NERVE BLOCKS�(PART I)

NERVE BLOCK

Close to the main nerve trunk

Distance from the site of operative intervention

FIELD BLOCK

Deposit near the larger terminal branch

Circumscribed anaesthetized area

Treatment is done in an area away from the site of injection

LOCAL INFILTRATION

Small terminal nerve endings in the area of dental treatment are flooded with local anesthetic solution

Treatment is done in the same area

SUPRA PERIOSTEAL INJECTION

INDICATIONS

• Pulpal anesthesia of maxillary teeth when treatment is limited to 1 or 2 teeth
• Soft tissue anesthesia in a circumscribed area

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AMOUNT TO BE DEPOSITED- 0.6ml over 20 sec.

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TECHNIQUE

• Beneath the mucous membrane
• Infiltrated slowly throughout the area

CONTRAINDICATION

• Infection or acute inflammation

DISADVANTAGES

• Multiple needle insertions
• Large volume of solution

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INTRALIGAMENTARY ANESTHESIA

USES:

• For extraction of teeth in hemophilic pts.
• Useful in pedodontic pts.
• Indicated prior to immediate replacement dentures

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TECHNIQUE:

• Finer needles of gauge 30 are inserted in the periodontal membrane to a depth of 2mm.
• Needle is inserted parallel with the long axis of the root of the tooth until it contacts the alveolar bone.
• 0.2ml of solution is injected over a period of 30secs.
• Maxillary Molars require 3 injections and mandibular molar 2 injections.
• Usually made on buccal/labial aspect as access is easier, if insufficient then injections given lingually or palatally.

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PERIOD OF ANESTHESIA

30-45 mins

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DISADVANTAGES

• Infection of the site
• Discomfort after the analgesia wears off

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INTRA OSSEOUS INJECTIONS

• Injection of analgesic solution into inner or cancellous portion of the bone

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• A path for the needle is usually made by drilling through the cortical bone.

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• Patient need to be warned about momentary increase in heart rate as the vasoconstrictor passes from the cancellous bone into the blood stream.

Intraseptal approach

• Safest method
• Injection is made interdentally about 4mm from the tip of the papilla
• Alternative method is to drill through bone near the apices of the teeth
• Rubber stopper should be placed to prevent back flow.
• 0.5ml of LA

Advantages

• Rapid onset
• Avoidance of soft tissue analgesia and swelling

Disadvantages

• More complex technique
• Duration of LA not longer than 10minutes
• Difficult to apply in molar region

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MAXILLARY INJECTION TECHNIQUES

INTRA ORAL TECHNIQUES

• POSTERIOR SUPERIOR ALVEOLAR NERVE BLOCK
• ANTERIOR SUPERIOR ALVEOLAR NERVE BLOCK
• MIDDLE SUPERIOR ALVEOLAR NERVE BLOCK
• GREATER PALATINE NERVE BLOCK
• NASO PALATINE NERVE BLOCK
• ANTERIOR MIDDLE SUPERIOR ALVEOLAR (AMSA) INJECTION
• MAXILLARY NERVE BLOCK
• Greater palatine canal approach
• High tuberosity approaches

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EXTRA ORAL TECHNIQUES

• INFRA ORBITAL BLOCK
• MAXILLARY NERVE BLOCK

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POSTERIOR SUPERIOR ALVEOLAR NERVE BLOCK

POSTERIOR SUPERIOR ALVEOLAR NERVE BLOCK

• PSA nerve block is commonly used dental nerve block.

Common names:

• Tuberosity block
• Zygomatic block

Nerve anesthetized:

• Posterior superior alveolar nerve

Area anesthetized:

• Pulps of the maxillary 3^rd ,2^nd and 1^st molars except for the mesiobuccal root of the maxillary 1^st molar.
• Buccal periodontium and bone overlying these teeth.

Indications:

• When the treatment involves two or more maxillary molars.
• When local infiltration is contraindicated or if it is ineffective.

Contraindication:

• When the risk of hemorrhage is too great(as with the hemophilic patients), in which case local infiltration or pdl injection is reccomended.

Positive aspiration:

• Approximately 3.1%

Technique

• A 27- gauge short needle (20 mm in length) is recommended.
• Area of insertion:
• Height of the mucobuccal fold above the maxillary second molar.
• Target area:
• PSA nerve that is posterior, superior and medial to the posterior border of the maxilla.

• Landmarks:
• Mucobuccal fold and its concavity.
• Zygomatic process of the maxilla.
• Infratemporal surface of the maxilla.
• Anterior border and coronoid process of the ramus of the mandible.
• Tuberosity of the maxilla.

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• Orientation of the bevel:
• Bevel is toward bone during the injection.

• Position of the operator:

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• For a left PSA nerve block, a right handed operator should sit at the 10 o’clock position facing the patient

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• For a right PSA nerve block, a right handed operator should sit at the 8 o’clock position facing the patient.

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• Prepare the tissue at the height of the mucobuccal fold of penetration.
• Dry with a sterile gauze.
• Apply a topical antiseptic.
• Apply topical anesthetic for a minimum of 1 minute.

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• Orient the bevel of the needle towards bone.

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• Partially open the patient’s mouth.

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• Retract the patient’s cheek with your finger (for visibility).

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• Pull the tissue at the injection site taut.

• Insert the needle into the height of the mucobuccal fold over the second molar.

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• Advance the needle slowly in an upward, inward and backward direction in one movement.
• Upward : superiorly at a 45 degree angle to the occlusal plane.
• Inward : medially toward the midline at a 45 degree angle to the occlusal plane.
• Backward : posteriorly at a 45 degree angle to the long axis of the second molar.

• Slowly advance the needle through soft tissue:

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• There should be no resistance and therefore no discomfort to the patient.

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• If resistance (bone) is felt, the angle of the needle in toward the midline is too great. So withdraw the needle slightly (but do not remove it entirely from the tissue) and bring the syringe barrel closer to the occlusal plane. And then readvance the needle.

• Advance the needle to the desired depth:
• In an adult of normal size, penetration to a depth of 16 mm places the needle tip in the immediate vicinity of the foramina through which the PSA nerves enter the posterior surface of the maxilla.
• When a long needle is used (average length, 32mm), it is inserted half its length into the tissue.
• With a short needle (average length 20mm), approximately 4 mm should remain visible.

• Aspirate in two planes:
• If both aspiration are negative then inject the anesthetic agent slowly over 30 to 60 seconds, deposit 0.9 to 1.8 ml of anesthetic solution.
• If aspiration is positive then LA is discarded and again the procedure is repeated with a new syringe.

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• Slowly withdraw the syringe.

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• Make the needle safe.

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• Wait minimally 3 to 5 minutes before commencing the dental procedure.

Advantages:

• Atraumatic as the bone is not contacted and also there is a relative large soft tissue area available

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• Only one injection compared with three infiltration

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• Total volume of LA solution is minimized

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Disadvantages;

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• Second injection necessary for treatment of 1st molar (mesiobuccal root not anesthetized by PSAN)

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Complications:

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1. HEMATOMA

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Can occur in following cases:

• when needle is inserted too far posteriorly into the pterygoid plexus of veins
• maxillary artery may be perforated

2) Mandibular nerve is lateral to the PSA nerves hence, if LA gets injected lateral to the desired location mandibular anesthesia is produced.

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Patient complains of tongue and lower lip getting anesthetized

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• Also called Anterior Superior alveolar nerve block.
• Pulpal and buccal soft tissue anesthesia from the maxillary centre incisor through the premolars ( 72% of patient)
• Used instead of supraperiosteal injection
• 0.9 to 1.2 ml versus 3.0 ml for supraperiosteal injection of the same teeth

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NERVE ANESTHETIZED:

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1. Anterior superior alveolar

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2. Middle superior alveolar

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3. Inbfraorbital nerve

a.inferior palpebral

b.lateral nasal

c.superior labial

AREAS ANESTHETIZED:�

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1. Pulp of the maxillary central incisor through the canine on the injected side.

2. In about 72%of patient, pulps of the maxillary premolas and mesiobuccal root of the first molar

3. Buccal periodontium and bone of these same teeth.

4. Lower eye lid, lateral aspect of the nose, upper lip.

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INDICATIONS:

1. Dental procedures involving more than 2 maxillary teeth and their overlying buccal tissues.

2. Inflammation and infection:if a cellulitis is present, the maxillary nerve block may be indicated in lieu of the ASA nerve block.

3. When supraperiosteal injections have been ineffective because of dense cortical bone.

CONTRAINDICATIONS:

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1.Discrete treatment area

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2.Hemostasis of localized area , when desirable , cannot be adequately achieved with this injection ; local infiltration into the treatment area is indicated.

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ADVANTAGES:

1.Simple technique

2.Comparatively safe

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DISADVANTAGES:

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1.Psycological;

a)Administration: there may be an initial fear of injury to the pt’s eye

b)Patient: an extraoral approach to the infraorbital nerve may prove disturbing

2.Anatomic:

difficulty defining landmarks…rare…

Positive Aspiration:

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• 0.7%.

ALTERNATIVES:

1.Supraperiosteal,pdl,infraorbital injection for each tooth.

2.Infiltration for the periodontium and hard tissues

3.Maxillary nerve block

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TECHNIQUE:

1. A 25 OR 27 gauge long needle is recommended.

2. 27 gauge short also be user for children and smaller adults.

3. Area of insertion: height of the mucobuccal fold directly over the first premolar.

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4. Target area: infraorbital foramen

5. Landmarks:

a..infraorbital ridge

b..infraorbital depression

c..supraorbital notch

d..infraorbital notvh

e..anterior teeth

f..pupils of the eyes.

5. Orientation of the bevel: toward bone.

6. PROCEDURE:

a. Assume the correct position.

for a right or left handed infraorbital nerve block , a right handed administration should be sit at the 10o’clock position, directly facing the patient.

b. Position the patient supine or semisupine with the neck extended slightly.

if the patient’s neck is not extended , the patient’s chest may interfere with the syringe barrel.

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c. Prepare the tissue at the injection site for penetration.

1.Dry with sterile gauze.

2.Apply topical antiseptic.

3.Apply topical anesthetic for a minimum of 1 minute.

d. Locate the infraorbital foramen

1.Feel the infraorbital notch.

2.Move your finger downward from the notch, applying gentle pressure to the tissue.

3.The bone immediately inferior to the notch is convex , this represents the lower border of the orbit and the roof of the infraorbital foramen.

4. As goes inferiorly , a concavity is felt; this is the infraorbital foramen.

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5.While applying pressure, feel the outlines of the infraorbital foramen at this site, the patient seen a mild soreness when the foramen is palpated as the infraorbital nerve is pressed against bone.

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Maintain your finger on the foramen or mark the skin at the site.

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Retract the lip, pulling the tissue in the mucobuccal fold taut and increasing visibility.a 2 by 2 inch sterile gauge placed beneath your gloved finger aids in retraction of the lip during the ASA injection.

g. Insert the needle into the height of the mucobuccal fold over the first premolar with the level facing bone.

h. Orient the syringe toward the infraorbital foramen.

i. The needle should be held parallel with the long axis of the tooth as it is advised, to avoid premature contact with bone.

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J. The general depth of the needle penetration is 16 mm for an adult of average height.

K. Before injecting the anesthetic solution , check for the following:

1.Depth of the needle penetration

2.Any lateral deviation of the needle from the infraorbital foramen; correct before injecting solution.

3.Orientation of the bevel.

L. Position the needle tip during injection with the bevel facing into the infraorbital foramen and the needle tip touching the roof of the foramen.

M. Aspirate in two planes.

N. Slowly deposit 0.9 to 1.2 ml in 30 to 40 sec. little or no swelling should be visible as the solution is deposited . if the needle tip is properly inserted at the opening of the foramen, solution is directed toward the foramen.

NEEDLE PATHWAY

• BICUSPID APPROACH- The needle is inserted in a line parallel with the supraorbital notch, the pupil of the eye, infra orbital notch, & 2^nd bicuspid tooth
• CENTAL INCISOR APPROACH- The needle bisects the crown of the central incisor from the mesio-incisal angle to the disto-gingival angle.

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• To transform the infraorbital nerve block to the anterior superior alveolar nerve block, do following:

Maintain firm pressure with your finger over the injection site both during and for at least 1 minute after the injection.

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Withdraw the syringe slowly and immediately make the needle safe.

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Q. Maintain direct pressure on the injection site for a minimum of 1 minute , preferably 2 minutes, after injection.

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R. Wait a minimum of 3 or 5 minutes after completion of the injection before commencing the dental procedure.

SIGN AND SYMPTOMES:

1.Subjective:tingling and numbness of and the lower eyelid, side of the nose, upper lip indicate anesthesia of infraorbital nerve.

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2.Subjective and objective: numbness in the teeth and soft tissues along the distribution of the ASA or MSA nerve block.

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3.Objective: - use of electrical pulp testing with no response from tooth

- Absence of pain during treatment.

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SAFETY FEATURES:

1. needle contact with bone at the roof of the infraorbital foramen prevent inadvertent overinsertiom and possible puncture of the orbit.

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2.a finger positioned on the infraorbital foramen helps direct the needle toward the foramen.

PRECAUTIONS:

1. For pain on insertion of the needle and tearing of the periosteum, reinsert the needle in a more lateral position,

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2. To prevent overinsertion of the needle, depth of penetration before injection exert finger pressure over the infraorbital foramen.

FAILURE OF ANESTHESIA:

1. Needle contacting bone below the infraorbital foramen:

anesthesia of the lower eyelid,lateral side of the node,upper lip may develop with little or no dental anesthesia ; a bolus of the solution may be felt beneath the skin in the area of deposition , which lie at the distance from the infraorbital foramen.

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To correct: keep the needle in the line with the infraorbital foramen during penetration.do nor direct the needle toward the bone. And estimate the depth of the penetration before injecting.

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COMPLICATIONS:

Hematoma.

• It is rare.
• May develop across the lower eyelid and the tissue between it and the infraorbital foramen.
• To manage , apply pressure on the soft tissue over the foramen for 2 to 3 minute.
• Hematoma is rare because pressure is routinely applied to the injection site both during and after administration of the ASA nerve block.

MIDDLE SUPERIOR ALVEOLAR

NERVE BLOCK

Missing in 50% patients.

When present, supplies MB root of 1^st molar and premolars.

Nerve is blocked at the same time as ASA when an infra-orbital injection is given, and solution diffuses back along the infraorbital canal to point where MSA usually originates.

If it arises in posterior part of canal, then it may not be accessible to the analgesic solution. But whatever its anatomical path, its branches are readily reached by an infiltration injection over teeth they supply and this is usually the method of choice.

Nerves Anesthetized

Middle superior alveolar and terminal branches.

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Technique

A 27-gauge short or long needle is recommended.

Area of insertion: height of the mucobuccal fold above the maxillary second premolar

Target area: maxillary bone above the apex of the maxillary second premolar

Landmark: mucobuccal fold above the maxillary second premolar

Insert the needle into the height of the mucobuccal fold above the second premolar with the bevel directed toward bone.

Penetrate the mucous membrane and slowly advance the needle until its tip is located well above the apex of the second premolar .

Aspirate. Slowly deposit 0.9 to 1.2 mL (one half to two thirds cartridge) of solution (approximately 30 to 40 seconds).

GREATER PALATINE

NERVE BLOCK

INTRODUCTION

• The greater palatine nerve block is quite useful during dental procedures involving the palatal soft tissue distal to the canine.
• Minimum volumes of solution

(0.45 to 0.6 ml)provide profound hard and soft tissue anesthesia.

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• Other Name : Anterior palatine nerve block

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• Nerve anesthetized : Greater palatine

AREAS ANESTHETIZED�

• Posterior portion of the hard palate and its overlying soft tissues
• Anteriorly as far as the first premolar
• Medially to the middle line.

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ANATOMICAL LANDMARKS

• Second and third maxillary molar
• Palatal gingival margin of second and third maxillary molar.
• Midline of the palate
• A line approximately 1cm from the palatal gingival margin toward the midline of the palate.

INDICATIONS

• When palatal soft tissue anesthesia is required for restorative therapy on more than two teeth.
• For pain control periodontal or oral surgical procedure involving the palatal soft and hard tissues.

CONTRAINDICATION�

• Inflammation or infection at the injection site

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• Smaller area of therapy(one or two teeth)

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ADVANTAGES�

• Minimizes needle penetrations and volume of solution

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• Minimal patient discomfort

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DISADVANTAGES�

• No hemostasis except in the immediate area of injection
• Potentially traumatic

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Positive aspiration : Less than 1%

ALTERNATIVES

• Local infiltration into specific regions

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• Maxillary nerve block

TECHNIQUE�

• A 27-gauge short needle recommended though the 25-gauge short may also be used
• Area of insertion : soft tissue slightly anterior to the greater palatine foramen
• Target area: greater palatine nerve as it passes anteriorly between the soft tissues and bone of the hard palate

• Landmarks: Greater palatine foramen and junction of the maxillary alveolar process and palatine bone.

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• Path of insertion: Advance the syringe from the opposite side of the mouth at a right angle to the target area.

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• Orientation of the bevel: toward the palatal soft tissue

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� PROCEDURE �ASSUME THE CORRECT POSITION�

• For a right greater palatine nerve block and a right handed administrator :

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Sit facing the patient at the 7 or 8’o clock position.

• For left greater palatine block and right handed administration :

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Sit facing in the same direction as the patient at 11’o clock

PATIENT’S POSITION

Request the patient ,who in a supine position to

• Open wide
• Extend the neck
• Turn the head to the left or right

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Locate the greater palatine nerve

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1. Place the cotton swab at the junction of the maxillary alveolar process and the hard palate.
2. Start in the region of the maxillary 1^st molar and palpate posteriorly by pressing firmly into the tissue with swab.

3) The swab will fall into the depression created by the greater palatine foramen.

4)The foramen is most frequently located distal to the maxillary second molar,but it may be either anterior or posterior to its usual position.

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Prepare the soft tissue at the injection site, just 1 to 2 mm anterior to the greater palatine foramen.

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• Clean and dry with sterile gauze
• Apply topical antiseptic
• Apply topical anesthetic

After 2 min of application, move the swab posteriorly so it is directly over the greater palatine foramen

1. Apply considerable pressure at the area of the foramen with swab in the left hand(if right handed)
2. Note ischemia(whitening of the soft tissues)at the junction site.
3. Apply pressure for a minimum of 30second and while doing this proceed to
4. Direct the syringe into the mouth from the opposite side the needle approching the injection site at a right angle.

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• Place the bevel of the needle gently against the previously blanched soft tissue at the junction site. It must be stabilized to prevent accidental penetration of the tissues.
• With bevel lying against the tissue
• Apply enough pressure to bow the needle slightly.
• Deposit a small volume of anesthetic . The solution is forced against mucous membrane and droplet forms.

Straighten the needle and permit the bevel to penetrate mucosa.

• (1) Continue to deposit small volumes of anesthetic throughout the procedure.
• (2) Ischemia spreads into adjacent tissues as the anesthetic is deposited

��������Continue to apply pressure anesthesia throughout the deposition of the anesthetic solution.Ischemia will spread as the vasoconstrictor decreases tissue perfusion�

���������Slowly advance the needle until palatine bone is gently contracted.��(1) the depth of penetration will usually be less than 5 mm�(2) continue to deposit small volumes of anesthetic. As the tissue is entered, there will be increased resistance to deposition of solution, which is entirely normal in the greater palatine nerve block.�

• Aspirate in two planes.
• If negative, slowly deposit (30 sec minimum) not more than one fourth to one third of a cartridge (0.45 to 0.6 ml).
• Slowly Withdraw the syringe.
• Make the needle safe.�Wait 2 to 3 mins before commencing the dental procedure.

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�����SIGNS AND SYMPTOMS��1. SUBJECTIVE: Numbness in the posterior portion of the palate��2.OBJECTIVE: No pain during dental therapy�

����SAFETY FEATURES���1. Contact with bone �2. Aspiration

����PRECAUTIONS��Do not enter the greater palatine canal. Although this is not hazardous, there is no reason to enter the canal for this technique to be successful

Failures of anesthesia

1. The greater palatine nerve block is not a technically difficult injection to administer.�It incidence of success is well above 95%.
2. If local anasthetic is deposited too far anterior to the foramen, adequate soft tissue anasthesia may not develop in the palatal tissue posterior to the site of injection.
3. Anesthesia on the palate in the area of maxillary 1^st premolar may prove inadequate because of overlapping fibers from the nasopalatine nerve

(A) to correct local infiltration may be neccesary as a supplement in the area of inadequate anesthesia.

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COMPLICATIONS

• Few of significance
• Ischemia and necrosis of soft tissues when highly concentrated vasoconstricting solution is used over a long period of time for hemostasis.
• Hematoma is possible but is quite rare.
• Sometimes soft palate becomes anesthetized.

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MAXILLARY NERVE BLOCKS�(PART II)

MAXILLARY INJECTION TECHNIQUES

INTRA ORAL TECHNIQUES

• POSTERIOR SUPERIOR ALVEOLAR NERVE BLOCK
• ANTERIOR SUPERIOR ALVEOLAR NERVE BLOCK
• MIDDLE SUPERIOR ALVEOLAR NERVE BLOCK
• GREATER PALATINE NERVE BLOCK
• NASO PALATINE NERVE BLOCK
• ANTERIOR MIDDLE SUPERIOR ALVEOLAR (AMSA) INJECTION
• MAXILLARY NERVE BLOCK
• Greater palatine canal approach
• High tuberosity approaches

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EXTRA ORAL TECHNIQUES

• INFRA ORBITAL BLOCK
• MAXILLARY NERVE BLOCK

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NASOPALATINE NERVE BLOCK

OTHER COMMON NAMES

• Incisive nerve block
• Sphenopalatine nerve block

NERVES ANESTHETIZED

• Nasopalatine nerve

AREAS AENESTHETIZED

• Anterior portion of the hard palate bilaterally

from the mesial of the right first premolar to the mesial of the left first premolar

INDICATIONS

• When anterior palatal soft tissue anesthesia is necessary for restorative treatment on more than two teeth
• For pain control during periodontal or oral surgical procedure involving palatal soft and hard tissue

CONTRAINDICATION

• Inflammation or infection at the injection site
• Smaller area of therapy

ADVANTAGES

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• Minimize needle penetration and volume of solution
• Minimal patient discomfort from multiple needle penetration

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DISADVANTAGES

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• No hemostasis except in the immediate area of injection
• Potentially the most traumatic intraoral injection

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POSITIVE ASPIRATION

• Less than 1%

ALTERNATIVES

• Local infiltration into specific region
• Anterior middle superior alveolar NB
• Maxillary NB

APPROACHES

Two approaches to this injection are presented

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• First approach involve only one tissue penetration, lateral to incisive papilla on palatal aspect of max. central incisors
• Second approach involve three needle punctures

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TECHNIQUE �

1) 27 gauge short needle is recommended

2) Area of Insertion: palatal mucosa just lateral to the incisive papilla; tissue here is more sensitive than other mucosa

3) Target area: incisive foramen beneath the incisive papilla

4) Landmarks: central incisor and incisive papilla

5) Path of insertion: approach the injection site at a 45 degree angle towards incisive papilla

6) Orientation of bevel: toward the palatal soft tissue

7) Procedure:

a) sit at 9 or 10 o’clock position facing in the same direction as the patient

b) request the patient to do the following

1)open wide

2)extend the neck

3)turn the head to the left or right for improved visibility

c) prepare the tissue lateral to incisive papilla

1)clean & dry with sterile gauze

2)apply topical antiseptic

3)apply topical anesthetic for 2 minute

d) After 2 minutes of topical anesthetic application, move swab directly onto incisive papilla

1)with swab in your left hand , apply pressure to the area of papilla

2)note ischemia at injection site

e) place the bevel against the ischemic soft tissue at injection site. Needle must be well stabilized to prevent accidental penetration of tissues

f) with the bevel lying against the tissue

1)Apply enough pressure to bow needle slightly

2)Deposit a small volume of anesthetic. The solution will be forced against the mucous membrane

g) straighten the needle and permit the bevel to penetrate the mucosa

1)continue to deposit small volumes of anesthetic throughout the procedure

2)observe ischemia spreading into adjacent tissues as solution is deposited

h) continue to apply pressure with cotton applicator stick while injecting the LA

i) slowly advance the needle until bone is gently contacted

-Depth of penetration about 5 mm

j) withdraw the needle 1 mm to prevent subperiosteal injection

k) aspirate in two planes

l) if negative slowly deposit about 0.45ml of solution

m) slowly withdraw the syringe

n) make the needle safe

o) wait for 2-3 min before starting the procedure

SIGNS & SYMPTOMS

• Subjective: numbness in the anterior portion of hard palate
• Objective: no pain during the therapy

SAFETY PROCEDURE

• Contact with bone
• Aspiration

PRECAUTION

Against pain:

• Do not insert directly into the incisive papilla
• Do not deposit solution too rapidly
• Do not deposit too much solution Against infection

if needle is advanced more than 5 mm into incisive canal and floor of nose accidentally 🡪 infection

FAILURES OF ANESTHESIA

1) Highly successful injection (>95% incidence of success)

2) Unilateral Anesthesia:

a)if solution is deposited to one side of incisive canal , unilateral anesthesia may develop

b)to correct: Reinsert the needle into already anesthetized tissue and reinject solution into unaenesthetized area

3) inadequate palatal soft tissue anesthesia in the area of maxillary canine and first premolar, if fibers from greater palatine overlap those of nasopalatine nerve

- to correct: local infiltration may be necessary as a supplement in the area inadequately anesthetized

COMPLICATIONS

• Hematoma is possible but extremely rare because density and firm adherence of palatal soft tissue to bone
• Necrosis of soft tissue is possible when highly concentrated vasoconstricting solution is used for hemostasis
• Because of density of soft tissue , anesthetic solution may ‘squirt’ back out of needle puncture site during administration or after needle withdrawal

TECHNIQUE�(MULTIPLE NEEDLE PENETRATIONS)

1) 27 gauge short needle is recommended

2) Area of insertion:

a)labial frenum in the midline b/w max. central incisors

b)interdental papilla b/w max. central incisors

c)if needed, palatal soft tissue lateral to incisive papilla

3. Target area: incisive foramen beneath incisive papilla
4. Landmarks: central incisors & incisive papilla
5. Path of insertion:

a)1^st injection: infiltration into labial frenum

b)2^nd injection: needle held at right angle to interdental papilla

c)3^rd injection: at 45degree angle to incisive papilla

6. Orientation of bevel:

a)1^st injection: bevel towards bone

b)2^nd injection: not relevant

c)3^rd injection: not relevant

7. Procedure:
• First Injection: infiltration of 0.3ml into labial frenum
• Prepare tissue at injection site
• Retract the upper lip to stretch tissues and improve visibility
• Gently insert needle into frenum and deposit 0.3ml of anesthetic in approximately 15 sec
• Anesthesia of soft tissue develop immediately. Aim is to anesthetize the interdental papilla b/w two central incisors

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b) Second injection: penetration through labial aspect of the papilla b/w the maxillary central incisor towards the incisive papilla

• retract upper lip
• needle at right angle to interdental papilla, insert , just above level of crestal bone
• soft tissue on labial surface have been anesthetized by first injection ,so there is no discomfort
• ischemia produced by local anesthetic can be seen
• needle tip as it nears the palatal aspects of incisive papilla

• aspirate in two plane when ischemia is noted in incisive papilla. If negative, administer 0.3ml of LA in approximately 15 sec.
• slowly withdraw the syringe
• make needle safe
• anesthesia within the distribution of right and left nasopalatine nerve usually develops in a minimum of 2 to 3 minute
• if clinically effective anesthesia is in adequate, proceed to third injection

c)Third injection:

• dry tissue lateral to incisive papilla
• ask the patient to open wide
• extend patient’s neck
• place the needle into soft tissue adjacent to incisive papilla, aiming towards the most distal portion of papilla
• advance needle until bone contact is made
• aspirate in two plane
• if negative slowly deposit 0.3ml of anesthetic approximately 15 sec
• withdraw the syringe
• make the needle safe
• wait for 2-3 min for onset of anesthesia before beginning dental treatment

SIGNS & SYMPTOMS

• Subjective: numbness of upper lip and anterior portion of hard palate
• Objective: no pain during the therapy

ADVANTAGE

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• Entirely or relatively atraumatic

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DISADVANTAGE

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• Requires multiple injection
• Difficult to stabilize the syringe during second injection
• Syringe barrel usually within the patient’s line of sight during second injection

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SAFETY PROCEDURE

• Contact with bone
• Aspiration

PRECAUTION

• Against pain: if each injection is performed as recommended , entire technique should be atraumatic
• Against infection: on third injection, do not advance needle into incisive canal. With accidental penetration of nasal floor, risk of infection is increased

FAILURE OF ANESTHESIA

• Highly successful injection
• Inadequate anesthesia of soft tissue around canine and first premolar because of overlapping fibers from greater palatine nerve
• To correct: local infiltration may be necessary as a supplement in the area

COMPLICATION

• Necrosis of soft tissue is possible when highly concentrated vasoconstrictor solution is used for hemostasis over a prolonged period
• Interdental papilla b/w maxillary incisors sometimes are tender for several days after injection

ANTERIOR MIDDLE SUPERIOR ALVEOLAR NERVE BLOCK

First reported by Friedman and Hochman during development of a C-CLAD system.

Effectively anesthetize maxillary teeth and associated gingival tissues extending from the buccal root of the first molar mesially to the central incisor with a single injection

The AMSA injection site is located on the hard palate at the intersection of a vertical line bisecting the premolars and a horizontal line halfway between the mid palatine raphe and the crest of the free gingival margin

To avoid patient discomfort due to the tightly bound nature of the palatal tissue, the anesthetic agent should be injected into the site at a methodic rate of 0.5 ml per minute

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After slow deposition of the anesthetic agent, the bound nature of the palatal tissue promotes diffusion of the anesthetic agent through the palatal bone via numerous nutrient canals.

Typically blanches the palatal tissue in a unilateral fashion that does not cross the midline.

Anesthesia is achieved typically innervated by the

• greater palatine nerve
• nasopalatine nerve
• anterior superior alveolar nerve
• middle superior alveolar nerve

ADVANTAGES

• elimination of repetitive transmucosal punctures 🡪improving patient comfort
• maintenance of upper lip function allows for continuous evaluation of gingival contours unimpeded by the ‘‘lip drooping’’ that typically occurs with traditional anesthetic techniques
• reduces the need for multiple reinjections to attain hemostatic control during graft harvest
• no vasoconstrictor affects the buccal gingiva, and outstanding blood supply is maintained for nourishment of the connective tissue graft

Disadvantages

• the use of a computer-assisted injection system is recommended as the best method for administering AMSA injections (Costly).
• long administration time. Some patients may find it disconcerting to have an injection last 4minutes (0.5 mL/min).
• Because the AMSA eliminates the need for multiple injections, less vasoconstrictor enters the buccal tissues, and a subsequent decline in hemostasis may obscure portions of the surgical field
• short-lived anesthesia in the maxillary central incisor region noted

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MAXILLARY NERVE BLOCK

OTHER NAMES:- Second division block, V2 nerve block

AREAS ANESTHETIZED:-

1) Maxillary teeth on the affected side

2) Alveolar bone & overlying structures

3) Hard palate, part of soft palate

4) Upper lip, cheek, side of the nose, lower eye lid

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ADVANTAGES

1) Minimizes the no. of needle penetrations

2) Minimizes the total volume of local anesthetic solution 1.8ml versus 2.7ml

3) High success rates

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For achieving profound anesthesia of hemi maxilla.

2 intra-oral approaches

1) Greater palatine canal approach

2) High tuberosity approaches

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GREATER PALATINE APPROACH

TARGET AREA:- Maxillary nerve as it passes through the pterygopalatine fossa, the needle passes through greater palatine canal to reach pterygopalatine fossa

LAND MARKS:- Greater palatine foramen, situated between the 2nd & 3rd molars about 1cm towards the midline of the palate from the palatal gingival margin.

AREA OF INSERTION:- Palatal soft tissue directly over the greater palatine foramen.

PROCEDURE:- 25 gauge 32 mm long needle used 1.8 - 2 ml of the solution in 1 minute is deposited at the target area, at a marked depth not to exceed 1½ inches

SYMPTOMS-

• OBJECTIVE- instrumentation necessary to demonstrate absence of pain sensation
• SUBJECTIVE- tingling & numbness of the upper lip, side of the nose, & lower eyelid

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COMPLICATIONS:-

• Hematoma
• Penetration of the orbit during greater palatine foramen approach if the needle goes too far
• Penetration of the nasal cavity occurs when the needle deviates medially during insertion

HIGH TUBEROSITY APPROACH

Technique:- 25 gauge 32mm long needle inserted in an upwards, inwards and backwards direction to a pre-marked depth of 1¼ inches. 2-4ml of solution is injected.

Area of insertion: height of the mucobuccal fold above the distal aspect of the maxillary second molar

LAND MARKS

• Muco buccal fold at the distal aspect of maxillary second molar.
• Maxillary tuberosity
• Zygomatic process of the maxilla

ADVANTAGES

• Atraumatic injection via the high-tuberosity approach
• Minimizes total volume of local anesthetic solution injected to 1.8 versus 2.7 mL
• Minimizes the number of needle penetrations necessary for successful anesthesia of the hemimaxilla

DISADVANTAGES

• Risk of hematoma with high tuberosity approaches
• Lack of hemostasis
• Overinsertion is possible because of the absence of bony landmarks

TARGET AREA

Maxillary nerve as it passes through pterygopalatine fossa

Superior & medial to the target area of PSA nerve block.

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Technique

• Place the needle into the height of the mucobuccal fold over the maxillary second molar.
• Advance the needle slowly in an upward, inward, and backward direction as described for the PSA nerve block
• Advance the needle to a depth of 30 mm.
• No resistance to needle penetration should be felt. If resistance is felt, the angle of the needle in toward the midline is too great.
• At this depth (30 mm), the needle tip should lie in the pterygopalatine fossa in proximity to the maxillary division of the trigeminal nerve.
• Aspirate in 2 planes.
• Rotate the syringe (needle bevel) one fourth turn and re-aspirate

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EXTRA ORAL TECHNIQUES

INFRA ORBITAL BLOCK

Indications: Infection, Trauma resulting in impossible intra oral approach .

Anatomical Land marks:

• Pupil of the eye.
• Infra orbital ridge.
• Infra orbital notch.
• Infra orbital depression.

Technique:

• Using the available landmarks,locate the infra orbital foramen. The skin & subcutaneous tissue is anesthesized by local infiltration. Finger kept over infraorbital margin to act as a guard.
• 25 gauge needle used, and is directed slightly upward & laterally which facilitates entrance into the foramen, which open downward & medially.

• The needle is inserted 1cm below the ridge and passed upwards and inwards at 45°, keeping syringe in same long axis as the line connecting the pupil, infraorbital notch, and the upper second premolar.
• Needle passes through – Skin, Subcutaneous tissue, Quadratus labii superioris muscle.
• Important structures near to final position of needle are – facial artery and vein which since they are very tortuous may lie on either side of the needle.

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• Needle slowly passed into the tissues to a depth of about 1cm, injecting as it proceeds until the analgesic can be felt by the finger being deposited at the foramen.
• After a delay of about 15-20 secs to attain local analgesia, foramen is gently felt for with the needle which is then passed into it for a few millimetres.
• The finger is pressed firmly over the foramen to seal it and prevent back-flow, and 1ml is slowly deposited, giving ample time for it to diffuse back through infraorbital canal.

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SYMPTOMS

SUBJECTIVE- tingling & numbness of the upper lip, side of the nose & lower eyelid

OBJECTIVE- instrumentation necessary to demonstrate absence of pain.

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Complications : Field and instruments should be sterile. Technique should never be used if infection is present. The venous drainage travels back to cavernous sinus and thus cavernous sinus thrombosis can occur.

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Small risk of entering anterior facial or infraorbital vein and thus injecting intravenously. Trauma to these vessels can also cause unsightly bruising of the skin which may take as long as 10-14 days to resolve.

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On rare occasions diplopia may occur due to analgesic entering the orbit.

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MAXILLARY NERVE BLOCK

Indications:

• During extensive surgery
• To block all sub divisions of maxillary nerve with one needle insertion
• Local infection and trauma causing difficulty for intraoral approach

Anatomical land marks:

• Mid point of the zygomatic arch
• Zygomatic notch
• Coronoid process of the ramus of mandible
• Lateral pterygoid plate

AREA ANAESTHETIZED-

• Maxillary teeth on the affected side
• Alveolar bone & the overlying structure
• Hard palate & soft palate
• Upper lip, cheek, side of the nose & lower eyelid
• Part of pharynx
• Nasal septum and floor of the nose
• Posterior lateral mucosa and turbinate bones
• Anterior temporal and Zygomatic regions.

Needle passes through following structures

• Skin
• Subcutaneous tissue
• Masseter muscle
• Mandibular notch
• External pterygoid muscle

Technique:

• The midpoint of the zygomatic process is located & the depression in its inferior surface is marked
• A 25 gauge needle used to raise skin wheal just below this mark, which the dentist identifies by having the patient open & close the jaw
• Using a 4 inch(8.8cm) 22 gauge needle, one measures 4.5cm and marks with a rubber stopper.
• The needle is inserted through the skin wheal, until the needle point gently contacts the lateral pterygoid plate
• The needle is withdrawn , with only the point left in the tissue, & re directed in a slight forward & upward direction until the needle is inserted to the depth of the marker.
• After careful aspiration, 2-3ml of LA is injected
• Care should be exercised to aspirate after each 0.5ml of solution injected.

When the needle is in contact with the lateral pterygoid plate, the following structures are near it :

• Superiorly, base of skull
• The internal maxillary artery that crosses inferiorly and curves up anterior to it, entering the lower part of the pterygomaxillary fissure .
• Temporal vessels from the internal maxillary artery that may lie on either side of it.
• Superficially, the transverse facial artery that may lie above or below it.
• Posteriorly, the foramen ovale, through which passes the mandibular nerve, and posterior to that, the foramen spinosum, through which passes the middle meningeal artery.
• Anteriorly, the pterygomaxillary fissure, through which the needle may pass into the pterygopalatine fossa.