Three-dimensional digital surface imaging measurement of the volumizing effect of injectable poly-l-lactic acid for nasolabial folds

Comprehensive Systematic Review of Poly-L-lactic Acid in Facial Clinical Application

OBJECTIVES

With the increasing global clinical application of regenerative injection materials, there is a growing recognition of the crucial role played by poly-L-lactic acid (PLLA). The aim of this study is to conduct a systematic review on the therapeutic efficacy and safety of PLLA in clinical applications for facial treatments.

METHODS

We conducted a search of the PubMed, EMBASE, Web of Science, and Wanfang databases, followed by screening of the retrieved articles based on predefined inclusion and exclusion criteria. We then performed an analysis on the final set of included articles that met our inclusion criteria. Within these included articles, quality assessment for randomized controlled trials (RCTs) was carried out using the Jadad scale, while non-randomized controlled trials (non-RCTs) were evaluated using the MINORS scale.

RESULTS

Our search of above database, using the relevant search terms, yielded a total of 1300 PLLA-related articles. After applying the inclusion and exclusion criteria, 1280 articles were excluded. Only 20 articles, 16 in English and 4 in Chinese, were included in our final analysis, among them 16 NRCTs and 4 RCTs. According to the different clinical evaluation standards, the treatment of PLLA has achieved good outcomes. Most PLLA injection-related adverse events are mild and self-limited, without any additional treatment requirement.

CONCLUSION

PLLA is a reasonably safe and effective facial injection material that can be applied in different facial injection areas and depth using various reconstitute and injection methods.

LEVEL OF EVIDENCE I

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Efficacy and Safety of Fillers for the Treatment of Nasolabial Folds: A Network meta-Analysis of Randomized Controlled Trials

BACKGROUND

Nasolabial fold formation is increasingly becoming a cause of concern for many people. However, no network meta-analysis has compared the efficacy of different fillers in treating nasolabial folds. This network meta-analysis simultaneously compared the efficacy and safety of various fillers.

METHODS

We included randomized controlled trials (RCTs) that used fillers to treat nasolabial folds. We extracted data of Wrinkle Severity Rating Scale (WSRS), Global Esthetic Improvement Scale (GAIS, investigator) scores, GAIS scores (self-reported) and adverse events.

RESULTS

We included 13 RCTs. WSRS scores at 6 months were higher in patients receiving HA than those receiving poly (L-lactic acid) (mean difference [MD] 0.630, 95% confidence interval [CI] 0.275, 0.985) but significantly lower in patients receiving HA than in those receiving bovine collagen (MD - 0.580, 95% CI - 0.777, - 0.383) and porcine collagen (MD - 0.525, 95% CI - 0.790, - 0.260). Regarding adverse events, HA was significantly less likely to cause nodule formation compared with bovine collagen (RR 0.593, 95% CI 0.438, 0.803).

CONCLUSION

HA is a safe filler for correcting nasolabial folds, and poly (L-lactic acid) showed potential in treating nasolabial folds.

LEVEL OF EVIDENCE I

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Using the depth deviation based on three-dimensional images to evaluate the correction of nasolabial folds: A prospective and quantitative analysis

BACKGROUND AND OBJECTIVE

The deepening of the nasolabial fold (NLF) is a common occurrence during the aging process, necessitating the development of an objective method to evaluate changes in NLFs. The objective of our study was to introduce a method of depth deviation based on three-dimensional (3D) image for evaluating the efficacy of hyaluronic acid (HA) injection in correcting NLFs.

METHODS

Between May 2019 and November 2019, we recruited 56 Chinese volunteers with moderate to severe NLFs for this study. The participants received HA injections and were followed up for a period of 12 months. Pre and posttreatment, we collected the Wrinkle Severity Rating Scale (WSRS) scores and 3D images. To assess the efficacy of NLF correction, we used the maximum value of depth deviation (MVD) based on 3D images and the Global Aesthetic Improvement Scale (GAIS) score. Additionally, we compared the relationship between MVD and other clinical parameters.

RESULTS

Fifty-four female participants completed the study and were included in the analysis. The HA injection resulted in a significant decrease in NLF severity (p < 0.05). One month after the injection, the average GAIS score was 4.72 ± 0.45, and the average MVD was 2.10 ± 0.56 mm. Both the GAIS score and the average MVD exhibited a decline over time during the follow-up period, with the average MVD showing a significant correlation with the GAIS score at all time points (p < 0.05).

CONCLUSIONS

Using 3D technology, we demonstrated that the quantitative data provided by MVD can serve as an objective method for evaluating the correction of NLFs.

Objective Assessment of the Long-Term Volumizing Action of a Polycaprolactone-Based Filler

Background

The polycaprolactone-based filler, (PCL-1, Ellansé-S), forms part of the recently growing portfolio of biodegradable collagen-stimulating fillers. It is comprised of a suspension of 25-50 micron diameter microspheres of polycaprolactone (PCL) (30%) in a carboxymethyl cellulose (CMC) gel carrier (70%) and has gained popularity due to its long-term volumizing action.

Objective

This study outlines a retrospective case series of nine patients injected with the PCL-1, for volume augmentation in the mid-face. Objective volume calculations were performed with the Canfield Vectra 3D Imaging System at two time points post-implantation, with the objective of determining the longevity of the volumizing effect of the bio-stimulating substance.

Results

A clear increase in volume, between 50-150%, was found in all of the patients at two years, over and above the volume initially injected. All the patients were satisfied with the longevity of the results.

Discussion

The PCL-based filler is believed to afford immediate volume restoration due to the CMC gel component and a long-term action due to neo-collagenesis, induced by the PCL microspheres. The CMC gel is known to dissipate within 6-8 weeks, only to be replaced by new collagen induced by the PCL particles. Thus soft-tissue formation induced by the PCL particles, ultimately leads to a sustained volumizing effect.

Conclusion

The PCL-based filler is shown to have a sustained volumizing effects of at least 2 years duration with clear evidence of increase in volume over and above the volume injected, in all of the cases studied. This is indicative of significant neo-collagenesis induced by the PCL microspheres.

Quantitative Evaluation of Nasolabial Fold by Three-Dimensional Imaging: A Comparison with WSRS Score

BACKGROUND

Nasolabial fold (NLF) reveals the aging of the face, and various treatments for NLF have been developed currently. However, most methods introduced to evaluate NLF are subjective and qualitative.

OBJECTIVES

This study was aimed to establish and validate a quantitative evaluation method by three-dimensional imaging, and thus accordingly to determine the relationship between quantitative measurements and wrinkle severity rating scale (WSRS) score.

METHODS

Seventy-five Asian female volunteers were enrolled for evaluating the severity of NLF based on both WSRS score and three-dimensional imaging. Three-dimensional imaging was used to collect the quantitative measurements of NLF, including length, width, and depth. The relationship between multiple WSRS scores and quantitative measurements was compared statistically. Besides, thirty patients with moderate or severe NLF were admitted to receive hyaluronic acid injection for NLF correction. All NLFs were evaluated quantitatively pre-injection and 3 months post-injection.

RESULTS

The results revealed a statistically significant positive relationship between the WSRS score and the length, width, and depth of NLF, respectively. After 3 months of hyaluronic acid injection, the mean WSRS score, the length, width, and depth of NLF were significantly reduced.

CONCLUSIONS

Three-dimensional imaging can be used to quantitatively assess the severity of the nasolabial folds, compensating for the deficiencies of traditional scales. This technique may help improve rejuvenation procedures for the aging nasolabial fold.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Cephalometric analysis following combined Sub-SMAS hyaluronic acid injection and subdermal and supraperiosteal poly-L-lactic acid injections in Asian women

Background

The aging face is characterized by skin laxity and volume loss. Attenuation of facial retaining ligaments significantly contributes to skin sagginess and soft tissue volume loss.

Aims

We designed a prospective cohort study to quantitatively assess the efficacy of hyaluronic acid (HA) with adjunct poly‐L‐lactic acid (PLLA) injections in strengthening the retaining ligaments.

Patients/Methods

A total of 12 Asian women were treated with HA injections to the orbital, zygomatic, buccal‐maxillary, and mandibular retaining ligaments with adjunct supraperiosteal and subdermal PLLA injections to the temporal region, midface, and lower face. Cephalometric measurements were done before treatment and 2, 4, 12, and 24 weeks post‐procedurally.

Results

Eyebrow peak and tail angles increased 20.0° ± 3.8° to 21.0° ± 3.8° (p < 0.05) and −2.9° ± 4.2° to −1.3° ± 3.3° (p < 0.001) at week 12. Eyebrow‐to‐orbital‐rim distance increased 1.9 ± 2.0 mm to 3.9 ± 1.5 mm (p < 0.001) at week 12. Eyebrow‐to‐upper‐eyelid distance increased 11.6 ± 3.0 mm to 12.7 ± 3.2 mm (p < 0.001) at week 24. Eyebrow‐peak‐to‐lateral‐limbus distance decreased 6.1 ± 3.1 mm to 5.3 ± 2.4 mm (p < 0.05) at week 4. Tragus‐oral‐commissure length and lower‐facial‐contouring length decreased 281 ± 11 mm to 275 ± 10 mm (p < 0.01) and 297 ± 14 to 292 ± 11 mm (p < 0.05) at week 12, respectively.

Conclusion

Hyaluronic acid injection for strengthening of facial retaining ligaments with adjunct PLLA is viable, safe, and effective in facial rejuvenation as supported by quantitative data.