Frontal branch of the superficial temporal artery: anatomical study and clinical implications regarding injectable treatments

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.

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.

Novel Hybrid Technique for Preservation of Frontal Branch of Facial Nerve: Subgaleal Preinterfascial Dissection

OBJECTIVE

The pterional approach is the workhorse of skull-base neurosurgery, which allows virtual access to any intracranial lesion around the circle of Willis. Preserving the frontotemporal branch of the facial nerve and conserving the temporal muscle's symmetry are fundamental objectives besides the access that can be obtained through this versatile neurosurgical technique. This manuscript proposes a subgaleal preinterfascial dissection, a novel hybrid technique that provides advantages of previously described temporal muscle dissection techniques while preserving the integrity of facial nerve branches and the unobstructed broad pterional region. We describe the subgaleal preinterfascial dissection as a safe and simple to technique to achieve preservation of the facial nerve frontal branches during anterolateral approaches.

METHODS

Two cadaveric heads were skillfully dissected and studied to perform a proper subgaleal preinterfascial dissection on both sides of each cadaver. Afterward, the same technique was employed in 108 patients during a pterional approach for different neurosurgical diseases, with a postoperative follow-up of 6 months.

RESULTS

None of the 108 patients presented postoperative frontotemporal branch palsy during postoperative follow-up. Likewise, no complications related to the proposed technique were present.

CONCLUSIONS

The subgaleal preinterfascial dissection is a reliable, safe technique that may be employed during a pterional approach with an unobstructed surgical view and excellent cosmetic and functional results, preserving the frontotemporal branch of the facial nerve.

Face painting as an anatomical learning tool based on individual ultrasonographic examination

Considering the shift to online education during the COVID-19 pandemic, new and easily accessible educational videos and content on clinical anatomy are necessary. This study utilized numerous references and data on the anatomy of Asian facial muscles and blood vessels to accurately depict human anatomy through face painting. It aimed to provide clinicians accurate educational video content on anatomy to help prevent possible complications during noninvasive facial and surgical procedures. A 26-year-old Korean-Chinese male volunteer was used as a face painting model. The location of the blood vessels of the face was confirmed through ultrasonography images using a real-time two-dimensional B-mode. The model's face was painted by an artist majoring in anatomy. To reveal most anatomical structures on both sides of the face, the left side showed the structures observed when the skin and superficial fat layer are removed, and the right side revealed the deeper layer structures that can be seen when some muscles are cut. Fifteen superficial and deep muscles important in esthetic procedures were meticulously painted on the face. The face painting took a total of 6 h, and the video was edited to 5 min. This study merged the advantages of 2D and 3D by painting directly on the skin surface of a living model. Thus, it can provide more dynamic surface anatomy data. These contents inform clinicians about 3D anatomic location, which can help avoid complications when performing clinical procedures on the face.

The Superficial Temporal Artery and Zygomatico-Orbital Artery: Superficial Arterial Distribution of the Anterior Temple Area

A hollow temple may give rise to a false impression of early facial aging. This is corrected with dermal fillers that are injected into the hollow temple area to produce a smoother facial contour. However, various complications of this procedure have been reported, with the most common being the inadvertent injection of the filler material into the superficial temporal artery (STA). The aim of this study was to investigate the topographic anatomy of the STA and zygomatico-orbital artery (ZOA) to provide essential anatomical information to aid in various clinical procedures involving the temporal region. The superficial arterial distribution of the temple area was studied in 43 hemisectioned Korean cadavers. The courses of the STA and ZOA were identified and classified based on the line connecting the tragus and the superciliary arch (TR-SA line). The ZOA was present in 85.2% of cases and bifurcated from the frontal branch of the STA, after which it ran along the TR-SA line. In this study, the STA pattern was classified into a typical pattern where the ZOA coexists with the STA and a lower pattern where the ZOA was absent. The current findings suggested that the ZOA ran close to the TR-SA line. Therefore, to minimize vascular complications during invasive procedures, injection into this area should be avoided. In addition, clinicians should verify the existence of ZOA and the course of STA before performing various clinical procedures.

Injection Guidelines for Treating Midface Volume Deficiency With Hyaluronic Acid Fillers: The ATP Approach (Anatomy, Techniques, Products)

Midface rejuvenation is among the most valuable indications of hyaluronic acid dermal fillers, because malar projection and full upper cheeks significantly contribute to a youthful appearance. Hyaluronic acid fillers have evolved over the past 2 decades to meet specific clinical needs such as strong projection capacity and adaptability to facial dynamism. As a result, they now represent the treatment of choice for midface rejuvenation throughout age ranges by offering the potential for noninvasive treatment, immediate results, and minimal downtime. Because the 5-layered structure of the midface plays a central role in the human face, injecting the midface area may also indirectly improve other aesthetic concerns such as infraorbital hollowing and nasolabial folds. Nonetheless, midface rejuvenation requires a tailored treatment approach and a thorough knowledge of anatomy to minimize procedural risks and achieve natural-looking results. This article provides an extensive anatomical description of the midface and of the usual course and depth of vascular structures circulating nearby to delineate a treatment area and minimize procedural risks. Furthermore, considering the differential mobility and mechanical constraints of each layer of the midface, a multilayer treatment algorithm is proposed for adapting the treatment strategy to patient specificities (including age, gender, skin type, and morphology). Emphasis is also placed on desirable filler properties to create deep structural support on the one hand and accompany facial movement on the other hand.

Topography of the deep temporal arteries and implications for performing safe aesthetic injections

BACKGROUND

Several studies have started investigating the safety of temporal rejuvenation using soft tissue fillers. However, as the temporal region is highly vascularized, adverse events due to intravascular injection are of primary concern. The scarcity of treatment guidelines to date have focused primarily on avoiding the superficial and middle temporal arteries. The aim of the present anatomical study was to describe the topography of the deep temporal arteries (DTAs) with reference to superficial landmarks, to aid clinicians who perform temporal injections.

METHODS

The tissue layers of eight fresh-frozen cephalic cadavers were dissected and assessed, bilaterally in the temporal region (N = 16). Distance (D) of the anterior (D1 and D3) and posterior (D2 and D4) arteries was measured from (i) the zygomaticofrontal suture line at the lateral orbital rim (D1 and D2) and (ii) the junction of the superior border of the zygomatic arch and lateral orbital rim (D3 and D4). The distance between the anterior and posterior DTAs was also recorded, at the two regions (D5).

RESULTS

Bifurcations of the DTAs were observed in 18.75% (3/16) and 12.5% (2/16) of cases, for the anterior and posterior branches, respectively. On average [mean (standard deviation)], D1 (anterior DTA to the zygomaticofrontal suture line at the lateral orbital rim) = 1.56 cm (0.59); D2 (posterior DTA to the zygomaticofrontal suture line at the lateral orbital rim) = 2.98 cm (0.70); D3 (anterior DTA to the junction of the superior border of the zygomatic arch and lateral orbital rim) = 1.14 cm (0.63); D4 (posterior DTA to the junction of the superior border of the zygomatic arch and lateral orbital rim) = 2.37 cm (0.62); and D5 (distance between the anterior and posterior DTAs) = 1.54 cm (0.68).

CONCLUSION

To help avoid vascular adverse events while performing temporal injections, aesthetic clinicians should be conscientious of safety implications related to the anatomical location of the DTAs and their ramifications.

Pre-injection ultrasound scanning for treating temporal hollowing

BACKGROUND

Hyaluronic acid filler injection is commonly administered to correct temple hollowness, typically through deep temporal injection. Since the vascular distribution at the injection site can be diverse, studies on avoiding damage to the corresponding blood vessels are needed.

AIMS

To assess the commonly used hyaluronic acid filler injection site in the temple region, 1cm lateral and 1 cm above from the end of eyebrow, using a Doppler ultrasound to detect any anatomic variations in the blood vessels.

PATIENTS/METHODS

Thirty patients (60 temples, right and left) were examined using Doppler ultrasonography. An 8-17 MHz ultrasound probe was used to discriminate between the anatomic layers of the temple. Blood vessels found in each anatomical layer were subsequently investigated.

RESULTS

Among the 30 patients included in this study, we found temporal region arteries 1 cm above and 1 cm lateral to the distal end of the eyebrow in 9 patients; However, no arteries were detected in the temples of 21 patients. The presence or absence of arteries was bilateral in all patients.

CONCLUSIONS

The anatomical layers with blood vessels varied among patients. The variability could give rise to complications. Possible anatomic variations at the temple should be carefully identified using pre-injection ultrasonography, and harming blood vessels should be avoided while injecting hyaluronic acid filler for temple augmentation.

Facial Defect Repair Using a Flap Based on the Superficial Temporal Artery

Background:

Although a local flap repair is optimal for facial defects, an extra flap or split-thickness skin graft may be needed if a sufficient local flap area is not available. In this study, we developed a distant axial pedicle flap procedure based on the inner transverse perforator of the ascending frontal branch of the superficial temporal artery to repair facial defects while meeting patients’ requirements for a like-for-like tissue reconstructive outcome.

Methods:

For defect repair after facial tumor removal, we designed upper frontal facial pedicle flaps based on the inner transverse perforator of the ascending frontal branch of the superficial temporal artery. Facelift procedures were applied concomitantly for donor site repair.

Results:

We applied the procedure to 12 patients who underwent curative lesion resection. Notably, all flaps survived. Venous congestion developed in only 1 case, in which the wound was covered with heparin sodium gauze to inhibit wound coagulation until the congestion gradually resolved. In all cases, the frontal donor site scars were adjacent to the hairline and were concealed very well by hair growth. During postoperative follow-ups of 8–43 months, the patients experienced only minor complications.

Conclusions:

The flap based on the inner transverse perforator of the ascending frontal branch of the superficial temporal artery is a useful alternative for facial defect repair surgery. The low incidence of complications and easy concealment of the donor site underscore the safe and aesthetically acceptable nature of the procedure.

Ultrasound to Improve the Safety and Efficacy of Lipofilling of the Temples

BACKGROUND

Autologous fat is known for a reliable and natural safety profile, but complications do occur-even serious vascular adverse events.

OBJECTIVES

The authors sought to examine doppler-ultrasound (DUS) imaging for the harvesting and subsequent facial implantation of autologous fat tissue.

METHODS

All patients underwent lipofilling treatment of the temporal fosse of the face. DUS examination was performed for preprocedural vascular mapping and imaging of previously injected (permanent) fillers. In addition, the injection of autologous fat was performed DUS-guided.

RESULTS

Twenty patients (all female; mean age, 57.9 years; range, 35-64 years). DUS examination showed that 16 of the 20 patients (80%) had been injected with resorbable or nonresorbable fillers elsewhere in the past. The temporal artery could be visualized and avoided in all cases. An average of 1.1 cc of autologous fat was injected in the temporal fossa per side. One case of edema and nodules was described, but no other adverse events were reported.

CONCLUSIONS

The utilization of DUS can add valuable information to a lipofilling procedure and should be considered an integral part of a safe lipofilling treatment.

LEVEL OF EVIDENCE: 4

The Superficial Temporal Artery: Anatomical Map for Facial Reconstruction and Aesthetic Procedures

BACKGROUND

The superficial temporal artery (STA), a terminal branch of the external carotid artery, supplies multiple regions of the scalp and face. Knowledge of the STA is important for reconstructive and aesthetic procedures of the head and face.

OBJECTIVES

The aim of this study was to map the STA in relation to anatomical landmarks.

METHODS

Computed tomographic head angiographies of 215 patients were included in this study; the final analysis comprised 419 STAs. The STA's main branches and variants were identified. The diameters of the STA and its frontal and occipital branches were measured, and the distance between the STA tree and anatomical landmarks was delineated.

RESULTS

Frontal and parietal branches were recorded in 98.1% and 90.7% of patients, respectively. The mean diameters, measured 1 and 7 cm from the STA bifurcation for the frontal branch, were 0.97 ± 0.32 and 0.81 ± 0.26 mm, respectively, and for the parietal branch, the diameters were 0.96 ± 0.28 and 0.76 ± 0.23 mm, respectively. The STA bifurcation point was located above the zygomatic arch (ZA) in 75.6%, below in 14.7%, and on the ZA in 9.7% of patients. The mean distance from the ZA center to the STA bifurcation was 16.8 ± 16.0 mm.

CONCLUSIONS

The STA artery and its main branches follow a conservative course, and serious anatomical variations are relatively rare. The STA and its main branches may be localized using simple anatomical landmarks. An anatomical map showing artery-free zones in the lateral forehead region was presented, which may prove useful for plastic, reconstructive, and aesthetic surgeons.

Level of Evidence: 4.

Practical Approach and Safety of Hyaluronic Acid Fillers

Supplemental Digital Content is available in the text.

Soft-tissue filler use has grown considerably related to the increasing popularity of minimally invasive cosmetic procedures. Hyaluronic acid products are currently the most utilized soft-tissue fillers. Proper working knowledge of individual products, limitations to use, and anatomic principles can improve outcomes. Prevention is key to minimize complications; however, when present, complications must be managed methodically. Complications are categorized based on the timing of presentation and include early, late, and delayed. Vascular compromise and tissue necrosis are among the most devastating complications seen with filler use. Nodules can be related to an inflammatory or infectious etiology but should be distinguished as treatment varies. Hyaluronidase is mandatory to have available as a reversal agent for hyaluronic acid products and can be used in treatment for many complications and untoward sequela.

Clinical importance of the superficial temporal artery in neurovascular diseases: A PRISMA-compliant systematic review

The superficial temporal artery (STA) plays a very important role in neurovascular diseases and procedures. However, until now, no comprehensive review of the role of STA in neurovascular diseases from a neurosurgical perspective has ever been published. To review research on the clinical importance of STA in neurovascular diseases, a literature search was performed using the PubMed database. Articles were screened for suitability and data relevance. This paper was organized following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. According to the literature, STA is one of the terminal branches of the external carotid artery and can give off scalp, muscle, and transosseous branches. STA-middle cerebral artery (MCA) bypass is very useful for intracranial ischemic diseases, including moyamoya disease, chronic ICA and MCA insufficiency, and even acute ischemic stroke. For intracranial complex aneurysms, STA bypass remains a major option that can serve as flow replacement bypass during aneurysmal trapping or insurance bypass during temporary parent artery occlusion. Occasionally, the STA can also be involved in dural AVFs (DAVFs) via to its transosseous branches. In addition, the STA can be used as an intraoperative angiography path and the path to provide endovascular treatments. Therefore, STA is a very important artery in neurovascular diseases.

Novel Anatomic Description of the Course of the Inferior Palpebral Vein for Minimally Invasive Aesthetic Treatments

BACKGROUND

The inferior palpebral vein (IPV) receives tributaries from the inferior palpebral part of the orbicularis oculi muscle (OOc). The aim of this study was to elucidate the venous distribution pattern of the IPV for dermal filler injection.

MATERIAL AND METHODS

Fifty hemifaces from 34 cadavers were used in this study. The various distribution patterns of the IPV were classified according to its relationship with the angular vein (AV) and facial veins.

RESULTS

The IPV can be classified into the following 4 types: Type I (58.0%), in which the origin of the IPV is located beneath the lateral part of the OOc; Type II (12.0%), in which the origin of the IPV is located beneath the inferior part of the OOc; Type III (8.0%), in which the origin of the IPV is located beneath both the lateral and inferior parts of the OOc; and Type IV (22.0%), in which the IPV is undeveloped.

CONCLUSION

The course of the IPV can be approximated by connecting the lateral orbital rim to the C point (the meeting point between the IPV and the AV). The lateral rim can be palpated and the location of the C point is suggested as a columnar area inferior to the pupil.

Parotid Branches of the Auriculotemporal Nerve: An Anatomical Study With Implications for Frey Syndrome

The auriculotemporal nerve is one of the many branches of the mandibular division of the trigeminal nerve. Of these, its superficial temporal branch has been most described. Although the parotid branches, secretomotor fibers to the parotid gland, are well known as the cause of Frey syndrome, there have been almost no descriptions of their anatomy. In this study, the authors dissected the parotid branches of the auriculotemporal nerve to elucidate their anatomy. A total of 10 sides from 7 adult and embalmed cadaver heads were used in this study. The specimens were derived from 3 males and 4 females, the age of cadavers at death ranged from 65 to 92 years old. Measurements included their diameter and the distance of their branching point from the main trunk of the auriculotemporal nerve from the middle of the tragus. Three of 10 sides had 2 parotid branches and 7 sides were found to have 1 parotid branch. The vertical distance between middle of the tragus to branching point of the parotid branch ranged from 1.79 to 16.17 mm. The horizontal distance between middle of the tragus to branching point of the parotid branch ranged from 3.03 to 12.62 mm. The diameter of the parotid branch ranged from 0.31 to 0.49 mm. An improved knowledge of the parotid branch of the auriculotemporal nerve might decrease injury to these structures with the potential for postoperative.

Neurovascular structures of the mandibular angle and condyle: a comprehensive anatomical review

BACKGROUND

Various surgical interventions including esthetic surgery, salivary gland excision, and open reduction of fracture have been performed in the area around the mandibular angle and condyle. This study aimed to comprehensively review the anatomy of the neurovascular structures on the angle and condyle with recent anatomic and clinical research.

METHODS AND RESULTS

We provide detailed information about the branching and distributing patterns of the neurovascular structures at the mandibular angle and condyle, with reported data of measurements and proportions from previous anatomical and clinical research. Our report should serve to help practitioners gain a better understanding of the area in order or reduce potential complications during local procedures. Reckless manipulation during mandibular angle reduction could mutilate arterial branches, not only from the facial artery, but also from the external carotid artery. The transverse facial artery and superficial temporal artery could be damaged during approach and incision in the condylar area. The marginal mandibular branch of the facial nerve can be easily damaged during submandibular gland excision or facial rejuvenation treatment. The main trunk of the facial nerve and its upper and lower distinct divisions have been damaged during parotidectomy, rhytidectomy, and open reductions of condylar fractures.

CONCLUSION

By revisiting the information in the present study, surgeons will be able to more accurately prevent procedure-related complications, such as iatrogenic vascular accidents on the mandibular angle and condyle, complete and partial facial palsy, gustatory sweating (Frey syndrome), and traumatic neuroma after parotidectomy.