anaesthetisation and sedation :) Flashcards
infiltration
- Attempts to stop action potentials in or very near the target tissue
- Delivered as near to the target tissue as possible
- Anaesthetises a circumscribed area
nerve block
- Attempts to stop action potentials in a main branch of the nerve before it branches to individual target tissues
- Anaesthetic is delivered at an accessible point stance from the target tissues
- Therefore, anaesthetises a wider field; i.e. all the nerve branches distal to the block
maxillary bone
thinner than mandibular
anaesthetic will diffuse through the the tissue
- infiltration can be used to anaesthetise maxillary teeth
mandibular bone
too thick to allow diffusion
nerve block used where nerve is acceptable
what is the exception for mandibuarl bone
incisors and canines
maxillary nerves
posterior superior alveolar nerve
anterior superior alveolar nerve
infraorbital nerve
what does the posterior superior alveolar nerve sipply
posterior teeth
buccal gingiva at the back
what does the anterior superior alveolar nerve supply and branch of …?
labial gingiva
apices of the anterior teeth
- branch of infra orbital nerve
Problems with maxillary infiltration
may be insufficient anaesthetic
can cause vasocontriction
infection in the areas makes it more difficult or swelling
how can maxillary infiltration cause vasoconstriction
aesthetic contains noradrenaline which vasoconstricts blood vessels
why does aesthetic have noradrenalin for
holds anesthetic in the area
innervation of the palate
nasopalatine nerve
greater palatine nerve
lesser palatine nerves
greater palatine nerve
supplies most of the palate
nasopalatine nerve
supplies the gingivae and maxillary anterior teeth
anaethisiing the hard palate
bound to underlying bone closely
need to inject slowly for the anaesthetic to diffuse slowly
innervation of buccal gingivae maxillary
PostSupAntN - posterior
InfFOrb nerve - anterior
innervation of maxillary teeth
PSAN - posterior teeth
AntSupAlveoN - anterior teeth
innervation of palatal gingivae
GreaPalaN - posterior
Naso P - anterior
innervation of buccal gingiva mandibular
long buccal nerve - posterior
mental nerve - antihero
innervation of mandibular teeth
inferior alveolar nerve
lingual gingiva mandbualr
lingual nerve
when would an infraorbital nerve block be used
when infiltration is contraindicated by presence of something else e.g. perioapical access
why would a periapical access mean a infiltration cannot work
pus tends to stop diffusion of anaesthetic
where is the infraorbital nerve is anaesthetised
infraorbital foramen
- anaesthetic diffuses along canal and blocks anterior superior alveolar nerves
where is the infraorbital foramen
- One fingers breadth below inferior orbital margin
- In line with pupil if patient looks straight ahead
- Palpable in most patients as a depression in maxilla
what does the infraorbital nerve supply
lower eyelid
upper lip
part of nasal vestibule
delivering an infraorbital nerve block
1) Palpate infraorbital foramen with index finger and retract lip with thumb
2) Introduce needle through mucogingival junction to level of index finger Keep finger pressed on the IF rim for 1 min after introduction of anaesthetic to prevent diffusion into orbit
inferior alveolar nerve (mandible)
running with the mandible
supplies lower teeth
out of mental foramen as mental nerve to supply chin and lip
lingual nerve (mandibular)
runs on inside of mandible
supplies anterior 2/3 tongue
floor of mouth
lingual gingiva
what are the nerves on the mandible
lingual nerve
inferior alveolar nerve
long buccal nerve
mental nerve
long buccal nerve
supplies the mucosa
crosses anterior border of mandible on occlusal plane
where should you place inferior alveolar and lingual nerve block
pterygoid space between the rams and medial pterygoid muscle
- at the level of the occlusal plane of mandibular teeth
how to inject for IA and lingual nerve block
1) Introduce syringe over opposite premolars keeping level with the occlusal plane
2) stretch the tissue as much as possible
3) Past finger and proceed gently lateral to the raphe until bone encountered then withdraw slightly
what should be used for IA and lingual nerve block
aspirating syringe
- presence of blood vessels in pterygoid space
- can cause worse bleeds especially if in anticoagulants
complications of IA block due to anatomical variation
1- anaesthesia does not work
-usually due to high mandibular foramen so angle needle slightly above occlusal plane
- successful if lip has gone numb
2- crossover innervation at incisor teeth
-infiltrate around affected teeth rather than that teeth
3- 8s still sensitive
-due to branches from lingual or mylohyoid nerve innervating these teeth so infiltrate on lingual side of affected teeth
potential complications due to operator error
1) Direct hit on IAN or lingual nerve
- Calm patient down, remove needle a bit and repeat injection
- Is potential cause of nerve damage
2) Injection too far medial
- Injection into medial pterygoid muscle leading to trismus where they cant open their mouth properly
3) Injection too far posterior
- injection into parotid gland
- Patients face will be paralysed and lose tone in muscle, look like they’ve has a stroke
mental nerve block
used for premolar teeth
mental foramen just between and below the apices of 4 and 5
- in line with the pupil if patient looking ahead
- palpable
long buccal nerve anaesthsia
usually for extractions of lower molars, wide spread
