AI assistance in aesthetic medicine-A consensus on objective medical standards.

BACKGROUND: Aesthetic medicine has traditionally relied on clinical scales for the objective assessment of baseline appearance and treatment outcomes. However, the scales focus on limited aesthetic areas mostly and subjective interpretation inherent in these scales can lead to variability, which undermines standardization efforts. OBJECTIVE: The consensus meeting aimed to establish guidelines for AI application in aesthetic medicine. MATERIALS AND METHODS: In February 2024, the AI Consensus Group, comprising international experts in various specialties, convened to deliberate on AI in aesthetic medicine. The methodology included a pre-consensus survey and an iterative consensus process during the meeting. RESULTS: AI's implementation in Aesthetic Medicine has achieved full consensus for enhancing patient assessment and consultation, ensuring standardized care. AI's role in preventing overcorrection is recognized, alongside the need for validated objective facial assessments. Emphasis is placed on comprehensive facial aesthetic evaluations using indices such as the Facial Aesthetic Index (FAI), Facial Youth Index (FYI), and Skin Quality Index (SQI). These evaluations are to be gender-specific and exclude makeup-covered skin at baseline. Age and gender, as well as patients' ancestral roots, are to be considered integral to the AI assessment process, underlining the move towards personalized, precise treatments. CONCLUSION: The consensus meeting established that AI will significantly improve aesthetic medicine by standardizing patient assessments and consultations, with a strong endorsement for preventing overcorrection and advocating for validated, objective facial assessments. Utilizing indices such as the FAI, FYI, and SQI allows for gender-specific, age adjusted evaluations and insists on a makeup-free baseline for accuracy.

A Gaze into the Eyebrow Standards of Asian Versus Caucasian Women.

BACKGROUND: Eyebrow position affects perceived facial expression and youthfulness, and its modification is a key component of facial rejuvenation. OBJECTIVE: This investigation aimed to assess the preferred vertical eyebrow position, apex location, and eyebrow shape in Caucasian and Asian individuals and to analyze gaze patterns during aesthetic judgment using eye-tracking technology. MATERIALS AND METHODS: The study included 76 Asian and Caucasian volunteers with no medical background. Eye movements were captured with a Tobii Pro Nano eye-tracker. Participants viewed AI-generated images of Caucasian and Asian females with varied eyebrow positions (ratios 1:1.3 to 1:2.5), shapes (angles 8° to 20°), and apex positions. Aesthetic preferences were rated on a 5-point Likert scale. Eye-tracking metrics and aesthetic ratings were statistically analyzed using ANOVA and bivariate correlations. RESULTS: Both genders across ethnicities preferred a moderate eyebrow position ratio of 1:1.6. For eyebrow shapes, a 12° angle received the highest ratings, while extremes were less favored, indicating a preference for moderately curved eyebrows. The most appealing apex position was above the lateral canthus for Asians, and halfway between the lateral limbus and lateral canthus for Caucasians. Eye-tracking revealed longer fixations on unattractive features, suggesting more complex cognitive processing, while attractive features were processed more efficiently. CONCLUSION: The study revealed that aesthetic preferences for eyebrow features are influenced by both ethnic background and gender, with a general preference toward moderately curved eyebrows and subtle variations in preferred positions. These findings suggest a need for culturally sensitive approaches in facial aesthetic procedures and highlight the potential of eye-tracking technology to enhance surgical planning. Surgeons are advised to adopt a conservative, patient-centered approach when modifying eyebrow features, considering individual and cultural aesthetics to maximize patient satisfaction. LEVEL OF EVIDENCE V: 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 .

Eye-Tracking Insights into the Perception of Buttocks.

BACKGROUND: Aesthetic enhancements to the buttock region have grown in demand due to media influence and evolving beauty standards. Using eye-tracking technology, we sought to uncover subconscious visual preferences regarding the buttock aesthetic. The objective of this investigation was to assess visual gaze patterns in assessing female buttocks among Caucasian and Asians through eye-tracking technology. MATERIALS AND METHODS: 67 participants viewed photographs of buttocks from various angles, and eye movements were analyzed using the Tobii Pro Nano eye-tracker. RESULTS: Males fixated on the intergluteal cleft for 0.96 ± 1.1 s and the thigh gap for 0.07 ± 0.2 s; while, females fixated for 0.81 ± 0.9 s and 0.06 ± 0.2 s on the same regions, respectively. Significant gender differences were observed in the intergluteal cleft (p = 0.002) and upper lateral buttock (p < 0.001). CONCLUSION: This study offers new insights into the observation of buttocks. The consistent attention toward the intergluteal cleft across demographics could be of potential significance in the aesthetic perception of buttocks. However, diverse gaze patterns also underscore the multifaceted nature of human attraction. These findings hold implications for plastic surgery, aesthetic medicine, and the sociocultural understanding of beauty. A deeper dive into aesthetic preferences is pivotal for a holistic understanding of human perceptions of attractive buttocks. 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 Table of Contents or the online instructions to Authors www.springer.com/00266 .

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.

In-depth analysis of ChatGPT's performance based on specific signaling words and phrases in the question stem of 2377 USMLE step 1 style questions.

ChatGPT has garnered attention as a multifaceted AI chatbot with potential applications in medicine. Despite intriguing preliminary findings in areas such as clinical management and patient education, there remains a substantial knowledge gap in comprehensively understanding the chances and limitations of ChatGPT's capabilities, especially in medical test-taking and education. A total of n = 2,729 USMLE Step 1 practice questions were extracted from the Amboss question bank. After excluding 352 image-based questions, a total of 2,377 text-based questions were further categorized and entered manually into ChatGPT, and its responses were recorded. ChatGPT's overall performance was analyzed based on question difficulty, category, and content with regards to specific signal words and phrases. ChatGPT achieved an overall accuracy rate of 55.8% in a total number of n = 2,377 USMLE Step 1 preparation questions obtained from the Amboss online question bank. It demonstrated a significant inverse correlation between question difficulty and performance with rs = -0.306; p < 0.001, maintaining comparable accuracy to the human user peer group across different levels of question difficulty. Notably, ChatGPT outperformed in serology-related questions (61.1% vs. 53.8%; p = 0.005) but struggled with ECG-related content (42.9% vs. 55.6%; p = 0.021). ChatGPT achieved statistically significant worse performances in pathophysiology-related question stems. (Signal phrase = "what is the most likely/probable cause"). ChatGPT performed consistent across various question categories and difficulty levels. These findings emphasize the need for further investigations to explore the potential and limitations of ChatGPT in medical examination and education.

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 .

Neural Interconnections of Extracranial Nerves in Headache Surgery: Anatomical Landmarks and Clinical Implications - A Review of Literature.

Headache disorders (HD) remain a nationwide challenge for the US healthcare system affecting nearly 60% of the US population. Surgical deactivation of the peripheral trigger site, also referred to as headache surgery, represents an effective treatment for patients with refractory HD pain or non-response to pharmacological regimes. Research stemming from other surgical specialties has underlined the clinical relevance of neural interconnections in refining diagnostic algorithms, adapting surgical techniques, and improving overall patient outcomes. While different HD trigger points have been identified, there is a paucity of studies discussing these mostly sensory neural interconnections between these trigger points in a comprehensive fashion. Herein, we aim to provide an overview of the specific nerves involved in HD and synthesize the current literature on HD nerve interconnections to, ultimately, deduce clinical implications. Overall, this line of research may help refine the perioperative workflow and enhance HD patient care.

Depth of the subcutaneous tissue in the nose: Application to filler injection.

INTRODUCTION: The nasal region plays a pivotal role in both facial esthetics and functionality. The use of volumizing fillers has emerged as a potential means to enhance nasal appearance. Preliminary findings from cadaveric studies have highlighted potential risks associated with deeper needle injection, leading to cartilage damage and lateral migration of filler material. Understanding the subcutaneous tissue depth is crucial to prevent such complications and ensure safe filler placement guided by anatomical knowledge. METHODS: This study aimed to employ ultrasonographic assessment to precisely measure the depth of soft tissue in the nasal area. Fifty-two participants without prior nasal surgery or filler injections underwent detailed ultrasonographic evaluation, focusing on seven key anatomical points: Glabellar, Sellion, Rhinion, between Rhinion and Pronasal, Pronasal, between Pronasal and Subnasal, and Subnasal. RESULTS: The ultrasonographic observation revealed varying depths of subcutaneous tissue across these points: Glabellar (4.11 ± 0.79), Sellion (5.21 ± 0.97), Rhinion (2.02 ± 0.74), Rhinion to Pronasal midpoint (6.45 ± 3.1), Pronasal (9.5 ± 2.2), between Pronasal and Subnasal (8.8 ± 0.8), and Subnasal (8.5 ± 0.5). DISCUSSION: The discussion underscores the significance of understanding subcutaneous tissue depth in guiding needle length and approach angles during filler injections. This knowledge aids in achieving effective filling while ensuring safe placement within the subcutaneous tissue.

Efficacy and Safety of LetibotulinumtoxinA in the Treatment of Moderate and Severe Glabellar Lines in Females 35 to 50 Years of Age: Post Hoc Analyses of the Phase 3 Clinical Study Data.

Background: Botulinum toxin type A (BoNT-A) injections continue to be widely used as a common treatment for both males and females. According to a recent survey conducted by the International Society of Plastic Aesthetic Surgeons, the majority of patients receiving these injections are females between the ages 35 and 50. Objectives: A post hoc analysis was conducted to examine whether there were variances in the effectiveness and safety of letibotulinumtoxinA for treating vertical glabellar lines between the broader female study population and a particularly defined group of female participants aged 35 to 50. Methods: For this post hoc analysis, data from females aged 35 to 50 were extracted and analyzed from the BLESS III study. In this Phase 3 clinical trial, 355 participants with moderate-to-severe glabella frown lines received either 20 U of letibotulinumtoxinA or a placebo. The study evaluated Glabella Line Severity (GLS) score, treatment onset, duration of effects, time to retreatment, and adverse events. A positive response was determined by achieving a GLS score of 0 or 1, as assessed by both patients and investigators, along with at least a 2-point improvement in GLS score relative to baseline at Week 4 after the injections. Results: Composite responder rates for patients aged 35 to 50 receiving active treatment were significantly higher than for the remaining female population receiving active treatment at Weeks 1, 2, and 4. Females aged 35 to 50 showed higher rates of GLS improvement of ≥1 at Weeks 1, 2, 4, 8, 12, 16, and 20 compared with the remaining female population receiving active treatment. At Week 4, a higher percentage of females aged 35 to 50 achieved a GLS score of 0 upon maximum frowning compared with the remaining females. Females aged 35 to 50 had a shorter median time to onset of GLS improvement compared with the remaining female population. Safety assessments showed a low incidence of treatment-related adverse events in females aged 35 to 50. Conclusions: LetibotulinumtoxinA showed significantly higher response rates in females aged 35 to 50 compared with other female patients at Weeks 1, 2, and 4. Response rates remained higher up to Week 16. The treatment demonstrated efficacy and safety in treating vertical glabellar lines in this patient group.

Increasing Precision When Targeting the Depressor Anguli Oris Muscle With Neuromodulators: An Ultrasound-Based Investigation.

BACKGROUND: Neuromodulator treatments of the perioral region are increasingly popular and aim to modulate the position of the modiolus. The predominantly targeted muscle is the depressor anguli oris (DAO) which allows for the modiolus to reposition cranially once temporarily relaxed. OBJECTIVES: The aim of this study was to identify the precise anatomic position of the DAO in relation to the marionette line, thereby increasing precision and reducing adverse events during neuromodulator treatments. METHODS: A total of n = 80 DAO muscles were investigated in n = 40 healthy, toxin-naïve volunteers (11 males, 29 females) with a mean [standard deviation] age of 48.15 [15] years and a mean BMI of 24.07 [3.7] kg/m2. The location of the DAO in relation to the labiomandibular sulcus, and its depth, extent, and thickness were investigated with high-frequency ultrasound imaging. RESULTS: The skin surface projection of the labiomandibular sulcus separates the DAO into medial and lateral portions. The distance between skin surface and muscle surface was on average 4.4 mm, with males having a greater distance (P < .001) and higher BMI being an important influencing factor for a greater distance (P < .001). The thickness of the DAO was on average 3.5 mm, with a range of 2.8 to 4.8 mm and with females having thinner muscles compared with males (P < .001). The most favorable injection depth was calculated to be 6.1 mm for intramuscular product placement. CONCLUSIONS: Understanding the perioral anatomy and the influence of age, sex, and BMI will potentially allow injectors to increase the efficacy and duration of neuromodulator treatments while expertly managing adverse events.

Pure Wisdom or Potemkin Villages? A Comparison of ChatGPT 3.5 and ChatGPT 4 on USMLE Step 3 Style Questions: Quantitative Analysis.

BACKGROUND: The United States Medical Licensing Examination (USMLE) has been critical in medical education since 1992, testing various aspects of a medical student's knowledge and skills through different steps, based on their training level. Artificial intelligence (AI) tools, including chatbots like ChatGPT, are emerging technologies with potential applications in medicine. However, comprehensive studies analyzing ChatGPT's performance on USMLE Step 3 in large-scale scenarios and comparing different versions of ChatGPT are limited. OBJECTIVE: This paper aimed to analyze ChatGPT's performance on USMLE Step 3 practice test questions to better elucidate the strengths and weaknesses of AI use in medical education and deduce evidence-based strategies to counteract AI cheating. METHODS: A total of 2069 USMLE Step 3 practice questions were extracted from the AMBOSS study platform. After including 229 image-based questions, a total of 1840 text-based questions were further categorized and entered into ChatGPT 3.5, while a subset of 229 questions were entered into ChatGPT 4. Responses were recorded, and the accuracy of ChatGPT answers as well as its performance in different test question categories and for different difficulty levels were compared between both versions. RESULTS: Overall, ChatGPT 4 demonstrated a statistically significant superior performance compared to ChatGPT 3.5, achieving an accuracy of 84.7% (194/229) and 56.9% (1047/1840), respectively. A noteworthy correlation was observed between the length of test questions and the performance of ChatGPT 3.5 (ρ=-0.069; P=.003), which was absent in ChatGPT 4 (P=.87). Additionally, the difficulty of test questions, as categorized by AMBOSS hammer ratings, showed a statistically significant correlation with performance for both ChatGPT versions, with ρ=-0.289 for ChatGPT 3.5 and ρ=-0.344 for ChatGPT 4. ChatGPT 4 surpassed ChatGPT 3.5 in all levels of test question difficulty, except for the 2 highest difficulty tiers (4 and 5 hammers), where statistical significance was not reached. CONCLUSIONS: In this study, ChatGPT 4 demonstrated remarkable proficiency in taking the USMLE Step 3, with an accuracy rate of 84.7% (194/229), outshining ChatGPT 3.5 with an accuracy rate of 56.9% (1047/1840). Although ChatGPT 4 performed exceptionally, it encountered difficulties in questions requiring the application of theoretical concepts, particularly in cardiology and neurology. These insights are pivotal for the development of examination strategies that are resilient to AI and underline the promising role of AI in the realm of medical education and diagnostics.

The Influence of Scar Patterns After Reduction Mammoplasty on Eye Movement and Gaze Pattern: An Eye-Tracking Investigation.

BACKGROUND: Given that scars are acknowledged as the primary cause of postoperative dissatisfaction following reduction mammoplasty, it is imperative to comprehend the patient's visual perception of different scar patterns in order to enhance patient satisfaction. To achieve this, eye-tracking technology provides an unbiased method of evaluating how observers assess breast scars. METHODS: 58 participants (32 females and 26 males) between the ages of 19 and 82 years (mean age of 29.47 ± 10.98 years) were shown 18 color photographs, taken at 3 viewing angles (right 45° oblique, frontal and frontal view with arms raised), from 6 patients undergone reduction mammoplasty with the inverted T-scar technique (3 patients) or no-vertical-scar technique (3 patients). The images were presented to every participant for a fixed duration of 5 s each. Eye-tracking device was used to collect and analyze the gaze data of viewers. RESULTS: The nipple-areola complex (NAC) and the periareolar scar captured observers' gaze faster, had longer duration and more count of eye fixation than all other parts of breast scars, regardless of the viewing angle and scar pattern. Moreover, the scar region in the inverted T-scar pattern received greater and faster visual attraction of observer's gaze than the no-vertical-scar pattern. CONCLUSION: The NAC and the periareolar scar seem to be perceived as the most important regions for breast aesthetics. The findings can be helpful to assist plastic surgeons in determining the most appropriate technique for reduction mammoplasty, meanwhile underlining the importance of a fine periareolar scar and symmetric NAC for excellent aesthetic outcomes. This is to our best knowledge the first study using eye-tracking technology in evaluating reduction mammoplasty outcomes. This study explored the influence of different scar patterns after reduction mammoplasty on eye movements and gaze patterns among observers. The study have validated the significance of the NAC and the periareolar scar for breast aesthetics and revealed that the scar region in the inverted T-scar pattern may be judged less visually attractive than the no-vertical-scar pattern. LEVEL OF EVIDENCE V: 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 .

Modern Machiavelli? The illusion of ChatGPT-generated patient reviews in plastic and aesthetic surgery based on 9000 review classifications.

BACKGROUND: Online patient reviews are crucial in guiding individuals who seek plastic surgery, but artificial chatbots pose a threat of disseminating fake reviews. This study aimed to compare real patient feedback with ChatGPT-generated reviews for the top five US plastic surgery procedures. METHODS: Thirty real patient reviews on rhinoplasty, blepharoplasty, facelift, liposuction, and breast augmentation were collected from RealSelf and used as templates for ChatGPT to generate matching patient reviews. Prolific users (n = 30) assessed 150 pairs of reviews to identify human-written and artificial intelligence (AI)-generated reviews. Patient reviews were further assessed using AI content detector software (Copyleaks AI). RESULTS: Among the 9000 classification tasks, 64.3% and 35.7% of reviews were classified as authentic and fake, respectively. On an average, the author (human versus machine) was correctly identified in 59.6% of cases, and this poor classification performance was consistent across all procedures. Patients with prior aesthetic treatment showed poorer classification performance than those without (p < 0.05). The mean character count in human-written reviews was significantly higher (p < 0.001) that that in AI-generated reviews, with a significant correlation between character count and participants' accuracy rate (p < 0.001). Emotional timbre of reviews differed significantly with "happiness" being more prevalent in human-written reviews (p < 0.001), and "disappointment" being more prevalent in AI reviews (p = 0.005). Copyleaks AI correctly classified 96.7% and 69.3% of human-written and ChatGPT-generated reviews, respectively. CONCLUSION: ChatGPT convincingly replicates authentic patient reviews, even deceiving commercial AI detection software. Analyzing emotional tone and review length can help differentiate real from fake reviews, underscoring the need to educate both patients and physicians to prevent misinformation and mistrust.

Radiofrequency and pulsed electromagnetic field application following liposuction-Clinical evaluation of performance and safety.

OBJECTIVE: With more than 1.5 million performed procedures, liposuction was the second most performed esthetic surgical procedure all over the world in males and in females in the year 2020. The objective of this open-label, evaluator-blinded study was to assess the efficacy and safety of an energy-based device that combines multipolar radiofrequency with pulsed electromagnetic field (PEMF) in patients that underwent liposuction. MATERIALS AND METHODS: A total of 30 subjects, of whom 24 were females (80%), with a mean age of 48.4 ± 11.0 years (range: 27-69 years) and a mean weight of 69.5 ± 11.7 kg underwent unilateral treatment with radiofrequency and application of PEMF after bilateral liposuction. One month after the last of a total of six weekly treatments, skin elasticity, visco-elasticity and net elasticity, as well as subject reported satisfaction on a 5-point scale ranging from -1 (worse) to 3 (very much improved) and esthetic improvement ranging from 0 (very unsatisfied) to 4 (very satisfied) rated by three independent reviewers were assessed. RESULTS: Three independent and blinded reviewers rated the improvement of the treated side on average as 1.17 + 0.07 compared with baseline. Subjects were very satisfied with their treatment, with a mean score of 3.24 (0.03) out of 4 at the 1-month follow-up visit. Cutometer measurements showed no significant changes. CONCLUSION: This study revealed that the subjective satisfaction with the results of the application of RF and PEMF after liposuction is high, while at the same time the esthetic appearance as rated by independent raters improved on the treated side.

An Experimental Model Exhibiting Anterograde and Retrograde Vascular Occlusion of Facial Fillers to Avoid Vision Loss.

Background: Facial filler injection techniques that help decrease the risk of vascular occlusion are an important growing area of study. This study demonstrates a model of injecting fillers into a simulated bifurcated arterial system, using different sized needle gauges at a constant injection pressure. Methods: Three facial fillers were injected into a bifurcated intravenous tubing with continuous irrigation at a constant pressure to simulate a vascular system. Videography was used to observe for retrograde flow through the simulated supratrochlear artery to the bifurcation point, where the filler was redirected by anterograde flow into the branch representing the ophthalmic artery. Results: Filler injection with retrograde flow to the bifurcation occurred with all the 27G needle trials. In comparison, the 30G needle trials were only able to reach the bifurcation point in three of the nine trials. The average time to the bifurcation point with subsequent ophthalmic artery anterograde flow with the 27G and 30G needles were 8.44 (95% confidence interval ±2.06) and 33.33 (95% confidence interval ±16.56) seconds, respectively. Conclusions: Larger 27G needles consistently reached retrograde flow and the bifurcation point faster than 30G needles. This study suggests thinner needles may be less likely to cause retrograde occlusion.

Novel Validated Five-point Photonumeric Scales for Assessment of Static and Dynamic Forehead Lines.

Background: The objective of this investigation was to create and validate five-point photonumeric scales which assess static and dynamic forehead lines. Methods: Two different novel five-point photonumeric scales for the assessment of static and dynamic forehead lines were developed. Moreover, a photoguide was created, including subjects from both sexes, all age groups, and different Fitzpatrick skin types. A total of 11 raters from all over the world were involved in the digital validation, whereas four raters performed a live validation. Results: The Croma Static Forehead Lines-Assessment Scale showed almost perfect inter and intra-rater agreement in both the digital and the live setting with inter-rater intraclass correlation coefficients of 0.86 [95% confidence interval (CI): 0.82-0.89] in the first digital rating and 0.82 [95% CI: 0.78-0.86] in the second digital rating. The Croma Dynamic Forehead Lines-Assessment Scale showed almost perfect inter and intra-rater agreement in the digital setting with inter-rater intraclass correlation coefficients of 0.83 [95% CI: 0.79-0.86] in the first digital rating and 0.80 [95% CI: 0.75-0.84] in the second rating and almost substantial agreement in the live setting. Conclusions: The Croma Static Forehead Lines-Assessment Scale and the Croma Dynamic Forehead Lines-Assessment Scale have excellent inter and intra-rater agreements to be justifiably used in the clinical and study setting, both digitally and live across ethnic groups.

Safety considerations for treating the parotid and submandibular glands with neuromodulators for facial slimming.

BACKGROUND: Neuromodulators have predominantly been used for the treatment of upper facial lines, but their use has expanded to include lower face and neck treatments. However, the injection sites for these treatments are based on skin surface landmarks, which may pose risks to nearby structures and result in undesired outcomes. OBJECTIVE: To investigate the spatial relationship between the FDA-approved skin surface landmarks for neuromodulator injections in the parotid and submandibular glands and the topographical anatomy of critical facial structures such as the facial artery, facial vein, external carotid artery, and retromandibular vein. MATERIALS AND METHODS: A cross-sectional retrospective analysis was conducted on contrast-enhanced cranial CT scans. The scans were analyzed for the morphology and location of the parotid and submandibular glands. Measurements were taken for gland volume, craniocaudal extent, anterior-posterior extent, and distances between the skin surface and gland capsule or nearby structures such as arteries. RESULTS: The study sample consisted of 53 subjects, including 7 males and 46 females, with a mean age of 36.91 years and a mean BMI of 23.28 kg/m2 . The mean volume of the parotid gland was 31.9 ± 3.0 cc in males and 28.5 ± 3.6 cc in females with p < 0.001, while the mean volume of the submandibular gland was 18.2 ± 2.0 cc in males and 14.5 ± 3.4 cc in females with p < 0.001. The mean distances between skin surface and the gland capsule were 5.98 ± 2.2 and 8.84 ± 4.0 mm for the parotid and submandibular gland, respectively. This distance increased with higher age and higher BMI values in a statistically significant manner with p < 0.001. CONCLUSION: The distances between FDA-approved skin surface landmarks and the parotid and submandibular glands varied significantly depending on gender, age, and BMI. Optimal injection depth and location for neuromodulator treatments cannot be generalized based on these landmarks alone, emphasizing the need for real-time ultrasound imaging guidance.

Arterial Embolism After Facial Fat Grafting: A Systematic Literature Review.

BACKGROUND: While autologous fat grafting of the face is considered a generally safe procedure, severe complications such as arterial embolism (AE) have been reported. OBJECTIVE: To summarize data on injection-related visual compromise, stroke, and death caused by arterial embolism after facial fat transplantation. MATERIALS AND METHODS: Plastic surgery societies were contacted for reports on AE after autologous facial fat injection. In addition, a systematic literature review was performed. Data extracted included study design, injection site/technique, symptoms, management, outcome, and etiology. RESULTS: 61 patients with a mean age of 33.56 ± 11.45 years were reported. Injections targeted the glabella or multiple facial regions (both n = 16/61, 26.2%) most commonly, followed by injections in the temples (n = 10/61, 16.4%) and the forehead (n = 9/61, 14.8%). The mean volume injected was 21.5 ± 21.5 ml. Visual symptoms were described most frequently (n = 24/58, 41.4%) followed by neurological symptoms (n = 20/58, 34.5%), or both (n = 13/58, 22.4%). Ophthalmic artery (OA, n = 26/60, 43.3%), anterior or middle cerebral artery (CA, n = 11/60, 18.3%) or both (n = 14/60, 23.3%) were most frequently occluded. Outcome analysis revealed permanent vision loss in all patients with OA occlusion (n = 26/26, 100%), neurological impairment in most patients with CA occlusion (n = 8/10, 80%), and vision loss in most patients suffering from both OA and CA occlusion (n = 7/11, 63.6%). Six patients died following embolisms. CONCLUSIONS: AE causes severe complications such as blindness, stroke, and death. Due to a lack of high-quality data, no evidence-based treatment algorithms exist. To increase patient safety, a database collecting cases and complications should be established. 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 .