Anatomical study of medial zygomaticotemporal vein and its clinical implication regarding the injectable treatments

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.

The Suitability of a Large Particle Hyaluronic Acid Filler for the Treatment of Temporal Hollowing

BACKGROUND

Hyaluronic acid (HA) fillers may be manufactured to have distinctive physical properties that optimize their use for specific indications. Fillers manufactured with large gel calibration (particle size; HA-V) may be particularly suitable for volumizing large surface areas such as the temporal hollows.

OBJECTIVE

To investigate the safety and effectiveness of HA-V for the treatment of temporal hollows.

MATERIALS AND METHODS

A prospective, open-label, single-cohort, clinical trial was conducted. Twenty-six women who presented with bilateral temporal hollows at baseline were recruited. All subjects received treatment with HA-V and were observed at 4 to 5 in-person visits over 16 weeks. Subjective and objective measures of safety and efficacy parameters were collected through 2- and 3-dimensional imagery, questionnaires/scales (i.e., subject satisfaction, global aesthetic improvement, temporal hollowing severity), and adverse event diaries.

RESULTS

To achieve optimal correction, the investigator used an average of 1.70 syringes per subject, per side. All treatments were performed using a bolus injection technique to place the product on the periosteum (bone) of the temporal region. Following optimal correction, all subjects (100%) displayed improvement in their global aesthetic appearance, and 25 of 26 subjects (96.15%) displayed ≥1 grade improvement on the temporal volume scale. Subject satisfaction was high, with 91.3% of subjects being satisfied with the appearance of their temporal regions following optimal correction.

CONCLUSION

In this pivotal trial, HA-V was evidenced to have an excellent safety profile and proven efficacy up to 16 weeks, making it a suitable HA filler for volumization of the temporal region.

Topography of the frontal branch of the facial nerve and its clinical implication for temporal direct browplasty

Due to anatomic proximity to the surgical site, iatrogenic trauma to the frontal branch of the facial nerve (FbFN) with resultant brow paralysis is a recognized major complication of temporal direct browplasty. This study was aimed to elucidate the course of the FbFN in the area superolateral to the brow in order to facilitate safer temporal direct browplasty by preventing facial nerve injury. Forty-five hemifaces from 32 embalmed Korean cadavers were dissected. A horizontal line connecting the tragion to lateral canthus was established. Then, an oblique line passing through the lateral canthus and 45° to the horizontal line was used as reference line. The mean distance from the lateral canthus to the points where the FbFN cross the reference line was measured. The angle between the FbFN and reference line at the crossing points were also recorded. After crossing the zygomatic arch, FbFN continues in an anteriorly inclining curve across the temporal region, passing near the lateral end of the brow as it heads toward frontalis muscles. During the course, the FbFN laying in the innominate fascial layer was divided into 3 branches. The anterior and posterior branch of FbFN crossed the reference line superiorly and laterally at 3 and 4 cm from the lateral canthus, respectively. In conclusion, the oculofacial surgeon must bring the dissection plane of the forehead tissue more superficially around the 3 cm superolaterally to the lateral canthus in the direction of 45° from the horizontal line in order to avoid nerve injury.

The Middle Temporal Vein on Computed Tomographic Angiography: Implications for Filler Injection and Reconstructive Surgery

BACKGROUND

Detailed knowledge of middle temporal vein (MTV) anatomy would benefit health care professionals when performing filler injection and reconstructive surgery. The purpose of this study was to assess the variation and course of the MTV using computed tomographic angiography.

METHODS

Computed tomographic angiography images of 300 MTVs from 150 Asian patients were evaluated in this study. The course and branching pattern of the MTVs were evaluated, as well as the relationship between the location of the MTV and the frontal branch of the superficial temporal artery. The diameter of the MTV and the distances between anatomic landmarks and temporal vessels were measured.

RESULTS

The MTV was identified in all images, with an average diameter of 2.98 ± 0.80 mm. All MTVs had at least one major trunk; 12.3% had two major trunks. According to the landmarks, the MTV ran 16.3 ± 8.1 mm, 24.8 ± 4.5 mm, and 24.2 ± 4.6 mm above bony lateral canthus, jugale, and zygion point, respectively. Regarding the relationship between the MTV and the frontal branch of the superficial temporal artery, most of the superficial temporal arteries (81.7%) were located above the MTVs, whereas only 9.0% of the superficial temporal arteries crossed the MTVs. The superficial temporal artery was located 43.5 ± 9.6 mm, 44.3 ± 11.9 mm, and 37.0 ± 11.9 mm above the bony lateral canthus, jugale, and zygion point, respectively.

CONCLUSION

Detailed knowledge of MTV anatomy will provide a valuable reference for safe filler injection and reconstructive surgery in the temporal region.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Brow Anatomy and Aesthetics of the Upper Face

The surgical approach to the brow has changed perhaps more than any other facial esthetic procedure in the past 20 years. Understanding the functional anatomy of the upper face is the best means of maximizing results and minimizing untoward events in this region. The surgical and clinical correlation is addressed in detail in this article. Cadaver and intraoperative photographs are used to illustrate critical points. Armed with the details of this anatomy, the reader will best be able to best individualize surgical treatment.

Three-Dimensional Computed Tomography Scanning of Temporal Vessels to Assess the Safety of Filler Injections

BACKGROUND

Temple filler injection is one of the most common minimally invasive cosmetic procedures involving the face; however, vascular complications are not uncommon.

OBJECTIVES

This study aimed to investigate the anatomy of the temporal vessels and provide a more accurate protocol for temple filler injection.

METHODS

Computed tomography (CT) scans of 56 cadaveric heads injected with lead oxide were obtained. We then used Mimics software to construct 3-dimensional (3D) images of the temporal vessels described by a coordinate system based on the bilateral tragus and right lateral canthus.

RESULTS

In the XOY plane, the superficial temporal artery (STA), middle temporal artery (MTA), zygomatico-orbital artery (ZOA), posterior branch of the deep temporal artery (PDTA), and lateral margin of the orbital rim divide the temple into 4 parts (A, B, C, and D). The probabilities of the STA, MTA, ZOA, and PDTA appearing in parts A, B, C, and D were 30.73%, 37.06%, 39.48%, and 77.18%, respectively. In 3D images, these vessels together compose an arterial network that is anastomosed with other vessels, such as the external carotid, facial, and ocular arteries.

CONCLUSIONS

3D CT images can digitally elucidate the exact positions of temporal vessels in a coordinate system, improving the safety of temple filler injections in a clinical setting.

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.

An Anatomical Study of the Middle Temporal Vein and the Drainage Vascular Networks to Assess the Potential Complications and the Preventive Maneuver During Temporal Augmentation Using Both Anterograde and Retrograde Injections

BACKGROUND

Non-thrombotic pulmonary embolism has recently been reported as a remote complication of filler injections to correct hollowing in the temporal region. The middle temporal vein (MTV) has been identified as being highly susceptible to accidental injection.

METHODS

The anatomy and tributaries of the MTV were investigated in six soft embalmed cadavers. The MTV was cannulated and injected in both anterograde and retrograde directions in ten additional cadavers using saline and black filler, respectively.

RESULTS

The course and tributaries of the MTV were described. Regarding the infusion experiment, manual injection of saline was easily infused into the MTV toward the internal jugular vein, resulting in continuous flow of saline drainage. This revealed a direct channel from the MTV to the internal jugular vein. Assessment of a preventive maneuver during filler injections was effectively performed by pressing at the preauricular venous confluent point against the zygomatic process. Sudden retardation of saline flow from the drainage tube situated in the internal jugular vein was observed when the preauricular confluent point was compressed. Injection of black gel filler into the MTV and the tributaries through the cannulated tube directed toward the eye proved difficult.

CONCLUSION

The mechanism of venous filler emboli in a clinical setting occurs when the MTV is accidentally cannulated. The filler emboli follow the anterograde venous blood stream to the pulmonary artery causing non-thrombotic pulmonary embolism. Pressing of the pretragal confluent point is strongly recommended during temporal injection to help prevent filler complications, but does not totally eliminate complication occurrence.

NO LEVEL ASSIGNED

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