Evaluation of facial artery course variations and depth by Doppler ultrasonography

Three-Dimensional Location of the Facial Artery in Relation to the Nasolabial Fold in Asian People: A Cadaveric CTA Study

BACKGROUND

Injection cosmetics have become popular in recent years. The nasolabial fold is one of the most important and dangerous regions in the midface, and its three-dimensional relationship with the facial artery remains unclear.

METHODS

Fifty-two cadavers infused with lead oxide contrast medium via the external carotid arteries were scanned by computed tomography (CT). The three-dimensional model was reconstructed using Mimics and Origin software, and the relevant data were calculated using validated algorithms.

RESULTS

There were three facial artery types according to its course in relation to the nasolabial fold. In the most common type, accounting for 83.7% of specimens, the facial artery evolves into an angular artery, with a horizontal distance between facial artery and nasolabial fold of - 1.90 ± 2.40, - 3.90 ± 2.95, - 5.18 ± 3.42, - 5.59 ± 3.53, - 5.59 ± 3.83, - 6.07 ± 4.10, - 6.92 ± 3.70, - 6.79 ± 3.37, - 4.52 ± 3.20, and - 2.76 ± 3.60 (mm) from the nasal ala to the oral commissure and a vertical distance of - 4.03 ± 2.56, - 3.27 ± 2.27, - 2.81 ± 2.57, - 2.1 ± 2.64, - 1.5 ± 3.32, - 0.71 ± 3.99, 0.92 ± 4.43, 0.4 ± 5.31, - 4.14 ± 5.14, - 7.05 ± 4.74 (mm).

CONCLUSIONS

The facial artery is vulnerable to damage when injecting filler in the nasolabial fold. For the upper 1/3 of the nasolabial fold, the supraperiosteal layer is recommended for injection, while for the lower 2/3 of the nasolabial fold, the dermal layer along the nasolabial fold is recommended.

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 .

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 amid an unregulated educational environment for practitioners. The absence of standardized educational pathways and quality control in aesthetic medicine, primarily provided by nonacademic institutions, highlights a critical need for establishing educational standards to ensure practitioner competence and patient safety.

OBJECTIVES

The aim of this study was to identify levels of competency for the aesthetic practitioner and 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, averages of 3.85 (1.8) years, 786.4 (2628) filler injections and 549.9 (1543) toxin injections were estimated to progress from novice to advanced injector, while averages of 6.10 (3.7) years, 1842.2 (4793) filler injections, and 1308.5 (3363) toxin injections were estimated to advance from advanced to expert injector. The nose and the perioral region have been ranked as the facial regions where it is 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

In this study we establish 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 1840 filler and 1310 neuromodulator injections for expertise. We also identify critical facial regions for targeted treatments by different expertise levels.

LEVEL OF EVIDENCE: 4

Ultrasonographic Evaluation of Facial Artery in the Nasolabial Fold for Gender Differences and Symmetry Between Hemifaces

OBJECTIVES

The aim of this study was to establish the relationship of facial artery with nasolabial fold by color Doppler sonography and to determine facial artery variations and their relationship with age, gender, or hemifaces.

METHODS

The study included 188 patients (94 women, 94 men) aged 18-60 years. Overall, 376 facial arteries in both hemifaces were evaluated for the course within nasolabial fold, symmetry, and relationship with gender.

RESULTS

The mean age of the patients was 39.29 ± 12.81 years. Type A (55.7%) was the most common type in both hemifaces. There was no significant relationship between the course of facial artery and age (P > .05). Asymmetrical course of facial artery was more common in females (54.3%). In both genders, type A was the type with highest symmetry detected.

CONCLUSIONS

Nasolabial fold is one of the important facial regions for filler injection. To prevent vascular injection, course of facial artery should be identified within the nasolabial fold. Type A was the most common type in both hemifaces and genders. Although the rates were close to each other, asymmetry in the course of the facial artery was observed in most of the patients. Ultrasonographic examination which is non-invasive and non-ionizing imaging method can be performed carefully before filler injection to determine vascular tissues.

Laser Speckle Contrast Imaging Guides Needling Treatment of Vascular Complications from Dermal Fillers

BACKGROUND

Although laser Doppler imaging (LDI) accurately delineates a hypoperfused area to help target hyaluronidase treatment, laser speckle contrast imaging (LSCI) is more appropriate for assessing microvascular hemodynamics and has greater reproducibility than LDI. This study investigated the use of LSCI in the evaluation and treatment of six patients who developed vascular complications after facial dermal filler injections.

METHODS

The areas of vascular occlusion were accurately defined in real time by LSCI and were more precise than visual inspections or photographic evidence for guiding needling and hyaluronidase treatment.

RESULTS

All patients had achieved satisfactory outcomes as early as Day 2 of treatment and no procedure-related complications were reported after a median follow-up of 9.5 (7-37) days.

CONCLUSION

LSCI accurately and noninvasively delineated vascular occlusions in real time among patients experiencing complications of facial dermal filler injections. Moreover, LSCI was more accurate than visual and photographic evaluations. Clinicians can use LSCI to reliably follow-up therapeutic outcomes after salvage interventions for vascular occlusions.

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 .

Superimposition Study to Determine the Angular Arterial Distribution and Its Clinical Application

BACKGROUND

The purpose of this study was to determine the distribution of the angular artery (AA) in the medial canthal area with the aim of defining an arterial course to prevent AA injury during facial surgery in this region.

METHODS

The authors dissected 36 hemifaces of 18 cadavers. The horizontal distance from the vertical level through the medial canthus to the AAs was measured. The AA course of each specimen was then recorded, and all of them were then superimposed to determine the AA course. The diameter and depth of the AA around the medial canthal area were also investigated using ultrasonography on living subjects.

RESULTS

The horizontal distances from the medial canthus level and 2 cm below the medial canthus were 9.0 ± 2.0 mm (mean ± SD) and 1.9 ± 2.4 mm, respectively. The superimposed image demonstrated that most of the AAs were present inside the vertical line through the medial canthus. Ultrasonography indicated that the AA was 2.3 ± 0.9 mm below the skin and 1.7 ± 0.3 mm in diameter.

CONCLUSIONS

The AA course was relatively constant along the nasojugal fold. The AAs were most often present between the middle of the medial canthus and the facial midline, but were very scarce in both the medial and lateral thirds. Knowledge of the detailed course of the AA may help surgeons to avoid arterial injury and decrease the risk of surgical morbidities around the nasal root and medial canthal area.

Evaluation of facial artery course variations, diameters, and depth by Doppler ultrasonography

BACKGROUND

The facial artery (FA) is the main blood vessel supplying blood to the face. It is essential to understand the anatomy of FA around the nasolabial fold (NLF). This study aimed to provide the detailed anatomy and relative positioning of FA to help avoid unexpected complications in plastic surgery.

METHODS

FA was observed from the inferior border of the mandible to the end of its terminal branch in 66 hemifaces of 33 patients with Doppler ultrasonography. The evaluation parameters were: (1) location, (2) diameter, (3) FA-skin depth, (4) relationship between the NLF and FA, (5) distance between the FA and significant surgical landmarks, and (6) the running layer. The FA course is classified based on the terminal branch.

RESULTS

The most common FA course was Type 1, which had an angular branch as the final branch (59.1%). The most common FA-NLF relationship was that the FA was situated inferior to the NLF (50.0%). The mean FA diameter was 1.56 ± 0.36 mm at the mandibular origin, 1.40 ± 0.37 mm at the cheilion, and 1.32 ± 0.34 mm at the nasal ala. The FA diameter on the right hemiface was thicker than that on the left hemiface (p < 0.05).

CONCLUSION

The FA mainly terminates in the angular branch, running in the medial NLF and in dermis and subcutaneous tissue, with a blood supply advantage in the right hemisphere. We suppose that a deep injection into periosteum around the NLF may be safer than an injection into the superficial musculoaponeurotic system (SMAS) layer.

Key Points to Select a Device for Dermatologic Ultrasound

What points to consider when selecting a device for practicing dermatologic ultrasound is an excellent question. After we met the requisites published in the guidelines for practicing dermatologic ultrasound, it is necessary to consider the main objective of the use because it is not the same to be focused mostly on the avoidance of the puncture of important facial vessels such as the case of injectors of cosmetic fillers in comparison to the use of operators that need to deal with the diagnosis and monitoring of a wide range of dermatologic pathologies. Currently, a broad variety of ultrasound devices meets the minimum requirements for practicing these examinations in the market. Thus, small, portable, and high-end devices may present advantages and limitations that must be balanced according to the primary purposes and the budget. Moreover, the shape and footprint of the probes can make difficult or facilitate a dermatologic procedure. Other points to consider are the type of storage and the need for technical service. In summary, there are key points that we need to consider when we select a dermatologic ultrasound device in dermatology or aesthetics.

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 .

Lateral branches of the facial artery and its clinical implications

The facial artery is the main artery supplying blood to the face and is known to have facial branches of the inferior labial, superior labial, lateral nasal and angular arteries. These known major branches of facial artery run medially, however, there are sometimes branches of the facial artery heading laterally. The purpose of the present study was to investigate the lateral branches of the facial artery in face. We dissected facial branches of the facial artery in 74 cadaveric hemifaces. We investigated the presence of the lateral branches of the facial artery. Following parameters were investigated: lateral branch presence, the location of its origin, and the lateral branch diameter. Among the lateral branches, we evaluated the prevalence and diameter of the premasseteric branch. Lateral branches were observed in 48 of the 74 hemifaces (64.9%). The total number was 81 in the 48 hemifaces. The most common origin was between the inferior border of the mandible and inferior labial artery origin (42 of 81, 51.9%). The mean diameter of all lateral branches of the facial artery was 0.7 mm. Among the lateral branches, the premasseteric branches were present in 38 of 74 specimen (51.4%) and the mean diameter was 0.8 mm. The lateral branches of the facial artery may be registered in Terminologia Anatomica based on their prevalence. Accurate knowledge of the anatomy of the lateral branches of the facial artery is helpful for clinicians to avoid complications during facial procedures or maxillofacial surgeries.

Signal and measurement considerations for human translation of diffuse in vivo flow cytometry

SIGNIFICANCE

"Diffuse in vivo flow cytometry" (DiFC) is an emerging technology for fluorescence detection of rare circulating cells directly in large deep-seated blood vessels in mice. Because DiFC uses highly scattered light, in principle, it could be translated to human use. However, an open question is whether fluorescent signals from single cells would be detectable in human-scale anatomies.

AIM

Suitable blood vessels in a human wrist or forearm are at a depth of ∼2 to 4 mm. The aim of this work was to study the impact of DiFC instrument geometry and wavelength on the detected DiFC signal and on the maximum depth of detection of a moving cell.

APPROACH

We used Monte Carlo simulations to compute fluorescence Jacobian (sensitivity) matrices for a range of source and detector separations (SDS) and tissue optical properties over the visible and near infrared spectrum. We performed experimental measurements with three available versions of DiFC (488, 640, and 780 nm), fluorescent microspheres, and tissue mimicking optical flow phantoms. We used both computational and experimental data to estimate the maximum depth of detection at each combination of settings.

RESULTS

For the DiFC detection problem, our analysis showed that for deep-seated blood vessels, the maximum sensitivity was obtained with NIR light (780 nm) and 3-mm SDS.

CONCLUSIONS

These results suggest that-in combination with a suitable molecularly targeted fluorescent probes-circulating cells and nanosensors could, in principle, be detectable in circulation in humans.

Imaging of the skin microvascularization using spatially depolarized dynamic speckle

SIGNIFICANCE

We propose a technique devoted to real-time high-resolution imaging of skin microvascularization.

AIM

The process utilizes the temporal variation of the spatially depolarized optical speckle field generated by moving red blood cells when illuminated with fully polarized coherent light.

APPROACH

Polarimetric filtering prevents the contribution of surface scattering from reaching the camera and thus favors the detection of multiscattered photons from the deeper layers of the skin.

RESULTS

Full-field images reveal the microvasculature with a spatial resolution of 80  μm. The acquisition speed allows for real-time applications.

CONCLUSIONS

We demonstrate the ability of this method to determine in 1 s a stable and reliable microvascular activity, enabling numerous clinical applications that require quantitative measurements.

The place of B-mode ultrasonography, shear-wave elastography, and superb microvascular imaging in the pre-diagnosis of androgenetic alopecia

PURPOSE

Androgenetic alopecia (AGA) is the most common cause of hair loss in males. Physical examination and history are the most important examinations in diagnosis of the disease. As yet, there is no diagnostic method to be able to determine which individuals will develop AGA. Shear-wave elastography (SWE) is a novel diagnostic tool, which can evaluate tissue stiffness. Superb microvascular imaging (SMI) can determine low flow in microvessels. The aim of the current study was to determine whether or not AGA would develop in individuals with normal hair and a family history of AGA using B-mode US, SMI, and SWE.

METHODS

The study included 26 patients clinically diagnosed with AGA and a control group of 26 volunteers.

RESULTS

Thickness with the distance from the epidermis to the calvarium (ECD) on the hairline and cranial subcutaneous tissue thickness (CSTD) were determined to be statistically significantly thinner in the AGA group than in the control group (p < 0.0001). For the differentiation of the AGA patients, the cutoff value was determined to be 5.5 mm for ECD and 4.05 mm for CSTD. The cranial epidermis-dermis (CED) stiffness values both as meter/second (m/s) and kilopascals (kPa) were statistically significantly lower in the AGA patients than in the control group (p < 0.0001). The cutoff values were 6.075 as m/s and 104.4 as kPa.

CONCLUSIONS

The results of this study demonstrated that differentiation could be made of individuals before the development of AGA from normal healthy individuals with CSTD measurement on B-mode US and CED stiffness measurement on SWE.