Therapeutic ultrasound for the face uses high-frequency sound waves to stimulate tissues beneath the skin’s surface. This non-invasive approach utilizes controlled energy delivery to induce biological changes that support skin health and appearance. The frequency of the sound wave, measured in megahertz (MHz), determines how deeply the energy penetrates. Focusing on the 1 MHz frequency allows the energy to reach deeper layers, making it a targeted method for various cosmetic facial treatments.
Defining 1 MHz Ultrasound
The 1 MHz frequency refers to one million oscillations of the sound wave every second. This relatively low frequency allows the energy to penetrate significantly deeper into the tissue compared to higher frequencies used in superficial cosmetic devices. For facial treatment, 1 MHz ultrasound energy can reach depths ranging from approximately 2.3 to 5 centimeters. In contrast, a 3 MHz device targets more superficial layers, generally penetrating only 0.8 to 1.6 centimeters deep. This deeper reach allows the treatment to affect the deep dermis, the subcutaneous fat layer, and the superficial muscular aponeurotic system (SMAS), making it uniquely suited for firming and contouring treatments.
The Mechanical and Thermal Effects on Skin
The energy delivered by 1 MHz sound waves produces two distinct biological responses: a mechanical effect and a thermal effect. The mechanical action, often called acoustic streaming or micromassage, results from the rapid oscillation of the sound waves, causing cells and tissue fluids to vibrate gently. This vibration induces stable cavitation, where tiny gas bubbles expand and contract, temporarily increasing cell membrane permeability and promoting local circulation. The thermal effect occurs as tissues absorb sound energy and convert it into heat. When applied continuously, this generates controlled, localized heating deep within the targeted tissue, which is necessary for initiating tissue remodeling processes.
Targeted Facial Benefits
The dual mechanical and thermal actions of 1 MHz ultrasound translate into specific benefits for facial structure and appearance. A primary outcome is the stimulation of new collagen production, known as neo-collagenesis. The controlled thermal energy delivered deep into the dermis and SMAS layer causes existing collagen fibers to denature and contract instantly. This thermal injury signals the body’s healing response, prompting fibroblasts to synthesize fresh collagen and elastin fibers over time. This gradual remodeling leads to a noticeable tightening and lifting effect, contributing to facial contouring and reducing skin laxity.
The mechanical effect also supports enhanced product absorption through sonophoresis or phonophoresis. The micro-vibrations temporarily disrupt the protective barrier of the stratum corneum, creating transient pathways between skin cells. This allows topically applied serums or moisturizing ingredients to penetrate the skin barrier more effectively than manual application. Furthermore, the thermal and mechanical energy can promote muscle relaxation and mild contouring effects by targeting the deep fibrous network connecting the muscles to the dermis.
Guidelines for Safe Application
To ensure the effectiveness and safety of 1 MHz ultrasound treatment, precise application guidelines must be followed. A conductive coupling gel is mandatory, as it eliminates air pockets between the transducer head and the skin. Without this gel, sound waves would be reflected instead of transmitted, potentially leading to device overheating and skin burns. The transducer head must be kept in constant, slow motion across the treatment area throughout the session. Holding the device stationary, even briefly, can result in an excessive concentration of heat, raising the risk of thermal injury to the underlying tissue. Ultrasound therapy is contraindicated for certain conditions, including active skin infections, open wounds, or metal implants (such as dental work or pacemakers) in the treatment path. Treatment should also be avoided in areas with diminished sensation, as the patient might not detect a damaging temperature increase.