Sihler's staining of the anterior belly of digastric muscle for botulinum toxin injection.

PURPOSE: The anterior belly of the digastric muscle (ABDM) is the target of botulinum toxin injection; however, anatomical considerations related to the injection point are absent. This study used Sihler's staining to analyze the intramuscular nerve distribution of ABDM to identify the most effective botulinum toxin injection points. METHODS: We used 12 specimens from 6 embalmed cadavers in this study. The specimens were manually dissected to preserve the mylohyoid nerve and subjected to Sihler's staining. From the gnathion to and hyoid bone, the ABDM was divided into three equal parts, distinguishing the anterior, middle, and posterior thirds. RESULTS: Only a branch of the mylohyoid nerve entered the ABDM, and its entry point was located in the middle-third region in all cases. The nerve endings were concentrated in the middle third (100%), followed by the anterior third (58.3%) and were not observed in the posterior third. CONCLUSION: The landmarks used in this study (gnathion and hyoid bone) are easily palpable on the skin surface, allowing clinicians to target the most effective injection site (middle third of ABDM). These results provide scientific and anatomic evidence for injection points, and will aid in the management of ABDM injection procedures in clinical practice.

Poly­d,l­lactic acid­enhanced atrophic scar treatment via transdermal microjet drug delivery in Asians.

BACKGROUND: Acne vulgaris often results in permanent scars, with atrophic scars being the most common type and posing a significant therapeutic challenge due to their prevalence and impact on patients' quality of life. Various treatment options exist, including the use of poly-d,l-lactic acid delivered via different methods. OBJECTIVE: This study aimed to assess the efficacy and safety of poly-d,l-lactic acid delivered via laser-assisted needle-free microjet injection for treating atrophic scars. METHODS: Five Korean participants with atrophic facial scars were recruited. Poly-d,l-lactic acid solution was administered via the Mirajet system in five sessions, with clinical assessments conducted at baseline, before each session, and at 12-week and 22-week follow-ups. Outcome measures included the Global Aesthetic Improvement Scale and patient satisfaction scores. RESULTS: Positive results were observed at the 12-week and 22-week follow-ups, with high patient satisfaction and improvements in atrophic scars and skin texture. Mild discomfort and transient side effects were reported, with no adverse events observed during the follow-up period. CONCLUSION: Poly-d,l-lactic acid delivered by a laser-assisted needle-free microjet injector was judged to be effective for improving atrophic the facial area. Further research, particularly through randomized controlled trials, is needed to validate these findings and assess the longer-term safety and sustainability of outcomes.

Spatiotemporal estimation of groundwater and surface water conditions by integrating deep learning and physics-based watershed models.

The impacts of climate change on hydrology underscore the urgency of understanding watershed hydrological patterns for sustainable water resource management. The conventional physics-based fully distributed hydrological models are limited due to computational demands, particularly in the case of large-scale watersheds. Deep learning (DL) offers a promising solution for handling large datasets and extracting intricate data relationships. Here, we propose a DL modeling framework, incorporating convolutional neural networks (CNNs) to efficiently replicate physics-based model outputs at high spatial resolution. The goal was to estimate groundwater head and surface water depth in the Sabgyo Stream Watershed, South Korea. The model datasets consisted of input variables, including elevation, land cover, soil type, evapotranspiration, rainfall, and initial hydrological conditions. The initial conditions and target data were obtained from the fully distributed hydrological model HydroGeoSphere (HGS), whereas the other inputs were actual measurements in the field. By optimizing the training sample size, input design, CNN structure, and hyperparameters, we found that CNNs with residual architectures (ResNets) yielded superior performance. The optimal DL model reduces computation time by 45 times compared to the HGS model for monthly hydrological estimations over five years (RMSE 2.35 and 0.29 m for groundwater and surface water, respectively). In addition, our DL framework explored the predictive capabilities of hydrological responses to future climate scenarios. Although the proposed model is cost-effective for hydrological simulations, further enhancements are needed to improve the accuracy of long-term predictions. Ultimately, the proposed DL framework has the potential to facilitate decision-making, particularly in large-scale and complex watersheds.

Sonoanatomy of injecting botulinum neurotoxin into the facial muscles.

INTRODUCTION: Ultrasonography (US) has become an essential tool for guiding botulinum neurotoxin (BoNT) injections in facial muscles, enhancing precision and safety. This narrative review explores the role of US in BoNT administration, particularly in complex anatomical regions, highlighting its impact on treatment customization, real-time visualization, and complication reduction. MATERIALS AND METHODS: A comprehensive literature search was conducted using PubMed, MEDLINE, Embase, and Cochrane Library for articles published from January 2018 to December 2023. Search terms included "Botulinum neurotoxin," "facial anatomy," "ultrasonography guided injection," and "facial muscle sonoanatomy." Studies focusing on US-guided BoNT injections in facial muscles were included. Data extraction and synthesis were performed independently by two reviewers, focusing on study design, ultrasonography techniques, outcomes, and conclusions. RESULTS: The review found that US guidance significantly enhances the precision of BoNT injections by providing real-time visualization of facial muscles and blood vessels, thereby reducing the risk of adverse events. US enables tailored injection strategies, ensuring symmetrical facial expressions and minimizing over-treatment. The technique also offers immediate feedback, allowing for on-the-spot adjustments to improve treatment efficacy and safety. However, the review identified limitations, including potential selection bias and variability in US techniques across different studies. CONCLUSION: US guidance for BoNT injections into facial muscles offers substantial benefits in terms of precision, safety, and treatment customization. Despite the identified limitations, the integration of US into clinical practice is poised to enhance patient outcomes in aesthetic and therapeutic procedures. Further research is needed to standardize US techniques and broaden the inclusivity of studies to validate these findings comprehensively.

Ultrasonographic Study of the Submandibular Gland for Botulinum Neurotoxin Injection.

BACKGROUND: Hypertrophied submandibular glands provide a bulky contour to the lower face. Botulinum neurotoxin injection methods are commonly used for facial contouring; however, no studies have suggested injection points because of the lack of delicate anatomical information on the submandibular gland. OBJECTIVE: The aim of this study was to determine the optimal injection site for botulinum neurotoxin injections in the submandibular gland. MATERIALS AND METHODS: Anatomical considerations when injecting botulinum neurotoxin into the submandibular gland were determined using ultrasonography. The thickness of the submandibular gland, its depth from the skin surface, and the location of the vascular bundle were observed bilaterally in 42 participants. Two cadavers were dissected to measure the location of the submandibular gland corresponding to the ultrasonographic observation. RESULTS: The thickest part of the submandibular gland measured 11.12 ± 2.46 in width with a depth of 4.63 ± 0.76. At the point where it crosses the line of the lateral canthus, it measured 5.53 ± 1.83 in width and 8.73 ± 1.64 in depth. CONCLUSION: The authors suggest optimal injection sites based on external anatomical landmarks. These guidelines aim to maximize the effects of botulinum neurotoxin therapy by minimizing its deleterious effects, which can be useful in clinical settings.

Effects of high-intensity interval robot-assisted gait training on cardiopulmonary function and walking ability in chronic stroke survivors: A multicenter single-blind randomized controlled trial.

BACKGROUND: Chronic stroke can impair cardiopulmonary function, mobility, and daily activities. This study assessed the impact of robot-assisted gait training (RAGT) on such impairments. OBJECTIVE: To investigate the effects of robot-assisted gait training on cardiopulmonary function, walking ability, lower extremity function and strength, activities of daily living (ADLs), and blood test results among individuals with chronic stroke. METHODS: A multicenter, prospective, single-blinded, randomized controlled trial with 22 chronic stroke participants compared RAGT against a control exercise regimen. RAGT involved three days weekly sessions of high-intensity interval training for 8 weeks (24 sessions) with a Morning Walk® device. The control group also performed home exercises. (24 sessions) Measures included VO2max, Functional Ambulatory Category, 2-minute walk test, 10-meter walk test, Motricity Index-Lower, Korean version of the Fugl-Meyer Assessment Scale, Modified Barthel Index, Berg Balance Scale, muscle strength, InBody body composition, and blood tests (cholesterol, lipid, glucose). RESULTS: RAGT significantly improved VO2max, gait, balance, and lower limb strength compared with controls, with significant improvements in 2-minute walk test, 10-meter walk test, Motricity Index-Lower, and Fugl-Meyer Assessment outcomes. No changes were seen in muscle mass or blood markers. CONCLUSION: RAGT enhances cardiopulmonary function and ambulatory capacity in chronic stroke patients, underscoring its potential in stroke rehabilitation.

Thread Lifting Materials: A Review of Its Difference in Terms of Technical and Mechanical Perspective.

Thread lifting involves the use of slender materials, reminiscent of threads, for aesthetic procedures. These materials are distinct from traditional sutures and vary in composition, purpose, and performance. The introduction delves into the literal and material significance of threads, establishing the broad concept of thread lifting materials. The article revisits the evolution of thread lifting materials, emphasizing the preexistence of cog threads for tissue manipulation before their widespread adoption in plastic surgery. Observations regarding the efficacy and longevity of absorbable versus non-absorbable threads are discussed, stressing the efficiency of high-quality absorbable cog threads. The conclusion underlines the proliferation of thread lifting materials beyond PDO, highlighting the importance of considering multiple factors beyond duration when selecting threads for lifting procedures.

Effective improvement methods for striae distensae: A novel approach utilizing laser-induced micro-jet injectors with poly-d,l-lactic acid.

INTRODUCTION: Striae distensae (SD), or stretch marks, result from rapid stretching of the skin due to various factors. Conventional treatments often yield unsatisfactory results, leading to the exploration of alternative methods. Laser-induced microjet technology offers a promising approach for drug delivery to target areas. This study investigates the efficacy of using a microjet injector with poly-d,l-lactic acid for treating SD. METHODS: Four female participants with SD were treated with poly-d,l-lactic acid solution using a microjet injector over five sessions. Patients were assessed based on severity scales before and after treatment. Topical anesthetics were applied to minimize discomfort. Injection techniques were optimized to reduce side effects such as bleeding and pain. RESULTS: All patients showed significant improvement in SD appearance after 5-7 treatments. Assessment scales indicated positive outcomes both immediately after treatment and at the 32-week follow-up. Minimal side effects, primarily petechiae, were observed. DISCUSSION: Laser-induced microjet technology offers several advantages, including rapid drug delivery and mechanotransduction effects, promoting skin regeneration. Poly-d,l-lactic acid injections demonstrated effectiveness in treating SD, particularly when delivered via microjet injectors. Patients expressed high satisfaction due to the procedure's minimal invasiveness and quick recovery. CONCLUSION: Utilizing a needleless microjet injector with poly-d,l-lactic acid shows promise as a treatment for SD, typically requiring 5-7 sessions for optimal results. Mild petechiae may occur as a common side effect. This approach offers an effective and minimally invasive alternative for addressing this common cosmetic concern.

Basic concepts in facial and neck thread lifting procedures.

In this review article, our objective is to elucidate fundamental principles and offer practical illustrations concerning the procedures involved in facial and neck thread lifting. Moreover, we aim to explore associated concepts such as the fixing point, hanging point, and anchoring point terminologies, along with the elucidation of vectors. Additionally, we will provide anatomically oriented explanations of the lifting process required for each facial region using thread lifting methods like V, U, and I techniques using floating type threads (Secrete line, Hyundai Meditech., Inc., Wonjusi, Republic of Korea). Furthermore, our intention is to delve deeply into the concepts of tensile strength, anchoring strength, and holding strength, contextualizing their practical applications within this specific field.

Self-crossing hyaluronic acid filler with combination use of polydioxanone thread in minipig model.

INTRODUCTION: The advances of self-crossing hyaluronic acid (SC-HA) fillers combination use with polydioxanone thread in minipigs were examined for compatibility, effectiveness, and immune response. MATERIALS AND METHODS: A 12-week experiment was conducted using 6 minipigs (3 male and 3 female each) to evaluate the effects of SC-HA filler. The molecular weight of SC-HA filler was fixed at 200 kDa and alternative storage modulus of G80, G250, and G500 were examined. The procedure involved injecting SC-HA filler and polydioxanone threads into the skin tissue of anesthetized minipigs, and tissue sampling after 1 month (three minipigs), and 3 months (three minipigs) for histological staining and analysis. The immune reaction was observed during the experiment. RESULTS: The practitioner reported it was easy to inject the SC-HA filler in combination with polydioxanone threads. All four storage modulus of SC-HA fillers were injectable within the polydioxanone thread containing cannula. Also, during the procedure, there were no immune responses at the treated sites. The results of the histological tissue examination confirmed that there was no chemical interaction between SC-HA filler and the existing polydioxanone thread, and it was observed that SC-HA filler was more uniformly distributed within the tissue with lower storage modulus, resulting in a higher production of collagen in the surrounding filler. When combined with scaffold polydioxanone thread, the scaffold polydioxanone thread helped spread the filler evenly, resulting in a more evenly distributed collagen around the filler. CONCLUSION: Today, the combination therapy of filler and polydioxanone thread in one procedure is challenging due to the high viscosity of conventional fillers. However, this study confirmed that combination therapy of filler and polydioxanone thread is possible with SC-HA fillers. Additionally, it was found that polydioxanone thread does not seem to interfere with the crosslinking reaction of SC-HA filler, and if used with a higher pH of polydioxanone, it may enhance the cross-linking reaction and achieve a higher viscosity value. Finally, the study resulted in the idea of concrete as SC-HA filler and reinforcing rod for polydioxanone thread.

Why do marionette lines appear? Exploring the anatomical perspectives and role of thread-based interventions.

The pathogenesis of marionette lines involves a complex interplay of anatomical, physiological, and age-related factors leading to the development of wrinkles around the oral commissures. This exploration delves into the distinct anatomical predispositions observed among different ethnicities, emphasizing the role of compact modiolus structures and muscle compositions. Notably, individuals of East Asian descent exhibit inherent facial structures that predispose them to pronounced sagging around the oral commissures during aging. The emergence of distinct facial lines, such as the commissural line and the melolabial fold, contributes to the formation of marionette lines. This specific wrinkle pattern, resembling a marionette puppet's mouth contours, is influenced by various factors like bone resorption, gravitational forces, fat compartment variations, muscle compression, ligament tethering, and skin aging. Treatment strategies for marionette lines encompass diverse interventions, including filler injections, botulinum neurotoxin, surgeries targeting fat reduction, thread lifting, and volumizing fillers. These approaches aim to address the underlying causes and mitigate the appearance of marionette lines. Botulinum neurotoxin injections, for instance, weaken specific facial muscles, reducing downward strain and aiding in tissue retraction. Anatomical considerations during procedures are crucial to avoid nerve or vascular damage. Delicate manipulation and precise entry points are essential to prevent inadvertent injuries, particularly concerning blood vessels like the facial artery and nerves like the mental nerve. Technical guidelines for procedures targeting marionette lines involve specific techniques like cogged thread reverse methods and volumizing thread placements. Attention to entry points, tissue engagement, and the direction of threads is crucial for effective treatment outcomes, minimizing complications, and ensuring patient safety.

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

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

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.

The efficacy and safety of neubotulinumtoxinA for the treatment of forehead horizontal lines in Asians - A clinical, prospective, interventional, split-face study.

BACKGROUND: Botulinum toxin injections are widely sought after in the field of medical aesthetics, offering consumers a variety of brand choices. Two commonly available botulinum toxin products, onabotulinumtoxinA and neubotulinumtoxinA, are featured in numerous clinics, leading many to question whether there are discernible differences in results, given their varying price ranges. OBJECTIVE: To evaluate the efficacy and safety of neubotulinumtoxinA for the treatment of forehead horizontal lines. METHODS: A 12-week prospective, single-centre, interventional split-face study was conducted, including 30 subjects. These enrolled subjects received a single treatment session, with neubotulinumtoxinA applied to the left side of the forehead and onabotulinumtoxinA to the right side. A superficial injection was performed in all individuals, where the product was injected subdermally in the frontalis muscle. Evaluation was conducted at baseline, 7 days, 14, days and 4, 8, and 12 weeks after treatment, both when the eyebrows were at maximum lift and in a resting position. Treatment efficacy was assessed by two physicians and self-assessed by the patients, using the Fitzpatrick Wrinkle Classification system. Adverse events were documented to evaluate safety. RESULTS: The study found no statistically significant difference in the efficacy of neubotulinum and onabotulinum for treating forehead wrinkles, as indicated by p-values above 0.05 for both static and dynamic conditions. No safety and adverse events were observed in both formulations. CONCLUSION: This study has demonstrated that neither formulation is inferior to each other in the treatment of forehead horizontal lines.

SMAS repositioning technique utilizing cog thread: Anatomical perspectives.

INTRODUCTION: Face-lifting surgeries were once common among individuals over 60 years old due to skin laxity, but recent trends favor thread lifting in this age group. Understanding dynamic changes in facial anatomy during postural shifts is essential. METHOD: Fresh cadaver studies have demonstrated the passage of threads through the superficial musculoaponeurotic system (SMAS) layer, confirming the efficacy of the technique. Proper insertion depth targeting SMAS repositioning, rather than superficial skin layers, is crucial. RESULT: The natural movement of tissues secured by thread (N-Cog and N-Fix, N-Finders Inc., Korea) insertion results in lifting effects. However, complications may arise if threads affect deeper facial muscles, leading to discomfort. Fibrous septa play a significant role in guiding thread placement, with different densities influencing thread maneuverability and tissue response during lifting. CONCLUSION: Procedures targeting SMAS repositioning using threads aim to maintain the new position of relocated tissues. Understanding structural variations in facial regions informs thread selection and placement. Aligning threads with tissue movement and the intended SMAS layer positioning is vital to prevent complications. Balancing thread insertion depth and tissue traction is critical for successful outcomes. Modern thread lifting techniques prioritize SMAS repositioning, enhancing lifting effects while ensuring procedure safety and efficacy.

Anatomy of the temporal region to guide filler injections.

Hollow temples are not typically considered aesthetically pleasing, and hollowness worsens with the aging process. When filling this region with fillers, there are several anatomical considerations, with injection techniques varying depending on the layer targeted. Specifically, injections between the superficial temporal fascia and the superficial layer of the deep temporal fascia are performed using a cannula, while periosteal layer injections involve the use of a needle to reach the bone before inserting fillers. Detailed anatomical insights encompass the boundaries of the temporal fossa and cautionary notes regarding blood vessels, supported by specific studies on veins and arteries in the temporal region. Complications, including vessel injuries, are discussed alongside an exploration of various injection techniques. This review provides a comprehensive exploration of anatomical considerations and the specific methodologies employed in temple augmentation with fillers.

Sonographic observation of the paradoxical masseteric bulging and clinical implication of functional compartment.

Masseter are commonly botulinum neurotoxin targeted muscle for facial contouring in aesthetic field. However, paradoxical masseteric bulging is common adverse effect that has not been discussed with ultrasonographic observations. Retrospective study has been conducted from October, 2021 to January, 2023, out of 324 patients have done blinded botulinum neurotoxin injection in the masseter at the middle and lower portion of the masseter with each side of 25 units (letibotulinum neurotoxin type A), 3 patients demonstrated paradoxical masseteric bulging has been reported and the image observed by ultrasonography by physician. Based on the observations made, we can infer that the function of the moving muscle involves twisting of the muscle fibers during contraction, along with the twisting of the deep inferior tendon, which causes the muscle to be divided into anterior and posterior compartments rather than into superficial and deep compartments of masseter. In ultrasonographic observe the skin surface of a patient with paradoxical masseteric bulging, it is observable that either the anterior or posterior part contracts significantly. The functional units of anterior and posterior compartment are observable as muscular contraction of inward movement of the muscle from either the anterior or posterior functional unit.