Explains about the maxillary injection technique

1. SUPERIOR ALVEOLAR NERVE BLOCK
BY
DEZLIN DARLY JOHN
IIIrd year

2. CONTENTS
 POSTERIOR SUPERIOR ALVEOLAR NERVE
BLOCK
 MIDDLE SUPERIOR ALVEOLAR NERVE BLOCK
 ANTERIOIR SUPERIOR ALVEOLAR NERVE BLOCK

3. POSTERIORSUPERIORALVEOLAR NERVEBLOCK

4. POSTERIOR SUPERIOR ALVEOLAR NERVE
BLOCK
 INTRODUCTION
 Most commonly used dental nerve block.
Other Common Names:-
Tuberosity Block , Zygomatic Block
Nerves Anesthetised:-
PSA and its Branches.

5.  AREAS ANESTHETISED
 Pulps of maxillary third, second and First Molar, except the mesiobuccal root.
 And hence a second supraperiosteal injection is indicated after PSA to
achieve an effective anaesthesia of first Molar.
 Buccal peridontium and bone overlying these teeth.

6.  INDICATIONS
 When the treatment involves two or more maxillary molar.
 When supraperiosteal injection is contraindicated ( acute inflammation).
 When the supraperiosteal injection has been proved ineffective.
 CONTRAINDICATIONS
 Risk of haemorrhage is great; such cases, periosteal / PDL injection
recommended.

7.  ADVANTAGES
 Atraumatic; if administered properly.
 High success rate
 Minimum number of necessary injections.
 Minimises the total volume of L.A. solution administered.
 DISADVANTAGES
 Risk of Hematoma
 Technique somewhat arbitrary.
 Second injection required for the Treatment of first molar.

8.  POSITIVE ASPIRATION - Approximately 3.1%
 ALTERNATIVES.
 1.Supraperiosteal / PDL infection for pulpal and root anaesthesia.
 2.Infilteration for the buccal peiodontium and hard tissues.
 3. Maxillary Nerve Block.

9.  TECHNIQUE
 1. A 25 gauge needle recommended, 27 gauge also
acceptable.
 2. Area of insertion:- height of the muccobuccal fold above
and maxillary 2nd molar.
 3.Target Area:- PSA Nerve- posterior, superior, medial to the
posterior border of the maxilla.
 4. Landmarks:-Mucobuccal fold
 Maxillary Tuberosity
 Zygomatic process of Maxilla
 5. Orientation of the bevel:- towards the bone during
injection. If the bone is accidently touched, the sensation is
less unpleasant.

10.  PROCEDURE
 a.) Assume the correct position:-
 Left PSA Nerve Block:- 10’o’ clock
position.
 Right PSA Nerve Block:- 8’o’ clock
position.
 b.) Prepare the tissue at the height of the
mucobuccal fold of penetration.
 c.) Orient the bevel of the needle towards the
bone.
 d.) Partially open the mouth of the patient , pulling
to the side of the injection.
 e.)Retract the cheek with fingers and pull the
tissues at the injection site taut.
 f.) Inject he needle to the height of the
mucobuccal fold over the second Molar.

11.  Advance the needle slowly in an upward, inward & backward direction in one moment.
 Upward:- superiorly at 45° to the occlusal plane.
 Inward:- medially towards the midline at 45° angle to the occlusal plane.
 Backward:- posteriorly at a 45°angle to the long axis of 2nd Molar.
 In an adult of normal size, penetration to a depth of 16mm;
 When a long needle of average length 32mm, half the length of the needle is to be inserted.
 With a short needle of 20mm, approximately 4mm should remain visible.
 The goal is to deposit the L.A close to the PSA Nerve, located posterosuperior and
medial to the maxillary tuberosity.
 Aspirate in two planes
 If both the planes are negative, slowly over 30-60sec, deposit 0.9-1.8ml of anesthetic
solution.
 Wait 3-5 min before commencing the dental procedure.

12.  SIGNS AND SYMPTOMS
 Subjective:- usually none
 Objective:-absence of pain during therapy.
 SAFETY FEATURES
 Slow injections and repeated aspirations.
 Careful observation is necessary as there is no anatomical safety features to
prevent over insertion.
 PRECAUTION
 Depth of penetration of the needle needs to be checked.
Overinsertion:- hematoma
Too shallow:- inadequate anaesthesia

13.  FAILURES OF ANESTHESIA
 Needle too lateral; to correct- redirect the needle tip medially.
 Needle not too high; to correct- redirect the needle tip superiorly.
 Needle too far posterior; to correct- withdraw the needle to the proper depth.
 COMPLICATIONS
 Hematoma:- when needle inserted too deeply into the pterygoid plexus. Use of a
short needle can avoid it.
 Visible intraoral hematoma:-usually noted in the buccal tissue of the mandible.
 Mandibular anesthesia:-As mandibular nerve is located lateral to PSA.

14. MIDDLE SUPERIOR ALVEOLAR NERVE BLOCK

15. MIDDLE SUPERIOR ALVEOLAR NERVE
BLOCK
 INTRODUCTION
 The Middle Superior Alveolar nerve is present only in 28%of the population; hence limiting the
clinical importance.
 Indicated if the infraorbital nerve fails to anesthetise the area distal to maxillary canine
 MSA Nerve Block is indicated for procedures on Premolar and for the mesiobuccal root of
Maxillary first Molar.
 Succes rate is high.
NERVES ANESTHETISED:-
Middle Superior Alveolar Nerve and its terminal Branches.

16.  AREAS ANESTHETISED BY MSA NERVE BLOCK
 Pulps of the Maxillary first and second premolar, mesiobuccal root of First Molar.
 Buccal periodontal tissues and bone over the same teeth.

17.  INDICATIONS
 Failure of infraorbital nerve block
 Dental procedures involving Maxillary premolars only
 CONTRAINDICATIONS
 Inflammations at the site of injection.
 ADVANTAGES
 Minimises the no. Of injections and the volume of solution.
 DISADVANTAGES
 None.
 POSITIVE ASPIRATION – Negligible (<3%)
 ALTERNATIVES
 1.Local infilteration( supraperiosteal), PDL
 2.Infraorbital Nerve Block

18.  TECHNIQUE
 A 25 gauge / long needle is recommended,
27 gauge perfectly acceptable.
 Area of insertion:- height of the mucobuccal
above the maxillary second Premolar.
 Target Area:- Maxillary bone above the apex
of the Maxillary 2nd Premolar.
 Landmarks:- Muccobuccal fold above
maxillary 2nd premolar.
 Orientation of the bevel:- towards the bone

19.  PROCEDURE
 a.) Assume the correct Position:-
 Right MSA Nerve Block: 10 ’o’ clock
 Left MSA Nerve Block: 8 / 9’o’clock
 b.) Prepare the tissue at the site of injection.
 c.)stretch the patient’s upper lip to make the tissues
taut and to gain visibility.
 d.)insert the needle to the height of the mucobuccal
fold above the second premolar with the bevel directed
towards the bone.
 e.) Aspirate
 f.)slowly deposit 0.9-1.2ml of solution in
approximately 30-40 sec.
 g.)wait for 3-5min before commencing the therapy.

20.  SIGNS AND SYMPTOMS.
 Subjective:- upper lip numb.
 Objective:- No pain during dental therapy.
 SAFETY FEATURES
 Relatively avascular area, anatomically safe.
 PRECAUTION
To prevent pain
 do not insert too close to the periosteum
 should not do too rapidly.

21.  FAILURE OF ANESTHETICS
 Anaesthetic solution not deposited high above the apex of second Premolar;
to correct: check radiograph ; increase the depth of penetration.
 Deposition of solution far from the maxillary bone with the needle placed in tissue lateral to the
height of the mucobuccal fold;
to correct: Reinsert at the height of the mucobuccal fold.
 Bone of Zygomatic arch at the site of injection preventing diffusion of anesthetic;
to correct : use supraperiosteal/ PSA injection in place of MSA.
 COMPLICATIONS
 1.Rare

22. ANTERIORSUPERIORALVEOLARNERVEBLOCK

23. ANTERIOR SUPERIOR ALVEOLAR NERVE BLOCK
 INTRODUCTION
 Used in place of supraperiosteal injections.
 High success rate
 Not so popular as PSA Nerve Block.
NERVES ANESTHETISED
1.)Anterior Superior Alveolar
2.) Middle Superior Alveolar
3.)Infraorbital Nerve
a.)Inferior Palpebral
b.)Lateral Nasal
c.) Superior Labial

24.  AREAS ANESTHETISED
 1.Pulps of maxillary Central Incisors through the canine on the injected side.
 2. Pulps of the maxillary premolars and mesiobuccal root of the first molar.
 3.Labial peridontium and bone over these teeth.
 4.Lower eyelid and lateral aspect of nose, upper lip.

25.  INDICATIONS
 Dental procedures involving more than two maxillary teeth
 Inflammations contraindicating supraperiosteql injections.
 Failure of supraperiosteal injection due to dense cortical bone.
 CONTRAINDICATIONS
 Discrete treatment areas
 Haemostasis of localised area, when desired ,cannot be achieved.
 Local infiltration into the treatment area is indicated.

26.  ADVANTAGES
 Comparatively simple technique.
 Comparatively safe ; minimises the volume of the L.A Solution used.
 Minimal number of needle puncture.
 DISADVANTAGES
 1.Psychological
 a.) Administrator: There may be initial fear of injury to the patients' eye. But
experience with the technique leads to confidence.
 b.)Patient: an extra oral approach of infraorbital nerve; however intraoral ones are
rarely a problem.
 c.)Difficulty in defining the anatomical landmarks.

27.  POSITIVE ASPIRATION- 0.7%
 ALTERNATIVES
 Supraperiosteal, PDL / IO injection foe each tooth.
 Infiltration for the periodontium and the hard tissues.
 Maxillary Nerve Block.

28.  TECHNIQUE
 1. 25Gauge needle is used.
 2. Area of insertion: height of mucobuccal fold directly over 1st
Premolar or over any tooth from second premolar to the central
incisors.
 Usually first premolar is preferred as it provides the shortest
route to the target area.
 3.Target Area: infraorbital foramen.
 4.Landmarks: Mucobuccal fold
 Infraorbital Notch
 Infraorbital Foramen
 5.)Orientation of the bevel: towards the bone.

29.  PROCEDURE
 a.) Assume the correct position-
 For both Right and Left ASA Nerve Block: 10 ’o ‘ clock position
 b.) Position of patient: supine position more preferred; semi supine position
with neck extended slightly.
 c.) Prepare the tissue at the injection site.
 d.) Locate he infraorbital foramen.
 1. Feel the infraorbital notch, apply gentle pressure to the tissues.
 2. The bone inferior to the notch is convex (lower border of the orbit) As
your fingers continue a concavity is felt; this is infraorbital foramen .
 3. Apply pressure , feel the outlines of infraorbital foramen, palpate it.
 e.) Mark the skin at the site.
 f.) Retract the lip, pulling the tissues in the mucobuccal fold over the first
premolar with the bevel facing bone.
 g.)Orient the needle towards the infraorbital foramen

30.  h.) The needle must be held parallel to the long axis of the tooth
as it is advanced to avoid premature contact with the bone.
 i.) The pt. Of contact should be the upper rim of infraorbital foramen.
 j.) The general depth of needle penetration is 16mm for an adult of
average height.
 k.) Before injecting the L.A Solution, check for the following.
 1.) Depth of needle penetration
 2.) Any lateral deviation of the needle from the infraorbital
foramen.
 3.) Orientation of the bevel facing the bone.
 l.) Position of the needle with the bevel facing into the infraorbital
foramen and the needle tip touching the roof of the foramen.
 m.) Aspirate
 n.) Slowly deposit 0.9-1.2 ml over 30-40sec.

31.  o.) The administrator is able to feel the deposited L.A.Solutin beneath the fingers.
 At the conclusion of the injection, the foramen should no longer be palpable.
 p.) Maintain firm pressure with your finger over the injection site both during and
for at least 1- 2 minute after the injection site to diffuse the L.A Solution into the
infraorbital foramen
 q.) Wait 3-5 minutes after the completion of injection before commencing the dental
procedure.

32.  SIGNS AND SYMPTOMS
 1.) Subjective:- tingling and numbness of lower eyelid, side of nose, upper lip
indicate anesthesia of infraorbital nerve not ASA/ MSA Nerve .
 2.)Subjective & Objective:- Numbness in the teeth and soft tissue along the
distribution of ASA and MSA ( develops 3-5 minute if pressure is maintained over
the injection site.)
 3.)Objective:- no pain during the dental therapy.
 SAFETY FEATURES
 1.Needle contact with the bone at the roof of the infraorbital foramen prevent over
insertion and possible puncture of the orbit.
 2. A finger placed directly over the infraorbital foramen helps to direct the needle
towards the foramen.
 3. The needle should not be palpable; if it is, then it is too superficial. To correct it
withdraw the needle slightly and redirect to the target area.

33.  PRECAUTIONS
 For pain on insertion of the needle and tearing of the periosteum, reinsert the
needle in a more lateral position.
 For over insertion of the needle, estimate the depth of penetration before injection
and exert finger pressure over the infraorbital foramen.
 Overinsertion is unlikely because the rim of the bone that forms the superior rim of
infraorbital foramen. The needle tip contacts this rim.

34.  FAILURES OF ANESTHESIA
 1.) Needle contacting the bone below the infraorbital foramen; causes anesthesia of the lower
eyelid, lateral side of nose and upper lip develop with little or no dental anesthesia.
 2.) A failed ASA is a supraperiosteal injection over the first Premolar; to correct: keep the needle
in line with the infraorbital foramen during penetration. Do not direct the needle towards the
bone.
 3.) Needle deviation medial or lateral to the infraorbital foramen; to correct; Direct the needle
towards the foramen immediately through the tissue.
 4.) Recheck the needle placement before aspirating and depositing the Anesthetic solution.

35.  COMPLICATIONS
1.) Hematoma:- rarely develops ; across the lower eyelid and tissues between it and
infraorbital foramen.
To manage, apply pressure on the soft tissue over the foramen for 2-3 minutes.
2. Hematoma is extremely rare as pressure is routinely applied to the injury site both
during and after ASA Nerve Block.

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