Mandibular Anesthesia Flashcards
What are the nerves involved in mandibular anesthesia?
Inferior alveolar nerve
Mental nerve
Lingual nerve
Long buccal nerve
What does the inferior alveolar nerve supply sensory innervation to?
The teeth and supporting structures of that particular side
What does the mental nerve supply sensory innervation to?
The chin, lips, facial gingiva from the mandibular foramen anterior to the midline
What will the lingual nerve supply sensory innervation to?
The lingual gingiva, anterior 2/3 of the tongue, and alveolingual sulcus
What will the long buccal nerve provide sensory innervation to?
The buccal gingiva of the mandibular molars and the mucosa of the cheeks
What is “block anesthesia”
Injection of the anesthetic agent in the proximity of the nerve trunk; will provide numbness from that part onward to the distal
What is “local infiltration”
injection of anesthesia into a small area; the nerve endings in that isolated area are anesthetized
What is the inferior alveolar nerve block?
This is the mandibular nerve block
It anesthetizes the inferior alveolar nerve, teeth, and supporting structures
BONUS: it will anesthetize the mental nerve, which is a branch of the inferior alveolar nerve (lip, chin, facial gingiva) and the lingual nerve, which is in close proximity to the inferior alveolar nerve (tongue and lingual gingiva)
What are the keys to a good inferior alveolar nerve block?
Identifying the position of the mandibular foramen in the center of the ramus
Understanding anatomic relationships of the pterygomandibular space
What is the pterygomandibular raphe?
Junction of the buccinator muscle (cheek muscle) and the superior constrictor (upper part of the throat)
Where is the pterygomandibular raphe?
From the tip of pterygoid hamulus to the most posterior mandibular molar
What are the landmarks for administering an inferior alveolar nerve block?
Gauge the width of the ramus by putting your thumb in the coronoid notch and the index finger on the posterior border of the ramus
How do you determine the vertical level for the injection of the inferior alveolar nerve block?
Using thumb position, bisect the thumbnail (higher for woman operator)
A class III foramen will be relatively higher (this person will have an underbite and therefore more forward growth than vertical)
For children, the foramen is lower and more posterior
Key: air to the HIGH side especially if you have small fingers
How do you identify the injection triangle?
Identify the anterior border of the ramus and the pterygomandibular raphe. When the patient opens very wide, the pterygomandibular raphe will be pulled very taught and create a fold
What is the syringe position for the inferior alveolar nerve block?
Syringe should be placed over the mandibular premolars on opposite side of the arch, parallel to the occlusal plane
Where will you insert the needle for the inferior alveolar nerve block?
Lateral the the pterygomandibular raphe
height is determined by your thumb nail!
What are the steps of the inferior alveolar nerve block?
Barrel of the syringe should be parallel to the occlusal plane of the mandibular teeth and over the contralateral premolars
Pierce the mucosa and buccinator muscle, then advance the needle between the temporalis tendon and medial pterygoid muscle
With the needle in the pterygomandibular space, continue until the needle contacts bone, back off slightly, aspirate, and inject
What will happen if your needle is too far lateral when you are giving the inferior alveolar nerve block?
you will contact bone - the temporal crest - right away
to compensate, withdraw slightly, swing barrel of syringe to lie over the teeth of the same side, and advance the needle far enough to clear the bone
THEN move syringe barrel back to the opposite premolar area and advance until bony contact and proceed
What will happen if you accidentally do not keep your syringe parallel to the mandibular occlusal plane and angle downward?
You may penetrate the medial pterygoid
Where will the needle be if the injection is too low? What will happen?
Below the mandibular foramen
The sphenomandibular ligament (which is attached to the lingual and rim of foramen) will block anesthetic from the nerve
What will happen if the needle contacts the lingual nerve or inferior alveolar nerve directly upon entry?
Seldom damage, but sudden sensation and rapid anesthesia
What will a positive lip sign tell you?
Inferior alveolar nerve was anesthetized
If the inferior alveolar is numb, what other nerve(s) will be numb as well?
Lingual nerve and mental nerve
If the lingual nerve is numb, what other nerves will also be numb?
NO OTHER NERVES!! Inferior alveolar will get you lingual and mental, but lingual will NOT get you any bonus nerves
Gow-Gates Block
Block injection very high in the pterygomandibular space
What is the goal of the Gow-Gates block?
To hit all of the branches of V3
What are the steps of the Gow-Gates Block?
- Pt. needs to open as wide as possible
- Needle penetrates mucosa opposite the maxillary 3rd molar
- Syringe must be parallel to plane from the corner of the mouth to the apex of the intertragic notch
- Needle is advanced until it contacts bone - neck of the mandible, below lat. pterygoid attachment
- After injection, must keep mouth open for 30 seconds to keep anesthetic where you put it
Mental nerve block
Anesthetizes the facial gingiva, the lip and the chin
How do you give a mental nerve block?
Locate the mental foramen on an x-ray and by palpation (also line up with supraorbital and infraorbital notches and pupil of eye
Insert needle into mucosa to approximate level of foramen and inject
If you want to anesthetize anterior teeth, also the tip of the needle must get into the foramen
Orient syringe downward and anterior, penetrate mucosa and gently probe the bone with needle until the needle passes into the foramen
As you inject, finger pressure over the foramen will direct anesthetic into foramen
Long buccal block
Anesthetizes the facial gingiva over mandibular molars
How do you give a long buccal block
Insert needle into mucosa just posterior and lateral to the last molar tooth
Mylohyoid nerve block
Anesthetizes mylohyoid nerve
How do you give a mylohyoid nerve block?
Aim the needle into the lingual mucosa toward the level of the apex of the mandibular teeth, one tooth behind the tooth that you are working on. MUST penetrate the mylohyoid muscle.
Nerve is INFERIOR to the mylohyoid muscle - needle has to be on the deep side of the muscle
