# Correction of Nasolabial Folds Using Polydioxanone Cog Threads Combined With Botulinum Toxin Type A: A Prospective Comparative Clinical Study

## TL;DR

This study shows that combining PDO cog thread lifting with botulinum toxin A improves and prolongs the results of nasolabial fold correction compared to thread lifting alone.

## Contribution

The study introduces a combined treatment protocol of PDO cog threads and botulinum toxin A for enhanced and longer-lasting nasolabial fold correction.

## Key findings

- The combination group showed significantly greater wrinkle depth reduction and higher patient satisfaction at 3 and 6 months.
- Combined treatment demonstrated sustained superiority over monotherapy, with no serious adverse events.
- Mild complications like bruising and swelling were comparable between the two groups.

## Abstract

Introduction

Nasolabial folds (NLFs) remain one of the most common concerns that drive patients toward minimally invasive facial rejuvenation. This prospective observational study aimed to compare the clinical efficacy and durability of polydioxanone (PDO) cog thread lifting alone and in combination with botulinum toxin type A (BoNT-A) for the correction of moderate NLFs.

Materials and methods

Thirty-two patients aged 40-65 years with Modified Fitzpatrick Wrinkle Scale (MFWS) grades 2-3 nasolabial folds were divided into two groups. Group A (n = 16) received PDO cog thread lifting alone, using bidirectional barbed threads inserted along the midfacial lifting vectors. Group B (n = 16) underwent an identical thread-lift procedure, followed by targeted BoNT-A injections into the perioral and nasolabial musculature 1h later. Standardized outcomes were assessed at baseline, 15 days, 3 months, and 6 months using wrinkle depth measurement, MFWS, the Global Aesthetic Improvement Scale (GAIS), patient satisfaction score, and complication profiling.

Results

Both groups showed early improvement; however, the combination group (Group B) achieved significantly greater reductions in wrinkle depth and MFWS scores, along with higher GAIS and patient satisfaction ratings at the 3- and 6-month follow-ups. Two-way analysis of variance (ANOVA) confirmed a significant group × time interaction favoring sustained superiority in the combined treatment arm. The complication profiles were comparable and consisted only of mild, self-limiting bruising, swelling, and temporary dimpling, with no serious adverse events.

Conclusion

Adjunctive BoNT-A significantly enhanced and prolonged the esthetic outcomes of PDO cog thread lifting for nasolabial folds by mitigating the dynamic muscular forces that counteract mechanical elevation. The combined protocol is safe, effective, and offers a synergistic minimally invasive strategy that provides more natural and durable midfacial rejuvenation than thread-lifting monotherapy.