11 Facial Danger Zone 2 – Temporal Region

10.1055/b-0040-177253

11 Facial Danger Zone 2 – Temporal Region

Rod J. Rohrich and Dinah Wan

Abstract

The superficial temporal artery and middle temporal vein lie within the temporal fossa in an intermediate plane. Inadvertent injection into the frontal branch of the superficial temporal artery can cause ocular compromise via retrograde embolization through the supraorbital system. Injection into the middle temporal vein may result in nonthrombotic pulmonary embolism via anterograde venous flow into the internal jugular vein. Filler injections in the temporal region should be performed either superficially in the subcutaneous tissue, or deeply in the preperiosteal plane to avoid inadvertent cannulation of at-risk vessels situated in the intermediate plane.

Key Points for Maximizing Filler Safety in the Temporal Region

Avoid injecting in the intermediate plane where vulnerable vessels lie in the temporal region.
Inject either superficially in the superficial subcutaneous tissue or deeply in the preperiosteal plane.
Inject with low pressure in an anterograde/retrograde motion.

11.1 Safety Considerations in the Temporal Region

The superficial temporal artery and middle temporal vein lie within the temporal fossa in an intermediate plane (▶ Fig. 11.1 ).
Intravascular injection of foreign material into the frontal branch of the superficial temporal artery can cause ocular compromise via retrograde embolization through the supraorbital system ¹ (▶ Fig. 11.2).
Dye injected into the superficial temporal artery has been found within ipsilateral and even bilateral globes in cadaver studies. ²
Although extremely rare, intravascular injection into the middle temporal vein can cause nonthrombotic pulmonary embolism via anterograde venous flow into the internal jugular vein. ³ ^, ⁴

**Fig. 11.1** The frontal branch of the superficial temporal artery and the middle temporal vein are potential sites of vascular injury during injections in the temporal region.

**Fig. 11.2** The frontal branch of the superficial temporal artery lies in the temporal fossa and is at risk for inadvertent cannulation during injection in the temporal region. This branch arborizes with the supraorbital vessels in the lateral brow, creating potential routes for retrograde embolization into the ophthalmic system.

11.2 Pertinent Anatomy of the Temporal Region

11.2.1 Superficial Temporal Artery – Frontal Branch

(▶Fig. 11.3) (Video 11.1)

**Fig. 11.3** The superficial temporal artery **(d)** is demonstrated ramifying its frontal branch **(b)**. The subcutaneous tissue **(c)** has been reflected anteriorly and posteriorly to delineate the course of the frontal branch artery within the superficial temporal fascia. The frontal branch artery **(b)** can be clearly seen anastomosing with the supraorbital artery **(a)** superficial to the frontalis muscle after transitioning to the subcutaneous plane.

Path is similar to the temporal branch of the facial nerve.
Originates 1 fingerbreadth anterior and 2 fingerbreadths superior to the tip of the tragus. ⁵
Runs in the intermediate plane within temporoparietal fascia 2 cm above zygomatic arch. ¹ ^, ⁶
Transitions to the subcutaneous plane 1 fingerbreadth superior to the peak of the brow near the lateral border of the frontalis. ¹
Anastomoses with the supraorbital artery above the lateral brow.