For humans our face has always been the focus when it comes to the process of the enhancing of features, be it simply with make up or more dramatically surgical intervention. Over time our knowledge and understanding of the facial anatomy & the way skin ages has enabled us to successfully treat ageing concerns more effectively. There has been major progression over the last 2 decades & advances in clinical interventions have enabled us to treat the root causes of ageing before it happens, or even reverse premature & accelerated ageing.
Our face plays crucial role in many human traits of society. It can influence how we are accepted & received in day to day life. It creates an impression of our potential age, ethnicity, social status, traits of personality, mood, demographic, hobbies & habits!
The ageing process is often not as noticeable in other parts of our body as it is in our face as our faces are stimulated by expression, emotion & the bare the brunt of extreme weather in hot and cold climates.
The opportunity to look younger is no longer just accessible to ‘rich and famous’ but to the vast majority of people worldwide in varying capacities. Social media means that we have never been as educated or as informed about treatments available to us and what to expect from them.
Regardless of how beautiful an individual was in their youth, the ageing process can strip attractiveness as we progressively mature. A loss of volume and proportion can be observed over the course of time.
When considering the anatomy of the face for rejuvenation with injectables, it is helpful to think of it in its entirety as a three-dimensional structure that consists of five unique layers running superficial to deep. This is important, so that we know which structures we are aiming to treat & the success we will gain from each approach.
We must remember, that the ageing process effects not only the most visible part of our face, the skin, but also other intrinsic factors that are at play including deep fat layer loss as well as loss of muscle laxity & ligament and bone deterioration dramatically accelerate ageing.
The first layer, the outer most layer of the face is the skin, comprises of both the epidermis and dermis. Beneath this you will find the subcutaneous layer that comprises of fatty tissue. The subcutaneous layer sits on top of the fascial layer that varies depending on the area of the face. For example, in the forehead the fascial layer contains the frontalis muscle, the temporal region contains the temporal parietal fascia and below the zygoma in the mid and lower, the fascia becomes the SMAS (superficial muscular aponeurotic system) which is fibro fatty and lymphatic fascial tissue that contains the muscles for facial expressions.
Underneath the SMAS layer is a layer that has traditionally been considered to be a loose areola tissue layer. We now understand that this deeper layer comprises of multiple discrete fat compartments and can be sometimes referred to as the deep fat layer. Beneath this is the periosteum of the facial skeleton.
Ligaments
There are a number of ligaments that run through these tissue plane, from deep to superficial. The true retaining ligament run from the periosteum through the SMAS layer to insert into the dermis. These include the orbital retaining ligament, the zygomatic cutaneous ligament and the mandibular ligament. A number of smaller ligaments are also present which can be described as condensations of fascia which run from the SMAS layer superior to the skin. The role of these multiple myocutaneous ligaments is to allow the transmission of movements of the muscles of facial expressions to the skin.
Arterial Blood Supply
The face contains two main arterial blood supplies. One arising from the external carotid artery system and one arising from the internal carotid artery system.
The external carotid artery gives rise to the facial artery which crosses the mandible, entering the face at the junction between the posterior one third and the anterior two thirds of the body of the mandible. This also corresponds to the anterior border of the masseter muscle and this can be palpated at this point as well as being identified by a facial artery notch that runs inferior along the edge of the mandible. This artery runs underneath the SMAS layer and traverses superior and medially towards the corner of the lip before giving rise to an inferior labial and superior labial artery, and then continuing in the deep nasal labial fat as the nasolabial artery. This continues along the side of the nose, as the angular artery, and gives rise to an alar branch to supply the skin over the ala of the nose and a lateral nasal branch to supply the skin of the lateral nose.
A further branch of the carotid artery is its terminal branch, the superficial temporal artery which divides into two main branches and supplies the skin of the temporal and forehead area.
The second main supply to the face arises from the internal carotid artery which gives rise via its various branches to the supraorbital and supratrochlear artery.