Week Three: Local Anaesthetic Anatomy and Armamentarium Flashcards
Describe a cartridge of LA
Closed. 1.8ml or 2.2ml of solution (clear) 4 parts • Cylindrical tube (glass or plastic) • Name, composition, vasoconstrictor, Expiry date • Rubber stopper • Aluminium cap • Rubber diaphragm
Describe a dental Needle
- Stainless steel /disposable, single use ONLY
- Consist of bevel, shank, hub & syringe end
- Length- given in mm
What are the main different needle lengths?
- long 40mm (Long)
* short 25mm (Short)
What is important about knowing the gauge of a needle?
Gauge- diameter of the lumen of needle
• The smaller the number the larger the diameter
• Generally 27 gauge & 30 gauge used
• Higher gauge than this may make it difficult to aspirate.
Describe a labelled needle.
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What is the bevel on a needle?
• Present to ensure easy, painless puncture of
soft tissue
• Bevel of needle must be orientated so that it
faces bone during injection. This is to avoid
pain from needle tip dragging across
persiosteum of bone.
What are some MUST KNOWS! About the needle?
Unscrew both ends simultaneously and bend
slightly for opening
!!!! After use disassemble with artery forceps needle and dispose in sharps container immediately!
!!! Bevel must face bone when performing injections
to avoid tearing of periosteum
What is the syringe?
• Provides the means of delivering the anaesthetic
solution from the cartridge, through the needle, to the
patient
• Non Aspirating, Aspirating or self aspirating
Describe a labelled syringe.
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What are the steps to load a syringe?
- Load cartridge into syringe by pulling pack piston/plunger
- Engage piston/plunger with rubber stop of cartridge (to enable aspiration)
- Needle inserted and screwed onto needle adapter/thread at front of barrel
- Needle penetrates adapter and pierces rubber diaphragm of cartridge
- Apply slight pressure onto thumb ring- check flow
Describe a self aspirating syringe.
- Spring mechanism that aids automatic aspiration
- After needle insertion into soft tissue, decrease the pressure on the thumb ring slightly (achieved by releasing thumb slightly)
- Goal is to create slight negative pressure, so that a few micro litres are sucked from tissue spaces into the syringe, and operator can assess if the needle is in a blood vessel or not
- +ve aspiration: (blood in cartridge) do not deposit solution, discard cartridge and replace
- -ve aspiration: SLOWLY deposit solution
The Trigeminal Nerve - How many divisions?
CNV - 3 Divisions
- Opthalmic CNV1 (sensory)
- Maxillary CNV2 (sensory)
- Mandibular CNV3 (sensory and motor)
What is this?
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Trigeminal ganglion
Ganglion = collection of cell bodies of sensory nerves
What type of nerve is the CNV1?
The ophthalmic division is a general sensory nerve.
Where does the CNV1 have all its cell bodies located?
Trigeminal ganglion
Where is the CNV1 cranial exit?
Superior Orbital Fissure
Where does the CNV1 distribute?
Superior CTR - Frontal: Supraorbital & Supratrochlear Within CTR - Nasocilary: Long ciliary, Ganglionic, Post. and Ant. Ethmoidal, Infratrochlear - Lateral CTR: Lacriminal
What are the functions of the CNV1
Sensory: Snesation from corneam skin of forehead, scalp, eyelids, nose and mucosa of nasal cavity and paranasal sinuses.
What type of nerve is the CNV2?
The maxillary Division is a general sensory nerve
Where are the cell bodies of the CNV2 located?
Trigeminal ganglion
Where is the cranial exit for the CNV2?
Foramen Rotundum
Where is the CNV2 distributed?
- Main trunk (middle Cranial Fossa)
Meningeal - Main trunk (Pterygopalatine Fossa)
Posterior Superior Alveolar (PMF > PSA canal & MT)
Zygomatic (IOF): Zygomatictemporal, Zygomaticofacial
Infraorbital (IOF->IO canal > Infraorbital foramen): , Middle Superior Alveolar, Anterior Superior Alveolar, Terminal branches ( Palpebral, nasal, Superior
labial)
Pterygopalatine Ganglion (Pterygopalatine Fossa) Palatine (PPC) Greater (GPC > GPF) Lesser (LPC > LPC) Nasal Nasopalatine (SPF) > IF) Posterior Superior Nasal (SPF) Orbital (IOF) Pharyngeal (PVC)
What is the function of the CNV2?
Sensation of the face over the maxilla, Upper lip, maxillary teeth, mucosa of the nose, hard and soft palate, maxillary sinuses.
What type of nerve is the CNV3?
The mandibular division is a general sensory and brachial motor nerve
Where are the cell bodies of the CNV3 located?
Sensory: Trigeminal Ganglion
Branchial Motor: Pons
Where is the cranial exit of the CNV3?
Foramen Ovale