Quantitative assessment of fixation strength in combined thread lifting: Comparative analysis of bidirectional-multidirectional versus double bidirectional thread combinations

Abstract

Background: The efficacy of thread lifting procedures for facial rejuvenation is significantly influenced by thread fixation strength and tissue stabilization capabilities. This study presents a quantitative biomechanical comparison between bidirectional threads (epiticon (R) BI, JETEMA Co., Ltd.) combined with multidirectional (epiticon (R) ORIGINAL, JETEMA Co., Ltd.) threads versus double bidirectional threads. Methods: Ex vivo testing was conducted on fresh cadaver tissue specimens (n = 30 per group). Two experimental configurations-bidirectional plus multidirectional and double bidirectional-were tested using standardized insertion techniques with l-type cannulas. Fixation strength was measured using calibrated tensile testing equipment. Results: The bidirectional and multidirectional combination demonstrated significantly higher mean fixation strength (52.1 +/- 2.13 N) compared to double bidirectional (47.35 +/- 2.19 N), representing an approximate to 10 % increase (p = 0.032). Qualitative assessment revealed more uniform tissue engagement patterns with the bidirectional and multidirectional combination, while the double bidirectional combination showed greater tissue concentration at the threads' central portions. Conclusions: The strategic combination of bidirectional with multidirectional threads provides superior fixation strength and more uniform tissue engagement compared to using bidirectional threads exclusively. These findings have direct clinical implications for optimizing thread selection in facial rejuvenation procedures, potentially enhancing the longevity and naturalness of aesthetic outcomes.