LA4- Maxillary anaesthesia anatomy and techniques

Question 1

what does choice of technique depend on?

Answer 1

• Patient
• Nature ,location and duration of planned procedure
• LA drug

Question 2

what foramen does the CN Vb exit through?

Answer 2

retundum

Question 3

what foramen does the CN Vc exit through?

Answer 3

ovale

Question 4

what nerve innervates the anterior teeth (incisors and canines)?

Answer 4

anterior superior alveolar nerve

Question 5

what nerve supplies the premolars and the mesio-buccal root of the upper 1st molar?

Answer 5

middle superior alveolar nerve

Question 6

what nerve supplies the molars?

Answer 6

posterior superior alveolar nerve

Question 7

what nerves supply the palate?

Answer 7

• incisive branch of nasopalatine nerve
• greater palatine
• lesser palatine nerve

Question 8

Name 3 local anaesthetic techniques.

Answer 8

• Topical anaesthesia
• Infiltration anaesthesia
• Regional (block) anaesthesia

Question 9

what are the supplementary techniques to LA?

Answer 9

– Intraosseous anaesthesia
– Intraligamentary anaesthesia
– Intrapapillary anaesthesia
– Intra-pocket anaesthesia
– Computer controlled anaesthesia

Question 10

what are the uses of topical (surface) anaesthesia?

Answer 10

– aid to pain-free injections
– very minor surgical procedures 
– abscess incision
– rubber dam clamps
-impressions

Question 11

what are different techniques of topical anaesthesia?

Answer 11

– solutions
– Sprays
– Pastes/gels
– refrigeration – ethyl chloride

Question 12

what are the 2 main techniques of LA?

Answer 12

• infiltration

- regional (block)

Question 13

what are the characteristics of the infiltration technique?

Answer 13

• Easy
• Safe
• Low risk of intravascular administration
• Low risk of nerve injury
• Local Haemostasis
• Local diffusion required
• Acts on nerve ‘endings’ rather than trunk

Question 14

what are the characteristics of the regional (block) technique?

Answer 14

• Can be difficult
• Less safe
• Higher risk of IV admin.
• Higher risk of nerve injury
• Acts on nerve trunk
• Widespread effect from single injection
• Can deposit away from infected areas

Question 15

what is infiltration?

Answer 15

Deposition / diffusion of LA solution close to, or in the target tissue

Question 16

what is the efficacy of infiltration governed by?

Answer 16

the ability of the solution to reach the target ( tooth apex)

Question 17

what needle is used in infiltration?

Answer 17

short needle (25mm-blue cap)

Question 18

where will infiltrations work?

Answer 18

• thin porous bone

- DIFFICULT - thicker bone due to zygomatic process /divergent roots

Question 19

where will infiltrations not work?

Answer 19

very dense outer cortical bone

Question 20

what is infiltrations useful for?

Answer 20

-Pulpal anaesthesia for most upper teeth

– Soft tissue anaesthesia where you put it – buccal. or palatal

Question 21

when is infiltration difficult?

Answer 21

pulpal anaesthesia upper 1st molars

Question 22

how does infiltration spread its effect?

Answer 22

ability of solution to diffuse -relatively localised anaesthesia

Question 23

what is needed before infiltration anaesthesia?

Answer 23

medical history

Question 24

what equipment is needed for infiltration?

Answer 24

• short needle

- appropriate anaesthetic – normally lidocaine in maxilla

Question 25

during infiltration, what is the patients position?

Answer 25

– operator preference / patient comfort

– supine (less likely to faint) or upright

Question 26

Describe the gels technique of topical anaesthesia.

Answer 26

• idenitfy site - site of minor soft tissue procedure
• dry site with 3 in 1
• apply gel - usually on cotton wool roll
• remove cotton wool

Question 27

how long does it take for topical anaesthesia to work?

Answer 27

between 3 and 5 minutes

-then deliver the injection or perform procedure ( be efficient as topical will not last but don’t rush)

Question 28

when injection needle, how are soft tissues retracted?

Answer 28

use mirror if possible

Question 29

Describe the injection of the needle

Answer 29

• hold tissues taught
• bevel facing bone and syringe as 45 degrees to bone
• gently insert needle until bone is contacted
• and withdraw needle by 1mm so its off the surface of the bone
• aspiration

Question 30

why is aspiration used?

Answer 30

reduce the risk of intravascular injection:
• Failure of LA
• Systemic side effects

Question 31

what is aspiration?

Answer 31

• Increase pressure inside cartridge (push plunger)
• Then decrease pressure inside cartridge (pull)
• Suction draws what is at needle tip into cartridge
• If blood – likely to be in a vessel
• If no blood – less likely to be in a vessel

Question 32

what happens if there is clear aspiration?

Answer 32

slowly inject solution

Question 33

how long does it take to inject 1ml of LA solution?

Answer 33

1 minute

Question 34

how are pain free injections carried out?

Answer 34

• Topical anaesthetic
  -Taught tissue – quick, precise needle
  penetration
  -Slow injection ~1ml/minute – drizzle!
• 2 stage injection for upper anteriors

Question 35

why are palatal infiltrations uncomfortable?

Answer 35

tightly keratinised mucosa on the palate almost immediately touch bone

Question 36

what anaesthetic is used for tooth extraction?

Answer 36

• buccal/labial infiltration

- palatal infiltration

Question 37

what nerves are normally blocked in palatal block anaesthesia?

Answer 37

greater palatine nerve

incisive nerve

Question 38

why is block anaesthetic in the maxilla used?

Answer 38

– Surgery involving palatal soft tissues in quadrant
– Reduces dose cf. multiple palatal infiltrations
– More comfortable than multiple palatal infiltrations