Local Anesthesia Techniques in Oral and Maxillofacial Surgery

بسم الله الرحمن الرحيم

Local Anesthesia Techniques in Oral and Maxillofacial Surgery



Overview:
• Purpose of local anesthesia
• Anatomy of maxillary and mandibular
nervous innervation
• Techniques of local anesthesia blocks
• Commonly used local anesthetics
• Complications with local anesthes

Local Anesthetics:
• Role:
-Decrease intraoperative and postoperative pain
– -Decrease amount of general anesthetics used
in the OR
– -Increase patients cooperation
-Diagnostic testing/examination
Anatomical considerations:
• Trigeminal nerve:
– Sensory divisions:
• Ophthalmic division V1
• Maxillary division V2
• Mandibular division V3

Motor division:
• Masticatory masseter, temporalis, medial and lateral pterygoids
• Mylohyoid
• Anterior belly of the digastric
• Tensor tympani
• Tensor veli palatine


Maxillary Division (V2):
• Exits the cranium via foramen rotundum of the
greater wing of the sphenoid
• Travels at the superior most aspect of the
pterygopalatine fossa just posterior to the
maxilla
• Branches divided by location:
–j kjInter-cranial
– Pterygopalatine
Infraorbital
– Facial

• Branches:
– Within the cranium -middle meningeal nerve
providing sensory innervation to the dura
mater
– Within the pterygopalatine fossa
• Zygomatic nerve
• Pterygopalatine nerves
• Posterior superior alveolar nerve
• Within the pterygopalatine fossa
Zygomatic nerve:
• Zygomaticofacial nerve-skin to cheek prominence
• Zygomaticotemporal nerve-skin to lateral forehead
Pterygopalatine nerves:
• Serves as communication for the pterygopalatine
ganglion and the maxillary nerve
• Carries postganglionic secretomotor fibers through
the zygomatic branch to the lacrimal gland



• Within the pterygopalatine fossa fossa-
– Pterygopalatine nerves:
• Palatine branches branches- greater (anterior) and lesser
(middle or posterior) palatine nerves
– Greater palatine: travels through the pterygopalatine
canal and enters the palate via the greater palatine
foramen. Innervates palatal tissue from premolars to
soft palate. Lies 1cm medial from 2 2nd nd molar region
– Lesser palatine: emerges from lesser palatine foramen
and innervates the mucous membranes of the soft palate
and parts of the tonsillar region


• Within the pterygopalatine fossa fossa-
– Pterygopalatine nerves:
• Pharyngeal branch branch- exits the pterygopalatine
ganglion and travels through the pharyngeal canal.
Innervates mucosa of the portions of the nasal
pharynx
• Posterior superior alveolar nerve (PSA): branches
from V2 prior to entrance into infraorbital groove.
Innervates posterior maxillary alveolus, periodontal
ligament, buccal gingiva, and pulpal tissue (only
for 1 1st st, 2 , 2nd nd, and 3 , 3rd rd molars)



• Infraorbital canal branches:
– Middle superior alveolar (MSA):
• Provides innervation to the maxillary alveolus,
buccal gingiva, periodontal ligament, and pulpal
tissue for the premolars only
– Anterior superior alveolar (ASA):
• Provides innervation to the maxillary alveolus,
buccal gingiva, periodontal ligament, and pulpal
tissue for the canines, lateral and central incisors
• Branches 6 6-8mm posterior to the infraorbital nerve
exit from infraorbital foramen

• Facial branches:
– Emerges from the infraorbital foramen
– Branches consist of:
• Inferior palpebral palpebral- lower eyelid
• External nasal nasal- lateral skin of nose
• Superior labial branch branch- upper lip skin and mucosa


• Facial branches:
– Emerges from the infraorbital foramen
– Branches consist of:
• Inferior palpebral palpebral- lower eyelid
• External nasal nasal- lateral skin of nose
• Superior labial branch branch- upper lip skin and mucosa



Mandibular division (V3):
• Branches:
– The sensory and motor roots emerge from
the foramen ovale of the greater wing of the
sphenoid
– Initially merge outside of the skull and divide
about 2 2-3mm inferiorly
– Branches:
• Branches of the undivided nerve
• Branches of the anterior division
• Branches of the posterior division

• Branches of the undivided nerve:
– Nervus spinosus spinosus- innervates mastoids and
dura
– Medial pterygoid pterygoid- innervates medial pterygoid
muscle
• Branches into
– Tensor veli palatini
– Tensor tympani


• Branches of the anterior division:
– Buccal nerve (long buccal and buccinator):
• Travels anteriorly and lateral to the lateral
pterygoid muscle
• Gives branches to the deep temporal (temporalis
muscle), masseter, and lateral pterygoid muscle

• Branches of the anterior division:
– Buccal nerve (long buccal and buccinator):
• Continues to travel in antero antero-lateral direction
• At level of the mandibular 3 3rd rd molar, branches exit
through the buccinator and provide innervation to
the skin of the cheek
• Branches also stay within the retromandibular
triangle providing sensory innervation to the buccal
gingiva of the mandibular molars and buccal
vestibule


• Branches of the posterior division:
– Travels inferior and medial to the lateral
pterygoid
• Divisions:
– Auriculotemporal
– Lingual
– Inferior alveolar

• Branches of the posterior division:
– Auriculotemporal: all sensory
• Transverses the upper part of the parotid gland
and posterior portion of the zygomatic arch
• Branches:
– Communicates with facial nerve to provide sensory
innervation to the skin over areas of the zygomatic,
buccal, and mandibular
– Communicates with the otic ganglion for sensory,
secretory, and vasomotor fibers to the parotid
• Branches of the posterior division:
– Auriculotemporal: all sensory
• Branches:
– Anterior auricular auricular- skin over helix and tragus
– External auditory meatus meatus- skin over meatus and
tympanic membrane
– Articular Articular- posterior TMJ
– Superficial temporal temporal- skin over temporal region

• Branches of the posterior division:
– Lingual:
• Lies between ramus and medial pterygoid within
the pterygomandibular raphe
• Lies inferior and medial to the mandibular 3 3rd rd
molar alveolus
• Provides sensation to anterior 2/3rds of tongue,
lingual gingiva, floor of mouth mucosa, and
gustation (chorda tympani)

• Branches of the posterior division:
– Inferior alveolar:
• Travels medial to the lateral pterygoid and latero latero-
posterior to the lingual nerve
• Enters mandible at the lingula
• Accompanied by the inferior alveolar artery and
vein (artery anterior to nerve)
• Travels within the inferior alveolar canal until the
mental foramen
• Mylohyoid nerve nerve- motor branch prior to entry into
Lingual

• Branches of the posterior division:
– Inferior alveolar:
• Provides innervation to the mandibular alveolus,
buccal gingiva from premolar teeth anteriorly anteriorly, and
, the pulpal tissue of all mandibular teeth on side
blocked
• Terminal branches
– Incisive nerve nerve- remains within inferior alveolar canal
from mental foramen to midline
– Mental nerve nerve- exits mental foramen and divides into 3
branches to innervate the skin of the chin, lower lip and
labial mucosa


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