How to choose thread for Thread lift? Differences in material and cog design

The threads used in Thread lift change their characteristics along two axes: material and cog (barb) shape. Material determines the speed of absorption and tissue response, while cogs determine the lifting force and risk of tissue damage; however, rigorous comparative studies of materials in humans are limited[1][2].

What's the difference in thread material? — Speed of absorption and tissue response

PDO (polydioxanone) is the most commonly used in clinical practice[2]. PDO has a predictable absorption timeline of 6–8 months, an established track record as a surgical suture material, and a documented effect of promoting collagen production[1]. PLLA and PCL are described as absorbing more slowly than PDO, but research comparing dermal collagen density between materials comes from aged rat models[3], and we could not confirm in this material a direct comparative trial in humans on which material lasts longest.

How does cog shape change the lifting method?

The presence and direction of barbs determine lifting force. Smooth threads without barbs work primarily through collagen neogenesis and skin quality changes, with limited lifting force[1]. Barbed threads are designed to catch and reposition tissue, and prospective studies using three-dimensional bidirectional cogs for the midface and nasolabial folds have been reported[1].

U-shaped or I-shaped — which is stronger?

The U-shaped design with temporal fixation achieves strong lifting but is reported to be more prone to skin dimpling and tissue damage at thread exit sites[4]. The I-shaped design minimizes tissue trauma and produces more subtle changes[4]. Biomechanical studies have measured fixation strength by combination, comparing bidirectional with multidirectional concurrent use and bidirectional concurrent use[5].

How do absorbable and non-absorbable threads differ in their roles?

In a multi-center review of over 110,000 cases, absorbable threads became the mainstream from 2000 onward, while non-absorbable threads remain an option despite risks of infection, extrusion, and foreign body sensation, particularly in cases requiring strong support or in elderly patients[6]. The decision here depends on how much support strength is desired and how much you can accept the possibility of removal or revision if complications occur.

If combining with liposuction, what do you decide first?

What is decided before thread selection is how much fat reduction to pursue. As subcutaneous fat becomes thinner, the layer through which threads are passed and how fixation points are taken changes[7]. A technique of adding lifting after liposuction causes the skin to shrink and sag has been shown[4], and it is worth discussing the scope and order separately.

What to confirm during consultation

You should ask about the thread material and shape being chosen, the number of threads used, where fixation points will be placed, and what options exist if the effect fades over time. Since there is no strong data comparing longevity by material, confirming the physician's rationale for thread selection provides additional material for your decision. Skin thickness, skeletal support, and the amount of sagging (skin laxity) are evaluated individually during consultation.