Is More Always Better? A Randomized Comparative Clinical Trial About the Impact of Polydioxanone Threads Quantity for Facial Lifting

Abstract

Background: Minimally invasive aesthetic procedures, such as the use of polydioxanone (PDO) threads, are increasingly popular for facial rejuvenation.

Objectives: This study investigates the impact of the number of PDO threads on tissue displacement, volume changes, and patient satisfaction.

Methods: This randomized controlled trial involved 22 patients seeking facial lifting using PDO threads. Participants were divided into 2 groups: G1 with 3 threads per hemiface and G2 with 6 threads per hemiface. Three-dimensional stereophotogrammetry was used to evaluate volumetric changes and tissue displacement at baseline, 20 days, and 60 days posttreatment. Patient satisfaction was assessed using the Global Aesthetic Improvement Scale (GAIS).

Results: Significant volumetric changes were observed over time in both midface and lower face regions (P < .05), but no significant intergroup differences were found (P > .6). Tissue displacement showed statistical significance over time (P = .039) but not between groups (P = .821). GAIS scores did not differ significantly between groups or between patients and specialists. Adverse events were minor and transient, primarily involving pain.

Conclusions: The number of PDO threads used did not significantly influence sustained lifting outcomes or patient satisfaction. Initial improvements in volume and tissue displacement diminished by 60 days, suggesting that additional threads do not enhance long-term efficacy. Further studies with longer follow-up are needed to better understand collagen stimulation's potential role in lasting effects.

Figure 1.

Schematic representation of the cannula entry point for (A) 6 (Group 1) and (B) 12 (Group 2) PDO-thread placement in a 54-year-old female patient seeking facial soft-tissue repositioning. Threads endpoints are positioned 1.5 and 1 cm apart in Groups 1 and 2, respectively.

Figure 2.

Schematic representation of the predefined middle face and lower face regions for (A) volumetric assessment in a 48-year-old female patient and (B) facial soft-tissue repositioning in a 53-year-old male patient using a stereophotogrammetry device. Arrows are pointing toward soft-tissue displacement direction.

Figure 3.

Assessment and comparison of volumetric changes between groups (Group 1—6 threads; Group 2—12 threads) at different timepoints in the middle face region. No significant differences were found between groups (P = .645). MF, midface.

Figure 4.

Assessment and comparison of volumetric changes between groups (Group 1—6 threads; Group 2—12 threads) at different time points in the lower face region. No significant differences were found between groups (P = .925).

Figure 5.

Assessment and comparison of tissue displacement between groups (Group 1—6 threads; Group 2—12 threads) at different time points. No significant differences were found between groups (P = .821).

Figure 6.

Subjective patient and investigator assessment using the Global Aesthetic Improvement Scale 60 days after treatment. No significant differences between groups (Group 1—6 threads; Group 2—12 threads) rated by the patient (P = .309) or the specialist (P = .558) were found. Also, no differences were found comparing both scores (patient vs investigator; P = .051).

Figure 7.

Photographic assessment of (A) a 38-year-old female patient from Group 1 and (B) a 47-year-old female patient from Group 2 at T0 (baseline), T1 (20 days), and T2 (60 days).