What is High Intensity Focused Ultrasound?
Multiple high energy ultrasound waves are transmitted through the superficial skin layers and focused on a single spot in the deeper levels, while leaving the superficial layers without damages. Multiple emissions are done on a short line, creating an almost continuous line of thermal injury.
What are the Effects?
HIFU creates a temperature of 60° Celsius and this technique has been proven to uplift and tighten skin laxity in different areas. There are 3 levels of liftings. When the energy is focused at 3–4.5mm depth it hits the SMAS (a fibrous layer connecting most of the facial tissues) layer and the heat will contract the whole SMAS layer and the connective tissues next to it, resulting in skin tightening and improvement of wrinkles.
3 mm penetration will focus on the deep dermis, and stimulate the regeneration and re-alignment of collagen and elastic tissues, smooth out the deeper wrinkles.
1.5mm penetration will focus on the superficial dermis, and is applicable to the thinner skin area such as around the eyes. It can reduce pores, smooth out fine lines, and improve skin tone.
More commonly treated areas include:
- Full face
- Lift up eyebrows
- The saggy lower face
- Under-chin and upper neck
Treatment Procedure
It is a non-invasive procedure without cutting, and the ultrasound is transmitted from outside the skin to deeper levels. Numbing cream is applied for 30 minutes before the procedure. According to different skin types and sagging situations, the therapist will choose to perform the HIFU over different areas on the face, with different selections or combinations of penetration depths, such as 4.5mm, 3mm and 1.5mm, as well the number of shots to be done. The whole procedure takes about 30 to 60 minutes, and the level of pain is rather minimal.
After the treatment, there is no wound, and usually there is no redness or swelling, and normal working or social schedules can be resumed immediately.
HIFU started as one time treatment in the early years but is modified to become a 3 sessions course, with each session separated by about 1 to 2 months. After a single treatment, there is mild to moderate facial skin tightening seen gradually over 1 to 2 months, and that continues to improve for about 6 months. After the whole course, the benefit can last for about 18 months, after which 1 more treatment can be repeated.
Is there any Risks?
Under the correct techniques in an experienced hand, there should not be any risks. Perhaps at most there may be some mild, short-lasting scratch-like redness and swelling. The therapist should aware of the distribution of nerves over the face, and avoid using 4.5mm probe over the sensitive areas, otherwise the nerves may be damaged, resulting in some long-lasting if not permanent nerve pain. A lot of aesthetic centres do not mention any risks and it is not so appropriate.
As the HIFU may have some effect in reducing fat to a certain extent, it has been in the literatures that some people complain of a worse looking, even more sagging facial appearance after the HIFU. This may happen in the thinner people and so it is better not to not HIFU if someone is thin and saggy, and these people would benefit more from volume enhancement such as by using Sculptra.
Finally, there are different HIFU models manufactured from the US, Korea, and even mainland China. According to experience, although the US model has a longer history and is more reputable, its treatment seems to be a lot more painful while the Korean models has only very mild discomfort during treatment, and yet the results are very comparable, if not the same or even better. The prices with the Korean models are also a lot more reasonable and as a result they are more popular in the local aesthetic market.