The Palatal Anterior
The P-ASA is another
modified injection for the anterior maxilla. It will allow the operator to
achieve bilateral anesthesia of the maxillary incisors and usually the canines
from a single needle penetration. In addition to pulpal anesthesia, profound
palatal anesthesia of the gingiva and mucoperiosteum as well as moderate
anesthesia of the facial gingiva associated with the teeth is achieved. The
recommended dosage is from 3/4 to 1 cartridge of anesthetic with the expected
duration of anesthesia of approximately 60 minutes. Of significant benefit is
that the lips, face and muscles of expression are not anesthetized with the
P-ASA. This results in greater patient comfort operatively and post
operatively. In addition, esthetic smile-line assessments are not hampered by
facial distortion associated with traditional mucobuccal fold injections in
this region.
The P-ASA is easily administered, requiring
from 2 - 4 minutes to complete.
Anesthesia is achieved within approximately 2 minutes of injection. The
patient should be prepared for the extra time required to administer the P-ASA
and advised they will likely experience only a minor sensation during the
injection. They will appreciate the lack of numbness to the face and lips.
A 30 gauge extra-short needle is
recommended. It is inserted adjacent to
the incisive papilla. If desired, topical anesthetic may be applied. The needle
bevel is initially oriented as parallel to the palatal tissue as possible. A sterile cotton tip applicator is employed
to apply pressure on the needle to “seal” the bevel to the tissue for the
“pre-puncture” phase of the insertion. (see pre-puncture section) The foot
control is depressed slightly to activate the slow flow rate for 8 - 10 beeps
prior to slow needle insertion. The cotton tip will help catch any anesthetic
drips that occur before the bevel is completely within the tissue. The needle
movements are extremely slow and gentle during penetration while the slow flow
rate is maintained. After penetration into the papilla, insertion is continued
until significant blanching of the papilla is observed. The needle is then
reoriented to gain entrance into the nasopalatine canal and advanced very
slowly
no more than 1 cm (approximately the depth of
a 1/2”needle). Maintain contact on bony
wall of the canal and then aspirate. Deliver the required dosage of 3/4 to 1cartridge. Significant blanching of the palate tissue and often the facial
tissue will be observed (with anesthetics containing vasopressor). Care should
be taken upon needle removal to reduce anesthetic solution dripping down the
palate. Do not advance the needle beyond 1/2” (1 cm) since the floor of the
nose can be penetrated which may lead to an infection.
Note:
It is critical that only the slow rate be used for this injection. Using the fast rate of flow may cause
excessive ischemia and tissue damage. It is recommended that anesthetic
containing vasopressor concentration of 1:100,000 or 1:200,000 be used. Caution should be exercised with 1:50,000
concentration of vasopressor. Excessive ischemia can result in soft tissue
damage.
[1] Friedman MJ,
[2] Dosage requirement for adequate anesthesia and duration may vary from one patient to another.
REVIEW
OF THE P-ASA INJECTION TECHNIQUE
1.
Prepare the patient for a slow
injection experience.
2.
Place topical anesthetic on the
incisive papilla if desired.
3. Orient a 30 gauge extra-short needle in
the groove just lateral to the incisive papilla.
4. Use a sterile cotton tip applicator for
the pre-puncture technique.
5. Initiate the slow flow rate and
maintain this rate throughout the injection.
6. After 8 - 10 beeps initiate axial
rotation and VERY SLOW forward movement but
continue slow flow rate.
7. Once the needle bevel enters below the
papilla, pause movement for 5 - 6 seconds.
8. After papilla is blanched, re-orient
the needle vertically to gain entrance to the nasopalatine
canal with slow axial rotation.
9. When the needle is in the canal and
contacting the inner bony wall, stop movement
and aspirate. DO NOT EXCEED 1 cm (length of 1/2” needle) penetration into
the canal.
10. If aspiration is negative, maintain
position and deliver 3/4-1 cartridge of nesthetic at the slow rate.
11. Cruise control can be activated if
desired.
12. Remove needle slowly to avoid excess
dripping into the mouth.