The anatomy of the face is pertinent for safe and effective placement of fillers and neuromodulators. A detailed understanding of facial blood vessels, nerves and musculature is essential to achieve consistent results when utilizing injectables in aesthetic medicine.
In this blog I will highlight key anatomy in the forehead, cheeks, temple area, nasal area and perioral regions of the face.
The facial artery in the neck is superficial and is covered by the integument, platysma and fascia. From here it passes beneath the stylohyoid and digastric muscles.
On the face, it passes the mandible superficially, lying beneath the dilators of the mouth. In the course over the face, it rests on the buccinators and levator anguli oris. Here dependent on the individual’s anatomy, it can pass either over or under the infraorbital head of the levator labii superioris
The anterior facial vein lies lateral to the artery and takes a more direct course across the face, where it is separated from the artery by quite a significant amount. However in the neck it lies very superficial to the artery. When injecting never forget that nerves as well as anastomoses are also present!
In order to treat the forehead with neuromodulators such as Botulin Toxin (Anti Wrinkle), injections into the frontalis muscle should be at least 2m above the orbital rim. This minimizes brow Ptosis.
The corrugator supercilii and procerus muscles make up the two main brow depressors. They are responsible for the glabellar rhytide. You injector should always keep in mind the bony origin and superior dermal insertions when injecting these muscles.
Some practitioners may however suggest intradermal filler injections if the dermal lines are too deep to enable the toxin to work. It has been noted in various reviews that the glabella region with the use of intradermal filler is the most common site leading to visual loss. So again it is pertinent that the anatomy of the client is well understood.
The frontalis branch of the temporal artery crosses the hollow area of the temporal area, within the temporoparietal fascia. Again, there are risks involved with injecting in this area. This includes ischemia (lack of blood supply) and blindness via anastomoses with the supraorbital and supratrochlear arteries that branch off. To avoid complications, it is advised to stay superficial within the subcutaneous fields.
Within this region, neuromodulator injections into the lateral orbicularis oculi that can treat periorbital rhytids. Injections should start below the tail of the brow proceeding inferiorly to the vertical plane of the lateral canthus. Again, the use of subdermal injections in this region will avoid paralysis of the zygomatic major, hence reducing the likelihood of a weakened ipsilateral smile.
Injections into the cheek has grown in popularity over the last year. Facial fat compartments are responsible for maintaining aesthetic facial contours and fullness. In practice, the infraorbital foramen, in theory lies around a fingerbreadth below the infraorbital rim, immediately lateral to the medial limbus. When injecting ensure the injections stay lateral to the infraorbital foramen. In the inferior two thirds of the nasolabial fold, fillers are to be injected in the superficial subcutaneous tissue or the deep dermal plane, this is so the facial artery that is located in this area is avoided. The facial artery becomes superficial superiorly, hence injectables in this region (superior third of nasolabial fold) should be injected in the deep dermal or preperiosteal plane.
Upper and lower lip injections should be less than 3 mm deep and within the vermilion cutaneous border, or the dry vermillion. To avoid injury to the facial artery, this technique and injecting proceeding in the superficial subcutaneous plane just within 1cm breadth of the angle of the mouth enable the avoidance of injury of the labial and facial arteries.
In regards to neuromodulators (Anti Wrinkle), various locations of injections exist within this region. However it is pertinent for the injector to understand the obvious relationship between the depressor labii inferioris and the depressor anguli oris. When injecting the depressor anguli oris, remaining more superficial and immediately medial to the mandibular ligament enables the avoidance of an inadvertent injection of the depressor labii inferioris which is not a desired outcome.