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.

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.

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.

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.

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 .

Understanding Platysma Muscle Contraction Pattern and Its Relationship to Platysmal Banding: A Real-Time Ultrasound Study

BACKGROUND

Addressing neck contouring with surgical and nonsurgical aesthetic procedures includes understanding the origin of platysmal banding. A theory was postulated to explain this phenomenon by isometric vs isotonic muscular contraction patterns. However, no scientific proof had been provided to date for its correctness.

OBJECTIVES

The aim of this study was to confirm the correctness of the platysmal banding theory based on isometric vs isotonic muscular contractions.

METHODS

Eighty platysma muscles from 40 volunteers (15 males and 25 females) were investigated (mean age 41.8; SD 15.2 years; mean BMI of 22.2; SD 2.3 kg/m2). Real-time ultrasound imaging was utilized to measure the increase in local muscle thickness inside and outside of a platysmal band as well as platysma mobility.

RESULTS

Within a platysmal band, the local thickness of the muscle increases during muscular contractions by 0.33 mm (37.9%; P < .001). Outside of a platysmal band the thickness of the platysma muscle decreased by 0.13 mm (20.3%; P < .001). It was identified that within a platysmal band no gliding was detectable, whereas outside of a band an average muscle gliding of 2.76 mm was observed.

CONCLUSIONS

The results confirm the correctness of the isometric vs isotonic platysma muscle contraction pattern theory: isotonic muscle contraction (gliding without increase in tension and therefore in muscle thickness) vs isometric muscle contraction (no gliding but increase in tension and therefore in muscle thickness). These 2 types of contraction patterns occur within the platysma simultaneously and are an indicator for zones of adhesion in the neck to guide surgical and nonsurgical aesthetic procedures.

LEVEL OF EVIDENCE: 4

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 .

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.

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.

The Suitability of a Large Particle Hyaluronic Acid Filler for the Treatment of Temporal Hollowing

BACKGROUND

Hyaluronic acid (HA) fillers may be manufactured to have distinctive physical properties that optimize their use for specific indications. Fillers manufactured with large gel calibration (particle size; HA-V) may be particularly suitable for volumizing large surface areas such as the temporal hollows.

OBJECTIVE

To investigate the safety and effectiveness of HA-V for the treatment of temporal hollows.

MATERIALS AND METHODS

A prospective, open-label, single-cohort, clinical trial was conducted. Twenty-six women who presented with bilateral temporal hollows at baseline were recruited. All subjects received treatment with HA-V and were observed at 4 to 5 in-person visits over 16 weeks. Subjective and objective measures of safety and efficacy parameters were collected through 2- and 3-dimensional imagery, questionnaires/scales (i.e., subject satisfaction, global aesthetic improvement, temporal hollowing severity), and adverse event diaries.

RESULTS

To achieve optimal correction, the investigator used an average of 1.70 syringes per subject, per side. All treatments were performed using a bolus injection technique to place the product on the periosteum (bone) of the temporal region. Following optimal correction, all subjects (100%) displayed improvement in their global aesthetic appearance, and 25 of 26 subjects (96.15%) displayed ≥1 grade improvement on the temporal volume scale. Subject satisfaction was high, with 91.3% of subjects being satisfied with the appearance of their temporal regions following optimal correction.

CONCLUSION

In this pivotal trial, HA-V was evidenced to have an excellent safety profile and proven efficacy up to 16 weeks, making it a suitable HA filler for volumization of the temporal region.

Treating facial overfilled syndrome with impaired facial expression-Presenting clinical experience with ultrasound imaging

BACKGROUND

Facial overfilled syndrome is an adverse event following minimally invasive soft tissue filler injections. It presents in most cases as excess midfacial volume and/or as unnatural smile which is difficult to detect due to the absence of standardized evaluation methods.

OBJECTIVE

To showcase how to identify, evaluate, and treat facial overfilled syndrome by utilizing facial ultrasound and simultaneous hyaluronidase injections.

METHODS

Twenty-eight consecutive patients (26 females, 2 males) were enrolled in this study in which facial ultrasound was performed to evaluate the location previously implanted filler material. The position of the oral commissure was objectively measured in relation to bony landmarks, and the severity of lateral canthal lines was assessed by independent and blinded raters.

RESULTS

The material was identified in 35.7% inside the subdermal fatty layer, in 28.6% inside the deep supra-periosteal fatty layer, in 10.7% inside the fibrous layer deep to the subdermal fatty layer, whereas in 25.0%, the product was not possible to locate clearly inside one specific layer. On average, 81.6 I.U. [range: 75-150] of hyaluronidase were injected. Lateral canthal line severity was before the treatment 2.28 (1.4) and was after the hyaluronidase treatment 2.02 (1.3) with p = 0.578. The position of the oral commissure increased by 0.60 cm in vertical and by 0.30 cm in horizontal directions (both p < 0.001).

CONCLUSION

Facial overfilled syndrome following aesthetic soft tissue filler injections can present as excess midfacial volume but also as unnatural smile. Targeted hyaluronidase injections into the culprit pockets inside the midfacial soft tissues have shown to re-establish a natural smile, to reduce excess midfacial volume, and to decrease lateral canthal line severity.

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 .

Periorbital venous stasis may be involved with filler induced malar edema-A duplex ultrasound-imaging-based case series

INTRODUCTION

Filler injections in the periocular region are regarded as a challenging and advanced maneuver in a high-risk area. Adverse events as malar edema due to filler treatment may occur. To evaluate the possible reasons, the ultrasound images, and medical data of patients that were prospectively referred with malar edema were evaluated.

MATERIALS AND METHODS

A total of 17 patients (26 eyes) with malar edema after hyaluronic acid filler treatment were included. All cases were assessed with an 18 MHz linear ultrasound device. Exact location of the filler material was noted. Relations with clinical data were analyzed using chi-square tests.

RESULTS

Onset of malar edema after treatment showed a wide range from immediate (0 days) to 3 years. Most patients had an early onset N = 13 (76%), a minority showed late onset N = 4 (24%). In 23 eyes, the filler material was found to be located inside the SMAS. In 3 cases filler material was located on the periosteum of the orbital rim. After duplex-ultrasound guided filler removal, restored venous flow could be seen in the superficial and/or deep fatty layer often accompanied by flow piercing through the SMAS. Minutes after treatment, clinical improvement of malar edema was observed.

CONCLUSION

Malar edema after by filler treatments in the periocular region may be caused by veno-lymphatic compression by filler deposits.

One-Year Data on the Longevity and Safety of Hyaluronic Acid Filler for Static Horizontal Neck Rhytids

BACKGROUND

The long-term efficacy and safety of hyaluronic acid fillers injected into the neck have yet to be analyzed in a prospective trial in the United States.

OBJECTIVE

Analyze the long-term efficacy and safety of a hyaluronic acid filler for static horizontal neck rhytids.

MATERIALS AND METHODS

Twenty-six subjects were enrolled in the study. Six subjects were randomized to receive saline and 20 subjects were randomized to receive HA RR. All subjects were randomized to use a cannula on 1 side and needle on the other with optional retreatment on day 30 and optional crossover treatment with different assignment on day 60. The subjects were graded using the Transverse Neck Line Scale, Canfield photography, and the Global Aesthetic Improvement Scale on day 360.

RESULTS

A significant improvement from baseline on day 360 was achieved on the Transverse Neck Line Scale according to the blind evaluator, subjects, and investigator without any delayed-onset or prolonged side effects. There was no significant difference in the average improvement from the short-term analysis on day 60 to the long-term analysis on day 360.

CONCLUSION

HA RR achieved significant long-term improvement in static horizontal neck rhytids without any long-term side effects.

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.

Percutaneous Computed Tomography-Guided Oxygen-Ozone (O2O3) Injection Therapy in Patients with Lower Back Pain-An Interventional Two-Year Follow-Up Study of 321 Patients

OBJECTIVES

To assess the effect of oxygen-ozone therapy guided by percutaneous Computed Tomography (CT) compared to corticosteroids in individuals experiencing lower back pain (LBP) not attributed to underlying bone-related issues.

METHODS

A total of 321 patients (192 males and 129 females, mean age: 51.5 ± 15.1 years) with LBP were assigned to three treatment groups: group A) oxygen-ozone only, group B) corticosteroids only, group C) oxygen-ozone and corticosteroids. Treatment was administered via CT-guided injections to the intervertebral disc (i.e., intradiscal location). Clinical improvement of pain and functionality was assessed via self-reported pain scales and magnetic resonance (MR) and CT imaging.

RESULTS

At all follow-up times, the mean score of the numeric rating scale and the total global pain scale (GPS) of study groups receiving oxygen-ozone (groups A and C) were statistically significantly lower than the study group receiving corticosteroids only (group B), with p < 0.001. There was a statistically significant difference between groups A and C at 30 days for the numeric rating scale.

CONCLUSIONS

The percutaneous application of oxygen-ozone in patients with LBP due to degeneration of the lumbosacral spine showed long-lasting significant pain reduction of up to two years post-treatment when compared to corticosteroids alone. Combination therapy of oxygen-ozone and corticosteroids can be useful as corticosteroids showed statistically significant improvement in LBP earlier than the oxygen-ozone-only treatment.

Is constant needle motion during soft tissue filler injections a safer procedure? A theoretical mathematical model for evaluating patient safety

BACKGROUND

The safety rationale behind the constant needle motion injection technique is based on the assumption that due to the constant needle motion and simultaneous soft tissue filler material administration a smaller amount of product per area may be injected into an artery if an artery within the range of the moving needle is inadvertently entered.

OBJECTIVE

To perform mathematical calculations for determining the probability for causing intra-arterial product administration when constantly moving the needle during facial aesthetic soft tissue filler injections.

METHODS

This study was designed as a theoretical investigation into the probabilities for causing adverse events due to intravascular injection of soft tissue filler material when constantly moving a 27-G needle during facial soft tissue filler administration.

RESULTS

It was revealed that with a higher number of conducted injection passes a greater soft tissue area can be covered by the needle. The odds of encountering an artery within the covered soft tissue volume and the odds of injecting any volume greater than zero into the arterial blood stream increases with the number of performed injection passes. This increase is greatest between 1 and 10 performed injection passes.

CONCLUSION

This model demonstrates that the constant needle motion technique increases the probability of encountering an artery within the treatment area and thus increases the odds for intra-arterial product administration. The constant needle motion technique does not increase safety but rather may increase the odds of causing intra-arterial product administration with the respective adverse consequences for the patient.

How to improve infraorbital hollows with neuromodulators-A clinical prospective interventional study about the application of facial biomechanics

BACKGROUND

A previous injection algorithm termed the "Toxin Lift" was recently introduced and described volume increases in the midface following neuromodulator treatments of the jawline. Increase in midfacial volume due to soft tissue repositioning could also affect the severity of infraorbital hollows.

OBJECTIVE

The objective is therefore to evaluate whether the severity of infraorbital hollows can be improved by injecting neuromodulators in the supra-mandibular segment of the platysma.

MATERIALS AND METHODS

A total of 35 volunteers (11 males/24 females) with a mean age of 39.8 (9.6) years and a mean BMI of 25.2 (5.2) kg/m2 were investigated. Bilateral infraorbital regions were evaluated via clinical assessment and semi-quantitative 3D imaging. The applied injection technique targeted the platysma via four injection points administering 5 I.U. per injection point resulting in a total of 20 I.U. per facial side.

RESULTS

Volume increase of the infraorbital region was 0.13 cc at 15 days (p = 0.001) and was 0.02 cc at 30 days (p = 0.452) whereas the skin displacement in cranial direction was 0.54 mm at 15 days (p < 0.001) and was 0.31 mm at 30 days (p < 0.001). Clinical evaluation revealed a highly statistically significant improvement of the tear trough, palpaebromalar groove, and of the lid-cheek junction when compared to baseline with all p < 0.001.

CONCLUSION

The results of this clinical prospective interventional analysis revealed that the "Toxin Lift" injection technique is capable to improve the clinical appearance of infraorbital hollows. The effects can be explained by the concepts of facial biomechanics.

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.

Superficial versus deep injections of the upper midface-A prospective interventional split-face study

BACKGROUND

Various injection algorithms have been proposed in the past which are in line with the three aesthetic principles: upper face first, lateral face first, and deep regions first. However, increasing evidence is provided that the upper midface can be targeted with superficial soft tissue filler injections alone too.

OBJECTIVE

To investigate in a prospective split-face study design whether superficial or deep upper midfacial injections provide superior aesthetic outcomes.

METHODS

A total of n = 20 study participants (100% females; age 43.95 (11.7) years; BMI 22.92 (2.6) kg/m2 ) were treated with superficial soft tissue filler injections on side of their face and deep injections on the contralateral side with a mean volume of 0.78 cc. Outcome was evaluated at 7 weeks follow-up for midfacial, and lower facial volume, for medial and lateral facial skin vector displacement, and for improvement of nasolabial, crow's feet, and upper cheek fullness severity scores.

RESULTS

No adverse events related to safety or product tolerability were observed during the entire study period. All semiquantitative scores improved statistically significantly after the observational period (p < 0.001) but displayed no difference between the two applied injection techniques (p > 0.05).

CONCLUSION

The results of this split-face study revealed that both the superficial and the deep cannula injection technique for midface volumization statistically significantly improve the midfacial volume, reduce nasolabial fold and crow's feet severity. No statistically significant difference was observed between the two injection techniques when compared via semiquantitative and objective outcome evaluation after 7 weeks follow-up.

ChatGPT's quiz skills in different otolaryngology subspecialties: an analysis of 2576 single-choice and multiple-choice board certification preparation questions

PURPOSE

With the increasing adoption of artificial intelligence (AI) in various domains, including healthcare, there is growing acceptance and interest in consulting AI models to provide medical information and advice. This study aimed to evaluate the accuracy of ChatGPT's responses to practice quiz questions designed for otolaryngology board certification and decipher potential performance disparities across different otolaryngology subspecialties.

METHODS

A dataset covering 15 otolaryngology subspecialties was collected from an online learning platform funded by the German Society of Oto-Rhino-Laryngology, Head and Neck Surgery, designed for board certification examination preparation. These questions were entered into ChatGPT, with its responses being analyzed for accuracy and variance in performance.

RESULTS

The dataset included 2576 questions (479 multiple-choice and 2097 single-choice), of which 57% (n = 1475) were answered correctly by ChatGPT. An in-depth analysis of question style revealed that single-choice questions were associated with a significantly higher rate (p < 0.001) of correct responses (n = 1313; 63%) compared to multiple-choice questions (n = 162; 34%). Stratified by question categories, ChatGPT yielded the highest rate of correct responses (n = 151; 72%) in the field of allergology, whereas 7 out of 10 questions (n = 65; 71%) on legal otolaryngology aspects were answered incorrectly.

CONCLUSION

The study reveals ChatGPT's potential as a supplementary tool for otolaryngology board certification preparation. However, its propensity for errors in certain otolaryngology areas calls for further refinement. Future research should address these limitations to improve ChatGPT's educational use. An approach, with expert collaboration, is recommended for the reliable and accurate integration of such AI models.

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.

Facial Anthropometric Measurements and Principles - Overview and Implications for Aesthetic Treatments

Facial anatomy is highly individual in each patient. Anthropometric measurements can be a useful tool to objectively analyze individual facial anatomy to allow for better comparability before and after treatments to ultimately improve standardization of facial procedures, both nonsurgical and surgical. The aim of this study was to provide a comprehensive overview over clinically relevant and feasible facial anthropometric measurements and principles for aesthetic medicine. A literature review was conducted to describe the most important and clinically relevant anthropometric measurements and principles for both the entire face and for three aesthetically relevant facial regions: the periorbital region, the nose, and the perioral region. A multitude of different anthropometric measurements and principles have been described in the literature for both the overall facial appearance and specific facial regions. Certain generally accepted anthropometric principles and proportions need to be respected to achieve aesthetic and harmonious results. For the overall facial appearance, a focus on symmetry, certain proportions, facial angles, and indices has been described. Principles and measurements were also described for the periorbital region, the nose, and the perioral region. Although attractiveness and aesthetic perception are subjective, objective evaluation of facial surface anatomy via anthropometric measurements can improve pre- and postinterventional analysis of the face and help the treating physician to individualize treatments, both nonsurgical and surgical.

Intralabial Lip Compartments and their Potential Clinical Relevance

BACKGROUND

Aesthetic soft tissue filler injections for lip enhancement are highly popular and are performed throughout the world. When injecting lips with cannulas, as the cannula is advanced, resistance is perceived in consistent locations potentially indicating boundaries between intralabial compartments.

OBJECTIVE

To investigate whether intra-labial compartments exist and (if so) to describe their volumes, location, boundaries, and dimensions.

METHODS

This cadaveric study investigated a total of n = 20 (13 males, 7 females) human body donors with a mean age at death of 61.9 (23.9) years and a mean body mass index of 24.3 (3.7) kg/m 2. The investigated cohort included n = 11 Caucasian, n = 8 Asian, and n = 1 African American donors. Dye injections simulating minimally invasive lip treatments were conducted.

RESULTS

Independent of gender or race, 6 anterior and 6 posterior compartments in the upper and lower lip were identified, for a total of 24 lip compartments. Compartment boundaries were formed by vertically oriented septations that were found in consistent locations. The anterior compartments had volumes ranging from 0.30 - 0.39 cc whereas the posterior compartment volume ranged from 0.44 - 0.52 cc. Centrally, the compartment volumes were larger and decreased gradually towards the oral commissure.

CONCLUSION

The volume and the size of each of the 24 compartments contribute to the overall appearance and shape of the lips. To achieve a natural and lip-shape preserving aesthetic outcome it may be preferable to administer the volumizing product using a compartment-respecting injection approach.

Applied Anatomy of the Lower Eyelids' Preseptal Space for Treating Ectropion and Retraction with Soft Tissue Fillers

BACKGROUND

Lower eyelid malposition can result from age-related changes such as ectropion or post-surgical changes like retraction following lower lid blepharoplasty. The current accepted treatment is surgical, but previously it was indicated that soft tissue fillers can be used as well with good outcome. However, the underlying anatomy is incompletely described when guiding practitioners toward minimally invasive injections of the lower eyelid.

OBJECTIVE

To describe a minimally invasive injection technique adjusted to the complex anatomy of the lower eyelid for the treatment of ectropion and retraction of the lower eyelid.

METHODS

A total of n = 39 periorbital regions of n = 31 study participants were retrospectively analyzed using photographs prior and post to reconstruction of the lower eyelid with soft-tissue fillers. Two independent raters assessed the degree of ectropion and lower eyelid retraction (DELER; 0 - 4, best-to-worst) before and after the reconstruction and the overall aesthetic improvement using the Periorbital Aesthetic Improvement Scale (PAIS).

RESULTS

The median DELER score improved statistically significantly from 3.00 (1.5) to 1.00 (1.0) with p <0.001. The mean volume of soft tissue filler material applied per eyelid was 0.73 cc (0.5). The median PAIS following the treatment was rated as 4.00 (0.5) indicating improvement of the periorbital functional and aesthetic appearance.

CONCLUSION

Anatomic knowledge of the lower eyelid and of the preseptal space is of clinical relevance when trying to reconstruct the lower eyelid with soft-tissue fillers. The targeted space provides optimal lifting capacities for improved aesthetic and functional outcome.

Investigating the Anatomic Location of Soft Tissue Fillers in Noninflammatory Nodule Formation: An Ultrasound-Imaging-Based Analysis

INTRODUCTION

Noninflammatory nodules may be persistent to dissolve. To evaluate the possible reasons, a case series of ultrasound images and medical data of patients who were prospectively referred with noninflammatory nodules were evaluated.

MATERIALS AND METHODS

A total of 27 patients with nodules but without signs of inflammation were included. All cases were assessed with an 18-MHz linear ultrasound device. Exact location of the filler material was noted. Relations with clinical data were analyzed using chi-square tests.

RESULTS

Early onset of complaints (<2 weeks) was found in 16 patients and late onset (>2 weeks) in 11. All patients had multiple nodules. In all cases, the filler nodule was found to be located inside the fascia. Extension to the subcutaneous tissue was seen in 8 cases and to the deeper planes in 5. In 14 cases, the filler material was completely located inside layers of the fascia, and migration was observed in 5 cases.

DISCUSSION

Accumulation of filler material in the superficial musculoaponeurotic system or fascia may be an important cause for the occurrence of persistent noninflammatory nodules, either by initial faulty injection technique or by later accumulation through the pathway generated with a needle or cannula. Ultrasound-guided injections are helpful to dissolve the nodule.

Histological effects of a combined collagen stimulation procedure consisting of microfocused ultrasound, soft tissue filler, and Ca-HA injections

BACKGROUND

An increasing demand for in-office aesthetic procedures aiming to improve collagen stimulation has been reported.

OBJECTIVE

To analyze the effects of combinations of different aesthetic collagen stimulation procedures using histological analysis.

METHODS

Histological analysis was performed on skin samples of the excess skin of a 60-year-old patient after sub-superficial musculo-aponeurotic system facelift surgery. The excess skin before facelift surgery was divided into three areas per hemiface. Each area-with exception of area A as a control-received an isolated or combined treatment of microfocused ultrasound (MFU), injections of calcium-hydroxylapatite/hyaluronic-acid-based soft tissue filler, and microneedling. The effect of the treatments was analyzed using histological analysis with H&E coloration and PAS staining.

RESULTS

A threefold increase of epidermal and dermal thickness was achieved by treating the skin with the proposed combined treatment comprising MFU and injections of calcium-hydroxylapatite- and hyaluronic-acid-based soft tissue fillers.

CONCLUSION

The investigated treatments act synergistically in the production of collagen and combining these treatments allows for an increase in collagen production.

Facial aesthetic minimally invasive procedure: More than just vanity, a social-psychological approach

BACKGROUND

Due to the great importance of the face in social interaction, minimally invasive treatments can-besides their ability to rejuvenate and enhance beauty-also change the way facial impressions of a person are perceived. In recent literature, three main character traits (attractiveness, trustworthiness, and competence) and subdomains essential for facial perception were described.

OBJECTIVE

To investigate whether minimally invasive procedures truly influence different character traits when evaluated by independent, objective observers.

METHODS

Photographs of n = 34 female faces before and after treatment with injectable fillers and botulinum toxin were rated by 393 individuals without aesthetic background with regards to different character traits on a 7-point Likert scale. Tests for dimensionality were performed, and composite scores of the impressions underlying each of the three dimensions were created and compared using within-subjects t tests.

RESULTS

Treatments statistically significantly improved the overarching character trait domains attractiveness, trustworthiness, and competence in posttreatment photographs compared with pretreatment. Posttreatment ratings of the respective subdomains also showed a statistically significant difference compared with pretreatment photographs, with the exception of the subdomain dominance which failed to reach statistical significance.

CONCLUSION

Impressions of facial attractiveness, trustworthiness, and competence can be improved by injectables while the naturalness of the face is left intact. An implication is that the improvement of traits highly relevant to social interaction will accommodate the patient's desires for beautification and rejuvenation.

Precision of Soft-Tissue Filler Injections: An Ultrasound-Based Verification Study

BACKGROUND

Uncontrolled product spread is an important issue to consider in facial filler injections. Lack of precision can result in reduced effectiveness and surface projection, as well as irregularities and product visibility.

OBJECTIVES

The authors sought to assess the precision of soft-tissue filler injections in the face by employing a cannula.

METHODS

This single-center observational study investigated soft-tissue filler distribution utilizing real-time non-invasive ultrasound imaging. Outcome parameters included (1) the tissue plane of product distribution, (2) the extent of horizontal as well as vertical product spread at the injection site, and (3) the product surface area taking into account the multifactorial influence of several independent variables. Participants were followed up to 30 days post-injection.

RESULTS

A total 100 facial injections were performed in 8 patients (2 males, 6 females) with a mean age of 37.20 (±6.34) years and a mean BMI of 22.21 (±1.39) kg/m.2. The plane of product distribution remained constant in approximately 90% of cases at day 0 (d0), d14, and d30. Mean horizontal product spread was higher compared with vertical spread, and both significantly decreased over all time points (P < .001). Mean product surface area was 22.51 ± 16.34 mm2 at d0, 15.97 ± 11.28 mm2 at d14, and 12.9 ± 9.15 mm2 at d30. Analysis employing generalized linear models revealed that injection volume and injection depth significantly influenced product surface area.

CONCLUSIONS

Injection of soft-tissue filler employing a cannula allows precise application of the product within the intended tissue plane. Precision can be improved by injecting less product into deeper tissue layers.

LEVEL OF EVIDENCE: 5

How We Look At Mature Faces-An Eye-Tracking Investigation Into the Perception of Age

BACKGROUND

It is still unclear which facial region contributes most to the perception of an aged face when evaluated by eye-tracking analyses.

OBJECTIVES

The authors sought to apply eye-tracking technology to identify whether mature faces require longer fixation durations than young faces and which facial region contributes most to the perception of a mature face.

METHODS

Eye-tracking analyses were conducted in 74 volunteers (37 males, 37 females; 43 ≤ 40 years, 31 > 40 years) evaluating their gaze pattern and the fixation durations for the entire face and 9 facial subregions. Frontal facial images of 16 younger (<40 years) and older (>40 years) gender-matched individuals were presented in a standardized setting.

RESULTS

Independent of age or gender of the observer, a younger stimulus image was viewed shorter than an older stimulus image with 0.82 (0.63) seconds vs 1.06 (0.73) seconds with P < 0.001. There was no statistically significant difference in their duration of a stable eye fixation when observers inspected a male vs a female stimulus image [0.94 (0.70) seconds vs 0.94 (0.68) seconds; P = 0.657] independent of the observer's age or gender. The facial image that captured the most attention of the observer (rank 9) was the perioral region with 1.61 (0.73) seconds for younger observers and 1.57 (0.73) seconds for older observers.

CONCLUSIONS

It was revealed that the perioral region attracts the most attention of observers and contributes most to an aged facial appearance. Practitioners should be mindful of the importance of the perioral region when designing an aesthetic treatment plan.

Aesthetic considerations when treating the Latin American patient: Thriving in diversity international roundtable series

BACKGROUND

The Hispanic/Latin American population is the fastest growing non-Caucasian group in the United States. Within this group, demand for aesthetic procedures is on the rise. High ethnic variability among these patients influences treatment approaches and patient priorities. Understanding these ethnic differences is central to providing optimal care.

AIMS

To discuss similarities and differences in anatomy and treatment preferences of Hispanic/Latin American patients both within the United States and internationally and explore how these differences may influence or inform aesthetic practices.

PATIENTS/METHODS

In support of clinicians who wish to serve a diverse patient population, a 6-part, international roundtable series focused on diversity in aesthetics was conducted from August 24, 2021 to May 16, 2022. In this roundtable, held in Medellin, Columbia, expert clinicians from across Latin America and the United States were invited to contribute and share best practices.

RESULTS

The results of the second roundtable in the series, the Latin American Patient, are described here. A special emphasis is placed on procedures that address the most commonly encountered concerns in these patients.

CONCLUSIONS

Hispanic and Latino patients represent a broad demographic with unique anatomical features, aesthetic preferences, and treatment priorities. Clinicians should consider these differences when treating this patient population.

Clinical validation of the upper face first principle-A clinical, prospective, interventional split-face study

BACKGROUND

Previous clinical and anatomic investigations have identified the clinical relevance of facial biomechanics. Based on this new understanding, principles for facial aesthetic procedures were established: Lateral Face First, Deep Layers First, and Upper Face First.

OBJECTIVE

To test the upper face first principle by showing that an injection sequence, starting in the upper face is superior to an injection sequence starting in the lower face.

METHODS

This study was designed as an interventional split-face study administering the same amount and type of soft tissue filler for the upper, middle, and lower face but in a different sequence: upper, middle, lower face versus lower, middle, and upper face. A total of 15 patients (5 males and 10 females) with a mean age of 39.4 years (9.6) and a mean BMI of 23.4 kg/m² (1.7) were studied. Follow-up at D0, D30, and D90 was conducted utilizing semiquantitative scores and objective 3D imaging.

RESULTS

Despite not reaching statistical significance, midfacial volume and jawline contouring were rated better at every follow-up visit (D0, D30, D90) when treated with the upper versus the lower face first injection algorithm. The global aesthetic improvement scale showed statistically significantly better values for the upper face first algorithm when compared to the lower face first algorithm at all evaluated time points with all p < 0.001.

CONCLUSION

Applying the upper face first injection algorithm seems to result in better aesthetic outcomes when directly compared to the lower face first algorithm. Semiquantitative and objective outcome measurements confirm its clinical effectiveness.

Ex-Vivo Product Distribution of Injectable Biostimulator Substances

BACKGROUND

Previously, an increasing demand for minimally invasive aesthetic treatments such as injection of biostimulator substances to induce the production of extracellular matrix (ECM) 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

To analyze ex-vivo product integration and distribution behavior of six different biostimulator substances after injection.

METHODS

A total of n = 21 abdominal soft tissue flaps were analyzed with regards to horizontal and vertical spread of six different injected biostimulator substances immediately after injection and after massaging using real-time ultrasound imaging. The six 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 to the product distribution immediately after the injection with all p < 0.001 with exception for the vertical dimension of the H-CaHA-based substance with p = 0.064. The PLLA-1-, PLLA-2- and H-HA-based substances showed smaller product spread after massaging when compared to the product distribution immediately after the injection with all p < 0.001 with exception for the horizontal dimension of the H-HA-based substance with p = 0.314 indicating higher tissue integration.

CONCLUSIONS

Different biostimulator substances behave differently when injected into subcutaneous soft tissues while differences exist at the level of initial product diffusion and during tissue integration.

Multimodal Analyses of the Aging Forehead and Their Clinical Implications

BACKGROUND

Recent research has indicated that in the upper face a delicate arrangement exists between the muscles of facial expression and the skin. This arrangement allows for immediate transmission of movements following muscle contraction which results in skin movements and skin rhytid formation.

OBJECTIVES

To investigate age-related changes to the biomechanical unit formed between facial muscles, connective tissue envelope, and skin in the upper face.

METHODS

A total of n = 76 Caucasian volunteers (30 males, 46 females) with a mean age of 42.2 (18.6) years and a mean body mass index of 24.58 (3.7) kg/m2 were investigated. Three upper facial regions were analyzed for skin firmness and elasticity via cutometry, vertical and horizontal skin vector displacement via 3D-imaging, and muscle activity via surface-derived electromyography.

RESULTS

Study participants of older age (> 42.2 years) (when compared to younger participants; ≤ 42.2 years) showed increased skin firmness with 0.20 mm vs 0.30 mm with p < 0.001, decreased skin elasticity with 53.2% vs 69.0% (p < 0.001), increased vertical (not horizontal) skin mobility with 3.56 mm vs 1.35 mm (p < 0.001), and decreased muscle sEMG derived signal of the frontalis muscle with 309 µV vs 174 µV (p = 0.039).

CONCLUSIONS

This study reveals that age-related changes occur in each of the components of the biomechanical unit formed between facial muscles, connective tissue envelope, and skin in the upper face. Knowledge and understanding of such changes can allow for more targeted and individualized surgical and non-surgical aesthetic treatments.

Ultrasound-Guided Targeted vs Regional Flooding: A Comparative Study for Improving the Clinical Outcome in Soft Tissue Filler Vascular Adverse Event Management

BACKGROUND

Adverse vascular event management following hyaluronic acid-based aesthetic injections relies on the administration of hyaluronidase which is capable of enzymatically degrading the injected product and improving clinical symptoms. Two protocols are currently available to manage such complications: "ultrasound-guided targeted" and "flooding".

OBJECTIVES

The aim of this study was to compare the 2 protocols in terms of the volume of hyaluronidase utilized, and the onset and degree of clinical improvement.

METHODS

A comparative case series of 39 patients was retrospectively evaluated. The patients were initially treated with the "flooding" protocol and then treated with the "ultrasound-guided targeted" protocol due to no or little improvement.

RESULTS

The "ultrasound-guided targeted" protocol utilized a mean [standard deviation] total of 122.5 [34] IU of hyaluronidase, whereas the "flooding" protocol utilized 1519.4 [1137] IU, which represents a statistically significant reduced amount of injected hyaluronidase (P = 0.028). There was no clinical improvement in 92.3% and only little improvement in 7.7% of the treated patients following the first applied "flooding" protocol, but there was a 100% immediate improvement when subsequently treated with the "ultrasound-guided targeted" protocol. Ultrasound imaging revealed that the application of hyaluronidase restored normal blood flow both in the perivascular space and in the superficially located subdermal soft tissues.

CONCLUSIONS

Despite its limitations in study design, this retrospectively evaluated case series revealed that the "ultrasound-guided targeted" protocol utilized less hyaluronidase and restored clinically visible symptoms faster. The effect of this protocol is best explained by the perforasome concept which will need to be investigated further in future studies.

LEVEL OF EVIDENCE: 4

Clinical outcomes after lip injection procedures-Comparison of two hyaluronic acid gel fillers with different product properties

BACKGROUND

Transient swelling is common after lip injections with hyaluronic acid (HA) based fillers. Swelling and other injection-site reactions may relate to the injection procedure itself, or to gel properties, which differ between fillers due to differences in manufacturing methods.

OBJECTIVES

To evaluate safety and effectiveness of lip injections with two HA fillers manufactured using different gel technologies.

METHODS

In a study sample of 40 subjects, treatment with two soft tissue filler product (HA_RK or HA_JUS ) was randomly assigned. Subjects were injected with 0.5 cc per upper and lower lip using a standardized injection procedure. Early-onset adverse events (AEs) were assessed by evaluation up to Day 14. Aesthetic improvement, subject satisfaction, and AEs post-Day 14 were assessed up to 24 weeks.

RESULTS

In subjects treated with HA_RK , the intensity of early onset swelling, erythema, and pain/tenderness was lower than in subjects treated with HA_JUS . Aesthetic improvement was achieved in both groups, and most subjects were satisfied with the appearance of their lips. Treatment-related AEs post-Day 14 mostly related to the implant site; most were mild-to-moderate, and none were serious.

CONCLUSIONS

The intensity of early-onset swelling, and other injection-site reactions was lower in subjects treated with HA_RK than in subjects treated with HA_JUS . Since both the injection volume and injection procedure were standardized, the difference in local tolerability between the two HA fillers may relate to differences in gel properties. Aesthetic improvement, subject satisfaction, and AE profiles post-Day 14, however, were similar between filler groups.

Introduction of the Lip Classification of Tubercles: A Novel Approach to Minimally Invasive Aesthetic Lip Treatments

Background

Lip enhancement procedures involving dermal fillers are one of the most sought after nonsurgical aesthetic treatments. However, current trends are associated with unnatural results and involve increased risks of complications and compromise to normal function. It appears that lips may be classified according to the presentation of their tubercles and this may be used to guide minimally invasive techniques which aim to preserve individual lip shapes and normal function.

Objectives

To test the reliability of a classification system based on lip tubercle morphology, named the Lip Classification of Tubercles (LCT).

Methods

To test the reliability of the LCT, a total of 214 high-definition photographs of patients' lips with no previous histories of lip treatments were classified independently by 4 experienced aesthetic practitioners on 2 separate occasions 3 months apart; the second followed a more detailed explanation of the classification.

Results

When inter-rater reliability was calculated for the first attempt, the results were 36% and 43% for upper and lower lips, respectively. The second attempt following an education process resulted in 79% for both lips. When 1 practitioner was considered the standard, the average score for the remaining 3 showed some individual variation but improved significantly from 58% to 85%.

Conclusions

The LCT is a reliable way to classify lip types based on the morphology of tubercles.

Level of Evidence 3

Invited Discussion on: A 7-Step Guide to High-Definition Liposuction

Athanasiou et al. present a 7-step guide to high-definition (HD) liposuction in the current issue of Aesthetic Plastic Surgery. [1] The guide was based on the authors vast experience in HD-liposuction performed in 568 patients (247 males and 321 females) with a mean age of 43 years (range, 22-64) and a mean BMI of 25.6 (range 21-29 kg/m²) over a 6-year time-period. The authors provide detailed information on their approach regarding pre-operative markings, methods of anesthesia and composition of tumescence solution, incision points and access, surgical technique, and fat transfer. In addition, they performed a time-dependent analysis of the type and quantity of observed complications over the study-period, as well as the mean surgical operative time. 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 http://www.springer.com/00266 .

Identifying the most attractive umbilical position - an eye tracking- and survey-based investigation

Abdominoplasty is a popular procedure in plastic surgery providing aesthetic, functional and psychological relief for patients suffering from excess abdominal tissue. Correct umbilical positioning is crucial for a successful aesthetic surgical outcome. This study aims to assess the most attractive position of the umbilicus by means of subjective and objective outcome measures. 58 Caucasian study participants with a mean age of 36.87 (15.6) years rated eight different umbilical positions. The various positions were determined based on the ratio of the distance between the xiphoid process and the umbilicus and the distance between the umbilicus and the infra-umbilical crease: 1:1, 1.25:1, 1.5:1, 1.75:1, 2:1, 2.5:1, 3:1 and 5.5:1. Semi-quantitative scoring of attractiveness based on a 5-point Likert scale and eye tracking analyses were utilized. The results revealed that the volunteers perceived as most attractive the ratio of 2:1 with 4.32 (out of possible 5.0). The ratio of 5.5:1 received the lowest rating with 1.8. The results of the objective eye tracking analyses confirmed the subjective rating as the 2:1 ratio was fixated last amongst all other displayed ratios with 1.85 s whereas the 5.5:1 ratio had the shortest interval between image display and first stable eye fixation with 0.94 s. The study confirms the concept of 'internal representation of beauty'. Abdominoplasty procedures could rely on this easy to perform ratio by dividing the distance into thirds and using the boundary between the inferior and middle third as a clinically reliable landmark.

Applied anatomy of the layers and soft tissues of the forehead during minimally-invasive aesthetic procedures

BACKGROUND

An increasing demand of minimally-invasive aesthetic procedures of the forehead concomitantly leads to higher numbers of adverse events. Adequate application of anatomical knowledge is required to increase safety and efficacy of different minimally-invasive aesthetic procedures in this anatomical region.

OBJECTIVE

To describe the layered anatomy of the forehead soft tissues with respect to their thicknesses and how they relate to different minimally-invasive aesthetic treatments.

METHODS

A total of n = 85 healthy study participants (69 females and 16 males) with a mean age of 40.84 ± 10.9 years and a mean body mass index of 22.65 ± 2.6 kg/m² were investigated with ultrasound-based imaging to measure the thickness of different forehead soft tissues.

RESULTS

The mean overall soft tissue thickness of the forehead was measured to be 4.18 ± 0.7 mm for the entire study population. Increasing BMI values correlated statistically significantly with increasing thickness of all measured forehead soft tissues with exception of the frontalis muscle. On a statistically significant level, males showed thicker forehead soft tissues than females, with exception of the retrofrontalis fat and the frontalis muscle.

CONCLUSION

On basis of the findings obtained in this study, basic treatment principles can be derived and improved for the injection of neuromodulators, hyaluronic acid as well as the application of polydiaxonane (PDO) threads and micro-focused ultrasound. Precise knowledge and thorough understanding of the layers and soft tissues of the forehead is required to guarantee safe and effective procedures in this aesthetically important facial region.