Estimating the Change in Facial Subunits During Positive and Negative Facial Expression Using Three-Dimensional Stereophotogrammetry Facial Analysis.

Background: A more refined and clinically related facial expression analysis is required for patients who wish to be perceived more emotionally positive. Objective: To measure the change in skin vector and volume in facial subunits when expressing positive expression (happiness) compared with negative expressions (sadness, fear, disgust, and anger), using three-dimensional (3D) stereophotogrammetry analysis. Methods: This study took 3D photographs of 20 volunteers' face at rest and during positive and negative expression. The directions of skin vector and volume changes in each facial subregion were recorded and calculated. Results: In the positive expression, 78.3% (95% confidence interval [CI] 66.8-89.9) of the medial midfacial subregions presented superolateral vector and volume increase, whereas volume decrease in 82.5% (95% CI 78.5-86.5) of the lip subregions could be observed. In the negative expression, the vector changes were predominantly inferomedial in 26.0% (95% CI 15.4-36.5) of the forehead and 36.8% (95% CI 33.2-40.3) of the upper eyelid subregions, whereas volume increases in 34.0% (95% CI 30.4-37.7) of the upper eyelid subregions were observed. Conclusions: This 3D stereophotogrammetry analysis presents the morphological difference between the positive and negative expression.

Retrospective Study of Vascular Complications Caused by Hyaluronic Acid Injection.

BACKGROUND: Complications from intravascular embolization of hyaluronic acid (HA) are not only no longer uncommon but also devastating. This study aimed to examine clinical aspects of patients referred to our hospital for care following complications from intravascular filler embolization. METHODS: We retrospectively reviewed data from all patients referred to our medical center for the management of complications associated with intravascular embolization of HA fillers including demographics, medical history, clinical features, and treatment between November 2013 and June 2022. RESULTS: A total of 116 patients with vascular complications (27 cases with vision loss and 89 cases with skin necrosis) were assessed. The highest risk injection sites for skin necrosis included the nasal region (58/115, 50.4%), temple (16/115, 13.9%), and forehead (11/115, 9.6%) and for vision loss included the nasal region (18/30, 60.0%) and forehead (7/30, 23.3%). In skin necrosis cases, a needle (60/89, 67.4%) carried a higher risk than that of a cannula (29/89, 32.6%), whereas in vision loss cases, nasal dorsum injections using a cannula (16/27, 59.3%) carried a higher risk than that observed using a needle (11/27, 40.7%). No treatment was completely successful in reversing these complications. CONCLUSION: Intravascular embolization of HA filler is a serious complication. Although some combination treatments have been proposed, there is no standard protocol for treating severe complications. 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 http://www.springer.com/00266 .

Age-Related Changes of the Zygomatic Ligament: An Experimental Animal Study.

BACKGROUND: Facial aging is a multifactorial process involving the skin, fat, muscles, bones, and ligaments. The role of facial ligaments in the facial aging process remains elusive. OBJECTIVES: The aim of this study was to identify whether age-related changes in facial ligaments exist and how to best quantify such changes when investigating the zygomatic ligament in the rat. METHODS: A total of 30 male Sprague-Dawley rats (10 young, 10 middle-aged, 10 mature) were investigated to visualize the zygomatic ligament. Samples of the ligaments spanning the zygomatic arch and the skin were taken and histologically examined with hematoxylin-eosin, Masson, Verhoeff's elastic, and picrosirius red staining. Quantification of the Type I/III collagen ratio and collagen content was performed by color deconvolution and electron microscopic imaging. RESULTS: With increasing age, collagen fibers inside of the examined ligaments appeared thicker and more closely arranged. The Type I/III collagen ratio was measured to be 1.74 in young animals, 3.93 in middle-aged animals, and 5.58 in mature animals. The ultra-microstructure of the ligament was less coordinated in direction and orientation in young and middle-aged animals than in mature animals, in which collagen fibers were bundled together in a strong and oriented mesh. CONCLUSIONS: Ligaments appeared thinner, transparent, more elastic, and less robust in young animals, whereas ligaments in mature animals appeared thicker, more fascia-like, less elastic, and more robust. An increase in the Type I/III collagen ratio, indicating greater stiffness and reduced elasticity, was observed with higher age of the investigated animals. These findings indicate that ligaments might increase in stiffness and rigidity with age.

A Computed Tomographic Investigation of the Ophthalmic Artery Volume and Its Relevance to Soft Tissue Filler Injections.

BACKGROUND: The measured intraarterial volume of cadaveric ophthalmic arteries was utilized for safety recommendations during facial soft tissue filler injections. However, its clinical practicability and model applicability have become questionable. OBJECTIVES: To measure the volume of the ophthalmic artery in living individuals by utilizing computed tomography (CT) imaging technology. METHODS: A total of 40 Chinese patients (23 males, 17 females) were included in this study with a mean age of 61.0 (14.2) years and a mean body mass index of 23.7 (3.3) kg/m2. Patients were investigated with CT imaging technology to evaluate the length, diameter, and volume of the bilateral ophthalmic arteries as well as the length of the bony orbits, resulting in a total of 80 investigated ophthalmic arteries and orbits. RESULTS: Independent of gender, the average length of the ophthalmic artery was 80.6 (18.7) mm, the calculated volume of the ophthalmic artery was 0.16 (0.05) mL and the minimal and maximal internal diameter of the ophthalmic artery were 0.50 (0.05) mm and 1.06 (0.1) mm, respectively. CONCLUSIONS: Based on the results obtained from the investigation of 80 ophthalmic arteries it must be concluded that current safety recommendations should be reevaluated. The volume of the ophthalmic artery appears to be 0.2 mL rather than 0.1 mL as previously reported. In addition, it appears impractical to limit the volume of soft tissue filler bolus injections to 0.1 mL due to the aesthetic requirements of each individual patient and treatment plan.

A Two-Center, Prospective, Randomized Controlled Trial to Evaluate the Efficacy and Safety of and Satisfaction with Different Methods of ART FILLER® UNIVERSAL Injection for Correcting Moderate to Severe Nasolabial Folds in Chinese Individuals.

BACKGROUND: Hyaluronic acid is the most popular dermal filler in the treatment of nasolabial folds. Injection methods vary among physicians. METHODS: A randomized, two-center, double-blind, intraindividual trial was designed to compare a new method of injecting ART FILLER® UNIVERSAL using the retaining ligament with the traditional method (linear threading and bolus injection) in moderate to severe nasolabial folds. Forty patients with moderate to severe nasolabial folds were randomized into groups A and B. Group A received injections via the traditional method on the left side and the ligament method on the right side, while group B received the reverse. Clinical efficacy and patient safety were independently assessed by a blinded evaluator, the injector, using the Wrinkle Severity Rating Scale (WSRS), the Global Aesthetic Improvement Scale (GAIS), and the Medicis Midface Volume Scale (MMVS) at 4 weeks (before and after the touch-up injection), 8 weeks, 12 weeks, and 24 weeks after the baseline injection. RESULTS: From the perspective of the blinded evaluator, the improvements in WSRS scores from baseline did not differ significantly between the ligament method (0.73 ± 0.61) and the traditional method (0.89 ± 0.61) at week 24 (p > 0.05). The mean GAIS score at week 24 was 1.41 ± 0.49 for the traditional method and 1.32 ± 0.47 for the ligament method (p > 0.05). CONCLUSIONS: The efficacy and safety of the ligament method for the management of nasolabial folds are comparable to those of the traditional method in terms of WSRS and GAIS score improvement in the long run. The ligament method is superior to the traditional method in that it improves midface deficits with fewer adverse events. LEVEL OF EVIDENCE II: 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 . CLINICAL TRIAL REGISTRATION: This study was registered with the Chinese Clinical Trial Registry under the registration number ChiCTR2100041702.

Three-dimensional Evaluation of Results After Dual-Plane Breast Augmentation with and Without Internal Suture Mastopexy.

BACKGROUND: In patients with breast atrophy and ptosis, it is necessary to correct both problems simultaneously. This study aimed to analyze breast morphological changes with a three-dimensional (3D) scanning technique to demonstrate the improvement effect of dual-plane breast augmentation combined with internal suture mastopexy. METHODS: 3D breast surface scans were performed preoperatively and postoperatively in 24 patients (n = 35 breasts) undergoing internal suture mastopexy combined with prosthetic augmentation through the periareolar approach and 24 patients (48 breasts) undergoing simple dual-plane breast augmentation. Changes in linear distance, breast volume and volume distribution, breast projection, and nipple position were analyzed to assess the breast morphology. RESULTS: Compared with simple breast augmentation, augmentation combined with internal suture mastopexy was associated with a higher upper pole volume increase and greater medial and upward nipple displacement. After the surgery, the upper pole volume increased by an average of 10.6% in combined augmentation group and decreased by an average of 2.2% in the simple breast augmentation group. The measured breast projections were 24.8 ± 2.2% lower than expected in the combined group and 23.1 ± 4.1% lower than expected in the simple group, based on implant parameters recorded by the manufacturer. The nipple moved 0.2 ± 0.5 cm laterally, 1.6 ± 0.6 cm upward, and 2.8 ± 0.7 cm anteriorly in the combined group and 0.9 ± 0.5 cm laterally, 0.7 ± 0.6 cm upward, and 3.0 ± 0.6 cm anteriorly in the simple group. CONCLUSIONS: Dual-plane breast augmentation in addition to internal suture mastopexy appears to reposition breast tissue from the lower pole to fill in the deficient upper breast, pull the nipple medially and superiorly, and ultimately correct mild to moderate breast ptosis. 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 .

Biofilm formation is a risk factor for late and delayed complications of filler injection.

Introduction: Biofilm formation is a major cause of delayed-graft complications. Similarly to implants, dermal fillers carry the risk of biofilm formation, which can lead to the development of nodules, chronic inflammatory reactions, abscesses and other complications. In this study, we investigated the late or delayed complications associated with biofilm formation on dermal fillers. Methods: In this retrospective analysis, we analyzed all cases of complications caused by filler injections at a single center between January 2017 and December 2022, the majority of which comprised nodule formation and chronic persistent inflammatory reactions. The risk of biofilm formation with fillers was summarized and analyzed based on the results of bacterial culture and pathological examination. Results: Sixty-one patients were enrolled, including 42 cases of nodule formation, 15 of chronic inflammatory reactions, and 4 of active infection. Bacterial culture of the tissue samples obtained from seven patients after surgical treatment were positive, and comprised four cases of Staphylococcus aureus, one case of Staphylococcus epidermidis, one case of Staphylococcus saprophyticus and one case of Mycobacterium abscessus. The corresponding histopathological results indicated extensive mononuclear lymphocyte infiltration, with a giant cell reaction in the fibrous connective tissue. Conclusion: The results of this study suggest that biofilm formation is a significant risk factor for late and delayed complications following filler injection, and is caused by the contamination of resident bacteria and recessive infection at the injection site.

Upper Facial Anastomoses Between the External and Internal Carotid Vascular Territories - A 3D Computed Tomographic Investigation.

BACKGROUND: Facial regions with a high risk for causing injection-related visual comprise are dual-supply vascular areas such as the nose, glabella, and forehead. These regions have in common that they receive arterial blood supply both by branches of the internal (ICA) and the external carotid artery (ECA). OBJECTIVE: The authors sought to investigate the anastomotic pathways between ICA and ECA branches in the upper face. METHODS: Postmortem computed tomographic angiographic scans of n = 38 Chinese non-embalmed hemifaces (25 males, 13 females; mean age, 37.79 [11.8] years; mean BMI, 21.90 [2.3] kg/m2) were conducted. Data analysis relied on the calculation of depth, distances, and pathways of forehead and temporal arteries to investigate the number of anastomotic connections, the connecting branches, and the layer of connection between ICA and ECA territories. RESULTS: Between ICA and ECA territories, only 1 connection in 57.9%, 2 connections in 31.6%, 3 connections in 5.3%, and 4 and 5 connections in 2.6% each were identified. A superficial connection was observed in 15.8% whereas in 84.2% the anastomotic connection was identified to be both superficial and deep. CONCLUSIONS: Adverse events following facial minimally invasive soft-tissue filler injections for aesthetic purposes are not frequent but devastating if they occur. Anatomic knowledge as presented in this study can help to increase awareness of 3-dimensional vascular anastomotic pathways and identify safer injection zones and safer fascial planes. Evidence-based injection techniques should be followed, and safety aspects should be placed over the aesthetic outcome.

Experimentally Induced Arterial Embolism by Hyaluronic Acid Injection: Clinicopathologic Observations and Treatment.

BACKGROUND: Although major complications of hyaluronic acid injection rarely occur, with the rapidly growing number of procedures performed and their expanding applications, such complications warrant greater attention. Our study was designed to explore optimal treatment methods for hyaluronic acid-related vascular occlusion. METHODS: In the first part of the study, 60 rats were given intraarterial hyaluronic acid injected into the bilateral inferior epigastric arteries to establish an animal model, and were euthanized at different postinjection time points. The inferior epigastric artery was retrieved for pathologic examination. In the second part of the study, bilateral abdominal flaps supplied by the inferior epigastric artery were elevated in six groups of rats, and hyaluronic acid was injected into the right side, with each group receiving a different intervention. The flap survival rate was calculated and analyzed. RESULTS: In the first part of the study, pathologic examination revealed that the composition of the emboli caused by arterial hyaluronic acid-induced occlusion changed from pure hyaluronic acid to a hyaluronic acid-thrombus mixture. In the second part of the study, flap survival rates (mean percentages) were as follows: group A, 43.29 ± 9.28 percent; group B, 54.17 ± 10.86 percent; group C, 59.27 ± 13.40 percent; group D, 64.37 ± 8.61 percent; group E, 71.92 ± 19.06 percent; and group F, 57.47 ± 13.64 percent. Group A differed significantly from groups B, C, D, and E (p < 0.001). No significant difference was observed between groups A and F (p > 0.05). CONCLUSIONS: The combined use of intravenous or subcutaneous hyaluronidase and urokinase was most effective in treating hyaluronic acid injection-related arterial embolism after 45 minutes and 24 hours. This treatment may be ineffective after 48 hours.