Maxillary Injection Techniques

Anatomy

Anatomy

Atraumatic Injection Protocol

3 Main Types of Maxillary Injections:

1) Local Infiltration

2) Field Block

3) Nerve Block

Local InfiltrationIncision (treatment) is done in the same area in which the local anesthetic was deposited (interproximal papilla before Scaling and Root Planing)

Field BlockLocal anesthetic is deposited toward larger nerve terminal branchesTreatment is done away from the site of local anesthetic injectionMaxillary injections administered above the apex of the tooth to be treated are properly referred to as field blocks not local infiltrations

Nerve BlockLocal anesthetic is deposited close to a main nerve trunk, usually at a site removed from the area of treatment (PSA, IANB, NPB)

Types of Injections1) Supraperiosteal Injection2) Intraligamentary (PDL) Injection3) Intraseptal Injection4) Intracrestal Injection5) Intraosseous Injection6) Posterior Superior Alveolar (PSA) Nerve Block7) Middle Superior Alveolar (MSA) Nerve Block8) Anterior Superior Alveolar (ASA) Nerve Block9) Maxillary Nerve Block (2nd Division)10) Greater Palatine Nerve Block11) Nasopalatine Nerve Block12) Anterior Middle Superior Alveolar (AMSA) Nerve Block13) Palatal Approach Anterior Superior Alveolar (P-ASA) Nerve Block

Maxillary and Mandibular InjectionsThe following are used in both arches:Supraperiosteal InjectionIntraligamentary (PDL) InjectionIntraseptal InjectionIntraosseous Injection

Supraperiosteal Injection

1) Supraperiosteal Injection

Used for pulpal anthesia in maxillary teeth

Anesthetizes large terminal branches of the dental plexus

Greater than 95% success rate

1 or 2 teeth

Supraperiosteal InjectionDense bone covering the apices of the teeth can lead to failure-maxillary molar of children (zygomatic bone obscures)-central incisor of adults (nasal spine obscures)

Negligible positive aspiration rate (less than 1%)

Should not be used for large areas (multiple sticks/large amount of local anesthetic solution must be used)

Technique Supraperiosteal Injection

1) 25 or 27 gauge short needle is recommended

2) Insert needle at height of mucobuccal fold over apex of desired tooth

3) Apply topical anesthetic for at least one minute

4) Orient bevel toward bone; lift lip pulling tissues taut

5) Hold syringe parallel to long axis of the tooth being anesthetized6) No resistance to penetration should be felt and no patient discomfort7) Aspirate twice8) Deposit .6 ml (one-third of a cartridge) into tissue over 20 seconds 9) Do not allow tissues to balloon10) Wait 3 to 5 minutes to begin dental treatment

Problems/Failures

If tooth does not anesthetize the needle tip could be below the apex of the tooth resulting in inadequate anesthesiaIf the needle lies too far from the bone then anesthesia will be inadequate because the solution was deposited in the soft tissue (lip)The needle must be oriented toward the periosteum but should be managed properly to avoid tearing the highly innervated periosteum

Supraperiosteal vs. InfiltrationThese two words are used incorrectly; what most practitioners refer to as an infiltration injection is actually a field block

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Posterior Superior Alveolar Nerve Block (PSA)

2) Posterior Superior Alveolar Nerve Block

Highly successful nerve block with greater than 95% success

Effective for maxillary 1st, 2nd and 3rd molars and buccal periodontium

Mesiobuccal root of the maxillary 1st molar is not consistently innervated by the PSA nerve

Short dental needle is used for all but the largest of patients

Average depth of soft tissue penetration is 16 mm (short needle is 20 mm in length)

28% of maxillary 1st molars mesiobuccal roots are innervated by the middle superior alveolar nerve (MSA)

When the risk of hemorrhage is too great as with a hemophiliac, you should use the supraperiosteal or PDL injections

Patient should feel no pain with this injection because bone is not contacted and there is a large area of soft tissue into which the solution is deposited

Positive aspiration risk is 3.1%

Patient will often say that they do not feel numb; reason why is because they are accustomed to the intense feeling of anesthesia experienced by the IANB; reassure patient that you are going to make sure they are comfortable during the procedure

Technique PSA Nerve Block

1) 25 gauge short needle is recommended

2) Insert needle at the height of the mucobuccal fold above the maxillary 2nd molar

3) Target area is the PSA nerve which is posterior, superior and medial to the posterior border of the maxilla

4) Apply topical anesthetic for at least one minute

5) Have patient open their mouth half way which makes more room

6) Retract the patients cheek with mirror

7) Pull the tissues taut

8) Orient bevel toward bone

9) Insert needle at height of mucobuccal fold over the 2nd maxillary molar

10) Advance needle upward, inward and backward direction

11) Odd feeling of having no resistance whatsoever 12) Penetrating to an average depth of 10-14 mm is adequate

13) Aspirate in two planes by rotating bevel one quarter turn

14) Deposit 0.9 ml of a cartridge (1/2 cartridge)

15) Wait 3 to 5 minutes to start treatment

Advance the needle in one movement, not threeseparate movements; usually atraumatic to most patients

Problems/Failures (PSA)

Hematoma formation if needle is overinserted too far posteriorly

Pterygoid plexus of veins leads to this hematoma

Visible intraoral hematoma develops within minutes; bleeds until the pressure of the extravascular blood equals that of the intravascular blood which can result in a large, unsightly hematoma

Patients will usually claim that they do not feel any anesthesia which is not uncommon because patients can not reach this area to gauge their own level of anesthesia

If using a long dental needle the maximum insertion should be one-half on its length or 16 mmProblems/Failures (PSA)

Middle Superior Alveolar Nerve Block (MSA)

3) Middle Superior Alveolar Nerve Block

Middle Superior Alveolar Nerve is not present in 28% of the population

When the infraorbital nerve block fails to provide anesthesia to teeth distal to the maxillary canines, the MSA is indicated

MSA provides anesthesia to 1st and 2nd premolars and mesiobuccal root of maxillary 1st molar; anesthetizes buccal periodontium and bone

If MSA is absent the premolars and mesiobuccal root of maxillary 1st molar is innervated by the ASA

Positive aspiration risk is less than 3% (negligible)

Infraorbital nerve block can block 1st premolar, 2nd premolar and mesiobuccal root of the maxillary 1st molar if you need an alternative block when the MSA is not adequate

Technique MSA Nerve Block

1) 25 or 27 gauge long or short needle

2) Insert needle at the height of the mucobuccal fold above 2nd maxillary premolar

3) Target is the maxillary bone above the apex of the 2nd maxillary premolar

4) Orient bevel toward bone to avoid tearing periosteum

5) Apply topical anesthetic for one minute

6) Pull tissues taut

7) Penetrate tissues placing bevel of needle well above the apex of the 2nd maxillary premolar

Technique- Middle Superior Alveolar Nerve Block

8) Aspirate

9) Slowly deposit 0.9-1.2 ml of solution

10) Wait 3 to 5 minutes before starting treatment

Problems/Failures MSA

Anesthetic not deposited above the apex of the 2nd premolar

Solution deposited into the soft tissue too far from the periosteum (lip)

Hematoma may develop; Dentist should apply pressure to the area with gauze for at least sixty (60) seconds; up to 2 to 3 minutes

Middle Superior Alveolar Nerve Block

Anterior Superior Alveolar Nerve Block (ASA)

Highly successful extremely safe block that causes hesitation in most clinicians

Provides profound pulpal and soft tissue anesthesia from the maxillary central incisor distal to the premolars in 72% of patients

Used in place of the supraperiosteal injection

Uses less anesthetic solution than the supraperiosteal injectionSupraperiosteal 3.0 ml solutionASA 1.0 ml solution

#1 fear is damage to the patients eye which is unfounded

Also known as the Infraorbital Nerve Block which is inaccurate

Failed ASA is just a supraperiosteal injection over the 1st premolar

Areas Anesthetized ASA Nerve Block

1) Pulp of the maxillary central incisor through the canine

2) 72% of patients have premolars and mesiobuccal root of 1st molar anesthetic

3) Buccal periodontium and bone of the above teeth

4) Lower eyelid, lateral aspects of the nose and upper lip

When Do I Use This Block?

1) Dental procedures involving more than one tooth, i.e., central and lateral incisor

2) Inflammation/Infection precluding the use of the supraperiosteal injection

3) Ineffective supraperiosteal injections due to dense cortical bone

Technique ASA Nerve Block

1) 25 gauge long needle is recommended

2) Insert needle at the height of the mucobuccal fold over the 1st premolar

3) Target: Infraorbital Foramen

4) Landmarks: Infraorbital Notch, Mucobuccal fold, Infraorbital Foramen

5) Apply topical anesthetic for at least one minute

6) Feel the infraorbital notch moving your finger down the notch palpating the tissues gently; the outward bulge is the lower border of the orbit which is the roof of the infraorbital foramen; continue the finger inferiorly until a depression is felt which is the infraorbital foramen

7) Maintain pressure over the foramen while inserting the needle down the long axis of the 1st premolar

8) Advance the needle slowly until bone is contacted gently which is the upper rim of the infraorbital foramen

9) 16 mm total advancement of needle;1/2 of long needle length

10) Estimate the distance between the infraorbital foramen and mucobuccal fold

11) Aspirate

12) Deposit 1.0 ml of anesthetic solution

13) Administrator can feel the anesthetic expanding the tissue with finger tip

14) Maintain finger pressure over the foramen for at least one minute to disperse the anesthetic solution

15) Needle should not be palpable in most patients

16) Wait 3 to 5 minutes for anesthesia to result

Problems/Failures (ASA)

Failure is from the needle deviating to the medial or lateral away from the infraorbital foramen

Failure to reach the infraorbital foramen will result in anesthesia of the lateral side of the nose, upper lip and lower eyelid but not the teeth

Hematoma formation can result although rarely; apply pressure to area for 2 to 3 minutes; at least 60 seconds

Palatal Anesthesia

Palatal Anesthesia

Easily one of the most traumatic experiences for dentists due to the pain that is sometimes elicited from the patients

Palatal injections can be administered atraumatically

STEPS- Results in painless palatal injections

1) Apply topical for two minutes

2) Apply pressure to site both before and during deposition of the solution

3) Deposit solution slowly

5 PALATAL INJECTIONS

1) Anterior (Greater) Palatine Nerve Block: no pulpal anesthesia 2) Nasopalatine Nerve Block: no pulpal anesthesia

3) Local Infiltration: no pulpal anesthesia

4) P-AMSA: pulpal and soft tissue

5) P-ASA: pulpal and soft tissue

Greater Palatine Nerve Block

GP Nerve Block (soft tissue and bone only)

Anesthetizes palatal soft tissue distal and medially to the canine (posterior portion of the palate)

Tissues around the Greater Palatine Foramen are able to accommodate a larger volume of solution than the tissue in the vicinity of the Nasopalatine Foramen less patient discomfort

Indications for palatal injections: 1) Scaling and root planing

2) Subgingival restorations3) Deep placed matrix bands

4) Extractions (oral surgery)

Technique Greater Palatine Nerve Block

1) 27 gauge short needle

2) Insert needle in soft tissue slightly anterior to the greater palatine foramen

3) Target is the greater palatine nerve as it passes from the foramen between the soft tissue and bone of the hard palate

Locate the Greater Palatine Foramen:

-use cotton swab/mirror handle

-place a cotton swab at the junction of the maxillary alveolar process and the hard palate

-press firmly into tissues moving posteriorly from the maxillary 1st molar

-swab falls into the depression of the greater palatine foramen

4) Foramen is most often located distal to the 2nd maxillary molar

5) Apply considerable pressure to cotton swab in area of foramen until a noticeable ischemia occurs; hold pressure for 30 seconds before injection

6) Continue to apply pressure throughout the injection with the cotton swab

7) Slowly advance the needle until bone is gently contacted

8) Depth of penetration is usually less than 10 mm

9) Aspirate

10) Deposit solution very slowly

Do not enter the greater palatine canal

There is no reason to have the needle penetrate the canal

There is no negative repercussion except post-operative pain

Nasopalatine Nerve Block

Nasopalatine Nerve Block (soft tissue and bone only)

Considered by many to be the most traumatic, painful injection of all the dental injectionsMost important injection to follow the protocol about to be explainedAnesthetizes the anterior portion of the hard palate (soft and hard tissues) from the mesial of the left premolar to the mesial of the right premolarUse this injection for the same reasons as Greater Palatine Nerve BlockTarget area is the incisive foramen beneath the incisive papilla

Technique Nasopalatine Nerve Block

1) 27 gauge short needle is recommended

2) Insertion point: palatal mucosa just lateral to the incisive papilla

3) Approach the injection site at a 45 degree angle

4) Apply topical anesthetic for two minutes

5) Apply considerable pressure to the incisive papilla until ischemia

6) Continue to apply pressure to the cotton applicator tip while injecting

7) Advance the needle until bone is gently contacted 8) Depth of needle penetration is usually 5 mm

9) Slowly deposit cartridge over a 30 second interval

10) Wait 2-3 minutes for anesthesia

Other Than P-ASA and Maxillary Nerve BlocksThere is no reason to enter the GreaterPalatine Foramen or the NasopalatineForamen when providing these injections

do not advance needle more than 5 mminto the incisive canal because it could enter the floor of the nose causing infection

Back SprayDuring palatal injections, the pressuregenerated within the syringe will causethe solution to spray into your mask/face;always wear the appropriate safety glasses and mask when giving any injectionregardless of how trivial it may seemat the time

2nd Example of Nasopalatine InjectionTechnique 2nd Example of Nasopalatine InjectionInsertion Points:1) Labial frenum; midline of maxilla (0.3 ml over 15 seconds)2) Interdental papilla of #8 and #9 (0.3 ml over 15 seconds)3) Palatal soft tissues lateral to the incisal papilla (contact bone)

2nd Example of Nasopalatine InjectionImportant Points:Topical and pressure anesthesia on the palate are not necessary because the first injection anesthetized the palatal tissuesContact bone on the 3rd injection (incisive papilla) onlyInterdental papilla between maxillary central incisors is sore for a few daysGreater palatine nerve may overlap and lead to inadequate anesthesia of the canine and 1st premolar

Local Infiltration of the Palate

Local Infiltration of the PalateAnesthetizes the terminal branches of the Greater Palatine Nerve and Nasopalatine Nerve

Anesthetizes the soft tissue in the immediate vicinity of the injection

Indications for Palatal Anesthesia:

1) Hemostasis during procedures of a minimal area of tissue

2) Palatogingival pain control for rubber dam clamps, retraction cord placement and small surgical procedures

Local Infiltration of the PalateImportant Points: -Gate control method (inhibitory neuron prevents the projection neuron from sending signals to the brain (gate is closed)) of pain removal is used with -these injections using a cotton swab for pressure resulting in blanching tissue -Target area is the palatal tissue 5 to 10 mm from the free gingival margin -Masticatory mucosa of the hard palate is only 3 to 5 mm thick -Palatal Infiltrations are safe areas anatomically to deposit anesthetic

P-ASA

P-ASA Palatal Approach Anterior Superior Alveolar Nerve BlockDescribed in the 1990s by the inventors of the CCLAD systemsComparative to the Nasopalatine Nerve BlockInsertion: lateral point of the incisive papilla but the big difference:

NEEDLE TIP IS POSITIONED IN THE INCISIVE CANAL

Deposit 1.4 1.8 ml of solution at 0.5 ml per minute

Primary method of achieving bilateral pulpal anesthesia of the maxillary anterior six teeth; anterior palatal 1/3rd

Provides profound soft tissue anesthesia of the gingiva and mucoperiosteum

Soft tissue of the facial attached gingiva is achieved anterior to the maxillary anterior six teeth

P-ASA is the 1st injection to produce bilateral pulpal anesthesia of the maxillary anterior six teeth from a single injection

MAIN POINT OF THIS INJECTION: P-ASA is designed to provide pulpal anesthesia of the maxillary anterior six teeth in addition to the facial gingival soft tissue and mucoperiosteum

it does not anesthetize the lip as with the regular mucobuccal fold approach; esthetic Dentistry can then be assessed without dealing with lip anesthesia when smiling

Palatal approach allows anesthesia to be limited to the subneural plexus for the maxillary anterior teeth and nasopalatine nerve

Minimum volume for injection is 1.8 ml (full cartridge) over 0.5 ml/minute

Insert needle very slowly

4% anesthetics should have volume reduced by (Prilocaine/Articaine)

Do not use 1:50,000 epinephrine

May need supplemental mucobuccal fold injections for canines because of their very long roots

Palatal ulcers develop from ischemia 1-2 days after treatment and are self- limiting; healing occurs in 5-10 days

Technique P-ASA

1) 27 gauge short needle is recommended2) Insert needle just lateral to the incisive papilla in the papillary groove3) Target is the nasopalatine foramen4) Needle held at 45 degree angle to the palate (same as central incisors)

5) Insert needle 6 to 10 mm; if resistance is found do not force needle6) Insert needle 1-2 mm every 4-6 seconds while administering solution7) Resistance means you have to reinsert the needle; careful of nose floor8) Aspirate9) Deposit 1.8 ml of anesthetic solution very slowly 0.5 ml/minute10) Patient may feel needle shock very disturbing to patient

Maxillary Nerve Block

1) Greater Palatine Approach

2) High Tuberosity Approach

Maxillary Nerve Block Facts

Also known as a 2nd Division block

Anesthetizes the maxillary division of the trigeminal nerve

Areas Anesthetized:

1) Pulpal anesthesia of all teeth on the side of injection (ipsalateral)2) Buccal periodontium and bone on the side of injection3) Soft tissues and bone of the hard palate/soft palate medial to midline4) Skin of lower eyelid, side of the nose, cheek and upper lip

Maxillary Nerve Block ApproachesIt would require 4 other injections to get the effect of the Maxillary Nerve Block i.e., PSA, Infraorbital, Greater Palatine and Nasopalatine

2 Approaches:1) Greater Palatine Approach2) High Tuberosity Approach

1) Greater Palatine Approach Technique

25 gauge long needle recommended

Insert into palatal soft tissue over greater palatine foramen

Target is the maxillary nerve as it passes through the Pterygo-palatine Fossa; the needle passes through the Greater Palatine Canal to reach the Pterygopalatine Fossa

Find the foramen by using a cotton swab until it falls into the foramen

Most often found at distal of the maxillary 2nd molar

Topical anesthetic for at least two minutes

Inject into the area adjacent to the Greater Palatine Foramen in order to block the nerve before probing into the actual foramen itself

1) Greater Palatine Approach Technique

Remember to apply constant pressure into this area until the tissue blanches which will lessen the discomfort of the needle penetrationProbe gently for the foramen with the needle tip at a 45 degree angleAfter finding the canal advance the needle 30 mm 5 to 15% of foramens have boney obstructions, so if you encounter an obstruction do not force the needle, try again then abort

Maxillary Nerve Block Complications1) Greater Palatine Approach Complications

Penetration of the orbit leading to a myriad of complicationsperiorbital swelling or proptosis (bulging eye)block of 6th cranial nerve producing diplopia (double vision)Retrobulbar (behind the eye) hemorrhage, corneal anesthesiaoptic nerve anesthesia loss of vision

Maxillary Nerve Block ComplicationsPenetration of the nasal cavity (medial wall of the pterygopalatine fossa is paper thin):

-patient complains of something draining down their throat

-large amounts of air will be aspirated into the cartridge

Maxillary Nerve Block 2nd Approach2) High Tuberosity Approach

25 gauge long needle recommendedInsert to the height of the mucobuccal fold distal to the 2nd molarTarget is maxillary nerve as it passes through the pterygopalatine fossaSuperior and medial to the target site of the PSA

Again, advance the needle to a depth of 30 mmUpward, inward and backward direction same as PSAResistance should not be felt, if it is, the angulation is too medialAt 30 mm the needle tip should lie within the pterygopalatine fossaAspirate several times and inject 1.8 ml (one cartridge) slowly

Maxillary Nerve Block 2nd Approach2) High Tuberosity Approach Complications

Hematoma develops rapidly if the maxillary artery is punctured with the needle tip

Thin, porous substance of the maxillary bone allows for rapid diffusion of solutions into the cancellous bone

Most Dentists rely solely on the supraperiosteal injection to provide anesthesia in the maxilla

PSA and ASA combined can deliver safe anesthesia to virtually all patients requiring maxillary anesthesia

Universal:

-applying topical anesthetic for one minute

-proper patient positioning

-aspiration

-making the needle safe after each injection with the scoop technique

ReferencesMalamed, Stanley: Handbook of Local Anesthesia. 5th Edition. Mosby. 2003