Investigating Facial Muscle Physiology Following Soft Tissue Filler Injections-A Surface-derived Electromyographic and Skin Vector Displacement Analytic Study.

The use of hyaluronic acid-based soft tissue fillers has often been reported to modulate the muscle, that is, to cause myomodulation. To our knowledge, there has been so far no scientific study investigating the potential of hyaluronic acid-based soft tissue fillers to modulate or actually alter the function of facial muscles. To further assess this three-dimensional (3D) surface imaging and electromyography (EMG)-based prospective study investigated the changes of facial muscle contraction after injection of strategically placed hyaluronic acid-based soft tissue fillers to assess the actual validity of the term myomodulation. A total of 13 subjects with a mean age of 37.8 years (12 females, 1 male) were injected according to a predefined injection protocol. Surface EMG and 3D surface imaging were performed prior to the injection and 5 days after the injection. The results showed no significant change in the strength of the muscles (measured in µV) after injection of hyaluronic acid-based soft tissue fillers. However, horizontal and vertical skin displacement upon contraction of the zygomaticus major muscle changed significantly between baseline and follow-up, with a mean horizontal skin displacement increase from 3.2 to 4.1 mm. Upon contraction of the depressor anguli oris muscle, the horizontal skin displacement did not change significantly (2.15 vs. 2.05 mm), while vertical skin displacement increased significantly from 2.9 to 4.3 mm. The modification of the surrounding tissue caused an alteration of the vectorial skin displacement upon contraction of the muscle. A potential explanation could be the increased distance between the origin and insertion of the muscle due to the material deposition in the proximity of the relevant facial muscles, leading to a change of contraction vector.

Understanding the Interplay Between Skin, Fascia, and Muscles of the Midface in Facial Aging.

BACKGROUND: Surgical, minimally-invasive, and non-invasive aesthetic procedures try to ameliorate the signs of facial aging, but also focus on enhancing various individual features of beauty in each patient. Herein, the midface plays a central role due to its location but also its importance for the aesthetic perception and facial expression. OBJECTIVE: To date, no study has investigated the interplay between facial muscles and its connecting subdermal architecture during facial aging to provide a more comprehensive understanding of the middle face. MATERIALS AND METHODS: A total of 76 subjects, consisting of 30 males (39.5%) and 46 females (60.5%) with a mean age of 42.2 (18.7) years [range 19-80] and a mean BMI of 24.6 (3.7) kg/m2 [range 18-35], were enrolled in this investigation. Cutometry (skin aging), 3D skin displacement analyses (subdermal connective tissue aging), and sEMG (muscle aging) analyses were utilized. RESULTS: The results revealed that overall skin firmness increased, and skin elasticity decreased (p < 0.001), sEMG signal of the investigated muscles decreased (p < 0.001), whereas midfacial mobility remained unaltered (p = 0.722). CONCLUSION: The results of this study indicate that midfacial aging is a measurable effect when utilizing individual measurement modalities for assessing skin, subdermal fascia, and midfacial muscles. The function of midfacial muscles revealed a potential threshold effect, which is not reached during midfacial aging due to the unchanged soft tissue mobility at older age. However, to understand its clinical presentation all midfacial soft tissues need to be factored in and a holistic picture needs to be created. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes review articles, book reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. 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 .

Ex Vivo Product Distribution of Injectable Biostimulator Substances.

BACKGROUND: Increasing demand for minimally invasive aesthetic treatments, such as injection of biostimulator substances to induce the production of extracellular matrix, has been reported. Recent studies have reported on a variety of different product characteristics influencing the integration and distribution of biostimulator substances after injection. OBJECTIVES: The aim of this study was to analyze the ex vivo product integration and distribution behavior of 6 different biostimulator substances after injection. METHODS: A total of n = 21 abdominal soft tissue flaps were analysed by real-time ultrasound imaging with regards to horizontal and vertical spread of 6 different injected biostimulator substances-based on hydroxylapatite (HA), polycaprolactone (PCL), and poly-L-lactic acid (PLLA)-immediately after injection and after massaging. The 6 different biostimulator substances were R-CaHA-based, H-CaHA-based, PCL-based, PLLA-1-based, PLLA-2-based and H-HA-based products. RESULTS: Overall, the R-CaHA-, H-CaHA-, and PCL-based substances showed greater product spread after massaging when compared with the product distribution immediately after the injection with all P < .001 with the exception of the vertical dimension of the H-CaHA-based substance (P = .064). The PLLA-1-, PLLA-2-, and H-HA-based substances showed smaller product spread after massaging compared with the product distribution immediately after the injection with all P < .001 with the exception of the horizontal dimension of the H-HA-based substance (P = .314), indicating higher tissue integration. CONCLUSIONS: Different biostimulator substances behave differently when injected into subcutaneous soft tissues; differences exist at the level of initial product diffusion and during tissue integration.

Combined Calcium Hydroxylapatite Plus Microfocused Ultrasound for Treating Skin Laxity of the Chest and Buttocks.

Microfocused ultrasound with visualization (MFU-V) and a calcium hydroxylapatite dermal filler (CaHA) were both developed to meet the patient demand for a noninvasive but effective means for lifting and tightening of lax skin. Recently, there has been growing interest in the use of dilute (1:1) and hyperdilute (1:≥2) CaHA to achieve skin tightening and stimulating neocollagenesis, and the combined use of difference techniques to obtain optimum aesthetic outcomes. Here, two patients with Grade 3 chest laxity on the Décolleté Wrinkling Assessment scale improved by 2 grade points after two treatment sessions because increasing the tissue layers treated with MFU-V and adding an additional syringe of CaHA per 100 cm2. Similarly, two addition patients with Grade 3 scores on the Gluteus Laxity Scale improved by 2 grade points after two or three treatment sessions. Customizing the number and depth of MFU-V treatment lines and the amount of CaHA should be considered when making a treatment plan for patients with severe skin laxity. Similarly, it is important to consider body mass index (BMI) when treating body areas such as the gluteus and the potential need for volume correction. J Drugs Dermatol. 2022;21(1):27-30. doi:10.36849/JDD.6368.

An Update on the Posterior Earlobe/Concha Mastoid Suspension Suture to Correct "Pixie Ear" Following Facelift: Review of 40 Cases.

BACKGROUND: Auricular displacement (AD) and earlobe distortion, such as "pixie ear," are commonly seen deformities after rhytidectomies. In 2018, the authors of this article published a prophylactic technique (posterior earlobe rotation flap [PERF] and concha-mastoid suspension suture [CMSS]) to prevent such cosmetic-related complications in primary facelift surgery. Here, the authors review the utilization of this technique to correct such deformities in patients receiving revision facelift surgeries. OBJECTIVES: The authors sought to demonstrate the usefulness of this technique in reconstructive cases suffering from such aesthetic deformities. METHODS: A total 25 secondary and 15 tertiary rhytidectomies were operated between 2015 and 2018. A combination PERF/CMSS technique was performed bilaterally during each revision facelift surgery (n = 80). A retrospective data analysis (preoperatively; 1 year postoperatively) was conducted to detect any deformities. RESULTS: No "pixie ear" deformities were seen in any of our patients postoperatively. AD was detected twice and unilateral hypertrophic scarring once. The postoperative photometric analysis showed a natural ptosis grade I/II in all our patients. The total rate of aesthetic-related complications in our patient cohort was 3.75% (AD: 2.5%; hypertrophic scarring: 1.25%). CONCLUSIONS: After demonstrating the effectiveness of the PERF and CMSS techniques in primary facelifts, the authors reviewed the technique's effectiveness for restoring earlobe distortion and AD in secondary or tertiary rhytidectomy cases. In addition to its prophylactic utilization, this method also possesses strong reconstructive power to change tension vectors applied on the face (CMSS) and/or to correct pre-existing aesthetic complications, such as "pixie ear" formation (PERF).

Safety of Combining Facial Lifting With Suspension Threads and Microfocused Ultrasound With Visualization.

Suspension threads are used to lift lax facial skin; however, there is concern about the safety of combining suspension threads with microfocused ultrasound (MFU) as it may change the structure and integrity of suspension threads or cause an inflammatory response. The objective of this study was to assess the safety of combining suspension threads with MFU in the face and neck. The structure and integrity of suspension threads was tested in an ex vivo animal model, an in vitro hot water bath and clinically in a human subject. Safety and subject satisfaction was assessed in a retrospective study. The structure and integrity of poly-L-lactic acid, polyethylene and polyamide threads was confirmed in an in vitro hot water bath and exposure to MFU in an ex vivo animal model. Clinically, exposure of poly-L-lactic acid threads to MFU resulted in greater neocollagenesis after 3 months compared to MFU alone. Among subjects treated with combined procedures (N=48), Aging Face Scale scores were significantly decreased after 90 days (P<0.001) and overall Satisfaction Scale scores were significantly increased after 90 days and 1 year (for each, P<0.001). There were no unexpected adverse events. Combining suspension threads with MFU is safe and results in greater efficacy by increasing neocollagenesis. J Drugs Dermatol. 2020;19(4):367-370. doi:10.36849/JDD.2020.4771.

Improving the Appearance of Surgical Facial Scars With IncobotulinumtoxinA and Microneedling.

BACKGROUND: The appearance of post-surgical scars on the face is a major concern for surgeons and a source of anxiety for patients after Mohs surgery due to nonmelanoma skin cancer (NMSC). The objective of this retrospective study was to assess the effectiveness of combining incobotulinumtoxinA and microneedling to improve the appearance of post-operative facial scars. Enrolled subjects underwent surgical removal of facial NMSCs followed by flap reconstruction by the same surgeon during 2014 (n=35) and 2015 (n=35). Sutures were removed 7 days after the procedure. Subjects treated during 2014 received no additional treatment and served as a control group. Subjects treated during 2015 also received micro-doses of incobotulinumtoxinA along the scar border and microneedling of the surgical area. Microneedling was repeated after 15 days. Scar severity was determined by the surgeon and an independent dermatologist using the modified Vancouver Scar Scale (VSS) scores on day 7 and day 30 following suture removal. Patient Satisfaction Scale scores were also determined using a 5-point scale on day 30. Mean (SD) VSS scores were 10.4 (1.14) on day 7 among treated subjects vs. 9.5 (1.88) among control subjects (P<0.05). On day 30, mean VSS scores had decreased to 1.1 (0.89) for treated subjects vs. 7.6 (1.72) for control subjects (P<0.05). Patient Satisfaction Scores were significantly higher among treated patients vs control subjects (4.45 vs 3.14; P<0.001). The use of incobotulinumtoxinA is a promising therapeutic option for improving scar appearance. Combined with microneedling, it significantly reduced VSS scores and improved overall satisfaction of treated subjects following surgery for NMSCs. J Drugs Dermatol. 2020;19(6): doi:10.36849/JDD.2020.4772.

The Influence of Different Treatment Combinations on Skin Laxity and Dimpling.

OBJECTIVE: The aim of the study was to identify the effectiveness of the combination of tissue stabilized guided subcision, microfocused ultrasound, and minimally invasive calcium hydroxylapatite injections in various sequences for treating skin surface irregularities of the buttocks and thighs. MATERIAL AND METHODS: 61 females (body mass index: 22.6 ± 2.4 kg/m², age: 37.2 ± 6.8 years) were enrolled in this randomized interventional prospective study. Treatment arms included a variable combination and sequence of three treatment modalities: (1) Tissue-stabilized guided subcision, (2) microfocused ultrasound, and (3) calcium hydroxylapatite injections. Six months after the final intervention skin laxity and skin dimpling severity scores were assessed by the study participants, the treating physicians and by eleven blinded independent board-certified experts. RESULTS: No adverse events were observed during the study that required intervention outside the standard of care treatment protocol. The combination of three treatment modalities was shown to provide greater improvement in skin laxity 1.88 (95% CI, 0.66–5.37) and skin dimpling 1.31 (95% CI, 0.61–2.81) scores as compared to any combination of two modalities. The combination of concomitant microfocused ultrasound and calcium hydroxylapatite injections followed three months later by tissue stabilized guided subcision yielded the greatest improvement in skin laxity 2.23 (95% CI, 0.51–9.82) and skin dimpling 1.79 (95% CI, 0.67–4.78) at 9-month follow-up. CONCLUSION: This study provides evidence for the effectiveness of combination therapies for the improvement of skin surface irregularities on the buttocks and thighs. J Drugs Dermatol. 2020;19(11): 1030-1038. doi:10.36849/JDD.2020.5117.

Calculating the Thickness of the Superficial Fatty Layer of the Body Using Age, Gender, and Body Mass Index

BACKGROUND: Injections of biostimulator agents are increasing in popularity as an alternative to surgical or energy-based skin tightening procedures. The present study was designed to develop a formula that helps to guide health care providers injecting biostimulators into the correct plane to enhance effectiveness and longevity by targeting precisely the superficial fascial system. METHODS: 150 Caucasian individuals (75 males and 75 females) were investigated with a balanced distribution of age (n=30 per decade: 20­29, 30­39, 40­49, 50­59, and 60­69 years) and body mass index (n=50 per group: BMI≤24.9kg/m2, BMI between 25.0 and 29.9kg/m2 BMI≥30kg/m2). The distance between skin surface and the superficial fascia was measured via ultrasound in the buccal region, premasseteric region, the lateral neck, posterior arm, abdomen, buttocks, anterior thigh, medial thigh, and posterior thigh. RESULTS: Mean thickness of the superficial fatty layer is variable between the different locations investigated with smallest values for the lateral neck of 3.71mm ± 0.55 [range, 2.00­5.00mm] and greatest values for the gluteal region with 20.52mm±10.07 [range, 6.10­38.40mm]. A formula was developed to estimate the thickness of the superficial fatty layer based on the targeted region, age, gender, and body mass index of the patient: Thickness of superficial fatty layer (mm): Region constant + (XX* BMI) - (YY*Age). CONCLUSIONS: Injections of biostimulators deeper than the calculated values might result in reduced efficacy as the superficial fascial system is not targeted and the effected collagen neogenesis does not affect the skin surface. J Drugs Dermatol. 2020;19(1):36-44. doi:10.36849/JDD.2020.4619

Rehabilitation of the Dysmorphic Lower Eyelid From Hyaluronic Acid Filler: What to Do After a Good Periocular Treatment Goes Bad.

BACKGROUND: Chronic, long-lasting edema accompanied by the Tyndall effect as a delayed reaction to hyaluronic acid (HA) filler injection seems to occur exclusively in the eyelids. OBJECTIVES: The authors sought to present a treatment algorithm for management of patients with chronic lower eyelid edema as a delayed complication of HA filler injection. METHODS: Retrospective study including 61 patients with delayed-onset chronic periocular edema following uneventful HA filler injection in the lower eyelids or cheeks. All patients underwent hyaluronidase enzyme dissolution followed by secondary treatment. Three retreatment options were presented: (1) observation, (2) secondary treatment with HA filler, and (3) lower eyelid blepharoplasty. RESULTS: All patients underwent filler dissolution using hyaluronidase. The mean age was 48 years and 97% of the patients were female. Single treatment was effective in 92% of patients with 8% requiring another hyaluronidase injection to completely eradicate residual edema. Six patients (10%) were satisfied after hyaluronidase only and 6 patients (10%) underwent lower eyelid blepharoplasty. Secondary treatment with HA filler was performed in 48 patients (80%). All were satisfied with final results without further edema in the follow-up period. CONCLUSIONS: Delayed-onset chronic lower eyelid edema is a frequent HA-related complication and cause of concern when considering periocular HA treatment. Previous treatment has been limited to either hyaluronidase only or blepharoplasty as a secondary solution after hyaluronidase, with only a minority of patients satisfied. Hyaluronidase, shortly followed by HA filler retreatment, is a safe and effective solution.

Influences of Age, Gender, and Body Mass Index on the Depth of the Superficial Fascia of the Arm and Thigh.

BACKGROUND: Nonsurgical skin-tightening procedures are increasing in popularity because of their noninvasiveness as the energy is transdermally applied to the subcutaneous tissues. OBJECTIVE: To provide precise data on the depth of the superficial fascia for potentially safer and better targeted treatments of arms and thighs. METHODS: One hundred fifty Caucasian individuals were investigated with an equal distribution of men and women (each n = 75) and a balanced distribution of age (n = 30 per decade). Ultrasound-based measurements were conducted, measuring the distance between skin and the superficial fascia in the posterior arm and the anterior, medial, and posterior thigh. RESULTS: Deep to the skin, 5 layers were consistently and bilaterally identified in both sexes: skin, superficial fat, superficial fascia, deep fat, and deep fascia. The overall mean distance between the skin surface and the superficial fascia was for the posterior arm 4.38 ± 0.9 mm; range (2.60-6.70), for the anterior thigh 7.90 ± 2.3 mm range (3.50-13.20), for the medial thigh 5.74 ± 1.2 mm range (3.10-8.20), and for the posterior thigh 7.77 ± 3.2 mm range (3.60-14.50). CONCLUSION: Knowing the precise depth of the superficial fascia for nonsurgical skin-tightening procedures could potentially guide practitioners toward safer and more effective outcomes.

Influence of Age, Sex, and Body Mass Index on the Depth of the Superficial Fascia in the Face and Neck.

BACKGROUND: Nonsurgical skin-tightening procedures are increasing in popularity, as patients seek aesthetic interventions that are safe with minimal downtime. OBJECTIVE: This study was designed to provide precise data on the depth of the superficial fascia-the structure of action-of the face and neck. METHODS: One hundred fifty Caucasian individuals (75 men and 75 women) were investigated with a balanced distribution of age (n = 30 per decade: 20-29, 30-39, 40-49, 50-59, and 60-69 years) and body mass index (BMI) (n = 50 per group: BMI ≤ 24.9 kg/m, BMI between 25.0 and 29.9 kg/m, and BMI ≥ 30 kg/m). The distance between skin surface and the superficial fascia was measured through ultrasound in the buccal region, premasseteric region, and lateral neck. RESULTS: The mean distance between skin surface and superficial fascia was for the buccal region 4.82 ± 0.9 mm, range (2.60-6.90); for the premasseteric region 4.25 ± 0.6 mm, range (2.60-5.80); and for the lateral neck 3.71 ± 0.5 mm, range (2.0-5.0). The depth of the superficial fascia increased with increasing BMI, whereas it decreased with advanced age. CONCLUSION: Knowing the precise depth of the superficial fascia for nonsurgical skin-tightening procedures will guide practitioners toward safer and more effective outcomes.

Validated Assessment Scales for Cellulite Dimples on the Buttocks and Thighs in Female Patients.

BACKGROUND: New treatment methods for cellulite require globally accepted scales for aesthetic research and patient evaluation. OBJECTIVE: To develop a set of grading scales for objective assessment of cellulite dimples on female buttocks and thighs and assess their reliability and validity. MATERIALS AND METHODS: Two photonumeric grading scales were created and validated for dimples in the buttocks in female patients: Cellulite Dimples-At Rest, and Cellulite Dimples-Dynamic. Sixteen aesthetic experts rated photographs of 50 women in 2 validation sessions. Responses were analyzed to assess inter-rater and intra-rater reliability. RESULTS: Overall inter-rater reliability and intra-rater reliability were both "almost perfect" (≥0.81, intraclass correlation efficient and weighted kappa) for the At Rest scale. For the Dynamic scale, inter-rater reliability and intra-rater reliability were "substantial" (0.61-0.80). There was a high correlation between the cellulite scales and body mass index, age, weight, and skin laxity assessments. CONCLUSION: Consistent outcomes between raters and by individual raters at 2 time points confirm the reliability of the cellulite dimple grading scales for buttocks and thighs in female patients and suggest they will be a valuable tool for use in research and clinical practice.

Validated Assessment Scales for Skin Laxity on the Posterior Thighs, Buttocks, Anterior Thighs, and Knees in Female Patients.

BACKGROUND: The demand for noninvasive skin-tightening body procedures is increasing. OBJECTIVE: To develop a set of grading scales for the objective assessment of skin laxity and assess their reliability and validity. MATERIALS AND METHODS: Two photonumeric grading scales were created and validated for skin laxity in female patients: Skin Laxity-Posterior Thighs/Buttocks, and Anterior Thighs/Knees. Fifteen aesthetic experts rated photographs of 50 women in 2 validation sessions. Responses were analyzed to assess inter-rater and intra-rater reliability. RESULTS: Overall inter-rater reliability according to intraclass correlation efficient (ICC) 2.1 and weighted kappa was at least "substantial" for both scales in both sessions, and "almost perfect" (≥0.81) for the Anterior Thighs and Knees scale in session 2. Intra-rater reliability was "almost perfect" for both scales (ICC 2.1) and "substantial" to "almost perfect" by weighted kappa. A correlation between the skin laxity scales and body mass index, age, weight, sun exposure, and cellulite severity was observed. CONCLUSION: The skin laxity photonumeric grading scales are valid and reliable instruments for assessing laxity on the posterior thighs and buttocks, and anterior thighs and knees. The scales will be of value for standardizing clinical evaluations and quantifying outcome measurements in research and clinical practice.

Facial Skin Tightening With Microfocused Ultrasound and Dermal Fillers: Considerations for Patient Selection and Outcomes

Introduction: Microfocused ultrasound (MFU) is a heat technology that is developed from focused ultrasound (FU) used in a high intense mode to generate heat (HIFU). Patient assessment is very complex and involves more than just addressing complaints. It is a challenge to evaluate, decide on options, and give treatments that guarantee the best outcomes. In order to facilitate the process, the authors divided the protocol into five steps: Assess (expectations, features); Decide (which depth to customize); Select (choose a number of lines to achieve the objective); Plan (combination, if needed); Treat (documentation, safety, and comfort). Methods: The PubMed search engine was used to search all publications from 1900­2019 that mention HIFU. The information collected was then grouped into the five protocol steps. Discussion: MFU is a focused ultrasound device that, at certain energy levels, produces heat over 55ºC at the focal point, which leads to thermal coagulation points (TCPs) in the target tissue. The creation of TCPs leads to a healing cascade, ending with neocollagenesis and neoelastogenesis. At different levels, this can bring about either a lifting effect or skin tightening, depending on the structure targeted. Therefore, the two most important tools for precision and efficacy of treatment are visualization with ultrasound and real-time evaluation of severity and structural changes (such as bone or fat loss). Conclusion: MFU-V is a well-known and, based on the evidence, an effective tool for non-invasive lifting and skin tightening. The secret to successful use of the device is to assess adequately patient needs and expectations and plan ahead for the combination of other treatment if necessary to achieve the desired outcome. J Drugs Dermatol. 2019;18(11):1075-1082.

Correction and Prevention of the Pixie Ear Deformity: A Combined Technique.

Background: Ear and earlobe deformities after surgical rhytidectomy are common and can significantly diminish the aesthetic outcome. The main causes of ear/earlobe distortion are skin overresection, an imbalance between vertical/horizontal skin-lift vectors, and tractional distortions through superficial muscularaponeurotic system (SMAS) tension. Objectives: To demonstrate a new method for earlobe suturing and ear fixation that would prevent aesthetics-related complications after facelift surgery. Methods: A total of 105 primary SMAS facelift surgeries were performed between 2015 and 2016 by the first author. A combination technique consisting of a posterior earlobe rotation flap (PERF) and a concha-mastoid suspension suture (CMSS) was executed bilaterally within each facelift procedure (n = 210). A retrospective data analysis was conducted (preoperatively and one year postoperatively) using our hospital information system and a photometric data analysis to assess auricular displacement, earlobe distortion, and hypertrophic scarring. Results: Pseudoptosis of the earlobe was noted in two cases, and auricular displacement was observed in four cases. Bilateral mild hypertrophic scarring was seen in one patient. The postoperative photometric analysis showed a natural ptosis grade I/II in all the patients, with a statistically significantly reduced postoperative earlobe size (P < 0.05). The total rate of aesthetics-related complications was 4% in our cohort (earlobe distortion with pseudoptosis: 1%; auricular displacement: 2%; hypertrophic scarring: 1%). Conclusions: Our modification of the facial flap anchoring at the ear base in combination with a CMSS stabilizes the natural position of the ear and prevents distortion while allowing better control over the earlobe's aesthetic shaping. This novel method reduces the incidence of ear/earlobe deformities and hypertrophic scarring at the ear base after rhytidectomy and, therefore, promises to be a valuable advancement.

Influences of Age, Gender, and Body Mass Index on the Thickness of the Abdominal Fatty Layers and its Relevance for Abdominal Liposuction and Abdominoplasty.

BACKGROUND: Liposuction and lipoabdominoplasty procedures frequently involve the treatment of the superficial and deep fatty layers of the abdomen. OBJECTIVES: The aim of the present investigation was to provide comprehensive data on the thickness of the abdominal fatty layers in relation to age, gender, and body mass index (BMI). METHODS: The study investigated 150 Caucasian individuals; there was an equal distribution of males and females (each n = 75) and a balanced distribution of age (n = 30 per decade: 20-29, 30-39, 40-49, 50-59, and 60-69 years) and BMI (n = 50 per group: BMI ≤24.9, 25.0-29.9, and ≥30 kg/m2). Ultrasound-based measurements of the superficial and deep abdominal fatty layers were performed. RESULTS: An increase in BMI was associated with an increase in total abdominal wall fat thickness. The measured increase was related more to the thickness of the deep fatty layer than to the thickness of the superficial fatty layer (Z = 1.80, P = 0.036). An increase in age was associated with a decrease in thickness of the superficial fatty layer (rp = -0.104, P = 0.071) but with an increase in thickness of the deep fatty layer (rp = 0.197, P = 0.001). CONCLUSIONS: Age and BMI can change the thickness of both the superficial and deep fatty layers of the anterior abdominal wall, thus influencing the plan and conduct of cosmetic surgical procedures. Knowledge of the layered anatomy of the anterior abdominal wall, as well as its associated blood supply, is important for surgeons performing procedures in this area.

Durability, Behavior, and Tolerability of 5 Hyaluronidase Products.

BACKGROUND: Hyaluronic acid (HA) dermal fillers are commonly used in cosmetic dermatology. Due to differences in their physical characteristics, HA fillers demonstrate different sensitivity to degradation by hyaluronidase (Hase) because of HA concentration and differences in cross-linking. Similarly, there are differences in the activity of Hase products depending on source and concentration. OBJECTIVE: The primary objective was to demonstrate the differences in potency and activity of 5 Hase products when used to degrade 5 different HA products using a human in vivo model. MATERIALS AND METHODS: The study subject was a healthy, consenting adult woman scheduled to undergo abdominoplasty. Skin to be excised was injected with 0.1 to 0.2 mL of each filler (10 injections each) leaving a visible lump. Immediately afterward, the HA lumps were injected with 4 IU of each Hase product every 2 minutes until the HA lumps were no longer visible or palpable. This procedure was repeated after 30 days. Injected tissues were excised after abdominoplasty for histological analysis. RESULTS: The 5 Hase products displayed a wide range of doses and times required to completely degrade the 5 HA products ranging from <2 to >16 minutes. CONCLUSION: Cosmetic practitioners should familiarize themselves with differences in HA and Hase products.

Global Consensus Guidelines for the Injection of Diluted and Hyperdiluted Calcium Hydroxylapatite for Skin Tightening.

BACKGROUND: Calcium hydroxylapatite (CaHA) is approved to correct moderate-to-severe wrinkles and folds and soft-tissue volume loss in the face and hands. More recently, subdermal injection using diluted CaHA has been used to improve skin laxity. OBJECTIVE: To review evidence for the safe and effective use of diluted CaHA in the face and body and provide best practice recommendations. METHODS: A global panel of expert aesthetic physicians convened to develop consensus-based guidelines for treating laxity and superficial wrinkles using diluted (ratio of 1:1) and hyperdiluted (≥1:2) CaHA. RESULTS: Diluted and hyperdiluted CaHA stimulates targeted neocollagenesis in the injection area to improve laxity and skin quality in the mid- and lower face, neck, décolletage, upper arms, abdomen, upper legs, and buttocks. Treatment can be used as an adjunct to volume augmentation or combined with additional modalities for optimal results. Adverse events are related to the injection and include bruising, swelling, mild pain, and induration. In thinner and darker skin, too-superficial injections of less diluted CaHA can lead to more adverse events. CONCLUSION: This report provides preliminary guidelines for the novel off-label use of CaHA for biostimulation in the face and body. Further trials will provide additional clarity regarding treatment paradigms for optimal outcomes.