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 i.e., 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 3 - 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 electromyography 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 mm to 4.1 mm. Upon contraction of the depressor anguli oris muscle, the horizontal skin displacement did not change significantly (2.15 mm vs. 2.05 mm), while vertical skin displacement increased significantly from 2.9 mm 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 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.

Truth Lies in the Depths: Novel Insights into Facial Aesthetic Measurements from a U.S. Survey Panel.

BACKGROUND: Aesthetic facial bone surgery and facial implantology expand the boundaries of conventional facial surgery that focus on facial soft tissue. This study aimed to reveal novel aesthetic facial measurements to provide tailored treatment concepts and advance patient care. METHODS: A total of n=101 study participants (46 females and 55 males) were presented with 120 patient portraits (frontal images in natural head posture; 60 females and 60 males) and asked to assess the facial attractiveness (scale 0-10; "How attractive do you find the person in the image?") and the model capability score (MCS; scale 0-10; "How likely do you think the person in the image could pursue a modelling career?"). For each frontal photograph, defined facial measurements and ratios were taken to analyse their relationship with the perception of facial attractiveness and MCS. RESULTS: The overall attractiveness rating was 4.3 ± 1.1, while the mean MCS was 3.4 ± 1.1. In young males, there was a significant correlation between attractiveness and the zygoma-mandible angle (ZMA)2 (r= - 0.553; p= 0.011). In young and middle-aged females, MCS was significantly correlated with facial width (FW)1-FW2 ratio (r= 0.475; p= 0.034). For all male individuals, a ZMA1 value of 171.79 degrees (Y= 0.313; p= 0.024) was the most robust cut-off to determine facial attractiveness. The majority of human evaluators (n=62; 51.7%) considered facial implants a potential treatment to improve the patient's facial attractiveness. CONCLUSION: This study introduced novel metrics of facial attractiveness, focusing on the facial skeleton. Our findings emphasized the significance of zygomatic measurements and mandibular projections for facial aesthetics, with FI representing a promising surgical approach to optimize facial aesthetics. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

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 .

Increasing precision during neuromodulator injections for frontal rhytids-Using ultrasound imaging to identify the line of convergence.

BACKGROUND: Recent research introduced the concept of the "line of convergence" as a guide for injectors to enhance precision and avoid complications when treating the frontalis muscle with toxins. However, currently, no pre-injection ultrasound scanning is employed to increase precision and reduce adverse events when searching for the line of convergence. OBJECTIVE: To explore the feasibility and practicality of implementing pre-injection ultrasound scanning into aesthetic neuromodulator treatments of the forehead. METHODS: The sample of this study consisted of n = 55 volunteers (42 females and 13 males), with a mean age of 42.24 (10.3) years and a mean BMI of 25.07 (4.0) kg/m2. High-frequency ultrasound imaging was utilized to measure the thickness, length, and contractility of the frontal soft tissue and to determine the precise location of the line of convergence during maximal frontalis muscle contraction. RESULTS: The results revealed that the line of convergence was located at 58.43% (8.7) of the total forehead height above the superior border of the eyebrow cilia without a statistically significant difference between sex, age, or BMI. With frontalis muscle contraction, the forehead shortens in males by 25.90% (6.5), whereas in females it shortens only by 21.74% (5.1), with p < 0.001 for sex differences. CONCLUSION: This study demonstrated the feasibility and practicality of pre-injection ultrasound scanning for facial aesthetic neuromodulator treatments. Knowing the location of the line of convergence, injectors can determine precisely and on an individual basis where to administer the neuromodulator deep or superficial or when the injection location is at risk to cause eyebrow ptosis.

From standard therapies to monoclonal antibodies and immune checkpoint inhibitors - an update for reconstructive surgeons on common oncological cases.

Malignancies represent a persisting worldwide health burden. Tumor treatment is commonly based on surgical and/or non-surgical therapies. In the recent decade, novel non-surgical treatment strategies involving monoclonal antibodies (mAB) and immune checkpoint inhibitors (ICI) have been successfully incorporated into standard treatment algorithms. Such emerging therapy concepts have demonstrated improved complete remission rates and prolonged progression-free survival compared to conventional chemotherapies. However, the in-toto surgical tumor resection followed by reconstructive surgery oftentimes remains the only curative therapy. Breast cancer (BC), skin cancer (SC), head and neck cancer (HNC), and sarcoma amongst other cancer entities commonly require reconstructive surgery to restore form, aesthetics, and functionality. Understanding the basic principles, strengths, and limitations of mAB and ICI as (neo-) adjuvant therapies and treatment alternatives for resectable or unresectable tumors is paramount for optimized surgical therapy planning. Yet, there is a scarcity of studies that condense the current body of literature on mAB and ICI for BC, SC, HNC, and sarcoma. This knowledge gap may result in suboptimal treatment planning, ultimately impairing patient outcomes. Herein, we aim to summarize the current translational endeavors focusing on mAB and ICI. This line of research may serve as an evidence-based fundament to guide targeted therapy and optimize interdisciplinary anti-cancer strategies.

Turn Your Vision into Reality-AI-Powered Pre-operative Outcome Simulation in Rhinoplasty Surgery.

BACKGROUND: The increasing demand and changing trends in rhinoplasty surgery emphasize the need for effective doctor-patient communication, for which Artificial Intelligence (AI) could be a valuable tool in managing patient expectations during pre-operative consultations. OBJECTIVE: To develop an AI-based model to simulate realistic postoperative rhinoplasty outcomes. METHODS: We trained a Generative Adversarial Network (GAN) using 3,030 rhinoplasty patients' pre- and postoperative images. One-hundred-one study participants were presented with 30 pre-rhinoplasty patient photographs followed by an image set consisting of the real postoperative versus the GAN-generated image and asked to identify the GAN-generated image. RESULTS: The study sample (48 males, 53 females, mean age of 31.6 ± 9.0 years) correctly identified the GAN-generated images with an accuracy of 52.5 ± 14.3%. Male study participants were more likely to identify the AI-generated images compared with female study participants (55.4% versus 49.6%; p = 0.042). CONCLUSION: We presented a GAN-based simulator for rhinoplasty outcomes which used pre-operative patient images to predict accurate representations that were not perceived as different from real postoperative outcomes. 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 .

Identifying Levels of Competency in Aesthetic Medicine: A Questionnaire-Based Study.

BACKGROUND: In 2022, the US experienced a significant increase in demand for minimally invasive aesthetic procedures, underscoring its rising acceptance amidst an unregulated educational environment for practitioners. The absence of standardized educational pathways and quality control in aesthetic medicine, primarily provided by non-academic institutions, highlights a critical need for establishing educational standards to ensure practitioner competence and patient safety. OBJECTIVES: To identify levels of competency for the aesthetic practitioner and for necessary achievement milestones during the educational path from novice to expert injector. METHODS: A total of n = 386 international study participants responded to an online questionnaire regarding their experience in aesthetic medicine practice. The questionnaire comprised 58 questions focusing on professional data, the perceived difficulty of injection and risk for the occurrence of adverse events for specific facial regions in soft tissue filler and toxin injections. RESULTS: Regardless of medical specialty and experience level, an average of 3.85 (1.8) years, 786.4 (2,628) filler injections, and 549.9 (1,543) toxin injections was estimated to progress from novice to advanced injector, while an average of 6.10 (3.7) years, 1,842.2 (4,793) filler injections, and 1,308.5 (3,363) injections was estimated to advance from advanced to expert injector. The nose and the perioral region have been ranked as the facial regions most difficult to achieve a perfect aesthetic outcome and with the greatest risk for the occurrence of adverse events for filler and toxin injections, respectively. CONCLUSIONS: This study establishes an educational framework in aesthetic medicine by defining the progression from novice to competent and expert injector levels, suggesting 4 years of practice and over 790 filler and 550 neuromodulator injections for competence, and at least 6 years with 1,840 filler and 1,310 neuromodulator injections for expertise. It also identifies critical facial regions for targeted treatments by different expertise levels.

Hard shell, soft core? Multi-disciplinary and multi-national insights into mental toughness among surgeons.

Background: With the prevalence of burnout among surgeons posing a significant threat to healthcare outcomes, the mental toughness of medical professionals has come to the fore. Mental toughness is pivotal for surgical performance and patient safety, yet research into its dynamics within a global and multi-specialty context remains scarce. This study aims to elucidate the factors contributing to mental toughness among surgeons and to understand how it correlates with surgical outcomes and personal well-being. Methods: Utilizing a cross-sectional design, this study surveyed 104 surgeons from English and German-speaking countries using the Mental Toughness Questionnaire (MTQ-18) along with additional queries about their surgical practice and general life satisfaction. Descriptive and inferential statistical analyses were applied to investigate the variations in mental toughness across different surgical domains and its correlation with professional and personal factors. Results: The study found a statistically significant higher level of mental toughness in micro-surgeons compared to macro-surgeons and a positive correlation between mental toughness and surgeons' intent to continue their careers. A strong association was also observed between general life satisfaction and mental toughness. No significant correlations were found between the application of psychological skills and mental toughness. Conclusion: Mental toughness varies significantly among surgeons from different specialties and is influenced by professional dedication and personal life satisfaction. These findings suggest the need for targeted interventions to foster mental toughness in the surgical community, potentially enhancing surgical performance and reducing burnout. Future research should continue to explore these correlations, with an emphasis on longitudinal data and the development of resilience-building programs.

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.

The "Central Tendency Bias" in the assessment of facial attractiveness in group-based and individual ratings-A survey-based study in 727 volunteers.

BACKGROUND: The increasing number of esthetic procedures emphasizes the need for effective evaluation methods of outcomes. Current practices include the individual practitioners' judgment in conjunction with standardized scales, often relying on the comparison of before and after photographs. This study investigates whether comparative evaluations influence the perception of beauty and aims to enhance the accuracy of esthetic assessments in clinical and research settings. OBJECTIVE: To compare the evaluation of attractiveness and gender characteristics of faces in group-based versus individual ratings. METHODS: A sample of 727 volunteers (average age of 29.5 years) assessed 40 facial photographs (20 male, 20 female) for attractiveness, masculinity, and femininity using a 5-point Likert scale. Each face was digitally edited to display varying ratios in four lip-related proportions: vertical lip position, lip width, upper lip esthetics, and lower lip esthetics. Participants rated these images both in an image series (group-based) and individually. RESULTS: Differences in the perception of the most attractive/masculine/feminine ratios for each lip proportion were found in both the group-based and individual ratings. Group ratings exhibited a significant central tendency bias, with a preference for more average outcomes compared with individual ratings, with an average difference of 0.50 versus 1.00. (p = 0.033) CONCLUSION: A central tendency bias was noted in evaluations of attractiveness, masculinity, and femininity in group-based image presentation, indicating a bias toward more "average" features. Conversely, individual assessments displayed a preference for more pronounced, "non-average" appearances, thereby possibly pointing toward a malleable "intrinsic esthetic blueprint" shaped by comparative context.

ChatGPT's Response Consistency: A Study on Repeated Queries of Medical Examination Questions.

(1) Background: As the field of artificial intelligence (AI) evolves, tools like ChatGPT are increasingly integrated into various domains of medicine, including medical education and research. Given the critical nature of medicine, it is of paramount importance that AI tools offer a high degree of reliability in the information they provide. (2) Methods: A total of n = 450 medical examination questions were manually entered into ChatGPT thrice, each for ChatGPT 3.5 and ChatGPT 4. The responses were collected, and their accuracy and consistency were statistically analyzed throughout the series of entries. (3) Results: ChatGPT 4 displayed a statistically significantly improved accuracy with 85.7% compared to that of 57.7% of ChatGPT 3.5 (p < 0.001). Furthermore, ChatGPT 4 was more consistent, correctly answering 77.8% across all rounds, a significant increase from the 44.9% observed from ChatGPT 3.5 (p < 0.001). (4) Conclusions: The findings underscore the increased accuracy and dependability of ChatGPT 4 in the context of medical education and potential clinical decision making. Nonetheless, the research emphasizes the indispensable nature of human-delivered healthcare and the vital role of continuous assessment in leveraging AI in medicine.

Horizontal necklines correction with absorbable braided polydioxanone threads: Case series.

INTRODUCTION: The prevalence of horizontal neck lines as a cosmetic concern is widely acknowledged, yet the available treatment options are limited, and no studies have investigated the use of polydioxanone-barbed threads. These threads, characterized by a finely braided structure, function as a scaffold to attract regenerative factors and facilitate the migration and proliferation of cells. This study aims to evaluate the outcomes of concurrent application of braided polydioxanone-barbed threads for addressing horizontal neck wrinkles. METHODOLOGY: A retrospective case series involving four female participants (aged 41, 43, 45, and 46) treated with polydioxanone-barbed threads for horizontal neck wrinkles between January 2023 and July 2023 was conducted. Adult patients were assessed at an 8-week follow-up, revealing a significant reduction in wrinkle intensity based on the Horizontal Neck Wrinkle Severity Scale. RESULTS: The analysis of horizontal neck lines demonstrated a notable decrease in wrinkle intensity according to the Horizontal Neck Wrinkle Severity Scale at the 8-week mark, and this improvement maintained statistical significance. Both patient Global Aesthetic Improvement Scale (GAIS) scores (90%-100%) and physician GAIS scores (100%) were rated as excellent. CONCLUSION: The subdermal application of polydioxanone-barbed threads for horizontal neck lines proves to be a secure and efficacious approach for treating horizontal neck wrinkles, with no observed Tyndall effect. This technique shows promise for rejuvenating the skin in the horizontal neckline region.

Increasing Precision When Targeting the Depressor Anguli Oris (DAO) 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: To identify the precise anatomic position of the DAO in relation to the Marionette Line for 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) having a mean age of 48.15 (15) years and a mean body mass index of 24.07 (3.7) kg/m2. The location of the DAO in relation to the labiomandibular sulcus (LMS), its depth, extent, and thickness were investigated with high frequency ultrasound imaging. RESULTS: The skin surface projection of the LMS 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 < 0.001) and higher BMI being an important influencing factor for a greater distance (p < 0.001). The thickness of the DAO was on average 3.5 mm with a range of 2.8-4.8 mm and with females having thinner muscles when compared to men (p < 0.001). The most favorable injection depth was calculated to be 6.1 mm for intra-muscular product placement. CONCLUSIONS: Understanding the perioral anatomy and the influence of age, sex, and BMI will potentially allow the injectors to increase efficacy and duration of neuromodulator treatments while expertly managing adverse events.

Gynecomastia Surgery in 4996 Male Patients Over 14 Years: A Retrospective Analysis of Surgical Trends, Predictive Risk Factors, and Short-Term Outcomes.

BACKGROUND: The high prevalence of benign male breast tissue enlargement (gynecomastia) has resulted in a marked increase of gynecomastia cases. While about one third of male adults experience some form of gynecomastia, gynecomastia surgery (GS) outcome research is limited to small study populations and single-center/-surgeon databases. In this study, we aimed to access the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database to identify preoperative risk factors for complications and investigate postoperative outcomes of GS. METHODS: In this retrospective study, we queried the ACS-NSQIP database from 2008 to 2021 to identify male adult patients who underwent GS. Postoperative outcomes involved the occurrence of any, surgical and medical complications, as well as reoperation, readmission, and mortality within a 30-day postoperative time period. Univariable and multivariable assessment were performed to identify risk factors for complications while adjusting for possible confounders. RESULTS: The study included 4,996 GS patients with a mean age of 33.7 ± 15 years and BMI of 28.2 ± 5.1 kg/m2. White patients constituted 54% (n = 2713) of the cohort, and 27% (n = 1346) were obese. Except for 2020, there was a steady increase in GS cases over the study period. Outpatient surgeries were most common at 95% (n = 4730), while general surgeons performed the majority of GS (n = 3580; 72%). Postoperatively, 91% (n = 4538) of patients were discharged home; 4.4% (n = 222) experienced any complications. Multivariable analysis identified inpatient setting (p < 0.001), BMI (p = 0.023), prior sepsis (p = 0.018), and bleeding disorders (p = 0.047) as independent risk factors for complications. CONCLUSION: In this study, we analyzed 4996 male adult GS patients from the ACS-NSQIP database, revealing an increased caseload and significant general surgeon involvement. Risk factors like bleeding disorders, inpatient status, and prior sepsis were linked to postoperative complications, while BMI was crucial for predicting adverse events. Overall, our findings may aid in enhancing patient care through advanced preoperative screening and closer perioperative management. 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 .

Complete lymph node dissection in cutaneous melanoma patients with positive sentinel lymph node: Outcome and predictors in a retrospective cohort study over 16 years.

BACKGROUND: In melanoma treatment, complete lymph node dissection (CLND) has been considered the therapeutic gold standard in patients with positive sentinel lymph node biopsy (SLNB). This long-held approach was revised in 2017, with recent evidence questioning the therapeutic benefit of CLND in malignant melanoma (MM) therapy. In this study, we aimed to fill this knowledge gap by retrospectively analyzing the impact of CLND on MM patients' survival. METHODS: We retrospectively analyzed the multi-center population-based Clinical Cancer Registry at the Tumor Center Regensburg (TUDOK) database (2004-2020) to identify patients who had been diagnosed with SLN-positive MM and underwent (non)invasive management thereof. Patient cohorts were subdivided according to the treatment received (CLND and waiving CLND). Primary outcomes included overall survival (OS), recurrence-free survival (RFS), and cumulative recurrence rate. RESULTS: We identified 1143 MM patients, of whom 126 (11.0%) had positive SLN status. CLND was waived in the majority of SLN-positive MM cases (n = 71; 56.3%), with 55 (43.7%) patients undergoing CLND. Univariable and multivariable Cox regression revealed no significant advantage for CLND patients compared to non-CLND patients in OS (HR=0.970, p = 0.915 and HR=1.295, p = 0.479, respectively), RFS (HR=1.050, p = 0.849 and HR=1.220, p = 0.544, respectively), and cumulative recurrence rate (HR=1.234, p = 0.441 and HR=1.220, p = 0.544), respectively). CONCLUSION: We found that CLND had no significant impact on patient survival and MM recurrence rate, thus corroborating the validity of current clinical guidelines.

Investigating the Contraction Pattern of the Zygomaticus Major Muscle and its Clinical Relevance: A Functional MRI Study.

BACKGROUND: Our understanding of facial anatomy has significantly evolved, yet the detailed contraction patterns of facial muscles and their presentation during clinical imaging remain largely unexplored. Understanding the contraction patterns and visual presentation of these muscles, particularly the zygomaticus major could enhance pre-surgical facial assessments and the development of new treatment strategies. METHODS: A total of 34 healthy young individuals (17 female, 17 male) with a mean age of 23.6 (2.4) years [range: 20-30] were investigated regarding the length, thickness, width, and angle of the zygomaticus major muscle in five different facial expressions (i.e., repose, anger, joy, surprise, and sadness) utilizing MR imaging. RESULTS: Joyful expressions caused a reduction in muscle length to 85.6% of its original length and an increase in width (103.4%), thickness (108.4%), and facial angle (2.72°) when compared to that in repose, suggesting isotonic contraction. Conversely, expressions of anger, surprise, and sadness generally led to muscle stretching, seen through changes in length (98.9%, 104.3%, and 102.7%, respectively), width (98.8%, 96.5%, and 99.4%, respectively), and thickness (91.2%, 91.0%, and 102.7%, respectively), with variable alterations in facial angle (0.55°, 1.85°, and 1.00°, respectively) depending on the specific expression. CONCLUSION: This MRI-based study indicates that the zygomaticus major muscle experiences isotonic contraction, characterized by decreased length and increased width and thickness. The findings underline the importance of muscle thickness as a reliable parameter in assessing facial muscle function and offer valuable guidance for practitioners in accurately evaluating muscle performance during different facial expressions. 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 .

Isolated and combined breast augmentation in transgender patients: Multi-institutional insights into early outcomes and risk factors.

BACKGROUND: The increasing demand for gender-affirming surgery (GAS) in transgender and gender-diverse healthcare highlights the importance of breast augmentation surgery (BAS) for transfeminine patients. Despite its significance, there is a lack of research on postoperative outcomes of BAS. METHODS: We analyzed the multi-institutional American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) (2008-2021) database to identify female transgender individuals (TGIs) who underwent BAS surgery, both isolated and combined with concurrent GAS procedures. We evaluated 30-day outcomes, including the incidence of mortality, reoperation, readmission as well as surgical and medical complication occurrence. RESULTS: Of 1699 female TGIs, 92% underwent isolated BAS and 7.7% underwent combined BAS. The mean age and body mass index (BMI) were 36 ± 12 years and 27 ± 6.6 kg/m2, respectively. Isolated BAS showed a 2.8% complication rate, while combined BAS had a higher rate with 9.1%. Specifically, all complications occurred in patients undergoing BAS with concurrent genitourinary surgery (n = 85; 14%), whereas no adverse events were recorded after combined BAS and facial feminization (n = 19) or chondrolaryngoplasty (n = 19). In patients seeking combined BAS, advanced age (p = 0.05) and nicotine abuse (p = 0.004) were identified as risk factors predisposing to adverse events, whereas American Society of Anesthesiology class 1 was found to be protective (p = 0.02). CONCLUSIONS: Isolated BAS in TGIs demonstrates a positive safety profile. Combined surgeries, particularly with genitourinary procedures, pose higher risks. Identifying risk factors such as smoking and advanced age is crucial for patient selection and surgical planning. These findings can aid in refining patient eligibility and inform surgical decision-making for BAS.

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.