LA5: Mandibular anaesthesia Flashcards
what is the supply to the lower premolars and molars?
Inferior alveolar nerve
what does the inferior alveolar nerve become after passing the mental foramen?
Incisive nerve
what supplies the lower incisor and canines?
incisive nerve
what supplies the mucosa in front of the lower anterior teeth (1-5)?
mental nerve
what supplies the mucosa in front of the posterior teeth (6-8)?
long buccal nerve
what supplies the mucosa posterior to the lower teeth?
lingual nerve
what can a block anaesthesia in the mandible do?
can anaesthetise large areas of mucosa and teeth?
Name some types of block anaesthesia in the mandible.
- 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
what nerve blocks require a long needle?
- inferior alveolar nerve
- lingual
what is the size of the long needle?
35mm and 27 gage
where do you aim to deposit the LA in IANB?
- close to IAN
- before nerve enters mandible
why is this a risk for IV injection?
nerve in vascular bundle with vein and artery
what lies in front of the injection site (IANB)?
the buccinator which attaches to the pterygomandibular raphe
what is the complex anatomy of the pterygomandibular space?
- Lateral: ramus
- Medial: medial pterygoid muscle
- Posterior: Parotid (+VII nerve)
- Anterior: buccinator
- Superior: lateral pterygoid muscle
what is required before block anaesthesia (IAB and lingual) ?
medical history
what equipment is needed for block anaesthesia (IAB and lingual)?
- long needle - 35mm
- appropriate anaesthetic -lidocain (not articaine)
what is the patients position in block anaesthesia?
- operator preference /patient comfort
- procedure dependent
- supine (less likely to faint) or upright
what are the stages of IANB?
- 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
what is the key sign of success of IANB?
number lower lip (mental nerve)
what indicates success of the lingual nerve block?
ipsilateral numb tongue
what is separate to injection to IAB and lingual?
long buccal nerve block
where do you insert needle for long buccal nerve block?
most lateral postion to teeth
Describe the mental/incisive nerve block.
Incisive nerve: teeth ; 1st premolar to contra lateral incisors
mental nerve : labial mucosa gingivae (not teeth)
( flow into foramen )
what is not reliable for lower incisors (and canines)?
block anaesthesia not reliable as there is a crossover
-bone is thinner
what is the success of a buccal infiltration alone (1ml) on lower incisors (+canines)?
50%
what is the success if you split the dose between buccal (0.5ml) and lingual (0.5ml)?
90%
what is the technique of buccal infiltration the same as ?
maxillary infiltration
what is the technique of lingual infiltration?
- more awkard
- in reflected mucosa near tooth apex
- 8-10 mins before pulpal anaesthesia
what is the reason for molar infiltrations as an alternative to IAB?
- more localised
- less likely to have intravascular injection
- more straightforward
what is better at anaesthetising lower molars by infiltration - lidocaine or articaine?
articaine
