Press Room

Local infiltration anaesthesia is commonly used in facial dermatological surgeries and cosmetic procedures. However, repeated injections at multiple points can cause swelling and tissue deformation in the surgical area, which may affect excision, suturing, and delicate cosmetic procedures. Nerve blocks, on the other hand, can anaesthetise a larger area with less anaesthetic while minimising morphological disturbances in the surgical area.

The most common facial nerve blocks target the branches of the trigeminal nerve. Today, we will look at the supraorbital/supratrochlear, infraorbital and mental nerve blocks. Which areas are suitable for these blocks? How do you locate the injection points? What risks need to be avoided during the procedure? Let’s take a look!

01. Suitable Scenarios

Facial nerve blocks can be used in various dermatological surgeries and cosmetic procedures. These include: – excision of large-area facial skin tumours
– skin resurfacing and peeling procedures (full face or localised areas).
– Lip fillers
– Large-area facial photodynamic therapy
– Fine-tuning procedures that require minimal swelling and morphological disturbance.
Facial nerve blocks are not intended to replace all local infiltration anaesthesia. Rather, they are designed to provide a larger anaesthetic area with less local anaesthetic in specific regions and procedures, while minimising surgical deformation and improving patient comfort.

02. General Operating Pprinciples

Facial nerve blocks usually involve the use of a 1-inch, 30-gauge needle to inject local anaesthetic around the target nerve trunk. As the needle is usually inserted to a greater depth than is required for standard local infiltration anaesthesia, aspiration should be performed prior to injection to confirm the level of anaesthetic and avoid intravascular injection.
Key points of operation:
– Each block usually requires 1–3 ml of local anaesthetic.
– Onset time is approximately 5–10 minutes.
– Larger diameter nerves may require a longer onset time.
– Inject slowly to reduce injection pain.
– Before the procedure begins, perform a needle prick test to confirm the adequacy of the anaesthetised area. If the block is incomplete, wait for it to take effect. If the target area is still not covered, consider repeating the block or supplementing with local infiltration anaesthesia.

03. Aesthetic Selection

Amide-based local anaesthetics are most commonly used for regional nerve blocks.
Common choices include: 1% lidocaine: It has a reliable onset of action, and when used alone for nerve blocks, its duration of action is approximately 75 minutes. Adding 1:200,000 epinephrine can prolong the duration of anaesthesia.
0.25% bupivacaine: It has an even longer duration of action, but this is not necessary for most routine facial procedures. For routine facial dermatology procedures, 1% lidocaine is sufficient. Whether to add epinephrine depends on the procedure site, haemostasis requirements, and clinical needs.

04. Pain Reduction Techniques

Although nerve blocks involve fewer injection points, they are not completely painless. Distracting the patient during the procedure, for example by gently pinching, vibrating or massaging the injection area, can reduce discomfort.

The supraorbital and supratrochlear nerves are both associated with the ophthalmic branch of the trigeminal nerve, and they primarily innervate the forehead, scalp, and upper eyelid on the same side of the face. Blocking these two nerves is useful for procedures relating to these areas.
Dosage: Approximately 2–4 ml of local anaesthetic.
Location: The supraorbital notch or foramen is palpable in most patients and is located approximately 27 mm lateral to the midline between the eyebrows.
Procedure: Insert the needle into the central region of the eyebrow to complete the supraorbital nerve block (see Figure 2a). Then, continue to advance the needle tip medially towards the eyebrow to block the supratrochlear nerve (see Figure 2b).
In some cases, this block may also affect the infratrochlear nerve region, thus covering the medial upper eyelid, the root of the nose, the nasal bridge and the upper lateral nasal region.

The infraorbital nerve is an important branch of the maxillary nerve and is commonly targeted in facial dermatological surgeries and cosmetic procedures. Applicable areas include the lower eyelid, lateral nasal wall, nasal alae, inner cheek, upper lip, columella, and anterior nasal mucosa.

1). Intraoral approach
This approach generally provides greater comfort and is more likely to result in a stable block.
Dosage: 2 ml of local anaesthetic.
Procedure: First, apply a topical anaesthetic gel to the gingival sulcus near the root of the canine tooth for one to five minutes. Then, position your non-dominant index finger at the infraorbital foramen to use as a target for needle insertion. Next, insert the needle into the gingival sulcus of the second-third interdental space, lateral to the midline, and advance it towards the infraorbital foramen (see Figure 3a). Repeat the needle insertion through the third–fourth interdental space to achieve a more complete block (see Figure 3b). If necessary, administer an additional 0.5 ml of local anaesthetic to the upper lip frenulum area to anaesthetise the upper lip (see Figure 3c).

2). Percutaneous approach
This approach involves gaining direct access to the infraorbital foramen through the facial skin.
Dosage: 2 ml of local anaesthetic.
Procedure: Insert the needle vertically approximately 1 cm below the infraorbital margin and at the midpoint of the pupil (see Figure 4a). Once the tip of the needle touches the bone, withdraw it slightly and inject the local anaesthetic. If necessary, supplement with an additional 1–2 ml of local anaesthetic both medially and inferiorly (see Figure 4b) and laterally and inferiorly (see Figure 4c) to cover the main branches of the infraorbital nerve.

The mental nerve is a terminal branch of the mandibular nerve. Blocking it can anaesthetise the skin and mucous membranes of the chin and lower lip area. This technique can be used for various procedures, including skin surgery on the lower lip, treatment of lower lip or chin lesions, and cosmetic procedures such as lip augmentation.

1). Intraoral approach

This approach generally provides more comfort and makes it easier to achieve an adequate block.
Procedure: First, apply topical anaesthetic gel to the gingival sulcus near the root of the canine for one to five minutes. Then, insert the needle into the sulcus through the third–fourth interdental space, lateral to the midline, and advance towards the mental foramen (see Figure 5a). For a more complete block, repeat the needle insertion through the fourth-fifth interdental space (Figure 5b). If necessary, supplement with 0.5 ml of local anaesthetic in the area of the lower lip frenulum to anaesthetise the lower lip (Figure 5c).

2). Percutaneous approach

This approach enables a nerve block to be performed via the mental foramen, which is located on the body’s surface.
Dosage: 2 ml of local anaesthetic.
Procedure: Insert the needle vertically near the midline of the pupil, approximately 1 cm above the lower border of the mandible (see Figure 6a). Once the tip of the needle has touched the bone, withdraw the needle slightly and inject the local anaesthetic. If necessary, supplement with an additional 1–2 ml of local anaesthetic, injected upwards and inwards (see Figure 6b), as well as downwards and inwards (see Figure 6c), to cover the main branches of the mental nerve.

Although complications from facial nerve blocks are rare and usually reversible, caution must still be exercised during the procedure to prevent vascular injury, nerve damage, and loss of blood clotting ability in the surgical area.
1. Do not continue if radiating pain occurs.
If this occurs suddenly during needle insertion, it indicates that the needle tip may be in direct contact with a nerve.
In this case, withdraw the needle and readjust its direction. Do not administer any more local anaesthetic. Accidentally injecting local anaesthetic into nerve fibres can cause significant pain or prolonged numbness.
2. A nerve block is not equivalent to haemostatic anaesthesia.
Unlike local infiltration anaesthesia, nerve blocks do not act directly on the surgical area and cannot provide the same level of local vasoconstriction.
Therefore, additional local infiltration anaesthesia containing epinephrine may still be necessary in the surgical area during dermatological surgical procedures requiring bleeding control.
3. It cannot replace all local infiltration anaesthesia.
Facial nerve blocks are suitable for areas with relatively well-defined nerve innervation, such as the forehead, midface, upper lip, lower lip, and chin.
However, for procedures involving a limited area with irregular boundaries that require precise haemostasis or supplemental local anaesthesia, local infiltration anaesthesia remains valuable. Depending on the location of the procedure and the specific surgical approach required, it is more reasonable to combine nerve block with local infiltration anaesthesia.