Maxillary Anaesthesia Flashcards
What are the 3 things the LA technique used depend on?
- Patient (bespoke technique - specific to patient)
- nature, location and duration of planned procedure
- LA drug; some drugs work better with specific techniques
label the the trigeminal nerve and its two devisions shown in the diagram.
label the branches of the maxillary devision of the trigeminal nerve. Explain how these branches arise
- The maxillary nerve gives rise to three branches within the skull:
- posterior superior alveolar nerve
- middle superior alveolar nerve
- anterior superior alveolar nerve
- The maxillary nerve exits the skull through infraorbital Forman as infraorbital nerve
What teeth do each posterior superior alveolar nerves, middle superior alveolar nerve and anterior superior alveolar nerve innervate?
Anterior superior alveolar nerve
- 1 2 and 3 (all anterior teeth)
Middle superior alveolar nerve
- 4, 5 and bucco-mesial root of 6
Posterior superior alveolar nerve
- Tooth 6, 7 and 8
Which three nerves innervate the palate, which part of the palate do they each innervate and where do they originate form?
- Incisive nerve: Nasopalatine nerve is a branch arising from the pterygopalatine ganglion, exits through nasopalatine foramen and supplies tissues on the palatal side of anterior teeth.
- Greater palatine nerve: a nerve that arises from the pterygopalatine ganglion (bilateral) and innervate the hard palate
- lesser palatine nerve: a nerve that arises from the greater palatine nerve and travel posteriorly to supply the soft palate.
Background:
- Pterygopalatine ganglion is a ganglion found within the pterygopalatine fossa, it comes from the maxillary branch of the trigeminal nerve. it is connected to the maxillary nerve via pterygopalatine nerve.
- The pterygopalatine ganglion has 3 relevant branches to know: greater palatine nerve, pterygopalatine nerve and nasopalatine nerve.
Mucosal innervation: label the diagram showing the nerves innervating the mucosa within the oral cavity. Explain where each nerve innervates.
- infraorbital nerve supplies the mucosa within the sulcus
- Anterior superior alveolar nerve supplies labial mucosa adjacent to anterior teeth
- Middle superior alveolar nerve supplies buccal mucosa adjacent to teeth 4, 5 and Mesio-buccal root of 6
- posterior superior alveolar nerve supplies mucosa adjacent to teeth 6, 7 and 8
- Incisive branch of nasopalatine nerve supplies the palatal mucosa adjacent to anterior teeth.
- Greater palatine nerve supplies the hard palate and mucosa adjacent to all posterior teeth (4-8)
- lesser palatine nerve supplies the soft palate including tonsil and uvula.
What are all the LA techniques used?
- topical anaesthesia
- infiltration anaesthesia
- regional/ block anaesthesia
- supplementary techniques: intraosseous, intraligamentary, intrapapillary, intra-pocket and computer controlled anaesthesia.
Give a brief explanation of how supplementary techniques are carried out: intraosseous, intraligamentary, intrapapillary, intra-pocket and computer controlled anaesthesia.
- Intraosseous: force needle into cortical bone/ create a proliferation in cortical bone using drill and inject needle to dispense LA.
- intraligamentary: inject directly into PDL space using ultrashort needle.
- Intrapapillary: inject LA into medial and distal papilla of tooth without injecting PDL.
- intra-pocket: inject in the pocket of tooth
- computer controlled: method used to reduce pain during LA, a device that slowly injects LA and uses computer system to control injection speed.
What are some uses of topical anaesthesia?
- aids painless injection
- very minor surgical procedures
- abscess incision
- rubber dam clamps
- impressions (can be risky because patient won’t feel that they swallowed any material)
what are some ways of delivering topical anaesthesia?
- solutions
- sprays
- gels/pastes
- refrigeration: ethyl chloride - not LA, it freezes the tissues
compare the two main LA techniques: infiltration and block
Infiltration
- Easy to do
- safe
- low risk of IV administration
- low risk of nerve damage
- local homeostasis: no blood flow due to vasoconstrictor in LA.
- local diffusion required so drug must be able to diffuse to required area - thick bone can make this hard.
- acts on nerve endings rather than trunk
- risk of cross infection if you inject multiple areas
Regional /Block
- can be difficult
- less safe
- higher risk of IV administration
- higher risk of nerve injury by putting needle into the nerve itself
- acts on nerve trunk
- widespread effect form single injection so useful if need multiple teeth anaesthetised but bad if only one tooth required.
- Reduces risk of transmitting infection from one place to another as you use the needle in one area only so no cross infection risk.
what does infiltration anaesthesia rely on to work? what is its efficacy dependent on?
- diffusion of anaesthetic to target tissue by injecting near the area
- for tooth, target is tooth apex
- efficacy depends on the ability of solution to reach target, thicker bone makes it harder for solution to reach
what needle do we use for infiltration anaesthesia?
- short needle (25 mm) - has a blue cap
which areas do infiltration anaesthesia work best and why?
Works best:
- Maxillary anterior teeth because it has thin porous bone so anaesthetic solution can diffuse easily
which area is more difficult for infiltration anaesthesia to work and why?
Upper molars because:
- thicker bone due to zygomatic process so more difficult for anaesthetic solution to diffuse through
- divergent roots so anaesthetic solution might not reach so could have to inject from the palate.