The Arteries of the Central Forehead: Implications for Facial Plastic Surgery

[Forehead injections: Anatomy, technics, products]

Knowledge of anatomy not only allows optimal treatment and therefore full satisfaction of our patients, but is also fundamental in the prevention of complications. A thorough understanding of aging allows for effective treatments, as most patients demand a natural result, removing the inevitable signs of aging, which can only be understood by considering their aging. Facial aging is a natural but complex multifactorial process, particularly for the forehead. In this article, we will focus on botulinum toxin as well as fillers in aging.

Arterial Vascularization of the Forehead in Aesthetic Dermatology Procedures: A Review

Background: The growing popularity of aesthetic procedures on the face raises the question of their safety. The forehead region is crucial aesthetically, but due to its abundant vascularization, it is also one of the most dangerous areas for dermatologic procedures, especially in the glabella area. The purpose of this article is to review the literature on the arterial vascularization of the forehead to identify potential high-risk zones for aesthetic dermatology procedures. Methods: A database search (PubMed, Web of Science, Scopus, and Embase) was conducted, and the titles and abstracts of all identified studies were screened, followed by full-text evaluation. Results: We identified 714 articles during the database search, and 25 articles were included in the review. The included studies used cadaveric dissection and computed tomography applied to cadavers as well as Doppler ultrasonography on volunteers to evaluate the forehead arteries (supratrochlear (STrA), supraorbital (SOA), central (CA), paracentral artery (PCA), and frontal branch of superficial temporal artery(FBSTA)). A total of 1714 cases involving the forehead arteries were analyzed. The included arteries were observed over a relatively large area, and their locations varied. The CA and PCA in cadaver studies were observed in an area of 0.2 to 10.8 mm and 0.8 to 16.2 mm, respectively, on the entire path from the glabellar point to the frontal prominence point. The distances from the midline in cadaveric studies at various measurement points ranged from 0.6 to 28.0 mm for the superficial branch of the STrA and 13.6 to 40.7 mm for the deep branch of STrA. In case of SOA, the distance from the midline ranged from 23 to 32 mm. Measurements from the midline in Doppler studies ranged from 0 to 23 mm for STrA and from 10 to 50 mm for the SOA. In studies using computed tomography, STrA was observed at a distance of 11 to 21 mm and the SOA at a distance of 21 to 32 mm, both lateral to the midline. Conclusions: Medical professionals should be aware of zones where frontal arteries are more likely to be encountered. The glabella region appears to be one of the most dangerous areas for dermatologic procedures. It is believed that the supratrochlear, supraorbital, and the paracentral arteries may cause ophthalmic complications due to occlusion of the ophthalmic artery, while this risk for the frontal branch of the superficial temporal artery seems to be low but cannot be completely excluded.

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 .

Aesthetic considerations for treating the Middle Eastern patient: Thriving in Diversity international roundtable series

BACKGROUND

The Middle East has a significant influence on the global aesthetic market. Within the United States and globally, patients with Middle Eastern heritage have a wide range of ethnic and cultural backgrounds that affect their perceptions of beauty and motivations to seek cosmetic treatment.

AIMS

The aim of this roundtable was to discuss similarities and differences in anatomy and treatment preferences of Middle Eastern patients and explore how these differences may influence 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.

RESULTS

The results of the fourth roundtable in the series, the Middle Eastern Patient, are described here. A discussion of treatment preferences is included, and specific procedural information is provided for  commonly treated areas in this population (forehead, infraorbital area, and jawline).

CONCLUSIONS

Middle Eastern patients have a variety of aesthetic preferences, which are influenced by a wide range of cultural backgrounds, making it difficult to develop general statements about this demographic. There is an unmet need for research into this diverse group of patients to help physicians understand and incorporate their unique needs and desires into clinical practice.

Transfer Patterns and Clinical Applications of the Forehead Flaps Based on the Supratrochlear Artery and Supraorbital Artery

This study aimed to describe the application of transferring preexpanded forehead flaps based on the supratrochlear and supraorbital arteries in 3 patterns for facial reconstruction: Pattern I, interpolated flap; Pattern II, island flap; and Pattern III, propeller flap, which was subdivided into direct propeller flap (Pattern IIIa) and indirect propeller flap (Pattern IIIb). During the first stage, a tissue expander was inserted underneath the forehead. After sufficient inflation of the expander, a forehead flap based on the supratrochlear or supraorbital artery was elevated and transferred to reconstruct the facial defects. Three weeks after the surgery, pedicle division was performed, in which Pattern I and Pattern IIIb flaps were used. Twenty-four patients underwent facial reconstruction. Twenty-three flaps survived without any perfusion-related complications. Venous congestion developed in an island flap. All patients were followed up after surgery, ranging from 2 to 156 (mean, 19) months. The color and texture of the flap matched those of the adjacent skin. The patients and their families were satisfied with the final functional and esthetic outcomes. The forehead flap based on the supratrochlear and supraorbital arteries provides reliable coverage of facial defects. The conventional interpolated flap continues to be the most dependable. Single-stage reconstruction using the island flap and direct propeller flap is applicable to patients who decline the pedicle division procedure. The novel technique of using the indirect propeller flap is safe for cheek reconstruction with minimal donor-site morbidity and esthetically pleasing results.

Bridging a Century-Old Problem: The Pathophysiology and Molecular Mechanisms of HA Filler-Induced Vascular Occlusion (FIVO)-Implications for Therapeutic Interventions

Biocompatible hyaluronic acid (HA, hyaluronan) gel implants have altered the therapeutic landscape of surgery and medicine, fostering an array of innovative products that include viscosurgical aids, synovial supplements, and drug-eluting nanomaterials. However, it is perhaps the explosive growth in the cosmetic applications of injectable dermal fillers that has captured the brightest spotlight, emerging as the dominant modality in plastic surgery and aesthetic medicine. The popularity surge with which injectable HA fillers have risen to in vogue status has also brought a concomitant increase in the incidence of once-rare iatrogenic vaso-occlusive injuries ranging from disfiguring facial skin necrosis to disabling neuro-ophthalmological sequelae. As our understanding of the pathophysiology of these injuries has evolved, supplemented by more than a century of astute observations, the formulation of novel therapeutic and preventative strategies has permitted the amelioration of this burdensome complication. In this special issue article, we review the relevant mechanisms underlying HA filler-induced vascular occlusion (FIVO), with particular emphasis on the rheo-mechanical aspects of vascular blockade; the thromboembolic potential of HA mixtures; and the tissue-specific ischemic susceptibility of microvascular networks, which leads to underperfusion, hypoxia, and ultimate injury. In addition, recent therapeutic advances and novel considerations on the prevention and management of muco-cutaneous and neuro-ophthalmological complications are examined.

Three-Dimensional Arterial Distribution Over the Midline of the Nasal Bone

BACKGROUND

A comprehensive understanding of arterial variations around the midline of the nose is of great importance for the safety of filler injection.

OBJECTIVES

The aim of the study was to clearly define the 3-dimensional location of the arteries along the midline of the nasal bone.

METHODS

The arterial structures overlapping the nasal bone along the midline were observed in 79 cadavers.

RESULTS

The present study found that 0 to 3 named arteries per nose segment could be identified. All the arterial structures were located in or above the superficial musculoaponeurotic system layer overlapping the nasal bone. The probability of encountering named arteries at 5 defined points, P1 to P5, was 5/79 (6.3%), 4/79 (5.1%), 1/79 (1.3%), 6/79 (7.6%), and 9/79 (11.4%), respectively. The depth of the main arterial trunk was 1.2 ± 0.4 mm, 1.6 ± 0.6 mm, 1.8 ± 0 mm, 1.0 ± 0.4 mm, and 0.9 ± 0.5 mm below the skin at P1 to P5, respectively.

CONCLUSIONS

The authors confirmed that sub-superficial musculoaponeurotic system injection along the midline through a needle is anatomically reliable and that a technique with 1 entry point through the rhinion via a cannula can easily keep the needle sufficiently deep for safe nasal filler injection.

Three-Dimensional Computed Tomographic Study of the Supratrochlear Artery and Supraorbital Artery to Determine Arterial Variations and Their Relationship

BACKGROUND

The forehead has high risks associated with filler injection considering its highly complex vascular system. This study aims to thoroughly describe the anatomical variations and relationships between the supratrochlear artery (STA) and supraorbital artery (SOA).

MATERIALS AND METHODS

We studied 56 cadaveric heads by computed tomography after contrast-agent injection.

RESULTS

The deep branch of the STA originated in the deep superior orbital arcade and the ophthalmic artery (OA), whereas that of the SOA originated at 3 locations: the deep superior orbital arcade, deep superior orbital artery, and OA. The superficial branch of the STA also had 3 origins: the superficial superior orbital arcade, OA, and angular artery, whereas the superficial branch of the SOA had 2 origins: the superficial superior orbital arcade and OA. Based on the relationship between the STA and SOA, 2 main arterial distribution patterns were observed in both superficial and deep layer arteries: STA/SOA connected pattern and STA/SOA disconnected pattern, of which the latter pattern has 3 subtypes.

CONCLUSION

The forehead arteries have complex origins. The relationship of the supratrochlear and supraorbital arteries could be categorized into 2 main patterns. The study elucidated the complexity of the forehead vasculature.

The Crest Injection Technique for Glabellar Line Correction and the Paracentral Artery

The glabella is a zone that carries a high risk of blindness after performing filler injections. The arteries beneath the glabellar lines were investigated by meticulous dissections in 30 geriatric embalmed cadavers with latex injections into the arterial system. The results showed that the supratrochlear artery, a direct branch of the ophthalmic artery, ascended from the muscular layer of the medial eyebrow along the medial canthal vertical line of the intercanthal vertical zone (53 in 60 hemifaces, or 88%). The dominant single paracentral artery from the radix artery was found within the radix vertical zone (eight out of 30 glabellae, or 27%). Among these, the dominant paracentral artery was near the midline in two cadavers and arose along the radix vertical line in six cadavers. The dominant paracentral artery may be the cause of ocular complications during injections of glabellar lines between the medial eyebrows, especially at the radix vertical lines. The supratrochlear artery might cause ocular complications when an injection is performed close to the medial eyebrows. Pinching to create a skin crest and evert glabellar line for a precise injection is recommended to temporarily occlude the paracentral artery.

Termination points of the facial artery-A meta-analysis

The facial artery (FA) is the main artery supplying the anterior face, making this artery a very important structure to consider while performing plastic and reconstructive procedures. The literature shows discrepancies in anatomical classifications and the frequency of occurrence of individual variations. Therefore, the goal of this meta-analysis is to provide surgeons with helpful knowledge about the variety of the termination of FA. Articles with data about the termination of the FA were found in major online medical databases such as PubMed, Scopus, Embase, Web Of Science, and Cochrane Library. A total of 1346 articles were initially evaluated by two independent reviewers. Out of those, 24 articles matched the required criteria, and were used in this meta-analysis. A total of 2119 studied FAs were included in this study. The FA termination patterns were divided into five previously classified types. The data show that the FA terminates most frequently as the lateral nasal or angular artery with the prevalence for this group being 69.81% (95% confidence interval [CI]: 59.83%-78.94%). Authors believe that this is the most accurate and up to date study regarding termination patterns and the prevalence of the FA. The results of this meta-analysis could provide a helpful tool for surgeons preforming plastic and cosmetic procedures, especially when injecting dermal fillers or choosing and preforming facial flaps. Detailed anatomical knowledge about the FA may prevent potential surgical complications.

The Usefulness of Magnetic Resonance Angiography to Analyze the Variable Arterial Facial Anatomy in an Effort to Reduce Filler-Associated Blindness: Anatomical Study and Visualization Through an Augmented Reality Application

BACKGROUND

The use of soft tissue fillers for facial rejuvenation is increasing rapidly and the complications, unfortunately, follow the same path. Blindness caused by intravascular filler injections is a rare but devastating complication. Knowledge of the individual arterial anatomy may aid the injector in avoiding injecting into an artery and thus to prevent blindness.

OBJECTIVES

To evaluate if the use of magnetic resonance angiography (MRA) may visualize the arterial facial anatomy in a contrast- and radiation-free way and study the individual arterial variations using an augmented reality (AR) image.

METHODS

The individual arterial anatomy of the 3 terminal branches of the ophthalmic artery (supraorbital [SO]; supratrochlear [STr]; and dorsal nasal [DN] arteries) of 20 volunteers was studied by a 3-Tesla MRI, combining infrared (IR) facial warming and 3-dimensional time-of-flight multiple overlapping thin slab acquisition MRA. The resulting visualization of the facial arteries was shown on the patient's face through AR technology.

RESULTS

The MRA was able to visualize the SO in 90.0%, STr in 92.5%, and DN arteries in 75% of the examined patients, as well as numerous variations in both vessel localization and path. Furthermore, a proof-of-concept of the AR visualization of the individual arterial anatomy was successfully implemented.

CONCLUSIONS

Dermal filler injectors should be aware of the risk of filler-induced blindness and familiarize themselves with the visualization of the variable facial vascular anatomy. The implementation of a one-time MRA and subsequent AR visualization may be useful in the accurate planning of minimally invasive facial rejuvenation procedures.

The Supratrochlear Artery Revisited: An Anatomic Review in Favor of Modern Cosmetic Applications in the Area

The supratrochlear artery represents a terminal branch of the ophthalmic artery. Cosmetic interventions may traumatize it, resulting in a circulation in the lesion in glabellar region and in the medial aspect of the forehead.

This review article aims to synopsise the existing knowledge of the anatomy of the supratrochlear artery in close correlation with minimally invasive cosmetic procedures in the facial area such as soft-tissue filler injections. Their possible adverse effects and their safe application based on the topographic anatomy were included.

A literature review was performed in PubMed/Medline online medical database.

The superficial course of the supratrochlear artery, as well as the rich, variable anastomotic network that it forms with the supraorbital, angular and dorsal nasal artery raise clinical questions in the case of soft-tissue filler injections in the nasoglabellar and central forehead area. Accidental cannulation of the supratrochlear artery and ultimately, the risk of embolization of the central retinal artery in a retrograde fashion might lead to injury with questionable cosmetic results.

Although the risk of complications from the use of soft tissue fillers is considered rare, once happen, the results could be devastating for the quality of life. Thus, the comprehension of the anatomy of the supratrochlear artery is paramount for the health practitioners.