Dr. Rehab Elsharkawy BDS, MS, Ph.D.y , ,Lecturer of Oral & Maxillofacial Surgery

Faculty of Oral & Dental Medicine ‐Cairo University

Anesthesia: it means the complete loss of all 

sensations including that of painsensations including that of pain.

Local anesthesia: loss of sensation in ai ib d f th b d d bcircumscribed area of the body caused by

depression of excitation in nerve endings or aninhibition of conduction process in peripheralinhibition of conduction process in peripheralnerves

General anesthesia: it is a condition in which thepatient does not react to any stimulus and does nothave any memory of what has happenedhave any memory of what has happened(unconscious).

Indications of local anesthesia:

Elimination of pain during treatment (painlessd ti t )dentistry).Diagnostic purposes for vague pain in andaround the face and neck.a ou d t e ace a d ecTo reduce hemorrhage (e.g. during surgery undergeneral anesthesia).Control of pain in the post operative period.

Nothing that is done by a dentist for a patient is ofgreater importance than the administration of a drugg p gthat prevents pain during dental treatment.

Yet the act of administrating a local anestheticfrequently induces great anxiety or is associated withpain in the recipientpain in the recipient.

Not only can the injection of LA produce fear or painNot only can the injection of LA produce fear or pain,it also may be a factor in the occurrence of emergencymedical situations.

LA administration should not be painfulLA administration should not be painful.

There are two components to an atraumatic

An injection may be routine for

There are two components to an atraumaticinjection: a communicative and a technical aspect.

An injection may be routine forthe dentist, but it is often anunpleasant experience for thepatient. Psychological support,p y g pp ,is essential, and will increasethe patient`s confidence in hisdentist.

During needle insertion.During needle withdrawal.gDuring soln deposition.

General principles involved in injection General principles involved in injection ddproceduresprocedures

Use a sterilized sharp needle1. Use a sterilized sharp needle.2. Check the flow of the local anestheticsolutionsolution.

3. Use anesthetic cartridge and syringewith temperature as close to roomwith temperature as close to roomtemperature as possible.

4. Proper positioning of the patient.

Comfort to the patientComfort to the patientpp

Tight fitting garments may partially obstruct the flow of Tight fitting garments may partially obstruct the flow of blood in the head and neck area. A blouse or shirt blood in the head and neck area. A blouse or shirt collar should be loosened to avoid thiscollar should be loosened to avoid this..

5. Dry the site of injection and remove anydebris to obtain adequate visibility.

6 Apply topical antiseptic6. Apply topical antiseptic.

7. Apply the topical anesthetic agentpp y p g(ointment or spray). Ointment is better as spray tend to tastebadly and it is difficult to be restricted.

8.. AlwaysAlways communicatecommunicate withwith thethe patientpatientusingusing reassuringreassuring wordswords andand praisepraise..NeverNever leaveleave thethe patientpatient alonealone afterafter ananinjectioninjection.. AllergicAllergic oror otherother reactionsreactions maymayoccuroccur instantaneouslyinstantaneously atat anyany timetime..

9 Always establish a firm hand rest during9. Always establish a firm hand rest duringthe injection procedure.

10 Stretch the tissue at the site of needle10. Stretch the tissue at the site of needlepenetration in areas with loose soft tissue.This allows the needle to penetrate withpless resistance.

11. Keep the syringe out of the patient’ssight as much as possible.

12 Slowly advance the needle through the12. Slowly advance the needle through themucosa to desired target.

13. Always aspirate prior to deposition of the13. Always aspirate prior to deposition of thedrug.

Sl l d i h l l h i l i (14.Slowly deposit the local anesthetic solution.(e.g.1ml/minute at least). Observe the patient duringinjection.j

15.Slowly withdraw the syringe. Cap the needle anddiscard.

16 Never leave patients unattended following16.Never leave patients unattended followingadministration of local anesthetic.

17.Record the injection in the patients chart.7 j p

Basic injection techBasic injection tech

Topical anesthesiaTopical anesthesiaIn this method the free nerve endings, in anaccessible structures as the skin and mucousmembrane , are rendered incapable ofstimulation by applying chemical ointment orstimulation by applying chemical ointment orsolution which penetrates through the epitheliumto reach the free nerve endings.

Infiltration AnesthesiaIn local infiltration small terminal nerve

di i th f th fl d dendings in the area of the surgery are flooded with local anesthetic solution, rendering them insensible to pain.p

Fi ld bl kField blockThe field block method of securing regional anesthesiaconsists of depositing a solution in proximity to thelarger terminal nerve branches so that the area to beganaesthetized is walled off or circumscribed to preventthe central passage of afferent impulses.

Nerve blockNerve block

The term nerve block applies to that method of securing regional anesthesia by depositing a suitable local anesthetic solution within closesuitable local anesthetic solution within close proximity to a main nerve trunk, and thus preventing afferent impulses from traveling p g p gcentrally beyond that point.

The methods of accomplishing field block and local infiltration are:and local infiltration are:

1. Submucosal injections2. Paraperiosteal injections (infiltration)3. Intraosseous injections

I t t l i j ti4. Intraseptal injections5. Intraligamentary injections (periodontal

ligament PDL)ligament, PDL)

Advantages of nerve block anesthesia ascompared with infiltration:1. More profound anesthesia2. Longer duration3. No local ischemic effect from the vasoconstrictor

agent is present. Good blood supply helps quickerhealing and less postoperative pain.

4. Fewer needle punctures5. If infection is present, the possibility of infection

dissemination by the infiltration needle is prevented6. Large field of operation by the use of few volume of

anesthetic solutions, thus decrease the chance fordevelopment of drug toxicity.

Factors that influence the choice ofFactors that influence the choice of the anaesthetic technique:q1. Area to be anaesthetized2. Profoundness requiredq3. Duration of anesthesia4. Presence of infection5. Age of the patient6. Condition of the patient7 H t i if d d7. Hemostasis, if needed8. Skill of the operator.

Anesthesia Anesthesia of the upperof the upperof the upper of the upper

jawjaw

Techniques of Maxillary Anesthesiaq f y

1. Supraperiosteal (Infiltration) technique.. Sup ape ostea ( t at o ) tec que.2. Greater (anterior) palatine nerve.3. Nasopalatine nerve block.3 p4. Middle and Anterior Superior alveolar (AMSA, Infraorbital) nerve block.

5. Posterior Superior Alveolar (PSA) nerve block.6. Maxillary nerve block.

Supraperiosteal InjectionSupraperiosteal InjectionSupraperiosteal InjectionSupraperiosteal InjectionPara periosteal or local Para periosteal or local pp

infiltrationinfiltration

Technique25‐27 gauge short needle.Lift the lip pulling the tissues taut.Hold the syringe parallel to the longHold the syringe parallel to the longaxis of the tooth.Orient needle so bevel faces bone.Insert the needle in the area at theInsert the needle in the area at theheight of mucobuccal fold above theroot apex.(Target area)Advance the needle until the bevel isAdvance the needle until the bevel isat the apex.Aspirate then deposit o.6ml slowlyover 20 sec.(don’t permit the tissues toover 20 sec.(don t permit the tissues toballoon).Slowly withdraw the needle.Wait for 3‐5 min before starting theWait for 3 5 min before starting theprocedure.

When contact is madewith the bone, a slowinjection of solution willinjection of solution willeffect anesthesia of thetarget teeth, and one, orboth, of the adjacentteeth.

The injection of thesolution will ensureadequate analgesia ofadequate analgesia ofthe tooth pulp in thisarea.

The area of soft tissueanesthesia correspondsanesthesia correspondsto the coloured zone.

Spread of analgesiaSpread of analgesiaSpread of analgesiaSpread of analgesia

PremolarsPremolarsPremolars Premolars

Th l f th jThe premolars of the upper jaware anaesthetized by infiltrationin the buccal fold next to theteeth. After puncture, the needle isadvanced axially.

MolarsMolarsMolars Molars

Buccal I filt tiInfiltration

( h ) dl d•A 25‐gauge (short) needle is used.• The point of insertion of the needle is located by the point of intersection oftwo imaginary lines.First is a vertical line parallel with the long axis of the tooth and dividing itFirst is a vertical line parallel with the long axis of the tooth and dividing it

into two equal halves.Second is a horizontal line made by the mucobuccal fold just above the apex

of the rootof the root.• The needle should be directed at 45 degree angle to the plane of the outercortical plate.

Buccal InfiltrationThe needle is inserted through the mucousmembrane and underlying connectivemembrane and underlying connectivetissue until it gently come in contact with theperiosteumwith the bevel facing the bone.p g

Palatal Infiltrationa ata t at o

The point of insertion of the needle is on the palatal side of theh d b h l f h h dp p

tooth, midway between the cervical margin of the tooth andthe midline of the palate.The needle should be at right angel with the palate (it shouldb d d f h i id ) l f hbe advanced from the opposite side), 0.2 to 0.3 ml. of theanesthetic solution is injected slowly.NB. Injection of large amount of the solution may causel hi d l ti f th l t l d tsloughing and ulceration of the palatal mucosa due toseparation of a large area of the dense palatal mucoperiosteumfrom the bone with subsequent loss of its blood supply.

Spread of analgesiaSpread of analgesia

Teeth and bone, and soft tissue anesthesia after buccal fold injection of 1.0ml solution.

After additional infiltration of the palatine nerves by injection at the palatal side.

To anaesthetize the palatal gingiva and mucosa in the premolar/molarregion, insert the needle 0.5‐1 cm above the gingival margin betweensecond and thirdmolars and at right angles to themucosasecond and thirdmolars and at right angles to themucosa.

When the needle reaches bone withdraw it 1mm and inject about o.1ml. slowly.

The The infraorbitalinfraorbitalnerve blocknerve block

The center of the inferior margin of the orbit is palpated with the indexfinger, then gently passed 1cm below the margin.

The upper lip is lifted with the index.The needle is introduced into the buccal fold directly over the first premolar.The needle is gently pushed forward near to the bone towards the tip of theindex finger.Aspiration is performed.About 1ml of solution is slowly injected.

The injection of 1ml at the infraorbital foramen willanaesthetize the teeth and bone within the colored areaanaesthetize the teeth and bone within the colored area.

Posterior Superior Alveolar NervePosterior Superior Alveolar Nerve Block (PSA)

Indications:1. When Supraperiosteal injection is contraindicated e.g.i f iinfection.

2.When treatment involves two or more maxillarymolarsmolars.

Contraindications: When there is a risk ofhemorrhage.hemorrhage.

Posterior Superior Alveolar Nerve Block p(PSA)

TechniqueTechnique:A 25‐gauge long needle isrecommended.Th l f i d i d hThe left index is moved over themucobuccal fold in a posteriordirection from the premolar region tillit reaches the zygomatic process till itit reaches the zygomatic process till itrests on a concavity in the mucobuccalfold.The finger is rotated so that fingernailThe finger is rotated so that fingernailfaces medially. Then the finger ismoved to be at right angle to themaxillary occlusal plane and at 45°y p 45angle to the sagittal plane.

Posterior Superior Alveolar Nerve Block (PSA)

The needle is inserted into theheight of mucobuccal fold overthe second molar in a line parallelto the fingerto the finger.The needle is slowly advanced forabout 16 mm, to come close to the

i l l fposterior alveolar foramen.Aspiration should be donecarefully to avoid the pterygoidcarefully to avoid the pterygoidvenous plexus.Slowly inject 0.9 to 1.8 ml ofl i isolution over one minute.

Posterior Superior Alveolar Nerve BlockPosterior Superior Alveolar Nerve Block (PSA)

Complications: 1 Hematoma formation1. Hematoma formation.2. Intravenous injectionPrevention:Prevention:1. The needle should never be inserted more than 

2.5cm to avoid penetration and/or injection of the 5 p / jpterygoid venous plexus. 

2. Aspiration before injection.