Singular entry point technique for forehead and temple filler augmentation: Anatomical and clinical perspectives.

BACKGROUND: The depressed volume of the forehead and temple is resolved by filler injection. However, the current method has the potential to cause pain and side effects in patients, depending on the skill of the clinician. Therefore, this study proposes a new method for safer and simpler injection using only one injection entry point. METHODS: Using the novel injection method, the filler was injected into the forehead and temple regions in three unembalmed cadavers and two healthy Korean volunteers. The cannula and filler locations were identified using dissection, ultrasonography, and three-dimensional (3D) scanning. RESULTS: Ultrasonographic images and dissection results showed that the filler injected into the cadavers was in the target layer. The cannula and filler were located on the layer as the supraperiosteal layer on the forehead and the supra deep temporal fascia layer in the temple. Finally, 3D scanning images showed that the filler was injected precisely and effectively into the forehead and temples of the volunteer who underwent the procedure. CONCLUSIONS: This method can reduce pain and minimize externally visible wounds caused by injections. The injected filler was naturally connected from the forehead to the temple and maintained for around 3 months. Additionally, it is possible to inject fillers into the forehead and temple at a constant and safe depth without requiring specific skills. It is expected that this method will become a universal method because it minimizes the burden on both patients and clinicians.

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.

Treatment of the Nasolabial Fold Using a Hyaluronic Acid-Based Filler with eXcellent Three-Dimensional Reticulation (XTR™) Technology: A Retrospective Study.

Purpose: The physicochemical characteristics of hyaluronic acid (HA) fillers can affect the outcome of minimally invasive aesthetic treatments. The effect of a novel HA-based filler manufactured with a novel 3D structure (XTRTM technology) was assessed in the nasolabial fold. Patients and Methods: We performed a retrospective study of patients who underwent treatment of the nasolabial fold with a novel HA filler in our clinic. Treatment outcome was assessed at 3 and 6 months with wrinkle score, GAIS, and VAS. Results: Eighteen patients were injected with the novel HA filler in the nasolabial fold. At six months, mean wrinkle scores were improved on both sides compared to baseline. GAIS and VAS were high at three and six months. Conclusion: The HA-based filler manufactured with XTRTM technology is safe and effective in treating the nasolabial fold. Good aesthetic results were seen for up to 6 months. Patient satisfaction was high during the entire follow-up.

A comparison of five point-of-care ultrasound devices for use in ophthalmology and facial aesthetics.

Introduction: Point-of-care ultrasound is becoming increasingly popular, and we sought to examine its role in evaluating ocular and periocular structures and facial vasculature. With the large number of point-of-care ultrasound devices available, it is difficult to determine which devices may be best suited for ophthalmic and facial aesthetic applications. This study compares five popular handheld point-of-care ultrasound devices to help guide clinicians in choosing the device best suited for their needs. Methods: We compared five point-of-care ultrasound devices: Butterfly IQ+ (Butterfly, Burlington, MA), L15 (Clarius Mobile Health, Vancouver, British Columbia, Canada), L20 (Clarius Mobile Health, Vancouver, British Columbia, Canada), Lumify (Philips, Amsterdam, Netherlands) and Vscan Air (GE, Boston, MA). Three ophthalmologists obtained the following views on three volunteers: eight arteries, four ocular and periocular structures and areas of filler injections. The image quality of each view was graded on a four-point Likert-type scale. In addition, graders filled out a survey. The data were analysed using analysis of variance tests with the significance level set to p < 0.05. Results: In terms of overall image quality, the L20 received the highest mean rating, followed by the L15, Vscan Air, Butterfly IQ+ and the Lumify (p < 0.05). With further stratification for structure type, the L20 was ranked first for filler, artery and orbital imaging (p < 0.05). Conclusions: The L20 received the highest image quality rankings. While image quality is an important aspect of point-of-care ultrasound device selection, other factors such as cost, wireless capabilities, range of presets and battery life should also be considered.

Subcutaneous injection of hyaluronic acid leading to emboliom and recanalization process monitored in real time by three-dimensional photoacoustic imaging.

This study describes a method for real-time examination of the microvascular system based on the three-dimensional photoacoustic imaging system to prevent arterial complications, especially vascular embolism, during hyaluronic acid (HA) injections. Chicken embryos were used to simulate the superficial blood vessels of human skin, and then the target area was imaged by the photoacoustic imaging system for three-dimensional vascular imaging, and then the syringe and blood vessels were monitored, and the syringe angle and penetration depth were adjusted in time using an injection device to avoid puncturing the arterial vasculature and clogging the blood vessels. HA was then injected into smaller vessels on the dorsum of the tongue in mice and into thicker vessels on the dorsal portion of the tongue in rats to mimic embolization, and the post-operative recovery was reflected by the changes in the pixel dots of the extracted part of the blocked blood vessels, and it was observed that the blood flow in the area of the fine vessels was restored in about 3 days, whereas blood flow in the area of the large vessels was restored in only about 1 h. The method presented in this paper allows precise guidance of injectable filler HA, which has good application prospects in improving the safety of injection micro-plastic surgery and reducing the experience requirements for medical personnel.

A treatment algorithm for hyaluronic acid filler related complications of the face.

BACKGROUND: Throughout the last decade, a notable increase in HA-filler-related complications have been observed, owing to the increase in demand for filler injections and availability of multiple products. OBJECTIVES: The aim is to provide practical advice on the best way to prevent and treat HA-filler-related complications. METHODS: Thirty patients who experienced visible and/or symptomatic complications localized within the facial area were treated according to our algorithm. Patients with inflammatory lesions underwent antibiotic and anti-inflammatory therapy, followed by hyaluronidase injections. Patients with abscesses were treated with antibiotics, incision, and drainage. Each patient completed the dermatology-specific quality of life questionnaire (DLQI) at the first and last examinations. RESULTS: Among the 29 patients who received antibiotic therapy, 3 healed without further treatment. However, 18 received hyaluronidase injections, 9 underwent incision and drainage, and 5 presented with fistulas and developed retracted scars. Moreover, 80% of the patients were completely healed, 13% significantly improved, and 3% did not show any improvement. The DLQI scores analysis showed a notable impact of patients' diseases on their quality of life, mainly in the terms of personal relationships and symptoms, with minor impacts on intimate relationships, ability to work, and study. We demonstrated that our algorithm resulted in a significant improvement in the overall quality of life at the last follow-up (p < 0.001). CONCLUSIONS: The use of filler injections requires caution and specific training because they can lead to serious complications. If these complications are recognized promptly, healing can be optimized. Our treatment algorithm demonstrated high rate of healing and significant improvement in the patients' quality of life.

A structured approach with Swiss cheese model to reduce vascular adverse events of filler injections.

BACKGROUND: Filler injection is among the most popular nonsurgical aesthetic procedures worldwide. Though relatively noninvasive, filler injection can lead to severe vascular adverse events. Even though the incidence is rare, it may cause devastating and irreversible outcomes. A Swiss cheese model has been widely applied for risk analysis and management approach in medical field. AIMS: In this review article, we adopt the Swiss cheese model and create a structured approach to prevent severe vascular complications caused by filler injections. METHODS: We reviewed the current literature regarding the knowledge and techniques of preventing vascular adverse events in the filler injection. RESULTS: We propose four structured strategies in this model to reduce the risk of severe vascular adverse events of filler injections, including clinical facial anatomy, safe filler injection principles, real time imaging and auxiliary instruments, and implication of checklist. CONCLUSION: This review provides clinicians a structured approach before and during the filler injection procedure to reduce the risk of vascular adverse events and improve its safety and outcome.

Treating the double chin with hyaluronic acid injection.

INTRODUCTION: Submental fullness (SMF), or the double chin, is a condition regarded as undesirable. Many treatment modalities are available for SMF reduction, such as energy-based devices, injection lipolysis, or surgery. However, of minimal invasive modalities, hyaluronic acid (HA) injection has not been explored for possible SMF treatment. CASE REPORT: A 52-year-old East Asian female patient with prominent SMF underwent HA filler injection. Aside from marked reduction of SMF prominence, an improvement of sagging over her cheeks and jawline, and a general improvement to facial aging signs was noted. CONCLUSION: HA filler injections for SMF offer an instant, zero downtime, and safe alternative, and can be considered in patients who wish to simultaneously achieve improvement in other facial areas.

Does injecting small amounts of fillers prevent the development of secondary blindness?

INTRODUCTION: Inadvertent entry of filler products into the supratrochlear, supraorbital, or dorsal nasal arteries, among other branches of the ophthalmic artery, might result in an immediate and devastating loss of vision. We wanted to examine how much filler could block the ophthalmic artery. MATERIALS AND METHODS: Twenty-nine fresh cadavers were examined. We exposed the arterial supply to the opthalmic artery by dissecting the orbital area. Thereafter, 17 filler injections were introduced into the supratrochlear, supraorbital, and dorsal nasal arteries each. The amount of filler injection that completely blocked the ophthalmic artery was measured. Additionally, one of the head specimens was processed using phosphotungstic acid-based contrast enhancement micro-computed tomography to analyze each arteries to obstruct its whole ophthalmic artery. RESULTS: The supratrochlear, supraorbital, and dorsal nasal arteries had mean volumes in milliliter (mean ± standard deviation) of 0.0397 ± 0.010 mL, 0.0409 ± 0.00932 mL, and 0.0368 ± 0.00732 mL, respectively. However, the arteries did not differ significantly. CONCLUSION: Even a modest amount of filler injection can completely block the ophthalmic artery, resulting in visual loss.

Purtscher-like retinopathy and paracentral acute middle maculopathy following breast filler injection.

BACKGROUND: To report a rare case of pulmonary and ocular complications with visual loss due to bilateral Purtscher-like retinopathy and paracentral acute middle maculopathy (PAMM) following a hyaluronic acid (HA) filler injection to the breast. Systemic and visual recovery was attained following corticosteroid therapy. CASE PRESENTATION: A 27-year-old lady presented with painless blurring of vision in both eyes for 2 weeks following hyaluronic acid breast filler injections by a non-medical practitioner. She was initially admitted to the medical ward for diffuse alveolar haemorrhage and altered sensorium. The presenting visual acuity was counting fingers in both eyes. Bilateral dilated fundus examination showed hyperaemic discs, concentric rim of retinal whitening around macula with patches of polygonal-shaped retinal whitening, generalised cotton-wool spots, tortuous veins, and flame-shaped haemorrhages. Spectral-domain optical coherence tomography (SD-OCT) macula revealed hyper-reflective bands at the inner nuclear layer (INL). Fluorescein angiography demonstrated hot discs, delayed arm-to-retina time, arterial filling, and arterio-venous transit time with staining of the vessels at the posterior pole. She was managed with a tapering dose of systemic corticosteroids. The visual acuity improved to 6/12 over 8 weeks with significant anatomical and functional improvement. Dilated fundus examination showed resolution of initial funduscopy findings. The hyper-reflective bands on the OCT had resolved with subsequent thinning of the INL and disorganisation of retinal inner layers. CONCLUSION: Filler injections are in increasing demand and are frequently being performed by non-medical practitioners. Visual loss from non-facial HA fillers is rare. Inadvertent entry of HA into a blood vessel may potentially cause systemic and sight-threatening ocular complications. Good anatomical knowledge and proper injection technique are vital in preventing this unfortunate sequela. There are limited reports on successful visual recovery following various treatment approaches and we hope this case provides valuable insights.

Retrospective Study of Vascular Complications Caused by Hyaluronic Acid Injection.

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

Acute diplopia after glabellar hyaluronic acid filler injection.

Purpose: Blindness is a well-known complication of filler injection in the glabellar region. Acute diplopia from filler injection without vision loss is a rare complication that typically results in clinical ophthalmoplegia which can have permanent sequelae. Here, we describe a patient who presented with acute diplopia with grossly intact full extraocular motility after glabella hyaluronic acid filler injection that resolved after 1 month. Observations: A previously healthy 43-year-old woman underwent her first hyaluronic acid injection in the glabella and developed immediate binocular double vision with severe pain and skin mottling above her right eyebrow and central forehead. Hyaluronidase injections, nitroglycerin paste, and aspirin were immediately administered. On exam, there was significant skin mottling over the glabella, extending to the forehead and nose with a small incomitant horizontal and vertical misalignment. No changes to her vision were observed and extraocular motility was grossly full. The rest of her exam was unremarkable. Over the course of the following month, the patient's diplopia resolved, but she developed skin necrosis and scarring. Conclusions: Importance: Proper knowledge of facial and periocular anatomy is critical for practitioners to safely perform filler injections and manage potential complications. Patients should be counseled about the potential rare risks of these elective procedures.

A novel predictive model for phthisis bulbi following facial hyaluronic acid cosmetic injection.

PURPOSE: To observe long-term prognosis of anterior segment ischemia (ASI) following hyaluronic acid (HA) injection, propose a severity grading system for ASI and a predictive model for phthisis bulbi (PB) based on long-term secretion dysfunction of ciliary process. METHODS: This is a retrospective case-control study. All enrolled 20 patients were divided into two groups and followed for at least 6 months to observe the formation and transformation characteristics of ASI and long-term prognosis based on the degrees of ciliary function damage. RESULTS: The severity of ASI following HA injection could be subdivided into 4 grades according to the degrees of ciliary function damage, comprising ASI grades 0, 1, 2 and 3. In 20 patients, ophthalmoplegia at 1-month follow-up, ASI within 1 month, ASI at 1-month follow-up, hypotony within 6 months were all significantly more common in study group than in control group (60% vs. 0%, P = 0.011; 100% vs. 20%, P = 0.001; 100% vs. 0%, P < 0.001; 80% vs. 0%, P = 0.001, respectively). Sensitivity, specificity and the area under the receiver operating characteristic curve (AUC) for predicting subsequent PB at 2-year follow-up through the co-occurrence of ophthalmoplegia at 1-month follow-up and hypotony within 6 months was 100%, 100% and 1.00, respectively. CONCLUSIONS: The new grading system for ASI and novel predictive model for PB we proposed could predict the long-term prognosis and probability of subsequent PB due to ASI following HA injection through several dynamic assessments within 6 months. LEVEL OF EVIDENCE: Level IV, observational prognostic study.

Deep Temporal Artery Anatomy: Implications for Improving the Safety of Deep Temporal Injections.

BACKGROUND: Knowledge of the anatomy of the deep temporal artery (DTA) is critical to ensure safe filling of the deep temporal region. However, current treatment guidelines still focus on how to avoid the superficial temporal artery and the middle temporal vein, and an understanding of the safety of avoiding DTA injury is lacking. OBJECTIVE: The purpose of this study was to determine the positioning and course of the DTA to help clinicians safely perform the injection and filling in the temporal region. METHODS: Computed tomography (CT) scans and dissections of the skulls of 34 fresh frozen cadavers perfused with lead oxide were performed. Reconstruction and trajectory analysis of all DTA branches were performed using Mimics and MATLAB software. RESULTS: In this study, the DTA was identified in all samples, which originated from the maxillary artery of the external carotid artery system. According to image reconstruction and anatomical observations, the distribution of the anterior and posterior branches of the DTA had two different distribution patterns. The anatomical level of the DTA is located between the temporal muscle and the periosteal layer. Compared with observations in previous studies, the anterior branch of the DTA is slightly different, and we found that its course is closer to the frontal area in Asian specimens. CONCLUSION: The anatomical information on the DTA described in this study may help improve awareness of the safety of temporal injection by aesthetic physicians. 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 Table of Contents or online Instructions to Authors www.springer.com/00266. .

Anatomical proposal for hyaluronic acid filler injection in subzygomatic arch depression: A dual-plane injection technique.

A subzygomatic arch depression creates a bulky face outline. To smoothen these depressions and correct facial contours, hyaluronic acid filler injection methods are frequently used. However, the complexity of the subzygomatic region make it difficult for practitioners to effectively volume the region. The conventional injection of single layer injection has limitations of lack in volume addition and unwanted undulations and spreading. The anatomical factors were reviewed with ultrasonography, three-dimensional photogrammetric analysis, and cadaver dissection. In this anatomical study, the present knowledge on localizing filler injection with a more precisely demarcated dual-plane injection was suggested. This study presents novel anatomical findings related to the injection of hyaluronic acid filler injection in the subzygomatic arch depression.

Case series of tongue necrosis from vascular complications after chin augmentation with hyaluronic acid: Potential pathophysiology and management.

BACKGROUND: Even though the chin is considered a safe injection area for facial filler augmentation, tongue necrosis is a rare complication in this area. OBJECTIVE: Our aim was to present case series of rare complications from chin filler augmentation with possible pathophysiology and management. METHODS: From our thorough literature search found only one case report of tongue necrosis from chin filler augmentation. We present case series of unilateral tongue necrosis from vascular occlusion following hyaluronic acid injection in the chin, which was successfully treated with a high-dose hyaluronidase injection resulting in complete recovery in all patients. RESULTS: Variation in vascular anastomosis leads to a possible cause of vascular occlusion. The lingual artery is the primary arterial supply for the tongue, which is an exclusive target for embolism. Two main responsible arteries and branches are the deep lingual and sublingual arteries. The submental artery variation was previously described as the cause of this event. We proposed potential pathophysiology of the occlusion, not only the variation of vasculature but bone. The midline lingual foramen, an anatomical bone variation on the surface of the midline inferior jaw, was found to be another possible cause. This foramen contains a branch of the submental and sublingual artery, which includes the perforating artery, median perforating artery, or both. Filler injection with a sharp needle on the bone can potentially increase the risk of this vascular incident. A high dose of hyaluronidase administered with multiplane injections was accomplished with complete recovery. CONCLUSIONS: Tongue necrosis from vascular complications after hyaluronic acid filler injection can occur. Not only vessels but bone variation pathology were possible causes.

Anatomic evaluation of the normal variants of the arteries of face using color Doppler ultrasonography: Implications for facial aesthetic procedures.

BACKGROUND: Knowledge of normal facial vascular variations could prevent catastrophic complications of cosmetic procedures as well as providing a guide for surgical planning. Color Doppler ultrasound is a safe and noninvasive method for real time vascular evaluation. OBJECTIVE: The aim of this study was to evaluate the normal variations of the facial, angular, transverse facial, supratrochlear and supraorbital arteries in a sample of normal individuals. METHODS: Normal individuals referred for dermal filler injection to the tertiary dermatologic center, were selected. Patients who were smoker or had a history of facial filler injection, facial surgery, or trauma were excluded from the study. Facial artery at three levels as well as angular, supratrochlear, supraorbital, and transverse facial arteries were evaluated by an 18 MHz ultrasound linear probe regarding their distance from facial reference lines and landmarks, and also their depths in various regions of face. RESULTS: A total number of 43 individuals were evaluated in this study. Thirty-one (72.1%) were women. The number of absent facial artery was zero in level one, three (3.48%) in level two, and nine (10.46%) in level three. The angular artery was absent in 10 (11.62%) participants. The transverse facial artery was absent in 27 (31.39%) assessed individuals. Distance from reference lines at level 2 and 3 of facial artery and its depth at level 2 were significantly different between left and right side (p-values: <0.001, 0.01, and 0.03, respectively). No significant difference was seen between depth and distance of two sides for angular and transverse facial arteries. The comparison of the depths and distances from the reference lines of the assessed arteries between two sexes revealed only a significantly greater value of facial artery distance in level 1 in males (p-value: 0.001). BMI was also significantly correlated with the depth of facial artery in level 2 (Pearson correlation coefficient = 0.471, p-value = 0.002) and level 3 (Pearson correlation coefficient = 0.357, p-value = 0.03) and the distance of the facial artery in level 1 (Pearson correlation coefficient = 0.333, p-value = 0.029). CONCLUSIONS: Color Doppler ultrasound could be used to map the arteries of face to prevent vascular complications and safely guide cosmetic procedures.

Acute unilateral vision loss and bilateral cerebral infarction following cosmetic filler injection.

The current case report describes acute unilateral vision loss and bilateral cerebral infarction as devastating complications following cosmetic injection of hyaluronic acid to the nasal bridge in a 34-year-old female. The patient reported the onset of sudden eye pain, headache, and vision loss in her right eye. At the initial visit to the hospital, the patient had no light perception in the right eye. Examinations revealed marked ptosis and complete ophthalmoplegia with no proptosis. At the time of the patient's hospital evaluation, computed tomography, and magnetic resonance imaging were ordered. Few mottled materials (denser than blood) were observed in the cavernous sinus with a density of 106 Hounsfield units (HU), yet no air was depicted in the cavernous sinus. MRI scan revealed multiple areas of bilateral intracranial infarcts. Although cosmetic injection of hyaluronic acid has been documented as a safe procedure, vision loss remains one of the most feared complications.

Positions of the Glabellar Arteries: Implications for Glabellar Injection.

BACKGROUND: Glabellar filler injection is linked to an increased risk of blindness. A thorough understanding of vascular changes in the glabellar area is critical for safety. The study's goal was to precisely determine the three-dimensional placements of the arteries in the glabellar area. METHODS: In 117 cadavers, the vascular structures in the glabellar area were examined. There were four segments (S1/S1'-S4/S4') and five points (P1-P5) specified. The number of identified arteries found in each section and at each position was tallied. Additionally, the depth of the underlying identified artery under each site was measured. RESULTS: One to three named arteries per glabellar segment were found. Each segment had at least one named artery, and the number of named arteries detected between S1/S1' and S4/S4' decreased. The chance of encountering identified arteries at the 5 designated locations, P1-P5, was 7/117 (6.0%), 6/117 (5.1%), 7/117 (6.0%), 6/117 (5.1%), and 16/117 (13.7%), respectively. At P1-P5, the major artery trunk was 1.8 ± 0.3 mm, 1.6 ± 0.3 mm, 1.4 ± 0.2 mm, 1.3 ± 0.3 mm, and 1.1 ± 0.2 mm below the skin. CONCLUSIONS: The site of the glabellar arteries was clearly shown in this investigation; these arteries were met at a rate of 14% from P1 to P5. We demonstrated that a single entry site through the glabella via cannula could readily keep the needle deep enough for safe glabellar filler injection. 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 .

Evaluation of Supratrochlear, Supraorbital and Angular Artery Course Variations and Depth by Doppler Ultrasound.

BACKGROUND: Supratrochlear (STA), supraorbital (SOA), and dorsal nasal artery (DNA) branches from the ophthalmic artery and angular artery (AA) from the facial artery are the primary suppliers of blood to the upper face. Filler injection without precise knowledge of its vascular topography poses a risk of severe complications. METHODS: Seventy-four hemifaces from 37 subjects with a median age of 25.0 (21.0, 35.0) years and a median body mass index of 21.2 (20.0, 25.4) kg/m2 underwent high-frequency ultrasound tests between March 2022 and April 2022. The bilateral location, depth, peak systolic velocity (PSV), and inner diameter (ID) of the four periorbital arteries (STA, SOA, DNA, AA) were measured. RESULTS: The average ID ranges from 0.6~1.0 mm, and the average PSV ranges from 9.2~24.9 cm/s. All arteries detected passed through the superficial subcutaneous fascia. Most subjects' STAs traveled within 1.0 to 2.0 cm from the midline (left 96.8%, right 93.8%), while SOAs were mainly concentrated within 2.0 to 4.0 cm (left 83.9%, right 81.3%). STAs were more superficial and had a larger internal ID and PSV than SOAs (p<0.001). Except for the ID of the right SOA2 being significantly larger than that of the left SOA2 (p<0.05), no dominant side was found. The depth of STAs and SOAs was moderately correlated with BMI (p<0.05), except for STA1 on the left side. The course of AAs presented a high variability. CONCLUSION: These findings emphasize that the periorbital arteries carry with it a likelihood of ocular complication risks during injection. Targeting the supraperiosteal layer in the STA area and the supramuscular layer in the SOA area of the inferior forehead during injection seems reasonable, and an area within 1.0~2.0 cm from the midline should be avoided. Additionally, the high variability of AAs will enhance the understanding of the anatomy of the facial artery terminals. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .