In school we mostly practiced anesthesia for patients who needed full quadrants of SRP rather than selective SRP. What type of injections would you recommend in a case where a patient has 5-7mm pockets on the distal of #7 and mesial of #4? Would you do a PSA, greater palatine and nasopalatine and numb the full quadrant for just teeth, or would you do something different?
If only the tissue and teeth of #4 and #7 need anesthesia you have two options: you can administer a Middle Superior Alveolar (MSA) or infiltration injection above tooth # 4. The MSA will anesthetize the mesial buccal root of the 1st molar and the pulpal and buccal soft tissue of the premolars. The infiltration will only anesthetize the tooth infiltrated and buccal soft tissue. I suggest you palpate the zygomatic process and the height of the mucobuccal fold above tooth #4. The primary difference in the administration between the MSA and an infiltration is the depth of insertion. For the MSA, insert the needle at the height of the mucobuccal fold between 4 -10 mm or 1/4 - 1/2 inches. If the zygomatic process does not allow for this depth of penetration, you may need to administer additional anesthesia. For an infiltration, insert and deposit the anesthetic at the apex of tooth #4 using a short 27 gauge needle. The needle should be fairly parallel with the periosteum/tooth and angled about 20 degrees medially. Depending on the length of time and the duration of anesthesia needed, administer between 1/2 and 2/3 of a cartridge for profound anesthesia. Depending on the anesthesia you choose, you may or may not need to administer a Greater Palatine injection for the mesial lingual tissue. Frequently, I have found Articaine (Septocaine) diffuses nicely on the maxilla and I do not need to administer a palatal injection.
To anesthetize tooth #7, I suggest either an Anterior Superior Alveolar (ASA) or infiltration injection. The ASA will anesthetize the canine to the central incisor. Palpate the canine fossae (beween the canine and lateral incisor) and the height of the mucobuccal fold. Insert a short 27 gauge needle at the height of the mucobuccal fold about 25 degrees medially to the periosteum/tooth approximately 4-6 mm or 1/4 inch. For an infiltration, insert and deposit above tooth # 7 and deposit at the apex of tooth #7. If the lingual tissues are sensitive, a nasopalatine injection may be needed. Articaine may diffuse enough to provide enough anesthesia to the lingual tissue for scaling procedures.
The Posterior Superior Alveolar (PSA) injection will anesthetize the molars (except the MB root of the 1st molar) and associated buccal tissue. Frequently, for profound anesthesia of the 1st molar, the PSA and the MSA or an infiltration above the first molar are necessary.