Mandibular Anesthesia

Question 1

What are the nerves involved in mandibular anesthesia?

Answer 1

Inferior alveolar nerve
Mental nerve
Lingual nerve
Long buccal nerve

Question 2

What does the inferior alveolar nerve supply sensory innervation to?

Answer 2

The teeth and supporting structures of that particular side

Question 3

What does the mental nerve supply sensory innervation to?

Answer 3

The chin, lips, facial gingiva from the mandibular foramen anterior to the midline

Question 4

What will the lingual nerve supply sensory innervation to?

Answer 4

The lingual gingiva, anterior 2/3 of the tongue, and alveolingual sulcus

Question 5

What will the long buccal nerve provide sensory innervation to?

Answer 5

The buccal gingiva of the mandibular molars and the mucosa of the cheeks

Question 6

What is “block anesthesia”

Answer 6

Injection of the anesthetic agent in the proximity of the nerve trunk; will provide numbness from that part onward to the distal

Question 7

What is “local infiltration”

Answer 7

injection of anesthesia into a small area; the nerve endings in that isolated area are anesthetized

Question 8

What is the inferior alveolar nerve block?

Answer 8

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)

Question 9

What are the keys to a good inferior alveolar nerve block?

Answer 9

Identifying the position of the mandibular foramen in the center of the ramus
Understanding anatomic relationships of the pterygomandibular space

Question 10

What is the pterygomandibular raphe?

Answer 10

Junction of the buccinator muscle (cheek muscle) and the superior constrictor (upper part of the throat)

Question 11

Where is the pterygomandibular raphe?

Answer 11

From the tip of pterygoid hamulus to the most posterior mandibular molar

Question 12

What are the landmarks for administering an inferior alveolar nerve block?

Answer 12

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

Question 13

How do you determine the vertical level for the injection of the inferior alveolar nerve block?

Answer 13

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

Question 14

How do you identify the injection triangle?

Answer 14

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

Question 15

What is the syringe position for the inferior alveolar nerve block?

Answer 15

Syringe should be placed over the mandibular premolars on opposite side of the arch, parallel to the occlusal plane

Question 16

Where will you insert the needle for the inferior alveolar nerve block?

Answer 16

Lateral the the pterygomandibular raphe

height is determined by your thumb nail!

Question 17

What are the steps of the inferior alveolar nerve block?

Answer 17

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

Question 18

What will happen if your needle is too far lateral when you are giving the inferior alveolar nerve block?

Answer 18

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

Question 19

What will happen if you accidentally do not keep your syringe parallel to the mandibular occlusal plane and angle downward?

Answer 19

You may penetrate the medial pterygoid

Question 20

Where will the needle be if the injection is too low? What will happen?

Answer 20

Below the mandibular foramen

The sphenomandibular ligament (which is attached to the lingual and rim of foramen) will block anesthetic from the nerve

Question 21

What will happen if the needle contacts the lingual nerve or inferior alveolar nerve directly upon entry?

Answer 21

Seldom damage, but sudden sensation and rapid anesthesia

Question 22

What will a positive lip sign tell you?

Answer 22

Inferior alveolar nerve was anesthetized

Question 23

If the inferior alveolar is numb, what other nerve(s) will be numb as well?

Answer 23

Lingual nerve and mental nerve

Question 24

If the lingual nerve is numb, what other nerves will also be numb?

Answer 24

NO OTHER NERVES!! Inferior alveolar will get you lingual and mental, but lingual will NOT get you any bonus nerves

Question 25

Gow-Gates Block

Answer 25

Block injection very high in the pterygomandibular space

Question 26

What is the goal of the Gow-Gates block?

Answer 26

To hit all of the branches of V3

Question 27

What are the steps of the Gow-Gates Block?

Answer 27

1. Pt. needs to open as wide as possible
2. Needle penetrates mucosa opposite the maxillary 3rd molar
3. Syringe must be parallel to plane from the corner of the mouth to the apex of the intertragic notch
4. Needle is advanced until it contacts bone - neck of the mandible, below lat. pterygoid attachment
5. After injection, must keep mouth open for 30 seconds to keep anesthetic where you put it

Question 28

Mental nerve block

Answer 28

Anesthetizes the facial gingiva, the lip and the chin

Question 29

How do you give a mental nerve block?

Answer 29

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

Question 30

Long buccal block

Answer 30

Anesthetizes the facial gingiva over mandibular molars

Question 31

How do you give a long buccal block

Answer 31

Insert needle into mucosa just posterior and lateral to the last molar tooth

Question 32

Mylohyoid nerve block

Answer 32

Anesthetizes mylohyoid nerve

Question 33

How do you give a mylohyoid nerve block?

Answer 33

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