Transcript WILDERNESS AND MOUNTAIN MEDICINE

FACIAL BLOCKS
N NDEBELE
28 JAN 2009
ANATOMY OF THE TRIGEMINAL
NERVE
• Is the largest of all the cranial nerves and is mixed i.e
contains both sensory and motor fibers.
• Larger sensory root originates in the anterior aspect of
the pons.
• It has 3 major branches:
1. Ophthalmic division (V1)
2. Maxillary division (V2)
3. Mandibular division ( V3).
The sensory fibers are distributed mainly to the skin of the
face and
the motor fibers supply muscles of mastication (masseter,
temporalis, medial and lateral pterygoid), mylohyoid,
anterior belly of the digastric, tensor velipalatini and
tensor tympani muscles.
ANATOMY CONT….
•
•
•
•
•
•
•
OPHTHALMIC NERVE (V1)
Is the smallest of the 3 divisions and is purely sensory.
It divides into 3 branches: Frontal
Nasocilliary and
Lacrimal nerves
1. Frontal Nerve
It runs beneath the roof of the orbit and divides into Supratrochlear
(smaller and more medial) and Supraorbital (larger and lateral)
nerves.
• The Supratrochlear supplies the skin and conjuctiva of the medial
portion of the upper eyelid and the skin over the lower forehead
close to the midline.
• Supra orbital supplies the skin and the conjuctiva of the central
portion of the upper eyelid, the skin of the forehead and
ANATOMY CONT……
• the scalp as farback as the vertex
•
.
ANATOMY CONT…….
2. NASOCILLIARY NERVE
• It runs forward on the medial wall of the orbit, continues
as the anterior ethmoidal nerve through the anterior
ethmoidal foramen. It then descends to enter the nasal
cavity where it gives off two internal nasal branches and
then continues as the external nasal nerve which supply
the skin at the apex and the ala of the nose and the
eyeball as well.
ANATOMY CONT..
3. Lacrimal Nerve
Is the smallest of the ophthalmic division and it runs along the lateral
wall of the orbit into the lacrimal gland.
It is distributed to the conjuctiva and the skin of the lateral portion of the
upper eyelid.
MAXILLARY DIVISION (V2)
• Is also purely sensory
• Originates from the trigeminal ganglion. It gives off Middle
Meningeal Nerve within the cranium.
• It later enters the space located behind and below the orbital cavity
known as pterygopalatine fossa to enter the orbit through the inferior
orbital fissure.
• It then continues as the infraorbital nerve in the inferior orbital
groove giving sensory fibers to the the skin of the face, side of the
nose and the upper gum.
ANATOMY CONT…..
Other branches of the Maxillary Nerve are:
1) Zygomatic Branch
Passes through the inferior orbital fissure and divides into
Zygomaticofacial and Zygomaticotemporal nerves supplying the skin
over the prominence of the cheeck and the skin over temple
respectively
2) Meningeal Branches
3) Ganglionic Branches
4) Posterior Superior Alveolar Nerve
5) Middle Superior Alveolar Nerve
6) Anterior Superior Alveolar Nerve
ANATOMY CONT…..
• MANDIBULAR NERVE(V3)
• Is the largest branch of the trigeminal and is both
sensory and motor.
• Sensory root arises from the trigeminal ganglion
and the motor root is from the motor nucleus of
the pons and the medulla oblongata. They both
leave the skull through foramen ovale. The
nerve trunk then divides into a small anterior
division and a large posterior division.
ANATOMY CONT…
• Branches from the posterior division include:
• 1) Auriculotemporal nerve which ascends behind the
temperomandibular joint medial to the parotid gland. It
supplies the skin of the auricle, the external auditory
meatus, the temperomandibular joint and the scalp.
• 2)Lingual nerve which enters the mouth to pass along
the side of the tongue to reach its tip. It supplies the
mucous membrane and the anterior two thirds of the
tongue and the floor of the mouth.
• 3) Inferior alveolar nerve which supply the teeth of the
lower jaw and end by dividing into incisive and mental
branch.
ANATOMY CONT…
• Branches of the main anterior trunk
include:
• 1) Meningeal branch
• 2) Nerve to the medial pterygoid muscle.
FACIAL BLOCK-TECHNIQUES