Microfocused ultrasound for facial rejuvenation: current perspectives

Abstract:

In contrast with ultrasound imaging, therapeutic ultrasound uses high energy levels >5 W/cm² and is tightly focused into a small point to rapidly heat and coagulate targeted tissues. The use of high intensity focused ultrasound has recently expanded from high-precision surgical procedures into the field of noninvasive cosmetic medicine. Microfocused ultrasound (MFU) differs from other energy technologies used for skin rejuvenation. A concave disk within the transducer focuses ultrasound energy with very high intensity at specific locations below the epidermis and can specifically target the dermis or superficial musculoaponeurotic system, a fibrous network consisting of collagen fibers, elastic fibers, and fat cells that connects the facial muscles with the dermis and is tightened during a facelift. Where applied, the temperature at the focal point rapidly rises while tissue above and below the focal zone are unaffected. Application of MFU causes collagen fibers to denature and contract and stimulates de novo synthesis of new collagen. MFU combined with visualization (MFU-V) can be applied to the skin with a high degree of precision to noninvasively lift and tighten the dermis and subdermal tissues. The desired treatment depth and the rate of heating can be selected by altering the ultrasound frequency and rate and intensity of energy delivery. One MFU-V device has been approved by the US Food and Drug Administration to noninvasively lift and tighten lax face and neck skin. Common adverse events associated with MFU-V include momentary discomfort during the treatment session, transient erythema and edema, and occasional bruising. Ongoing studies by independent investigators are evaluating the safety and efficacy of MFU-V for lifting and tightening lax skin in other anatomical areas.

Keywords::

• high intensity focused ultrasound
• microfocused ultrasound
• noninvasive
• facial rejuvenation
• skin laxity
• skin tightening

Acknowledgment

The author gratefully acknowledges the editorial assistance of Dr Carl Hornfeldt during preparation of the manuscript.

Disclosure

The author reports no conflicts of interest in this work.