MSA

Question 1

What is the bony landmark for the MSA?

Answer 1

Superior and slightly distal to the apex of the second premolar

Question 2

What is the soft tissue landmark for the MSA?

Answer 2

Height of Mucobuccal fold over the second premolar

Question 3

What is the orientation for an MSA?

Answer 3

Same as if a buccal infiltration

Question 4

What is the required needle depth for a MSA?

Answer 4

Tip depth is above apex of second premolar. Short needle 25mm

Question 5

How much LA is deposited in a MSA?

Answer 5

Approx. 0.9-1.2 ml approx. half cartridge

Question 6

What is the target nerve for the MSA?

Answer 6

Middle superior alveolar nerve

Question 7

What structures are anaesthetized in the MSA?

Answer 7

Pulp tissue, alveolar bone, connective tissue, PDL and buccal gingiva corresponding to the premolars and MV. Roof the maxillary 1st molar on ipsilateral side of injection

Question 8

What are the precautions/considerations for a MSA?

Answer 8

Lateral aspect of maxilla slight concave may need to angle slightly medially.

• facial artery branches present in this region - need to aspirate
• technique may be slightly angled as working towards posterior region of mouth

Question 9

How many planes do you aspirate in for MSA?

Answer 9

One