Microneedling as a Treatment for Acne Scarring: A Systematic Review

Dual-Plane Treatment With Highly Concentrated Hybrid Cooperative Complexes of Hyaluronans for Facial Atrophic Acne Scars

BACKGROUND

Managing patients with acne scars remains an important challenge, as scarring negatively affects psychosocial wellbeing. Hyaluronic acid (HA) cross-linked fillers have demonstrated good efficacy and tolerability for the correction of acne scars but are limited by their reduced biological activity and low concentrations.

OBJECTIVE

This study investigated the efficacy and safety on scars of a high-concentration (4.5%) HA-based filler with hybrid cooperative complexes (HCC) of high-molecular-weight and low-molecular-weight HA.

METHODS

Participants received treatment twice; the first was provided at baseline (T0) and the second after 4 weeks (T1). Data were collected at T1 and after 4 months (T2) by photographs and instrumental evaluation of the skin.

RESULTS

The study population included 28 patients. Improvements in the mean Goodman and Baron grade were significant across time points T0 and T1 (12% improvement; p = .0002) and T0 and T2 (31% improvement; p < .0001). Instrumental evaluation of the skin surface demonstrated a 20% reduction in the average deepness of acne scars after 4 months (p < .0001). No serious adverse events were reported during the study procedure.

CONCLUSION

Highly concentrated (4.5%) HCC appears to be an effective option for the correction of facial acne scars.

A Comparative Analysis of the Advances in Scar Reduction: Techniques, Technologies, and Efficacy in Plastic Surgery

The study provides a comprehensive analysis of the latest methodologies and treatments aimed at improving scar management. Scar formation results from the replacement of normal skin with fibroblasts, leading to a structured unidirectional collagen bundle, as opposed to the collagen sheet matrix found in healthy skin. This review categorizes scars into hypertrophic scars and keloids, each with distinct pathophysiological characteristics. It highlights the importance of consistent scar assessment using scales such as the Vancouver Scar Scale and the Patient and Observer Scar Assessment Scale, emphasizing the need for standardized evaluation methods. The study systematically reviews various scar management techniques, ranging from traditional surgical methods to innovative treatments. Conventional approaches such as pressure garments and silicone gel sheeting are explored, noting their roles in maintaining hydration and occlusion. The efficacy of intralesional corticosteroid injections and laser therapies is discussed, with particular attention given to their combined use for optimal outcomes. The review also covers advanced techniques such as microneedling, platelet-rich plasma therapy, and stem cell-based treatments, detailing their mechanisms and potential benefits in scar remodelling. Additionally, the study underscores the emerging role of botulinum toxin A in both preventive and corrective scar treatments, offering promising results in reducing movement-induced scar exaggeration. The systematic review includes a thorough examination of existing literature, clinical trials, and meta-analyses to evaluate the effectiveness of these interventions. It concludes by calling for further research to refine these techniques and enhance their application in clinical practice, aiming to achieve better aesthetic and functional outcomes for patients with scars.

A Network Meta-analysis to Explore the Effectiveness of the Different Treatment Modalities in Acne Scars

BACKGROUND

Multiple treatments are used to treat acne scars, but comparing the effectiveness of these treatments have not been studied yet. This research aimed to conduct a complete analysis of the effectiveness of commonly used therapies in acne scars.

METHODS

PubMed, Embase, and Cochrane's Library (Cochrane Center Register of Controlled Trials) databases were searched through May 2023. We used patient satisfaction score as the primary outcome and Goodman Baron qualitative scar grading system as the secondary outcome to evaluate the effectiveness of different commonly used therapies for acne scarring, including laser, microneedling (MN), platelet-rich plasma (PRP), autologous fat grafting and combined therapies.

RESULTS

Herein, 495 patients from 13 studies were included. Our results showed that PRP combined with laser was the most effective among therapies in treating acne scars. Ranking of effectiveness by the surface under the cumulative ranking (SUCRA) curve for patient satisfaction score was as following: PRP + laser (96.2%) > laser (71.2%) > MN (45.5%) > MN + PRP (42.0%) > autologous fat grafting (24.5%) > PRP (20.5%). Additionally, ranking of effectiveness by the SUCRA curve for Goodman Baron qualitative scar grading system was as following: PRP + laser (86.3%) > laser (64.2%) > MN + PRP (54.2%) > MN (37.2%) > PRP (8.1%).

CONCLUSION

This network meta-analysis indicated that the combined therapy of PRP and laser might be the most effective. Additionally, more high-quality randomized controlled trials are needed to verify our findings.

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 .

Evaluation of Ultrasound Changes With the Use of Microneedling Versus Fractional CO2 Laser in Atrophic Acne Scars

INTRODUCTION

Atrophic acne scarring, a common sequela of acne, can be treated by different interventions, including microneedling and laser resurfacing.

OBJECTIVES

We sought to evaluate the comparative efficacy of microneedling versus fractional CO2 laser in treating atrophic acne facial scars using imaging with high and ultra-high frequency ultrasound.

METHODS

Participants received 2 sessions, separated by 1 month, of microneedling on the left side of the face and fractional CO2 laser on the right. Color Doppler ultrasound evaluations (24 and 70 MHz) were conducted at baseline and 3 months after treatment. Each patient completed questionnaires on satisfaction, pain, and adverse effects.

RESULTS

Nine subjects were enrolled. The frequency order of scar types was boxcar, ice-pick, and rolling. At 3 months, using the acne scar clinical evaluation scale, a decrease in scar scores of both methods was observed for total scars (P = 0.0005), ice-pick scars (P = 0.0128), and rolling scars (P = 0.0007). Twenty-two scars analyzed by ultrasound demonstrated a trend to decrease in size; however, no significant changes were observed for either microneedling or CO2 laser treatments. Moreover, there were no significant differences between these methods. Both treatments were rated as good or very good by patient assessments. There was a low frequency of pain and hyperpigmentation reported with both modalities, albeit somewhat higher with microneedling.

CONCLUSIONS

Both microneedling and CO2 laser improved atrophic acne scars. Ultrasound did not show significant differences between these modalities.

Evaluation of microneedling depth of penetration in management of atrophic acne scars: a split-face comparative study

BACKGROUND

Microneedling is a technique of repeated puncturing or drilling of the skin to induce repair and collagen induction. There are many reported important factors determining the efficacy of microneedling treatment. The extent of injury needed to produce the desired effect in each condition is one of these important factors.

OBJECTIVES

We designed the present split-face comparative study to evaluate the use and effectiveness of two different depths of penetration of Dermapen needles in the management of atrophic postacne scars.

PATIENTS AND METHODS

The present study involved 14 subjects with atrophic postacne scars. In each patient, both sides of the face were treated with six sessions of microneedling, using Dermapen at 2-week intervals. A split-face study design was performed. The right (Rt) side of the face was treated with Dermapen using 2.5 mm needle length, while the left (Lt) side was treated using 1.5 mm needle length.

RESULTS

There was a significantly better percentage of improvement of acne scars on the Rt side of the face compared to the Lt side (P = 0.02) after six sessions. Both sides of the face showed improvement of collagen bundles and elastic fibers characteristics after six sessions.

CONCLUSIONS

The use of 2.5 mm depth proved to be more effective both clinically and histologically in the management of atrophic postacne scars.

A Comparative Study on the Usefulness of Fractional CO2 and Fractional Er:YAG in Acne Scars: A Split-Face Trial

Background

Acne is a dermatologic condition with a high burden in terms of psychosocial consequences as a result of scars remaining on the skin. Its effects are severe in adolescence and finding treatments with short therapy courses, superior results, and fewer adverse effects are of high importance.

Materials and Methods

We included 30 individuals with acne vulgaris scars in Al-Zahra academic training hospital from June 2018 to Jan 2019. Each individual received both fractional CO₂ and fractional Er:YAG lasers on right and left sides of the face, respectively. Three sessions of laser treatment were applied to each side with one-month intervals. Results were evaluated by patients according to subjective satisfaction and physicians' assessment and photo evaluation by two blinded dermatologists. Improvement was graded by a quartile grading scale: less than 25%: mild, 25% to 50%: moderate, 51% to 75%: good, and 76% to 100%: excellent response. Assessments were obtained at baseline and one month after the last visit.

Results

Based on subjective satisfaction (p < 0.05) and physicians' assessment (p < 0.01), fractional CO₂ laser was significantly more effective than Erbium:YAG laser. Also, Post-treatment side effects were mild and transient in both groups.

Conclusion

Laser therapies are common in the treatment of scars and each modality has special advantages and disadvantages. Choosing among them should be based on various criteria. Fractional CO₂ lasers have been revealed favorable results in most reports. Large comprehensive trials could help experts in choosing among alternatives for different subgroups.

3D printing of microneedle arrays for hair regeneration in a controllable region

Hair loss is a common skin disease that causes intense emotional suffering. Hair regeneration in a personalized area is highly desirable for patients with different balding conditions. However, the existing pharmaceutical treatments have difficulty precisely regenerating hair in a desired area. Here, we show a method to precisely control the hair regeneration using customized microneedle arrays (MNAs). The MNA with a customized shape is fast fabricated by a static optical projection lithography process in seconds, which is a 3D printing technology developed by our group. In the mouse model, MNA treatment could induce hair regrowth in a defined area corresponding to the customized shape of MNA. And the regenerated hair promoted by MNAs had improved quality. Cellular and molecular analysis indicated that MNA treatment could recruit macrophages in situ and then initiate the proliferation of hair follicle stem cells, thereby improving hair regeneration. Meanwhile, the activation of the Wnt/β-catenin signaling pathway was observed in hair follicles. The expressions of Hgf, Igf 1 and Tnf-α were also upregulated in the treated skin, which may also be beneficial for the MNA-induced hair regeneration. This study provides a strategy to precisely control hair regeneration using customized microneedle arrays by recruiting macrophages in situ, which holds the promise for the personalized treatment of hair loss.

Efficacy and tolerability of a microneedling device for treating wrinkles on the face

OBJECTIVES

A microneedling pen has been cleared by the US Food and Drug Administration, indicated for improving the appearance of adult facial acne scars. The objective of this study was to assess the device's effectiveness for treating wrinkles of the face area.

MATERIALS AND METHODS

Healthy adults seeking to improve the appearance of face wrinkles were enrolled (N = 35), receiving four monthly microneedling procedures by a trained aesthetician who treated the face skin per manufacturer instructions. Wrinkle assessments were performed by two trained blinded raters by comparing baseline images of each subject with images obtained at 90 days post-procedure. Subsequently, the two raters were unblinded for the Clinician's Global Aesthetic Improvement Scale (CGAIS) assessment. Subjects completed the Subject's Global Aesthetic Improvement Scale (SGAIS) and a Satisfaction Questionnaire at 30 and 90 days post-treatment.

RESULTS

The study was completed by 32 subjects with a mean (SD) age of 56.3 (5.0) years. Wrinkle assessments demonstrated significant improvement in the face areas (p < 0.001). The SGAIS scores showed significant improvements after 30 and 90 days post-treatment (for each, p < 0.001). The CGAIS scores also showed significant improvements at 90 days post-treatment (p < 0.001). Most subjects reported some level of improvement in their appearance at 30 days (73.3%) and 90 days (68.8%) post-treatment. The satisfaction questionnaire showed high levels of improvement in wrinkles (93.8%), satisfaction with the treatment procedure (87.5%) and would recommend microneedling to friends and family members (80.6%) on the face and neck.

CONCLUSION

Microneedling is a viable, minimally invasive option for treating wrinkles of the face.

CLINICALTRIALS

gov Identifier: NCT03803059.

Microneedling Outcomes in Early Post-Surgical Scars

BACKGROUND

Scars are a vexing sequela of surgery. Microneedling, also known as Minimally Invasive Percutaneous Collagen Induction (MIPCI), has demonstrated impressive improvements in chronic acne scars; however, no evidence exists for treating post-surgical scars during active wound healing. The purpose of this study was to demonstrate the utility and safe use of MIPCI in acute post-surgical scars.

METHODS

Twenty-five subjects who underwent surgery had scars treated with 3 treatments of MIPCI in the postoperative period. Scar assessment was measured by Vancouver Scar Scale (VSS), Patient & Observer Scar Assessment Scale (POSAS) and Global Aesthetic Improvement Scale (GAIS) after each of the 3 treatments and at final 2 month follow up.

RESULTS

Patients had positive improvement in VSS, POSAS and GAIS at 16-week post treatment initiation evaluation compared to initial measurement (p value<0.001). No statistically significant differences were noted when comparing the age of the patient, location of scars or Fitzpatrick Phototype Scales between patients. However, when comparing patients who began treatment early (week 6 to 7 post-op) to those who began treatment late (week 13 to 16 postop), there was a statistically significant difference in the POSAS group (p value <0.04).

CONCLUSIONS

Post-surgical scars treated with MIPCI in the maturation and remodeling phase had no adverse outcomes. Interestingly, our data shows treatment initiated early in the maturation phase (6-7 weeks post-op) while natural collagen formation was tapering off demonstrated improved aesthetic outcomes compared to treatments initiated late in the maturation phase (13-16wk post-op).

Microneedling Monotherapy for Acne Scar: Systematic Review and Meta-Analysis of Randomized Controlled Trials

INTRODUCTION

Acne scarring, formed by the deposition of collagen following inflammatory acne, not only represents a cosmetic problem but also poses a psychological health risk to patients. As microneedling has become a common treatment for acne scarring, an increasing number of studies have compared the efficacy and safety of microneedling. In this study, we conducted a meta-analysis of randomized controlled trials (RCTs) comparing microneedling with other treatments.

METHOD

Three databases, namely Embase, PubMED, and Cochrane library, were searched until June 20, 2021, for RCTs only. Studies using microneedling in both treatments were excluded.

RESULTS

Twelve studies, totaling 414 participants, were included in our meta-analysis. For objective scar improvement, the pooled estimate analysis of the first group, treated with microneedling without radiofrequency, yielded a mean difference of 0.42 (95% CI-0.12-0.73%) with a significant difference at the 5% significance level. The second group, treated with fractional radiofrequency microneedling, exhibited no significance at the 5% significance level. Regarding subjective satisfaction, most results exhibited no significant difference between microneedling and other treatments. Although no case of secondary scarring or infection was reported in our study, the pooled result of postinflammatory hyperpigmentation was significant at the 5% significance level and preferred microneedling treatment.

CONCLUSION

Microneedling without radiofrequency achieved superior results in terms of scar improvement. No form of microneedling caused postinflammatory hyperpigmentation-an advantage in acne scar treatment. Thus, microneedling is a favorable choice for the treatment of acne scarring.

LEVEL OF EVIDENCE III

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 Tolerability of a Microneedling Device for Treating Wrinkles on the Neck

Background

A microneedling pen has been cleared by the US FDA and is indicated for improving the appearance of facial acne scars in adults.

Objectives

The aim of this study was to assess the effectiveness of this microneedling pen for treating wrinkles. This paper focuses on the results on the neck, an area of recent importance with video meetings placing physical stress on the neck area, leading to wrinkles.

Methods

Healthy adult men and women were enrolled (N = 35). Subjects received 4 monthly microneedling procedures at depths of up to 2.5 mm. Wrinkle assessments were performed by 2 trained blinded raters by comparing images of each subject at baseline and at 90 days postprocedure. The 2 raters were unblinded for the Clinician’s Global Aesthetic Improvement Scale assessment. Subjects completed the Subject’s Global Aesthetic Improvement Scale and a questionnaire regarding satisfaction with the treated areas of the face and neck at 30 and 90 days posttreatment.

Results

The study was completed by 32 subjects. Wrinkle assessments demonstrated significant improvement in the neck areas (P < 0.001). Both Global Aesthetic Improvement Scales showed significant improvements at 90 days posttreatment (P < 0.001). Most subjects reported some level of improvement in their appearance at 30 days (73.3%) and 90 days (68.8%) posttreatment. The satisfaction questionnaire showed high levels of improvement in wrinkles (93.8%), satisfaction with the results (87.5%), and would recommend microneedling to friends and family members (80.6%).

Conclusions

Microneedling is a viable, minimally invasive option for treating wrin kles of the neck.

Level of Evidence: 4

A Single-Center Trial to Evaluate the Efficacy and Tolerability of Four Microneedling Treatments on Fine Lines and Wrinkles of Facial and Neck Skin in Subjects With Fitzpatrick Skin Types I-IV: An Objective Assessment Using Noninvasive Devices and 0.33-mm Microbiopsies

BACKGROUND

Although ablative techniques are the standard of care for the treatment of fine lines and wrinkles, microneedling offers a minimally invasive alternative.

OBJECTIVES

The purpose of this study was to assess the efficacy of microneedling on facial and neck fine lines and wrinkles.

METHODS

Thirty-five subjects between 44 and 65 years old with Fitzpatrick skin types I to IV received 4 monthly microneedling treatments over the face and neck. Subjects returned 1 and 3 months posttreatment. At every visit, high-resolution ultrasonography and optical coherence tomography were performed, and transepidermal water loss and skin elasticity were measured. Microbiopsies (0.33 mm) were collected pretreatment, before the fourth treatment and 3 months posttreatment.

RESULTS

Thirty-two subjects (30 females, 2 males) completed all 7 visits. Facial dermal and epidermal density increased 101.86% and 19.28%, respectively, from baseline at 3 months posttreatment. Facial elasticity increased 28.2% from baseline at 3 months posttreatment. Facial attenuation coefficient increased 15.65% and 17.33% at 1 and 3 months posttreatment, respectively. At study completion, blood flow at a depth of 300 µm decreased 25.8% in the face and 42.3% in the neck. Relative collagen type III and elastin gene expression was statistically higher 3 months posttreatment. However, total elastin protein levels were unchanged from baseline values. Dermal muscle formation was observed in 58% of biopsies extracted 3 months posttreatment compared with 15.3% at baseline.

CONCLUSIONS

The results illustrate the effects of microneedling treatments. Noninvasive measurements and biopsy data showed changes in skin architecture and collagen/elastin gene expression, suggesting skin rejuvenation, with new extracellular matrix production and muscle formation.

LEVEL OF EVIDENCE: 3

Safety Profile for Microneedling: A Systematic Review

BACKGROUND

Microneedling is a minimally invasive procedure that stimulates collagen and elastin proliferation. It is used in the treatment of various skin pathologies, that is, scarring, photodamage, and hair loss; however, its safety profile has yet to be comprehensively reviewed.

OBJECTIVE

This review will discuss the reported side effects of microneedling in the current literature and delineate factors that increase the risk of complications.

MATERIALS AND METHODS

A literature search in August 2019 was conducted using the PubMed database to identify studies reporting adverse events (AEs) after microneedling therapy.

RESULTS

Eighty-five articles were included in this systematic review. The most common reported AEs are transient procedural events that are expected postprocedure lasting up to 7 days, such as transient erythema/edema and pain, postinflammatory hyperpigmentation (PIH), dry skin/exfoliation, lymphadenopathy, and irritant contact dermatitis. Persistent serious adverse effects included PIH, tram-track scarring, and granulomatous reactions. Factors that increase the risk of events are active infections, darker skin, and metal allergies.

CONCLUSION

Microneedling is a relatively safe therapy. Most reported AEs are minimal, resolving quickly and spontaneously. Caution should be taken in patients with active infection, darker skin types, metal allergies, and when used in conjunction with products not approved for intradermal use.

Preliminary Prospective and Randomized Study of Highly Purified Polynucleotide vs Placebo in Treatment of Moderate to Severe Acne Scars

BACKGROUND

Managing acne scars is a challenge and therapies are divided into nonsurgical and surgical. Highly Purified Technology Polynucleotides (PN-HPT) is a compound that contains a mixture of DNA polymers of different lengths. Numerous studies have shown that PN-HPT also serves as an energy source, thus influencing cellular growth and cell vitality.

OBJECTIVES

The authors aimed to assess the improvement in dermal quality and acne scars after PN-HPT vs placebo according to Antera 3D and the patient responses to the patient satisfaction questionnaire after a comparison of pretreatment and posttreatment photographs at 1 and 3 months.

METHODS

Included were women aged 30 to 50 years with grade 3 to 4 moderate-to-severe atrophic scars according to the Goodman classification; nonsmokers; and had not had active acne during the past 5 years. Ten patients (PN-HPT group) were treated with 4.0 mL of PN-HPT, and 10 patients (control) were treated with 4.0 mL of normal saline. All medical treatments were performed in a double-blinded manner; neither the injection doctor nor the patient knew if the PN-HPT or the placebo was being administered.

RESULTS

Twenty women who fit the inclusion criteria were enrolled in this study. Only patients in the PN-HPT group improved significantly at 1 and 3 months after treatment compared with baseline.

CONCLUSIONS

This prospective and randomized study showed that PN-HPT in monotherapy was safe and effective treatment for atrophic scar acne compared with placebo. Prospective and randomized studies will be necessary to investigate the clinical effectiveness in a larger cohort of patients and for a longer follow-up.

LEVEL OF EVIDENCE: 2

[Scientometric analysis of evidence-based studies of physical methods of post-acne scar correction]

The scope of physical methods for correcting the pathological skin scars is rapidly growing but the results of their use are often unsatisfactory. An inadequate approach to therapy without taking into account the assessment of their effectiveness leads to relapses, increased growth of scar tissue or the absence of a clinically significant effect which requires strict scientific evidence in the course of benign scientific studies.

OBJECTIVE

Scientometric analysis of evidence-based studies on the use of therapeutic physical factors in the correction of post-acne scars.

MATERIAL AND METHODS

The analysis of evidence-based studies in electronic databases (PEDro, PubMed, eLibrary) and in databases of systematic reviews (Cochrane database) for the period from 2015 to 2020 was carried out. The following terms in Russian and English were taken as key words: acne scars (acne scarring), physical therapy (physical therapy). The final assessment of physical methods of correction included mainly data from foreign systematic reviews, meta-analyzes of RCTs, data from individual RCTs in English and/or Russian and tests rated at 4 points or higher on the PEDro scale.

RESULTS

The clinical effects and supposed mechanisms of action of the currently proven therapeutic physical factors in the treatment of patients with post-acne scars are considered in detail. The most studied physical methods are technologies of high-intensity laser therapy (44.2%), fractional radiofrequency therapy (17%), combined methods of exposure (high-intensity laser therapy or micro-needling in combination with peels, fillers, PRP injection) (25%), micro-needling as monotherapy (5.8%) and microdermabrasion (4.5%) causing the most significant clinical changes and pronounced remodeling of the extracellular matrix of the skin in the area of scars.

CONCLUSION

There is a need for regular synthesis and analysis of existing evidence-based studies, as well as the implementation of new high-quality randomized controlled clinical trials to study the effect of physical correction methods on post-acne scars which serve as the basis for the development of clinical guidelines.

The Current Status of Clinical Research Involving Microneedles: A Systematic Review

In recent years, a number of clinical trials have been published on the efficacy and safety of drug delivery using microneedles (MNs). This review aims to systematically summarize and analyze the current evidence including the clinical effect and safety of MNs. Three electronic databases, including PubMed, were used to search the literature for randomized controlled trials (RCTs) and clinical controlled trials (CCTs) that evaluated the therapeutic efficacy of MNs from their inception to 28 June 2018. Data were extracted according to the characteristics of study subjects; disorder, types, and details of the intervention (MNs) and control groups; outcome measurements; effectiveness; and incidence of adverse events (AEs). Overall, 31 RCTs and seven CCTs met the inclusion criteria. Although MNs were commonly used in skin-related studies, evaluating the effects of MNs was difficult because many studies did not provide adequate comparison values between groups. For osteoporosis treatment, vaccine, and insulin delivery studies, MNs were comparable to or more effective than the gold standard. Regarding the safety of MNs, most AEs reported in each study were minor (grade 1 or 2). A well-designed RCT is necessary to clearly evaluate the effectiveness of MNs in the future.

Prospective and randomized comparative study of calcium hydroxylapatite vs calcium hydroxylapatite plus HIFU in treatment of moderate-to-severe acne scars

BACKGROUND

Acne scars are the most common sequelae of the severe inflammatory process of acne, and its managing is a challenge. Objective of this study was to assess safety and effectiveness of calcium hydroxylapatite monotherapy and its association with high-intensity microfocused ultrasound for treating moderate-to-severe atrophic acne scars.

METHODS

Women with moderate-to-severe atrophic scars of the face were enrolled on the study. Assessments were made by digital macrophotographs, Vectra H2, and Antera 3D.

RESULTS

From October to December 2019, twenty women which fitted the inclusion criteria signed a consent form and received 3.0 mL of calcium hydroxylapatite and after 4 weeks, 400 lines of HIFU. No major side effects were reported during the study, and all patients completed the follow-up after 6 months. At 1 month, patients treated with calcium hydroxylapatite (group 1) improved wrinkles and skin texture compared to placebo (group 2). At 3 and 6 months, all patients improved acne scars.

CONCLUSION

Our study showed that that both calcium hydroxylapatite and HIFU in monotherapy were safe and effective treatments for atrophic scar acne. Calcium hydroxylapatite was clinically effective when compared with placebo, though the combination of calcium hydroxylapatite and HIFU did not enhance the clinical efficacy compared to monotherapy.