers / square jaw patients

4. Anatomy variability
• Masseter has multiple compartments
• If only one layer is treated → others enlarge

⸻

How to fix it

1. Touch-up Botox
• Inject the bulging segment specifically
• Usually:
• 5–15 units per side (targeted)
• Focus on deep + superficial layers of the bulge
• Improvement seen in 2–4 weeks

My heart ❤️ my love 💕 my everything 🌎