Investigating Facial Muscle Physiology Following Soft Tissue Filler Injections-A Surface-derived Electromyographic...

Area of Science:

• Aesthetics
• Biomedical Engineering
• Dermatology

Background:

• Hyaluronic acid (HA) fillers are widely used for soft tissue augmentation.
• The term "myomodulation" suggests HA fillers can alter muscle function.
• Scientific evidence directly investigating HA filler effects on facial muscle function is limited.

Purpose of the Study:

• To investigate the effect of HA-based soft tissue fillers on facial muscle function.
• To assess the validity of the term "myomodulation" in the context of facial fillers.
• To evaluate changes in muscle contraction patterns post-filler injection.

Main Methods:

• Prospective study involving 13 subjects.
• Utilized 3D surface imaging and surface electromyography (EMG).
• Measurements taken before and 5 days after strategic HA filler injections.

Main Results:

• No significant changes in muscle strength (measured in μV) were observed.
• Significant alterations in skin displacement occurred during zygomaticus major and depressor anguli oris muscle contractions.
• Horizontal skin displacement increased for zygomaticus major; vertical displacement increased for both muscles.

Conclusions:

• HA fillers do not appear to directly alter facial muscle strength.
• Filler deposition can modify surrounding tissue, altering the vector of skin displacement during muscle contraction.
• The observed changes suggest an indirect influence on muscle function, potentially due to altered muscle mechanics.