The greater palatine nerve block is useful for anesthetizing the palatal soft tissues distal to the canine. It is less traumatic than the nasopalatine nerve block because the palatal tissue in the area of the injection site is not as anchored to the underlying bone. It is indicated when palatal soft tissue anesthesia is necessary for restorative treatment on more than two teeth (insertion of subgingival matrix bands) and periodontal and oral surgery. It is contraindicated when there is infection or inflammation in the area of the injection site.
- A 25 or 27 gauge short needle may be used.
- Locate the greater palatine foramen.
- Place a cotton swab at the junction of the hard palate and the maxillary alveolar process.
- Starting in the region of the maxillary first molar (or second primary molar in the primary dentition) apply pressure with the cotton swab while moving posteriorly.
- The swab will fall into the depression created by the greater palatine foramen.
- Prepare the tissue at the injection site, 1–2mm anterior to the greater palatine foramen.
- Clean and dry the area with a sterile gauze.
- Apply topical anesthetic with a cotton applicator for two minutes.
- Move the cotton applicator posteriorly so it is directly over the greater palatine foramen and apply sufficient pressure to blanch the tissue for 30 seconds.
- Direct the syringe into the mouth from the opposite side of the mouth from the injection site at a right angle to the target area with orientation of the needle bevel toward the palatal soft tissue.
- Place the bevel of needle gently against the blanched tissue and apply enough pressure to slightly bow the needle.
- Deposit a small volume of anesthetic.
- Straighten the needle and allow the needle to penetrate the mucosa, while depositing a small amount of anesthetic solution.
- Slowly advance the needle approximately 8mm until palatine bone is contacted.
- Withdraw 1mm and aspirate.
- If negative, inject ¼ cartridge of anesthetic solution over 30 seconds.
- Withdraw the needle and recap.
- Wait 2-3 minutes before commencing treatment.
Palatal anesthesia in the area of the first premolar may be inadequate due to overlapping fibers from the nasopalatine nerve. To correct this it may be necessary to supplement the anesthesia with local infiltration.