LA5: Mandibular anaesthesia

Question 1

what is the supply to the lower premolars and molars?

Answer 1

Inferior alveolar nerve

Question 2

what does the inferior alveolar nerve become after passing the mental foramen?

Answer 2

Incisive nerve

Question 3

what supplies the lower incisor and canines?

Answer 3

incisive nerve

Question 4

what supplies the mucosa in front of the lower anterior teeth (1-5)?

Answer 4

mental nerve

Question 5

what supplies the mucosa in front of the posterior teeth (6-8)?

Answer 5

long buccal nerve

Question 6

what supplies the mucosa posterior to the lower teeth?

Answer 6

lingual nerve

Question 7

what can a block anaesthesia in the mandible do?

Answer 7

can anaesthetise large areas of mucosa and teeth?

Question 8

Name some types of block anaesthesia in the mandible.

Answer 8

• inferior alveolar nerve (lower teeth)
• lingual (lingual soft tissues
• long buccal (buccal tissues in posterior teeth)
• mental (labial soft tissues )
• incisive (lower incisors but NB cross-over

Question 9

what nerve blocks require a long needle?

Answer 9

• inferior alveolar nerve

- lingual

Question 10

what is the size of the long needle?

Answer 10

35mm and 27 gage

Question 11

where do you aim to deposit the LA in IANB?

Answer 11

• close to IAN

- before nerve enters mandible

Question 12

why is this a risk for IV injection?

Answer 12

nerve in vascular bundle with vein and artery

Question 13

what lies in front of the injection site (IANB)?

Answer 13

the buccinator which attaches to the pterygomandibular raphe

Question 14

what is the complex anatomy of the pterygomandibular space?

Answer 14

• Lateral: ramus
• Medial: medial pterygoid muscle
• Posterior: Parotid (+VII nerve)
• Anterior: buccinator
• Superior: lateral pterygoid muscle

Question 15

what is required before block anaesthesia (IAB and lingual) ?

Answer 15

medical history

Question 16

what equipment is needed for block anaesthesia (IAB and lingual)?

Answer 16

• long needle - 35mm

- appropriate anaesthetic -lidocain (not articaine)

Question 17

what is the patients position in block anaesthesia?

Answer 17

• operator preference /patient comfort
• procedure dependent
• supine (less likely to faint) or upright

Question 18

what are the stages of IANB?

Answer 18

• mouth open wide (identify pterygomandibular raphe
• place supporting thumb in coronoid notch of anterior border of rams
• identify injection point (parellel to occlusal plane and 1cm above)
• insert needle until bone is touched (after approx 2.5 cm)
• withdraw needle by 1-2mm then aspirate
• if no blood aspirated, start to slowly inject
• inject 1.5-2ml

Question 19

what is the key sign of success of IANB?

Answer 19

number lower lip (mental nerve)

Question 20

what indicates success of the lingual nerve block?

Answer 20

ipsilateral numb tongue

Question 21

what is separate to injection to IAB and lingual?

Answer 21

long buccal nerve block

Question 22

where do you insert needle for long buccal nerve block?

Answer 22

most lateral postion to teeth

Question 23

Describe the mental/incisive nerve block.

Answer 23

Incisive nerve: teeth ; 1st premolar to contra lateral incisors
mental nerve : labial mucosa gingivae (not teeth)
( flow into foramen )

Question 24

what is not reliable for lower incisors (and canines)?

Answer 24

block anaesthesia not reliable as there is a crossover

-bone is thinner

Question 25

what is the success of a buccal infiltration alone (1ml) on lower incisors (+canines)?

Answer 25

50%

Question 26

what is the success if you split the dose between buccal (0.5ml) and lingual (0.5ml)?

Answer 26

90%

Question 27

what is the technique of buccal infiltration the same as ?

Answer 27

maxillary infiltration

Question 28

what is the technique of lingual infiltration?

Answer 28

• more awkard
• in reflected mucosa near tooth apex
• 8-10 mins before pulpal anaesthesia

Question 29

what is the reason for molar infiltrations as an alternative to IAB?

Answer 29

• more localised
• less likely to have intravascular injection
• more straightforward

Question 30

what is better at anaesthetising lower molars by infiltration - lidocaine or articaine?

Answer 30

articaine