A Retrospective Observational Study of Combination Treatment of Thread Lift and High-intensity Focused Ultrasound for Facial Aging

Abstract

Background:

Current literature lacks guidelines on the optimal treatment number of threads for specific indications and provides limited evidence on the efficacy of combining thread lift with other materials or devices for synergistic effects.

Methods:

This study evaluates the therapeutic outcomes of combining thread lift therapy with high-intensity focused ultrasound. Fifty-eight participants, divided into 2 groups of 29, received 3 treatments, each involving unilateral insertion of four 17-cm-long barbed Miracle threads and 200 lines of ultrasound therapy with a 4.5-mm UTIMS probe on the middle and lower face.

Results:

Wilcoxon signed-rank tests showed significant improvements in physician-evaluated Merz aesthetic scores between the second and first visits (Z = −6.057, P < 0.01), the third and second visits (Z = −5.112, P < 0.01), and between the photograph session and both the third (Z = −5.425, P < 0.01) and first visits cumulatively (Z = −4.943, P < 0.01). Additionally, Wilcoxon 2-tailed signed-rank test revealed significant reductions in jowl fat pad distance across treatment sessions.

Conclusions:

The treatment sequence did not affect facial lifting outcomes, and 3 sessions of combined thread lift and high-intensity focused ultrasound therapy sustained effects in partial participants.

Takeaways

Question: This study aimed to determine whether the use of consecutive combination therapies can enhance final facial lifting outcomes.

Findings: The treatment sequence did not affect facial lifting outcomes, and 3 sessions of combined thread lift and high-intensity focused ultrasound therapy sustained effects in partial participants.

Meaning: Consecutive combination therapy can prolong and enhance the treatment effect.

INTRODUCTION

Thread lift is a nonsurgical cosmetic procedure involving the insertion of bioabsorbable threads into the skin tissue to achieve facial contouring and address issues such as skin laxity and signs of aging.^1,2 This method is commonly used to enhance facial features, offering a shorter recovery period and reduced trauma compared with traditional surgical approaches.³ High-intensity focused ultrasound (HIFU) is a type of treatment modality that utilize high-energy ultrasound waves to stimulate deep-layer collagen production in the skin.^4,5 The absorbable suture materials used in thread lifting procedures have variable absorption times depending on their composition, typically ranging from several months to over a year.^6–8 Research on the longevity of results from a single session of HIFU (such as Ultherapy) for facial aging is limited, because it can vary depending on individual factors such as skin condition, age, and lifestyle. However, clinical studies suggest that the effects of a single session of ultrasound treatment can last for a period of up to 1–2 years.^9–11

The combined therapeutic approach of thread lift and Ultherapy has yielded inconsistent outcomes as recorded in previous literature. Varied results have been reported regarding the efficacy of this combined treatment in addressing facial skin laxity and aging indicators.¹² Combination treatments typically utilize supplementary interventions to extend and optimize the outcomes of primary procedures. This study aimed to determine if the concurrent application of complementary therapies enhances aesthetic improvements and prolongs their duration.

MATERIALS AND METHODS

This study adopted a retrospective design, covering the period from January 1, 2021, to December 31, 2023. By retrieving relevant treatment codes from the clinical information center of our institution, including those for thread lifting and ultrasound therapy, a total of 58 eligible participants were identified after applying the specified selection criteria. The study was approved by the institutional review board of Taichung Veterans General Hospital (approval code CE23546B). The inclusion criteria were as follows: participants’ age ranged from 25 to 70 years. Individuals who had undergone any cosmetic medical procedures or surgery within the preceding 6 months, as well as those who were pregnant or lactating, were excluded. Participants were divided into 2 groups based on their preference for the order of thread lift and HIFU treatments. Each group consisted of 29 enrolled patients, receiving a total of 3 treatments at intervals of 3–6 months, as shown in Figure 1. Throughout the study period, participants were prohibited from undergoing any additional cosmetic procedures or surgical procedures within a 12-month period (Fig. 1).

Fig. 1.

Participants were divided into 2 groups. The upper line represents group 1, which received HIFU first, followed by thread lifting on the same day. The lower line represents group 2, which received thread lifting first, followed by HIFU on the same day.

This study explored the superimposition of threads and aimed to conduct retrospective observational research on their effectiveness and durability. A vertical line from the lateral orbital rim divides the face into the mobile anterior and fixed lateral regions. The size of the polydioxanone (PDO) cog thread used for face lifting typically ranges from 1-0 to 3-0. Cog threads are biocompatible, absorbable barbed sutures designed for nonsurgical facial lifting, providing immediate mechanical support while stimulating collagen production for long-term skin tightening and contour enhancement.¹³ The primary placement layer is the subcutaneous tissue layer. Placing the lifting thread in the mobile area can cause protrusion and slippage, whereas continuous facial expressions may also hinder thread fixation, leading to a short-lived effect. Therefore, it is more appropriate to place PDO cog threads in the fixed areas. As shown in Figure 2, the vertical vector from the hairline to the mandibular line is often the primary direction for thread lifting in the midface and lower face. This technique improves the mandibular contour, jowl fat, and nasolabial folds.^14,15

Fig. 2.

A 1-session treatment for the combination therapy of thread lift and HIFU.

Each overlay treatment involved the unilateral insertion of four 17-cm-long barbed Miracle threads for thread lifting, along with 200 lines of ultrasound therapy using a 4.5-mm probe of UTIMS. A targeted reinforcement of ultrasound therapy comprised 50 lines in the areas of the nasolabial folds and marionette lines (Fig. 2). Before each treatment session, all participants underwent imaging using the QuantifiCare skin quality analysis device. Facial soft tissue distance measurements in both the longitudinal and transverse dimensions of the fat pads on both sides were obtained using soft tissue ultrasound with the LeSONO handheld ultrasound device. This change was categorized as increased (+): posttreatment scores higher than pretreatment scores; regression (−1): posttreatment scores lower than pretreatment scores; and no change (0): posttreatment scores remain the same as pretreatment scores. The percentage change in Merz aesthetic scores in clinical photographs was calculated by 2 dermatologists by subtracting posttreatment measurements from pretreatment measurements. This change was categorized as improvement of 0%–25%: small improvement compared with pretreatment scores; improvement of 26%–50%: moderate improvement compared with pretreatment scores; improvement of 51%–75%: substantial improvement compared with pretreatment scores; and improvement of 76%–100%: near-complete or complete improvement compared with pretreatment scores. A 100% improvement indicates that the posttreatment measurement has completely resolved or reversed the issue initially assessed by the Merz aesthetic score. In this study’s scoring system, more than 100% improvement is not possible. The scoring system is designed to measure improvement up to complete resolution or the best possible outcome, with 100% representing the maximum achievable improvement. Any further progress beyond this threshold would still be categorized as 100%. The 2 dermatologists were blinded to the group assignments, and patient serial numbers were de-identified.

Analysis Methods Explanation

Descriptive Statistics and Frequency Distribution

1. Descriptive statistics and frequency distribution included parameters such as age, intervals between the first and second visits, second and third visits, third visits and photograph sessions, as well as distance measurements (in millimeters) at each visit.

2. The frequency distribution included the percentage change in distance measurements of the jowl fat pad, categorized as an increase (+), regression (−1), or no change (0).

3. The frequency distribution included the percentage change in Merz aesthetic scores, categorized as an increase (+), regression (−1), no change (0), or improvement ranges of 0%–25%, 26%–50%, 51%–75%, and 76%–100%.

Kolmogorov–Smirnov Test

The Kolmogorov–Smirnov test was used to assess whether the millimeter values from the first, second, and third visits, as well as the photograph session (measured at right 1, right 2, left 1, and left 2), followed a normal distribution. A significance level below 0.05 indicated nonnormality, requiring nonparametric analysis. Left 1 refers to the longest transverse diameter of the left cheek fat pad as measured by the LeSONO handheld soft tissue ultrasound device, whereas left 2 refers to its longest longitudinal diameter, with the transverse and longitudinal diameters differing by a 90-degree angle. Similarly, right 1 represents the longest transverse diameter of the right cheek fat pad, and right 2 represents its longest longitudinal diameter, also differing by a 90-degree angle.

Nonparametric Spearman Correlation

The Spearman correlation coefficient was applied to examine the nonparametric relationships between variables.

Wilcoxon Two-tailed Signed-rank Test

The Wilcoxon test was used to assess 2 aspects: millimeter values and improvement effectiveness. It uses the median as the reference point to evaluate the difference in the number of observations on either side of the median. A P value less than 0.05 indicates significance, suggesting a substantial difference in improvement.

Chi-square Test

The chi-square test was used to compare the proportions of improvement effectiveness between different experimental groups. A significance level less than 0.05 indicated significant differences in improvement proportions among groups, suggesting that the experimental conditions influenced treatment outcomes. Conversely, a P value greater than 0.05 indicated no significant differences among the experimental conditions regarding improvement proportions.

RESULTS

The Wilcoxon signed-rank tests revealed statistically significant changes in physician-evaluated improvement efficacy based on Merz aesthetic scores across various comparisons. Significant improvements were observed between the second and first visits (Z = −6.057, P < 0.01) and the third and second visits (Z = −5.112, P < 0.01), as well as between the photograph session and both the third visit (Z = −5.425, P < 0.01) and the first visit cumulatively (Z = −4.943, P < 0.01).

Regarding the frequency distribution of improvement, the analysis of improvement distributions between visits and the final photograph session yielded 2 key findings. First, the majority of improvements fell within the 0%–25% range between the first and second visits. Both dermatologist 1 and dermatologist 2 consistently reported substantial proportions (over 50%) in the 0%–25% improvement category across facial areas. Second, between the second and third visits, dermatologist 1 noted a significant proportion categorized as “no change” (50.00%), whereas dermatologist 2 recorded the highest proportion (63.79%) in the 0%–25% improvement category. As natural aging progressed from the third visit to the photograph session, the highest proportion across all facial areas was categorized as “no change,” with a slight increase observed in the “worsening” category.

Additionally, distance measurements via sonography of the jowl fat pads, analyzed using the Wilcoxon two-tailed signed-rank test, showed significant reductions across sessional treatments as illustrated in Figure 3. Between consecutive visits and the photograph session, significant decreases were noted in millimeter values, indicating improvements in both facial laxity and contouring. Notably, during all treatment periods, the reductions were greatest in the following order: left 2, right 2, left 1, and right 1.

Fig. 3.

Changes in facial fat pads (nasolabial fat pads, superior jowl fat pads, and inferior jowl fat pads) as determined by distance measurement at different visits.

Through the analysis of improvement proportions, new trends were identified. Comparisons between consecutive visits (second versus first and third versus second) revealed higher proportions of improvement. In contrast, the comparison between the photograph session and the third visit showed a higher proportion categorized as decreased improvement, indicating slight regression in the absence of further treatments. Notably, the comparison between the photograph session and the first visit demonstrated a higher proportion of improvement, suggesting cumulative treatment efficacy. Standardized before-and-after images of actual study patients are shown in Supplemental Digital Content 1, whereas the Merz scale used for evaluation is presented in Supplemental Digital Content 2. (See figure, Supplemental Digital Content 1, which displays standardized before-and-after pictures of actual study patients showing positive results [age 33, scale number: from 4 to 3 in first treatment, from 3 to 2 in the second treatment, from 2 to 1 in the third treatment]; average results [age 33, scale number: from 3 to 1 in the first treatment, from 1 to 1 in the second treatment, and from 1 to 1 in the third treatment]; and poor results [age 37, scale number: from 4 to 3 in the first treatment, from 3 to 3 in the second treatment, from 3 to 3 in the third treatment], https://links.lww.com/PRSGO/E143.) (See figure, Supplemental Digital Content 2, which displays the scale used for evaluation: Merz scale,¹⁶ https://links.lww.com/PRSGO/E144.)

Overall, no significant differences were found in improvement proportions between the experimental groups, indicating consistent treatment efficacy across the studied variables, as shown in Figure 4. Age did not show a significant correlation with distance measurements or improvement effects, possibly due to the relatively homogeneous age distribution within the sample.

Fig. 4.

The flowchart of facial condition improvements in the experiment, showing that the sequence of thread lifting and ultrasound treatments on the same day did not affect the final treatment outcomes in this study.

DISCUSSION

Facial thread lifting is a well-established technique for facial rejuvenation. Fixation methods for the thread include using the barbs of the thread itself or employing threading shapes such as ring, U-shaped, W-shaped, zigzag, staggered, looping, or figure 8 patterns. Overly complex methods may lead to prolonged postoperative recovery periods, with complications such as pain, excessive swelling, skin depression, and difficulty opening the mouth. Therefore, simpler techniques, such as the straight-line approach (straight in, straight out) combined with the barbs of the thread itself, remain the mainstay of treatment in current practice, as demonstrated in this study.

The durability of thread embedding remains a controversial topic. Although the longevity of PDO threading can extend up to one year, clinically observed effects vary significantly. In this study, the efficacy of multiple superimposed therapeutic interventions in ameliorating facial laxity was investigated, with the reduction of facial fat pad hypertrophy emerging as a notable outcome. The sustained effect achieved during the follow-up period in most participants (above three-quarters) through a 3-time intervention sequence highlights the enduring impact of this multifaceted therapeutic regimen on facial tissue integrity.

Several studies have discussed the combination therapy of thread lifting and hyaluronic acid injections, concluding that this combination offers longer-lasting effects and superior facial rejuvenation outcomes without increasing the risk of complication.¹⁷ Other studies have integrated several injectables, such as botulinum toxins and calcium hydroxyapatite, for comprehensive facial aging management^.18 Additionally, some studies have combined thread lifting with small-incision rhytidectomy or lipotransfer for facial rejuvenation, reporting long-term aesthetic improvements, but also complications such as subcutaneous nodule formation.^19,20 However, no direct studies have investigated the combination of thread lift and HIFU for comparison, as seen in our study.

A limitation of our study is the absence of a control group, which would have allowed for a scientific comparison between treatment outcomes and standard treatments (eg, HIFU alone or thread lifting alone) to validate whether the observed effects correspond to the conclusions.

CONCLUSIONS

The 3-treatment sequence, involving thread lifting or ultrasound treatments on the same day, did not affect the final treatment outcomes for facial lifting in this study. Combination therapy using thread lift and HIFU was shown to prolong the treatment effect in most participants during the follow-up period. This study is the first to evaluate the effects of combining thread lifting and HIFU. However, further large-scale prospective studies are needed to clarify these findings.

DISCLOSURE

The authors have no financial interest to declare in relation to the content of this article.

ACKNOWLEDGMENTS

The authors thanks Dr. Hsu Hao, Director of the Jolie & Jeune Clinic, Taichung, Taiwan, as well as Dr. Tzeng, Yu-kai, Aesthetic Physician at the Diamond Cosmetic Clinic, Taichung, Taiwan.

DECLARATION OF HELSINKI

This study was performed in accordance with the principles of the Declaration of Helsinki.