Background; Thread lifting is currently one of the most commonly used minimally invasive options in facial rejuvenation procedures. In particular, the absorbable polydioxanone (PDO) thread effectively strengthens the contours of the face due to its collagen-stimulating properties, corrects the shape of a round and saggy face, and increases skin elasticity, while enabling relatively short downtime due to its minimally invasive properties.
Purpose; This study evaluated the efficacy of PDO thread with combination of cog type and press cog type thread (Ncog & Nfix) and cog type thread (Ncog) alone, Secondarily, it was conducted to evaluate the effect and safety of applying very fine braided type PDO threads(N-scaffold) additionally to the aged lower eyelid.
Method; A total of 30 patients with slightly sagging facial skin who had undergone thread lifting using a PDO thread were targeted.
The subjects were divided into two groups of 15 in each group. The first group performed only midfacial thread lifting using PDO cog thread ("non-SCA" group), and the second group performed midface thread lifting with twisted PDO thread to improve tear trough deformation ("N-SCA(Scaffolds) group). The results were subjectively based on patient satisfaction, and pre- and post-operative photo evaluations were conducted by an objective evaluator.
Result; The average age of the subjects was 51.8 years (range 65-34 years). There was a statistically significant difference between preoperative and postoperative results with an average of 1.94±0.43 points (p<0.05). Also, the combination of Ncog and N fix showed slightly better results than Ncog alone. As for patient satisfaction, all patients were satisfied with the clinical results.
According to Barton's grading system, after 7 months of treatment, there was a statistically significant difference of 1.733±0.74 in the non-SCA group and 0.733±0.83 in the N-scaffold group (p<0.05). According to the patient's self-satisfaction evaluation, there was a significant difference after 7 months of treatment: 2.86 ± 0.84 in the "non-SCA" group and 3.76 ± 0.90 in the "N-scaffold" group, p < 0.05. Complications such as persistent swelling, hematoma, skin irregularity, and infection were not observed during the follow-up period.
Conclusion; It was confirmed that the PDO thread is effective in rejuvenating aged skin, increasing and supporting soft tissue elasticity, and is a safe procedure with relatively few complications. In thread rejuvenation of the mid-face, in particular, when thin twisted PDO thread (N-scaffold) was applied to the aged lower eyelid, effective wrinkle and skin improvement effects were confirmed for a certain period of time.


References
1. Khan G, Ahn KH, Kim SY, Park ES. Combined press cog type and cog PDO threads in comparison with the cog PDO threads in facial rejuvenation. J Cosmet Dermatol. 2021 Oct;20(10):3294-3298.
2. Khan G, Kim BJ, Kim DG, Park ES. Retrospective study of the absorbable braided polydioxanone threads' usefulness in the aged lower eyelids' rejuvenation. J Cosmet Dermatol. 2022 Nov;21(11):5952-5956.
3. Ha YI, Kim JH, Park ES. Histological and molecular biological analysis on the reaction of absorbable thread; Polydioxanone and polycaprolactone in rat model. J Cosmet Dermatol. 2022 Jul;21(7):2774-2782.