Chapter 13 - Palatal Injections

Question 1

1. For a nasopalatine NB the deposition site is:

a. Within the nasopalatine canal.
b. Near the wall of the incisive canal
c. Anterior to the opening of the anterior palaatine foramen.
d. Near the junction between the vertical alveolar process and the horizontal palatal process.

Answer 1

b. Near the wall of the incisive canal

Question 2

2. The most common cause of failure for palatal injection technique is:

a. Depositing too far from the associated bone or foramen.
b. Inadequate volumes are deposited
c. B only
d. Both A and B.

Answer 2

d. Both A and B.

Question 3

3. AMSA technique can provide anesthesia for which one of the following groups of injections?

a. ASA, MSA, PSA, NP, GP
b. ASA, MSA, NP, GP
c. PSA & GP
d. NP and MSA

Answer 3

b. ASA, MSA, NP, GP

Question 4

4. NP nerve blocks ….

a. … have the highest rate of positive aspiration in the palate
b. … have the second-highest rate of positive aspiration in the palate
c. … provide more durable anesthesia compared with other palatal techniques.
d. … provide bilateral anesthesia

Answer 4

d. … provide bilateral anesthesia

Question 5

5. Important consideration in all palatal LA procedures?

a. always apply topical for 1 to 2 minutes
b. always administer solutions slowly
c. always use patch anesthetics

Answer 5

b. always administer solutions slowly

b = best answer (applying topical for 1-2 minutes is typical of many injections, whereas slow deposition is crucial to avoid damage to tissue, reduce pain, and enhance safety

Question 6

6. AMSA nerve blocks provide bilateral anesthesia of palatal tissues at least 20% of the time.

a. True
b. False

Answer 6

b. False; provides injected side anesthesia only

Question 7

Q13-1: When is the nasopalatine nerve block indicated for pain management?

Answer 7

A13-1: Nasopalatine nerve blocks are indicated for pain management for palatal soft and osseous tissue in the anterior third of the palate, approximately from canine to canine.

Question 8

Q13-2: Describe the needle pathway and deposition site for the nasopalatine nerve block.

Answer 8

A13-2: The needle advances under the incisive papilla through dense mucosal tissues to contact the opposite wall of the incisive canal near its entrance. The deposition site is near the center of the incisive canal.

Question 9

Q13-3: Describe the two step method of pre-anesthesia.

Question 10

Q13-4: Explain the Gate Control Theory of Pain Perception related to the use of pressure anesthesia.

Answer 10

A13-4: The Gate Control Theory of Pain Perception states that there are certain locations or gates within the spinal nervous system. When flooded with impulses from less painful stimuli, impulses generated from more painful and subsequent stimuli, such as needle penetrations, can be blocked.

Question 11

Q13-5: Explain the rate and volume of deposition of local anesthetic solution for a nasopalatine nerve block.

Answer 11

A13-5:
- to avoid discomfort, the rate of deposition should be reduced to 0.4 mL over 40 seconds, i.e. palatal rate of 1.8mL / 3 min (vs. standard injection rate of 1.8 mL/1 min or 0.4 mL/13 to 14 seconds).

• In addition to providing increased comfort, slow rates also avoid unnecessary tissue trauma.

Question 12

Q13-6: Although a nasopalatine nerve block was administered correctly with bone contacted on the opposite wall of the incisive canal, and 0.4 mL of anesthetic solution was administered, complete anesthesia was not achieved. Give possible reasons why failure occurred.

Answer 12

A13-6:
Given correct administration, possible causes of failure include:
- inflammation or infection in the area of deposition
- inadequate diffusion of solution
- overlapping innervations by the greater palatine nerve

Question 13

WE DID NOT STUDY P-ASA & M-ASA
Q13-7: When is a palatal anterior superior alveolar (P-ASA) nerve block indicated for pain management?

Answer 13

A13-7: The P-ASA nerve block is indicated for pain management of maxillary anterior sextants and is especially useful for cosmetic procedures that involve assessment of the patient’s “smile-line” and when public speaking is anticipated after appointments, because P-ASA nerve blocks do not usually result in labial numbness or motor disturbances.

Question 14

WE DID NOT STUDY P-ASA & AMSA

Q13-8: What are the penetration and deposition sites and the depth of penetration for P-ASA nerve blocks?

Answer 14

A13-8: The optimum site of penetration for the P-ASA is the palatal mucosa lateral to the widest anteroposterior dimension of the incisive papilla. The deposition site is within the nasopalatine canal at a penetration depth of 6–10 mm.

Question 15

WE DID NOT STUDY P-ASA
Q13-9: What is a typical volume of anesthetic solution for P-ASA nerve blocks?

Answer 15

A13-9: Deposit a minimum of 1.4 mL of anesthetic solution for a P-ASA nerve block.

Question 16

WE DID NOT STUDY P-ASA & AMSA

Q13-10: What are two significant benefits of the anterior middle superior alveolar (AMSA) nerve blocks?

Answer 16

A13-10:
1. reduces the number of injections (replaces ASA, IO, MSA, NP, and GP approaches)
2. lack of labial anesthesia in AMSA blocks allow for normal patterns of speech and facial expression.

Question 17

WE DID NOT STUDY P-ASA & AMSA
Q13-11: Describe the penetration site for the AMSA nerve block.

Answer 17

A13-11:
- between the premolars ~ halfway along an imaginary line drawn from the median palatine raphe to the gingival margin on the side to be anesthetized
- i.e., junction b/w vertical & horizontal aspects of the palate directly above free gingival margin between maxillary premolars on the side to be anesthetized.

Question 18

WE DID NOT STUDY P-ASA & AMSA
Q13-12: How is the AMSA nerve block modified when excessive tissue blanching and bulging occur when depositing anesthetic solution?

Answer 18

A13-12:
- If either excessive tissue blanching or bulging occurs, continue with the deposition only after pausing to allow for diffusion and absorption of the solution from areas of swelling and after a return to normal coloration from a stark white appearance when there is excessive blanching.
- This reduces tissue injury from stretching and allows normal blood flow to return to the area. In either instance, when deposition resumes, the rate should be slowed from the previous rate (less than 1.8 mL per 3 minutes for 2% or 3% drugs).

Question 19

Q13-13: Describe the field of anesthesia for the greater palatine nerve block.

Answer 19

A13-13:
- structures innervated by the greater palatine nerve and its terminal branches
- includes the posterior portion of the hard palate and its overlying soft tissues, anteriorly as far as the first premolar and medially to the midline.

Question 20

Q13-14: Describe the location of the greater palatine foramen.

Answer 20

A13-14:
- location is variable; usually palatal to the apices of 2nd & 3rd max. molars, depending on size & age of patient.
- may be more posterior than commonly expected
- in children, often anterior to typical adult locations, close to the second primary molar.

Question 21

Q13-15: What is the angle of insertion for a greater palatine nerve block?

Answer 21

A13-15: The angle of insertion is perpendicular to the palatal bone at the foramen, with the syringe barrel near the lower lip.

Question 22

Q13-16: Discuss common causes of inadequate anesthesia for GP nerve blocks.

Answer 22

A13-16:
- deposition too shallow/ lateral/ too medial to foramen
- inadequate volumes of solution
- inflammation or infection

Question 23

Q13-17: Discuss benefits of using computer-controlled local anesthetic devices (CCLADs) for palatal injections.

Answer 23

A13-17: CCLADs are ideal for palatal injections because they provide electronically regulated, slow rates of injection recommended for all palatal techniques and accomplish this without causing hand fatigue.

Question 24

Q13-18: Discuss the use of 4% local anesthetic drugs for palatal injections.

Answer 24

A13-18:
- If admin 4% solutions in the palate, max volume delivered should be reduced to half of normal deposit
- A 4% solution should be administered no faster than half the rate of any 2% or 3% solution

–> This means that a maximum of 1/2 cartridge of 4% articaine should be administered no faster than full cartridge of 2% lidocaine (3 minutes)
in the palate, regardless of the technique.