JM 1
LOCAL ANESTHESIA IN PEDIATRIC DENTISTRY
JEAN MICHAELBatch 4/RDC
Presented By
JM 2
PAIN
• It is defined as an unpleasant sensational experience initiated by noxious stimulus & transmitted over a specialized neural network to CNS where it is interpreted as such
JM 3
LOCAL ANESTHESIA
Transient loss of sensation in a circumscribed area of the body caused by a depression of excitation in nerve endings or an inhibition of the conduction process in peripheral nerves.
JM 4
CONSTITUENTS OF LOCAL ANESTHETIC SOLUTION
1. Local anesthetic agent2. Vasoconstrictors3. Reducing agents4. Preservatives5. Fungicide6. Vehicle
JM 5
Local Anesthetic Agent
ESTERSEsters of BENZOIC ACID Cocaine, Butacaine, Benzocaine, Tetracaine etcEsters of PARA-AMINOBENZOIC ACIDProcaine, Chloroprocaine, propoxycaine etc
AMIDESBupivacaine, lidocaine, articaine, prilocaine
QUINOLONESCentbucridine
JM 6
Vasoconstrictors
Pyrocatechin derivativeEPINEPHRINE & NOREPINEPHRINEBenzol derivativeLEVONORDEFRINEPhenol derivativePHENYLEPHRINE
JM 7
Functions of Vasoconstrictors
• ↓ the blood flow to the injection site• Absorption of LA into CVS is slowed leading to lower
LA level in blood• ↓ the risk of toxicity due to LA• ↑ the duration of action of the LA• ↓ bleeding and are useful when increased bleeding
is anticipated
JM 8
• Most commonly used agent – Phenylephrine (1:2500)• Limit – 4 mg at a time (Cardiac patients – 1/4th of normal dose)
• Contraindication – THYROTOXICOSIS
• If the LA solution is exposed to sunlight for a long time before administration, vasoconstrictor in the solution gets degraded by oxidation
JM 9
Reducing Agent (Sodium metabisulphite)
Preservative (Xylotox)
Fungicide (Thymol)
Vehicle(Modified Ringer’s solution)
JM 10
Mechanism of Action of LASpecific Receptor Theory – 1. Displacement Of Calcium ions from the Sodium
Channel Receptor Site2. Binding of LA molecule to this receptor site3. Blockade of sodium conductance4. Decrease in Sodium Conductance5. Depression in the rate of electrical depolarization 6. Failure to attain the threshold potential level7. Lack of development of propagated action
potentials8. Conduction Blockade
JM 11
Biotransformation(Alteration of the drug within the living organism)
• Ester LAs are hydrolyzed in plasma by the enzyme pseudo-cholinesterase. The one that undergoes hydrolysis readily is the least toxic. Allergic reactions are mostly due to the major metabolic product – para-aminobenzoic acid
• Amide LAs are primarily metabolized in the liver. Liver function and hepatic perfusion significantly influence the rate of biotransformation.
JM 12
Techniques of Local Anesthesia
JM 13
THE TRIGEMINAL NERVE
JM 14
Local Infiltration
• Small terminal nerve endings in the area of surgery are flooded with LA solution rendering them insensitive to pain. In this method, incision is made through the same area in which the solution has been deposited.
• This technique is usually successful for treatment of mandibular deciduous canines, incisors and even in molars.
JM 15
Field Block
• Here the LA solution is deposited in proximity to the large terminal nerve branches so that the area to be anesthetized is circumscribed to prevent the central passage of afferent impulse
• Maxillary injections administered above the apex of the tooth can be termed field blocks
JM 16
Nerve Block
• Method of securing local analgesia in which suitable local anesthetic solution is deposited within close proximity to the main nerve trunk, thus preventing nerve impulses from travelling centrally beyond that point.
JM 17
Other Techniques
• Intraligamentary
• Intraseptal
• Intrapapillary
• Intrapulpal
JM 18
The child should never see the injection needleThis creates anxiety and fear towards dental treatment
JM 19
Keep the syringe away from the Line of sight of the patient
JM 20
Maxillary InjectionTechniques
JM 21
• Supraperiosteal (Local infiltration)• Periodontal Ligament Injection• Intraseptal Injection• Intraosseous• Posterior Superior Alveolar Nerve Block• Middle Superior Alveolar Nerve Block• Anterior Superior Alveolar Nerve Block• Greater Palatine Nerve Block• Nasopalatine Nerve Block• Maxillary Nerve Block (Infraorbital Nerve Block)
JM 22
Supraperiosteal Injection
• Most frequently used technique for obtaining pulpal anesthesia in maxillary teeth
• Indicated whenever dental procedures are confined to only one or two teeth
JM 23
Nerves AnesthetizedLarge terminal branches of dental plexus
Areas Anesthetized• The entire region innervated by the large
terminal branches of dental plexus1. Pulp and root area of the tooth2. Buccal periosteum3. Connective tissue4. Mucous membrane
JM 24
INDICATIONS• Pulpal anesthesia of the maxillary teeth when
treatment is limited to only one or two teeth• Soft tissue anesthesia when indicated for
surgical procedures in a circumscribed areaCONTRAINDICATIONS• Infection or acute inflammation in the area of
injection• Dense bone covering the apices of teeth (maxillary central incisors and 1st molars)
JM 25
ADVANTAGES• High success rates (>95%)• Technically easy injections• Usually entirely atraumaticDISADVANTAGES• Not recommended for large areas due to
1. Need for multiple needle insertion2. Necessity to administer large total volumes
of local anesthetic
JM 26
TECHNIQUE• 25 or 27 gauge needle is used• Area of insertion – height of mucobuccal fold
above the apex of the tooth being anesthetized• Target area – apical region of the tooth to be
anesthetized• Landmarks
1. Mucobuccal fold2. Crown of the tooth 3. Root contour of the tooth
JM 27
PROCEDURE• Prepare the tissue at the injection site• Orient the needle so that bevel faces the bone• Lift the lip, pulling the tissue taut• Hold the needle parallel to the long axis of the
tooth• Insert the needle into the height of the
mucobuccal fold over the target tooth
JM 28
• Advance the needle until its bevel is at or above the apical region of the tooth
• Aspirate 2 times• If negative, deposit approximate 0.6 ml of LA
over 20 seconds• Slowly withdraw the syringe• Make the needle safe• Wait for 3 to 5 minutes before starting the
dental procedure
JM 29
SUPRAPERIOSTEAL INJECTION
JM 30
BEVEL ORIENTATION OF NEEDLE
JM 31
PAIN
JM 32
JM 33
MINIMAL PAIN
JM 34
MANDIBULAR INJECTION TECHNIQUE
JM 35
Inferior Alveolar Nerve Block
• Needle Used – 25 Gauge• Nerves Anesthetized –
Inferior Alveolar NerveLingual Nerve
• Site Of Injection – Region where the IAN enters the mandible
through the Mandibular Foramen• Amount of solution deposited – 1 to 1.8 ml
JM 36
Area anesthetized• Mandibular teeth of the injected side• Body of the mandible, inferior portion of the ramus• Buccal mucoperiosteum, mucous membrane
anterior to the mandibular 1st molar• Anterior 2/3rd of tongue and floor of the
mouth• Lingual soft tissue and periosteum
JM 37
INDICATION• Procedures on multiple mandibular teeth in
one quadrant• When buccal soft tissue anesthesia (anterior
to the first molar) is necessary• When lingual soft-tissue anesthesia is
necessaryCONTRAINDICATION• Infection or acute inflammation in the area of
injection
JM 38
TECHNIQUE• 25 gauge needle is used• Area of insertion – Mucous membrane on the
medial side of the mandibular ramus near the mandibular foramen
• Target area – Inferior alveolar nerve as it passes downward towards the mandibular foramen but before it enters the foramen
JM 39
• Landmarks 1. Coronoid notch2. Pterygomandibular raphae3. Occlusal plane of the mandibular
posterior teeth
JM 40
• Patient position – supine or semisuppine• Operator position –
1. Right IANB – 8 o’clock position2. Left IANB – 10 o’clock
LEFT RIGHT
JM 41
PROCEDURE• With the left thumb, palpate the coronoid
notch• With the same finger, pull the buccal soft
tissue laterally to gain visibility and make the tissue taut
• The needle insertion point lies three fourths the anteroposterior distance from the coronoid notch to the deepest portion of pterigomandibular raphae
JM 42
• Prepare the tissue of injection site• Place the barrel of the syringe in the corner of
the mouth on the contralateral side• Penetrate the tissue with the needle and
slowly advance till bony resistance is felt
JM 43ABOVE 12 YEARS
6 – 12 YEARS
BELOW 6 YEARS
PEDIATRIC PATIENT
JM 44
• Average depth of penetration is 20 – 25 mm• When bone is contacted, withdraw 1 mm to
prevent sub-periosteal injection• Aspirate• If negative, slowly deposit 1.5 ml of anesthetic
over a period of 1 minute• Slowly withdraw the syringe till half of its
length remains in the tissue
JM 45
• Re-aspirate• If negative, deposit a portion of remaining
anesthetic (.1 ml) to anesthetize lingual nerve• Withdraw the syringe slowly and make the
needle safe• After about 20 seconds, return the patient to
upright or semi-upright position• Wait for 3 to 5 minutes before commencing
the dental procedure
JM 46
Buccal Nerve Block
• Needle used – 25 Gauge• Nerve Anesthetized – Buccal Nerve (branch of anterior division of
mandibular nerve)• Site of injection – Mucous membrane distal and buccal to the
most distal molar tooth in the arch• Amount of LA required - .3 ml
JM 47
Area Anesthetized• Soft tissue and periosteum
buccal to the mandibular molar teeth
JM 48
INDICATION• When buccal soft tissue anesthesia is
necessary for dental procedures in the mandibular molar region
CONTRAINDICATION• Infection or acute inflammation in the area of
injection
JM 49
TECHNIQUE• 25 Gauge long needle is recommended• Area of insertions – mucous membrane distal
and buccal to the most distal molar tooth in the arch
• Target area – Buccal Nerve as it passes over the anterior border of the ramus
• Landmarks – mandibular molars & mucobuccal fold
• Orientation of bevel – towards the bone
JM 50
PROCEDURE• Operator position
Right BNB – 8 o’clock positionLeft BNB – 10 o’clock position
• Patient position – supine or semisupine• Prepare the tissue for needle penetration• With left index finger, pull the buccal soft
tissues in the area of injection laterally to improve visibility and make the tissue taut
JM 51
OPERATOR AND PATIENT POSITIION FOR BNB
LEFT RIGHT
JM 52
• Align the needle parallel to the occlusal plane and buccal to the teeth and direct it towards the injection site
• Penetrate the mucous membrane at the injection site, distal and buccal to the last molar
JM 53
• Advance the needle until mucoperiosteum is gently contacted
• Depth of penetration – 1 to 2 mm• Aspirate• Slowly deposit .3 ml of LA over 10 seconds• Withdraw the syringe slowly and immediately
make the needle safe• Wait for approximately 1 minute before
commencing the dental procedure
JM 54
IANB & BUCCAL NERVE BLOCK
JM 55
INTRAPULPAL INJECTION
JM 56
• Here local anesthetic solution is delivered directly to the pulp using a bent needle
• mostly used to anesthetize mandibular 1st molar which may be sometimes difficult to achieve using other procedures like nerve blocks in case of inflammation in the site of infection
• Advantages of Intrapulpal injection – • Requires minimum volumes of LA solution• Immediate onset of action• Very few post operative complications
JM 57
• Nerve anesthetized – Terminal nerve endings at the site of injection
in the pulp chamber and canals of the involved tooth
• Areas anesthetized – tissues within the injected toothINDICATION when pain control is necessary for pulpal
extirpation or other endodontic treatment in the absence of adequate anesthesia from other technique
JM 58
TECHNIQUE• Insert a 25 or 27 gauge short or long needle
into the pulp chamber or the root canal • Wedge the needle firmly into the pulp
chamber or root canal• Deposit .2 to .3 ml of anesthetic solution
under pressure• Resistance to the injection of the drug should
be felt Bend the needle, if necessary, to gain access to the canal
JM 59
• When the intrapulpal injection is performed properly, a brief period of sensitivity (ranging from mild to very painful) usually accompanies the injection
• Pain relief occurs immediately thereafter, permitting instrumentation to proceed atraumatically
• Instrumentation may begin approximately 30 seconds after the injection
JM 60
TOPICAL ANESTHESIA
• It is the method of obtaining anesthesia by the application of suitable agent to an area of either the skin or mucous membrane through which it penetrates to anesthetize superficial nerve endings
• It is commonly used to obtain anesthesia of the mucosa prior to injection
JM 61
Topical anesthetic Sprays
Active ingredient – 10% Lignocaine HydrochlorideOnset of Action – 1 minuteDuration of Action – 10 minutesAvailable in different fruit flavors
JM 62
Technique
• Dry the area of application (mucous membrane)• Spray an appropriate quantity of the solution
into a small cotton roll• Place the cotton role on the site of injection in
the sulcus• Wait for 1 minute before inserting the needle to
allow the topical anesthetic to act
JM 63
Topical Anesthetic Ointments & Jelly• Ointments – 5% Lignocaine (onset of action is 3-4 minutes)• Emulsions – 2% Lignocaine
BENZOCAINE – • Odorless white crystalline powder
(soluble in alcohol and fatty oils)• Safe – due to its low aqueous solubility, It is
very slowly absorbed from the oral tissues and wounds
JM 64
RECENT ADVANCES IN LA
JM 65
EMLA (Eutectic Mixture of LA)
• Mixture of LIGNOCINE & PRILOCAINE• EMLA cream is used for numbing the skin
before inserting the needle• It is designed to go through intact skin• Potential for toxic effects of LA is minimal• Use in children under 6 months is
contraindicated due to the possibility for developing methemoglobinemia due to prilocaine
JM 66
Intraoral lignocaine patch
• Contains 10% or 20% lignocaine • Placed for 15 minutes on the buccal mucosa of
the maxillary or mandibular premolar area, 2 mm apical to the mucogingival junction
JM 67
Electronic Dental Anesthesia
• Uses the principle of Transcutaneous Electrical Nerve Stimulation (TENS)
• Requires good patient co-operation• It increases salivary blood flow
JM 68
Complications Of LA(Pediatric Patient)
JM 69
NUMB FEELING• Invites the possibility of an unnecessary
emotional upset of the child
How to Avoid ?• The dentist should explain beforehand to the
child that he/she will experience the numbness after the administration of LA
JM 70
LIP BITING
How to avoid ?• Warning should be given immediately following
injection procedure. Warning should be repeated before the child leaves the dental chair.
• Parents should also be warned about this possible complication if not attended properly
JM 71
JM 72
Complication due to Injection of LOCAL ANESTHETIC SOLUTION
3 TYPES –
1. Method of deposition of the drug2. Drug dosage dependent reactions3. Hypersensitivity reactions
JM 73
Method of deposition of drug
VASOVAGAL SYNCOPE• Due to peripheral pooling of blood and
reduction in cerebral blood flow
• Rarely encountered in children due to constant movement of extremities coupled with crying out loud which prevents the peripheral pooling of blood
JM 74
BROKEN NEEDLE• Due to sudden movement during administration
of the LA solution
FAILURE TO ACHIEVE ANESTHESIA• This may be due to
1. Improper Technique of administration2. Normal anatomic Variation
JM 75
FACIAL NERVE PARALYSIS
• Encountered during IANB• Due to injection of LA solution into parotid
gland• Facial Nerve gets temporarily paralyzed• Effects wears off over a period of time during
which the eye needs to be protected
JM 76
TRISMUS• Due to trauma to muscles or blood vessels of
infra temporal fossa• Intramuscular or supramuscular injection of
LA• Hemorrhage• Hematoma and scar formation
How to Avoid ?• Avoid repeated injections or multiple
insertions into the same area• Use only minimum effective volume of LA
JM 77
Drug Dosage Dependent Reactions• At Low levels - ↑ Heart rate and Cardiac Output• At High levels - ↓ Cardiac Output & Circulatory
Failure• Methemoglobinemia – Caused by Benzocaine & PrilocainHow To Avoid ?• Use Of Aspiration Technique• Keeping the amount of agent administered
below toxic limit
JM 78
CAUSES OF TOXICITY• Use of excessive dose of LA• Inadvertent intravascular injection• Slow detoxification or biotransformation• Slow elimination or redistributionMajority of the toxic reactions to LA are
immediate, mild and transientThey can be avoided by closely monitoring
during the injection, injecting slowly and withdrawing the needle at the first signs of an adverse response
JM 79
TOXICITY DUE TO VASOCONSTRICTORS• They causes local ischemia and thus retard
their own absorption• Patients with ischemic heart diseases and
hypertension are at high risk of toxicity if administrated intravascularly
JM 80
Manifestation Of Toxicity
• Cardiac Depression• Coma• Convulsions• Unconsciousness• Muscular twitching• Visual and auditory disturbances,
light headedness, numbness of tongue
Conc
entr
ation
of
LA i
n P
lasm
a
JM 81
Hypersensitivity (rare)
Manifests as • Utricaria • Facial edema• Breathlessness
Methyl paraben (protein) is the main allergent• It has been replaced in recent times
JM 82
THANK yOU
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