Anterior or Greater Palatine Nerve Block – Local Anesthesia Technique

Anterior or Greater Palatine Nerve Block: Used to block the Anterior palatine nerve.

As the name suggests it blocks the Anterior Palatine Nerve Block, the nerve is anesthetized as it exists the Greater Palatine Foramen which is located on the hard palate on the posterior portion. Let us look in detail about How to give Anterior Palatine Nerve Block and what are the symptoms and complications seen in it

Anatomical land marks for Anterior Palatine Nerve Block:

• Second and Third maxillary molars
• Gingival margin of second and third maxillary molars on palatal side
• Mid line of Palate 
• A point 1 cm away from the palatal Gingival margin toward the mid line of palate 

Nerves anesthetized:

Anterior palatine nerve as it leaves the greater palatine foramen

Areas anesthetized:

Posterior Portion of hard palate
Soft tissue up to the first bicuspid area on the side injected
At the first bicuspid area, branches of nasopalatine nerve will be met

Indications of Anterior Palatine Nerve Block:

• For anesthetizing soft tissue in maxillary posterior region to support the posterior superior alveolar nerve block or middle superior alveolar nerve block.
• For Extraction of bicuspids, 1st, 2nd, 3rd Molars
• For Alveoloplasty in the maxillary posterior region
• For Implant placement or Sinus Lift surgeries in the Posterior Maxillary region
• For the surgery of posterior portion of hard palate.

Anterior Palatine Nerve Block Injection Technique:

The path or location of the injection can be mentally determined if you know the exact location of the nerve or the structures from which it is emerging from.

The anterior palatine nerve emerges onto the palate through the greater palatine foramen which is located, about 1cm from the palatal gingival margin towards the midline between the second and third maxillary molars.

Image Source: K. Carter

Location of the Greater Palatine Foramen:

Source of this study and percentage is taken from “Handbook of Local Anesthesia by Malamed“. It will be very helpful in determining the exact location of the Greater palatine nerve as it is not always in the exact location in every patient. 

• Anterior half of second molar: 0%
• Posterior half of second molar: 39.87%
• Anterior half of third molar: 50.63% 
• Posterior half of third molar: 9.49%

Path of Injection:

The Injection / needle should be inserted from the opposite side using a, 1-inch, 25-gauge needle, the needle has to be kept at a right angle to the palatal curvature of the maxillary bone. Use your index finger to feel a slight depression at 1 cm towards the palatal midline between the maxillary first and second molars.The Needle should inserted (point of insertion slightly anterior to the foramen is recommended) very slowly until the palatal bone is contacted (It is a comparatively painful nerve block, so comfort the patient). 0.25 to 0.5ml of anesthetic solution should be injected very slowly as the tissue in the hard palate is not much, you cannot deposit more than 0.5ml.

Inserting the needle slightly anterior to the foramen and depositing the anesthetic solution in this location can be useful as the nerve emerges from the foramen and moves anteriorly. This will help in blocking the nerve at any point along its anterior course after it emerges from the foramen. The soft tissue or mucoperiosteum covering the palate anterior to the site of injection will be anesthetized (mostly upto the bicuspid).

So in cases where the bicuspid area is to be anesthetized, it is advantageous to insert the Needle and deposit the solution in the palatal curvature opposite to the bicuspids. The palatal soft tissue beside the bicuspids is supplied by the Nasopalatine nerve also, hence it is recommended to deposit the anesthetic solution near the biscuspid area which will help in anesthetising the nasopalatine nerve extensions in this region.

Symptoms of Anterior Palatine Nerve block Anaesthesia:

It is important to check the symptoms of a nerve block before starting the procedure as some nerve blocks might fails due to many reasons and it has to be confirmed before starting the procedure to keep the patient pain free.

Subjective symptoms:

The patient will feel numbness in the posterior palate area on the side of injection when contacted with tongue as compared to the other side of the palate.

Objective symptoms:

Instrumentation should be done to make sure that there is no pain sensation in the palatal region on the side of injection.

References: 

• Handbook of Local Anesthesia by Malamed
• Local Anesthesia and pain control in Dental Pracrice – Monheim’s, C Richard bennett