Subcutaneous plane: what it means in injection
Quick facts
- Definition
- Layer of fat and connective tissue just below the dermis.
- Role
- Provides volume, softness and protection, and houses vessels and nerves of varying caliber.
- Variation
- Thickness changes with the area, the patient and aging.
- Comparison
- Deeper than the intradermal plane; more superficial than the submuscular and supraperiosteal planes.
The subcutaneous plane is the layer of fat and connective tissue that lies between the dermis and the deeper structures, such as muscle and bone. The tissue has its own technical name, subcutaneous tissue, and when "subcutaneous plane" is used in injection, the term describes the depth level at which a product is deposited.
How does this plane fit into the layers of the face?
The face has successive layers, and the subcutaneous plane is the first one below the skin. Its thickness varies a lot: it is thicker in the cheeks and thinner in the eyelids and the dorsum of the nose. See layers of the face.
| Plane | Characteristic |
|---|---|
| Intradermal | Within the dermis |
| Subcutaneous | Fat under the dermis |
| Submuscular | Below the muscle |
| Supraperiosteal | On the bone |
The classification is descriptive. It helps in talking with colleagues and reading the literature, and does not replace hands-on training or assessment of the case.
What is in the subcutaneous layer?
- Fat: organized in compartments and fat pads, whose loss contributes to facial aging. See fat pads.
- Vessels: of varying caliber, from capillaries to the arterial and venous branches that run between the layers.
- Sensory nerves: cutaneous branches that carry sensation to the skin.
- Cutaneous ligaments: fibers that anchor the skin to the deep planes and delimit the fat.
Because the layer is rich in vessels, bruising and swelling are expected after injections. Most are self-limiting, but larger-caliber vessels may lie in this plane, which calls for attention.
Why does the plane matter in HOF?
The plane determines the type of effect. A product in the subcutaneous fat tends to give a softer, more diffuse filling effect, while a product in a deeper plane acts on support. The choices depend on the product, the area, the thickness of the skin and the goals. On a public page, the point is to understand the vocabulary:
- A more superficial plane raises the risk of irregularity and of the Tyndall effect.
- A deeper plane raises the importance of anatomical knowledge and vascular care.
- Thinner patients have less fat, and small changes are more visible.
Also known as: subcutaneous layer, hypodermis.
Frequently asked questions
What does injecting in the subcutaneous plane mean?
It means depositing the product in the layer of fat under the skin. It is a classification term, and the choice of plane and technique belongs to the qualified professional, after assessment.