Maxillary & Palatal Injections

Chapter: Maxillary Buccal Injections: Infiltration, PSA, MSA, ASA and Infraorbital

Maxillary buccal techniques

Technique	Insertion and target	Anesthetizes	Watch for
Supraperiosteal (infiltration)	Mucobuccal fold over the apex of the tooth	One tooth's pulp and its buccal tissues	Fails over dense bone or infection
PSA	Mucobuccal fold above the maxillary second molar; needle up, in and back (about 45° each), about 16 mm deep, 25-gauge short needle	Maxillary third, second and first molars (the MB root of the first molar is missed in some patients) and their buccal tissues	Pterygoid plexus hematoma if too deep; aspirate
MSA (when present)	Mucobuccal fold above the second premolar	Premolars, often the MB root of the first molar, buccal tissues	Nerve absent in many people
ASA	Mucobuccal fold above the canine (usually as an infiltration)	Central and lateral incisors, canine, facial tissues
Infraorbital (ASA + MSA) block	Mucobuccal fold over the first premolar toward the palpated infraorbital foramen, about 16 mm deep	Incisors and canine; premolars and MB root of the first molar in about 72% (Malamed); lower eyelid, side of the nose, upper lip	Keep a finger on the foramen; avoid entering the orbit

Technique	Target	Anesthetizes	Notes
Greater palatine block	Greater palatine foramen, usually palatal to the second or third molar, about halfway between the gingival margin and the midline	Posterior hard palate and its gingiva from the third molar to the first premolar, to the midline	0.45–0.6 mL; contact bone; no pulpal anesthesia
Nasopalatine block	Incisive papilla, needle just lateral to it	Anterior hard palate and palatal gingiva from canine to canine	Most uncomfortable injection; use pressure anesthesia; no more than about 0.45 mL
AMSA	Palate midway between the gingival margin and midline, between the premolars	Pulps of incisors through premolars plus palatal and facial gingiva (no lip numbness)	Slow, computer-controlled delivery helps
V2 block	Pterygopalatine fossa via the high tuberosity or greater palatine canal approach (about 30 mm)	Half the maxilla: teeth, buccal and palatal tissues, side of the nose, upper lip	Hematoma and orbital complications possible

Pressure anesthesia: press firmly with a cotton applicator until the tissue blanches before and during palatal injections.
Palatal tissue is tightly bound, so small volumes blanch the tissue; too much solution causes pain and sloughing.

Expecting the PSA to cover the whole first molar: the MB root may need an MSA or infiltration.
Inserting a PSA needle too deep: 16 mm in an average adult; less in small patients.
Expecting pulpal anesthesia from a greater palatine or nasopalatine block.
Injecting large volumes into palatal tissue.

Pick an answer to see right away whether it is correct and why.

After a PSA block, the maxillary first molar still responds on its mesial side. Which additional injection is most useful?
What is the most common complication of a PSA injection given too deep?
Which block anesthetizes the anterior hard palate from canine to canine?
The infraorbital block reliably anesthetizes the pulps of:
Which technique gives pulpal anesthesia of maxillary incisors through premolars from a single palatal injection without numbing the lip?

0 of 5 answered

Answer key: 1 A · 2 A · 3 B · 4 C · 5 B

Dental School Map · Original study material, written and checked by our team; always confirm clinical decisions against current guidelines.