Local Anaesthetic Flashcards
What does the anterior superior alveolar nerve supply?
Upper 1-3 anterior teeth
Anastomoses with the adjacent side - corss over
What does the middle superior alveolar nerve supply?
Hard and buccal soft tissues of upper MB 6, 5 and 4
Not always present and innervation is past to the posterior superior alveolar nerve
What does the posterior superior alveolar nerve supply?
Hard and buccal soft tissue of upper 8, 7, 6 (+/- 5 and 4)
Anastomoses with mid sup alveolar if present
What does the nasopalatine nerve supply?
Palatine tissues of the premaxilla area
What does the greater palatine nerve supply?
Palatine tissue from the last molar to the first premolar/canine area
What does the buccal nerve supply?
Buccal soft tissues of lower 8-5 area
What does the lingual nerve supply?
Lingual gingiva of lower teeth and aspects of the tongue
What does the inferior alveolar nerve supply? and its exception?
Hard and soft tissues of the lower teeth except the buccal tissues of 8-6
What does the incisive nerve supply?
Extension of the IAN and ruins in canal and supplies the incisors and structures
What does the mental nerve supply?
Continuation of the IAN but exits canal at apices of premolar teeth to supply soft tissues of lower lip and chin
Which scenarios are best for the infiltration technique? what allows this?
All maxillary teeth and supporting teeth, both buccally and palatally
Mandibular anterior teeth and supporting tissues
Thin cortical plate allows diffusion
Which scenarios should you avoid an infiltration? but what is the exception? and what stops it?
Anything posterior to the lower premolar
except lower first molar using 4% articaine
This is due to the bone being very dense for adequate penetration
Where is the inferior alveolar nerve found and its course?
IAN passes between the lateral an medial pterygoid muscle, behind the lingual nerve via the mandibular foramen into the mandibular canal
Where is IAN block achieved?
Mandibular foramen located on the medial aspect of the ramus, before it enters the canal
Where to inject to achieve IAN block?
Through the lateral side of the mouth into the fat of the pterygomandibular space
What needle size and gauge is needed for a IAN block?
Long needle
27 gauge
How to place and manipulate the patient to achieve a successful IAN block?
Patient supine or semi recumbent
Mouth open wide
What are the clinical anatomical landmarks to remember to aid an IAN block?
Mandibular foramen
External oblique ridge at anterior aspect of ascending ramus
Pterygomandibular raphe (runs from the pterygoid hamulus down to a point on the mandible in the retromolar region)
Forms a V shape
Where should the thumb or finger palpate for an IAN?
At the ramus whilst the injection is given
Where should the needle be positioned before entry for an IAN?
Introduced from premolar area of opposite side
Barrel of syringe parallel to lower occlusal plane
Where should the needle enter for an IAN?
Lateral to the pterygomandibular raphe
Medial to ramus of mandible
Within the V
Halfway up the thumb from palpating ramus
To what extent should you advance the needle?
Advance until bone is felt
Then withdraw slightly
Aspirate
Then deposit 2mL of LA
What diagnostic feature can tell you that the IAN block was successful?
Fast anesthesia of the lower lip and lateral aspect of the tongue
Tingling feeling
What must be incorporated with an IAN block?
Buccal infiltration of the long buccal nerve
Explain the Gow-Gates technique?
All sensory nerves v3
Extra-oral landmarks
Explain the Vazirani-Akinosi technique?
Closed mouth approach
Good for trismus
Difficult to visual path of entry
No bony contact
Explain how the incisive and mental nerve block works?
Depositing LA into the mental foramen (found between the apices of the first and second premolar)
Enters the foramen and blocks the incisive nerve to the premolar and the anterior mandibular teeths and soft tissues
Where is the mental foramen found?
Between the apices of the first and second premolar
What is the incisive and mental nerve block indicated for?
Multiple anterior teeth
Explain the technique for incisive and mental block/
Patient mouth party open
Insert needed at 1st and 2nd premolar
Aim for bone
Once contacted bone, withdraw, aspirate and deposit 1.5mLs slowly
What is anaesthetised when performing a supraperiosteal injection?
Pulpal anaesthesia in all maxillary upper teeth
If using articaine also mandibular premolars and molars
Excellent soft tissue anaesthesia
Multiple teeth require multiple injections
What needle size and gauge for a infiltration?
Short needle
27 or 30 gauge
How should you position and manipulate the patient to allow a successful infiltration?
Semi recumbent or fully back
Advise patient about to commence
Pull tissues taut
Target apex of tooth
What are the landmarks for an infiltration?
Mucobuccal fold
Crown of tooth
Root contour
Explain the technique used during an infiltration? and what not to do?
Orient needle so bevel faces bone Insert needle into mucobuccal fold over target tooth at 45 degree angle Advance until bevel is above apex Stabilise needle with finger stop Don't advance until bone is hit Don't inject into frenum Deposit drops of LA Aspirate Deposit 1/2 cartridge over 30s
Which injection method is best for the upper jaw? and why?
Infiltration
Outer bone covering the maxillary teeth is thin
What innervates the upper incisors, buccal gingiva and canines?
Anterior superior alveolar nerve
What innervates the palatal gingiva?
Nasopalatine nerve
Where to aim for when anaesthetising the upper incisors and canines?
Near or into the buccal fold, towards the apex of the tooth
Slow injection of 1-2mLs
What innervates the upper premolars?
Middle and posterior superior alveolar nerve
What innervates the palatine soft tissue near the premolar?
Greater palatine
but anastomosis via the nasopalatine
What makes the maxillary molars difficult to anaesthetise? and its solution?
Achieving close proximity with the root apices of the 6s
Zygomatic arch can be obstructive
2 infiltrations mesially and distally to the 6s
What innervates the maxillary molars and buccal gingiva?
Posterior superior alveolar nerve
What innervates the palatal soft tissue near the molars?
Greater palatine nerve
When injecting into the palate, what must you always avoid?
Never inject posterior to the vibrating line
Avoid rugae
Avoid foramen
Explain the process of performing a palatal injection?
Uncomfortable
Apply pressure to the target before injection
Used AFTER buccal infiltration
Aim for an equidistant point between median raphe and the gingival margin of target tooth
Inject slowly small amounts
Blanching indicates successful anaesthesia
What is the technique for an alternative to palatal injection?
Palatal infiltration via the buccal papilla
Needle introduced at 90 degrees into papilla and advanced into the palatal mucosa
What stops simple infiltration of the lower premolars and molars? but what could work?
Covered by a thick compact lamina, stopping diffusion
4% articaine with 1:100,000 ADR
What innervates the lower incisors and canines? and what technique can be used?
Incisive nerve
Infiltration technique
Anastomosis - innervation across midline
Explain the infiltration technique for the lower incisors and canines?
Tip of needle must be closely angled to the apex, to stop solution escape
For canines a mental block may need to be administered
Explain the supplementary lingual nerve injection process?
Infiltration under the attached gingiva on lingual aspect
Interpapillary injection
Small amount of LA required
Explain the buccal infiltration process prior to the IAN block?
Depositing solution in the buccal tissues just distally to the tooth of interest
Explain the interpapillary injection process?
Insert needle to the centre of papilla near the crest bone Small amount slowly injected Blanching confirms analgesia Following infiltration injection Ultra small needle
Explain the aspiration technique?
Insert needle
Aspirate by pulling back plunger, check for blood, if +ve reposition needle
if -ve proceed to inject LA
