Download technics of local anaesthesia

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Local Anaesthesia in Dentistry
DEFINITIONS
Nerve Block Anaesthesia
In nerve block anaesthesia anaesthetic solution is deposited extraneurally or paraneurally to
the nerves supplying the area to be operated.
Infiltration Anaesthesia
In infiltration anaesthesia anaesthetic solution is injected into the soft tissues covering the
operative area, so that the nerve endings in this area are anaesthetized.
Advantages of nerve –block anaesthesia as compared to infiltration anaesthesia
1. more profound anaesthesia
2. longer duration anaesthesia
The technic for introduction of local anaesthetic requires a few materials:
-solution of local anaesthetic in various concentrations (0,5-4%)
-sterile container
-sterile syringes and needles to fit the syringes
-sterile gauze
-emergency kit
NERVE BLOCK ANAESTHESIA
INTRA-ORAL TECHNIC for THE INFERIOR ALVEOLAR NERVE INJECTION
This technic results in anaesthesia of the inferior alveolar nerve and the lingual nerve.
1.Direct method:
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Place the patient and ask to open the mouth as wide as possible. Occlusal plane of the
mandible is parallel to the floor.
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Stand on the right front side of the patient.
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Hold the syringe containing the anaesthetic solution with a mounted needle in your
right hand (operating hand).
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Place the thumb of the left hand in the mucobuccal fold opposite the bicuspids or the
bicuspid area if the mandible is edentulous. Move the finger posteriorly until the
anterior border of the mandible ramus is reached. The index finger places on the
posterior border of the ramus outside the mouth.
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Keep the syringe on the premolars in opposite side of the mouth and parallel to
occlusal plane of the mandibular teeth.
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Inject the lateral border of the pterygomandibular fold in the middle of the distance
between maxilla and mandible. The mandibular foramen is in the middle of the width
of the mandibular ramus and therefore your left hand will indicate the foramen.
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Penetrate the tissue until you reach the bone.
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Aspirate by drawing back the plunger to check if you are not in the lumen of a vessel.
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Deposit two thirds of the anaesthetic solution slowly. Don’t withdraw the syringe.
Keep in position.
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Withdraw the needle slowly until 1 cm is still embedded in the tissue.
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Deposit the remaining one third of anaesthetic solution to anaesthetize the lingual
nerve.
2. Weissbrem injection for Inferior alveolar nerve block anaesthesia
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Ask patient to open his mouth as wide as possible.
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Keep the syringe on the premolars in opposite side of the mouth and parallel to
occlusal plane of the mandibular teeth
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Inject the anterior border of the pterygomandibular fold 0.5 cm beneath occlusal plane
of maxillary teeth( 1.5 cm if the patient is edentulous )
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Penetrate the tissue until you reach the bone.
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Aspirate by drawing back the plunger to check if you are not in the lumen of a vessel.
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Deposit 3/4 of the anaesthetic solution slowly
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The rest of the solution deposit withdraw the the needle slowly until it’s still
embedded in the tissue.
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The adventage of this method is that we anaesthtize all three nerves(alveolar inferior,
lingual and buccal) useing only one injection
LINGUAL NERVE ANAESTHESIA alone.
If you want to anaesthetize the trunk of the lingual nerve only, you should deposit anaesthetic
solution in soft tissue on the ligual surface of the alveolar process in the last molar area.
BUCCAL NERVE ANAESTHESIA
The buccal nerve supplies the soft tissues from lower second premolar to lower second molar.
If you want to anaesthetize the buccal nerve you should deposit anaesthetic solution in the
recess of vestibule in region of extracted tooth.
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If you want to anaesthetize the trunk of buccal nerve you should deposit anaesthetic solution
into soft tissue of the cheek at the level of the upper molar teeth.
INTRA-ORAL TECHNIC for THE POSTERIOR SUPERIOR ALVEOLAR NERVE
INJECTION
Technic
1. Insert the needle below the roof of the oral vestibule in the second upper molar region.
2. Pass the needle in contact with the bone backwards and upwards for 2cm.
3. Aspirate.
4. Deposit ¾ of anaesthetic solution.
5. Pass the rest of anaesthetic solution to anaesthetize the endings of the anterior palatal
nerve in an extracted tooth area.
INTRA-ORAL TECHNIC for THE ANTERIOR and MIDDLE SUPERIOR ALVEOLAR
NERVE INJECTION
The anterior and middle superior alveolar nerve are branches of infraorbital nerve, which is
located in infraorbital foramen.
Technic to anaesthetize right nerve
1. Keep the left thumb inside the mouth and the left index finger on lower infraorbital edge to
prevent injecting the solution into the orbit.
2. Locate the infra-orbital foramen which is found 8milimeters under the lower infraorbital
edge and 0.5 cm medially from the pupil line. Instruct a patient to look straight forward.
3. Inject between the first and second incisor. Pass the needle towards lower infraorbital
foramen.
4. Aspirate.
5. Deposit anaesthetic solution.
THE NASOPALATINE NERVE INJECTION
The nasopalatine nerve is located in the incisive foramen on the maxillary palatal surface. The
foramen is covered by the incisive papilla. Anaesthesia of this nerve produces loss of
sensation in the area between the canines.
Technic
1. Insert the needle on lateral side of incisive papilla 1cm away from the alveolar edge.
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2. Aspirate.
3. Deposit anaesthetic solution.
ANTERIOR PALATINE NERVE INJECTION
This nerve enters the hard palate through the greater palatine foramen which is 0.5 cm away
from the alveolar edge and between the second and third upper molars in the palatal
depression.
Technic
1. Insert a needle into palate at a point where the greater palatine foramen is found.
2. Penetrate the tissue until the bone is reached.
3. Aspirate.
4. Deposit anaesthetic solution.
TECHNIC for INFILTRATION ANAESTHESIA
This method of injection is widely used for anaesthetizing upper teeth and lower incisiors and
canines, for removal of hypertrophied soft tissues and high muscle attachments. The success
of infiltration anaesthesia depends on diffusion of the anaesthetic solution through the minute
foramina in the cortical plate and into the cancellous bone until the nerve fibers are reached.
Because of the paucity of foramina in the cortex of the mandible, this method of injection is
unsuitable for lower premolars and molars. This method is contraindicated when there is
inflammation in the injection site.
Technic
1. Insert the needle into the mucobuccal or the mucolabial fold below the vestibular
recess in the midline along the tooth prior to the one to be extracted. The needle
should be positioned with a beveled side towards the bone.
2. Pass the needle through the submucous tissue until periapical region of extracted tooth
is encountered.
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Inject ¾ of anaesthetic solution in this area slowly.
To achieve profound anaesthesia, inject the palatal tissue to anaesthetize the endings of
anterior palatine nerve.
1. Insert at 45° angle into the palatal tissue 1 cm away from the alveolar edge in the
periapical region of a tooth to be extracted.
2. Make aspiration to check if you are not in the lumen of the vessel.
3. Inject ¼ of anaesthetic solution slowly.