During the past 20 years, our understanding of the facial anatomy has been widely changed. A plethora of studies revealed new insights into the anatomy of the face and the age-related changes of the structures involved: bone, ligaments, fat compartments, muscles and skin. The general concept of the layered arrangement has been introduced and has laid down the keystone for safe and most effective rejuvenate procedures of the face.

However, the concept of the 5-layers of the face has already been exchanged and adapted as in the tear trough only 3 layers are present, whereas in the temporal region 10 layers can be identified. The concept of the superficial and deep fat compartments has been introduced, which is pivotal for the application of different soft tissue fillers independently, whether they are based on hyaluronic acid or on other materials. Only recently the deep fat compartments of the forehead were published and more will follow. The deep fascia of the face has been postulated but no study to date was able to provide robust evidence for its existence. Especially with the increased rate of complications and the most severe of all, irreversible blindness, the understanding of the facial anatomy is more needed than ever. Still the rigid and unchangeable anatomy reveals new insights and it is expected that there will be more to come in the near and far future.

In regards to the course of the facial nerve, one has to understand that this nerve provides motor supply to the muscles of facial expression and that this nerve always travels in protected pathways. The nerve is either sheltered by fat or by fibrous septae that protect the nerve branches. In the lower temporal compartment the nerve can be identified in Layer 4 and is surrounded by deep fat. In the midface the nerve travels deep to the parotideomasseteric fascia until it reaches the anterior boundary of the masseter muscle. There it changes plane towards more superficial layers and connects to the muscles of facial expression in general from deep and posterior. In the lower face, the facial nerve (here: marginal mandibular branch) travels superficially to the facial artery and vein when they cross the mandible.

The fat located around the eye can be classified according to the layer where it is situated, thus it is important to understand the underlying anatomy and to respect the layered arrangement. The peri-orbital fat is also different in color, in lobule size, in extra-cellular matrix composition and in adipocite histochemistry. The subcutanous fat located deep to the eyebrow is more white-ish because it is interspersed with fibro-connective tissue and muscular fibers. This is understandable as here the underlying muscles are connected to the eyebrow skin for movement. In the area around the eye the fat is again different as here no fibrous tissues connect the skin to the underlying structures. One has to be aware that when passing inferiorly towards the pre-septal region again, another type of fat can be identified. Here the fat is more orange-ish, the lobules are bigger in size and the fat is looser. It resembles the arrangement of the buccal fat pad (Bichat). When looking at the layered arrangement of the forehead one has to understand the layers of the forehead. Fat can be found superficial and deep to the frontalis muscle, which is separated by the branches of the supraorbital and supratrochlear neuro-vasculature. Deep to the deep fascia of the frontalis muscle the deep forehead compartments can be identified. This is the deep central and the deep lateral compartments. They are separated by the branches of the supraorbital neurovasculature.

In the midface the facial artery and vein are separated by a fascia. This fascia is the anterior lamina of the parotideo-masseteric fascia, which encloses the facial vein and forms together with the posterior lamina the facial-vein-canal. Anterior to this lamina the buccal space can be found and within this space the facial artery is located.

Understanding the facial anatomy is crucial for safe and long lasting results when applying soft tissue fillers and neuromodulators.