Why I use threads and filler together: rebar and concrete

Nose LINE ON, our non-surgical nose shaping treatment, combines LSCO threads with filler. I’m often asked why I don’t use just one or the other.

The materials are different. A thread is closer to a solid, while filler is closer to a gel-like fluid that can flow. To raise the nasal tip, it’s better to set it firmly with threads, like driving in rebar; for fine detail, it’s better to shape it with filler, the way concrete gives a structure its form. It’s the same principle as using rebar and concrete together to put up a building.

Skin is elastic, so when it’s stretched, it pulls back. If you build all the volume you want with filler alone, that pressure can push the filler outward and make it spread over time. If the structure is set with threads and filler is used only to refine the details, you need less filler, and the shape lasts longer.

LSCO is an L-shaped lifting suture designed for shaping the nose. Older straight threads had to hold the tip up on their own, so their sharp ends could push through the skin. I designed LSCO so that its folded L-shaped part fills the tip and supports it over a broad surface, to make the effect on the tip last longer and lower the risk of the thread pushing through.

I developed LSCO, and it is now exported to Indonesia, Vietnam, the United States and Brazil.

Here is what the research shows. How well filler holds its shape depends on the gel’s elasticity and cohesiveness (its viscoelastic and cohesive properties). A 2015 review of filler properties explained that these two properties determine how well filler holds up when pressed from the side or from above and below, and how much it spreads. The nose sticks out from the face, so it’s a place where these limits show clearly. A 2019 report summarizing experience with 96 people who had nose filler noted that nose filler spreads easily, so the crisp shape seen right after treatment is hard to maintain, and the area between the eyes often becomes blunt.

In a 2020 Korean study that followed 31 people treated with both threads and filler for 6 months, 93.5% were satisfied, the angle between the nose and upper lip increased by an average of 6.3°, and complications were few and mild. However, no study has yet directly compared using threads and filler together with using filler alone. The rebar-and-concrete comparison is an explanation based on the properties of the two materials.