Nerve Blocks for Facial Injuries

The nerves that supply sensation to the areas most commonly affected
by facial trauma exit the skull along a line drawn perpendicular to the
midpoint of the pupil. These nerves, designated as V1, V2, and V3, are
branches of the fifth cranial (trigeminal) nerve.
Lidocaine and/or bupivacaine can be used for facial nerve blocks. Add
bicarbonate if it is available. Epinephrine is often a useful addition to
the anesthetic solution.
V1: Supraorbital Nerve Block
The supraorbital nerves supply sensation to the upper eyelid and overlying
forehead. A supraorbital nerve is located on each side of the face.
Anatomy. If you divide the supraorbital rim into thirds, the supraorbital
nerve exits the skull at the point where the central and medial
thirds meet.
Procedure
1. Insert the needle into the eyebrow overlying the point where the
nerve exits the skull.
2. Inject 1 ml of anesthetic solution into the superficial tissues.
3. Advance the needle downward to the bone. You will feel the needle
hitting against a hard surface when it meets the bone.
4. Back the needle 1–2 mm away from the bone, and inject another 2–3
ml of local anesthetic.


Anatomy of the trigeminal nerve branches (V1, V2, and V3). These nerves provide
sensation to the face and are amenable to nerve blocks.

V1: Supratrochlear Nerve Block
The supratrochlear nerve supplies sensation to the medial upper
eyelid, upper nose, and medial forehead.
Anatomy. The supratrochlear nerve exits the skull along the medial
aspect of the supraorbital rim just lateral to the area where the rim
meets the nose.
Procedure
1. Insert the needle into the soft tissues overlying the point where you
expect the nerve to exit the skull.
2. Inject 1 ml of anesthetic solution into the superficial tissues.
3. Advance the needle tip downward to the bone.
4. Back the needle 1–2 mm away from the bone, and inject another 1–2
ml of the solution.



Caution: For a forehead wound above the medial third of the eyebrow,
both the supraorbital nerve and supratrochlear nerve probably need to
be blocked on the side of the injury.
V2: Infraorbital Nerve Block
The infraorbital nerves supply sensation to the upper lip, cheek, lateral
aspect of the nose, and lower eyelid. There is one nerve on each side of
the face.
Anatomy. The infraorbital nerve comes out of the skull about 1⁄2 cm
below the orbital rim along the vertical line drawn perpendicular to
the midpoint of the pupil.
Procedure
1. Insert the needle into the cheek skin at the point where the vertical
line drawn perpendicular to the midpoint of the pupil meets a horizontal
line drawn from the bottom of the nose.
2. Advance the needle tip 2–3 mm into the tissues.
3. Inject 1 ml of solution.
4. Advance the needle tip further, going in a slightly superior direction
as you pass through the tissues until you hit the underlying bone.
The tip ultimately should travel superiorly about 1 cm.
5. Back the needle out 1–2 mm, and inject another 2–3 ml of the anesthetic.
V3: Mental Nerve Block
The mental nerves supply sensation to the lower lip and the skin immediately
below it. There is one mental nerve on each side of the
face.
Anatomy. The mental nerve exits from the mandible a few mm below
and 5–10 mm lateral to the inferior aspect of the lower canine tooth
root.
Procedure.
1. The mental nerve block is performed in the mouth.
2. Insert the needle into the mucosa a few mm below and 5–7 mm lateral
to the root of the lower canine tooth.
3. Advance the needle tip until it hits the bone.
4. Inject 2–3 ml of solution.
Nerve Block Overview