Download Dental and Facial Anesthetic Blocks

Dental and Facial Anesthetic Blocks
INTRODUCTION
Dental and facial anesthesia can be used in the Emergency Department to provide temporary
anesthesia for painful dental disorders, and facial injuries as well as to facilitate laceration repair
of complex lacerations or incision & drainage of abscesses that may be difficult to directly
anesthetize.
GOALS OF THE PROCEDURE
Provide adequate analgesia for procedures of the mouth or face or to aid with pain control in
painful dental disorders.
INDICATIONS
!
Laceration repair of the forehead, ear, cheek, lip, or chin
!
Incision and drainage of dental or facial abscesses
!
Pain control for odontalgia
GENERAL CONTRAINDICATIONS
!
Overlying infection of the injection site
!
Allergy to anesthetic
!
Patient uncooperation
!
Bleeding diathesis or anticoagulation (relative)
COMPLICATONS:
!
Introduction of infection
!
Intravascular injection
!
Needle breakage
!
Anesthetic toxicity (when exceeding maximum amounts)
!
Bleeding
!
Allergy to anesthetic
!
Pain
EQUIPMENT
!
PPE (gloves and eye protection)
!
Chloroprep or betadine if entering skin
!
Sterile 2x gauze
!
Local anesthetic (generally 1% lidocaine or bupivicaine)
!
Topical anesthetic (cetacaine spray or lollipops)
!
Dental syringe
!
Needle, generally 25-guage (specific to dental syringe)
ANATOMY
General considerations
Dental anesthesia is generally divided into maxillary (upper teeth) and mandible
(lower teeth) approaches. Both the anesthesia of the buccal (outer) and lingual
(inner) aspects of the tooth must be considered.
Maxillary anesthesia
In general, anesthesia for maxillary teeth is achieved with local infiltration of the
buccal and lingual aspects of each individual tooth to anesthetize the individual
dental nerves.
Alternatively, multiple teeth can be anesthetized
by blocking the individual nerves that arise from
the maxillary nerve (V2), with the most common
being the posterior superior alveolar nerve block,
nasopalatine nerve block, and anterior palatine
nerve block.
Mandible anesthesia:
Aside from the central incisors, the denser bone in the mandible limits the
effectiveness of supraperiostial infiltration. Thus, anesthesia for mandibular teeth
is most commonly achieved via the infra-alveolar (IA), long buccal, and mental
(incisive) nerve blocks.
Infra-alveolar nerve/mental nerve
The infra-alveolar nerve (IA) is a branch of
the mandibular nerve (off of V3) and
travels along the medial aspect of the
ramus of the mandible and then enters the
mandibular canal before giving off the
mental nerve through the mental foramen.
IA nerve block provides anesthesia to the
ipsilateral lip, teeth, lingual aspect of the
gums, and buccal gingival of the anterior
teeth, and chin. Patients will also often
have ipsilateral tongue numbness from an associated lingual nerve block.
Long buccal nerve
The long buccal nerve is a branch of the maxillary nerve and courses between
the two heads of the lateral pterygoid muscle before coursing under the masseter
muscle. It provides sensation to the buccal aspect of the second and third
molars.
Supraorbital nerve
The ophthalmic nerve is a branch of the V1
cranial nerve and exits through the
supraorbital notch, which can be found along
the superior orbital rim and in line with the
pupil. Supraorbital nerve block provides
anesthesia to the forehead from the level of
the eyebrow and above.
Infraorbital nerve
The infraorbital nerve is a branch of V2 and exits through the infraorbital foramen.
It can be found just inferior to the infraorbital ridge and is in line with the pupil
while the patient is looking straight ahead. Infraorbital nerve block provides
anesthesia to the middle and superior alveolar nerves, skin of the upper lip, nose,
cheek, and lower eyelid.
STEPS
Supraorbital nerve block
Used for anesthesia of the forehead and scalp to the level of the lambdoid suture.
1. Palpate the supraorbital foramen along the superior orbital ridge, in line
with the pupil as the patient looks straight ahead.
2. With a finger or gauze roll held just below
the orbital rim (to prevent swelling of the
eyelid), inject 1-3mL of anesthetic into the
area of the foramen.
3. The patient will generally feel
parasthesias of the forehead to signify
successful placement. If not elicited,
inject a small amount of anesthetic in a
line along the superior orbital ridge from
medial to lateral.
4. Patients may experience a small hematoma or periorbital ecchymosis the
following day.
MAXILLA ANESTHESIA
Supraperiostial infiltration
Used for anesthesia of a single tooth.
1. Apply topical anesthetic to the
mucosal and/or palatal area to be
injected, especially if anterior to the
canine as this site is more painful.
2. Orient the needle parallel to the
vertical axis of the tooth with the bevel
toward the bone.
3. Pull the skin taught and enter at the
mucobuccal fold
4. Advance the needle approximately 5mm, aspirate, and inject 0.8-1.0 cc or
½ of the cartridge
5. To anesthetize the lingual surface of
a single tooth, orient the needle 45
degrees toward the gingiva,
approximately 5-10mm from the
center of the tooth and with the bevel
aimed toward the palate.
6. Advance the needle until bony contact (3-5mm), aspirate, and inject 0.20.3cc (1/8 cartridge) of anesthetic until the area blanches.
Infraorbital nerve block (IO)
Ideal for complex lip and facial lacerations as well as anesthesia of the anterior
teeth. Can be approached intraorally and transdermally; the intraoral approach
will be discussed below.
1. Palpate the infraorbital foramen, which can
be found inferior to the pupil as the patient is
looking straight ahead.
2. After applying topical anesthetic, orient the
needle vertically and enter the mucobuccal
fold at the first premolar.
3. Advance the needle toward the infraorbital
foramen until bony contact (approximately
half of the needle). Retract needle slightly
and aspirate.
4. Inject 0.9-1.2cc of anesthetic and massage
the area to help manipulate the anesthetic
into the foramen.
Posterior superior alveolar block (PSA)
Used for anesthesia to the second and third molars, and in some patients, the
first molar.
1. Apply topical anesthesia to the mucobuccal
fold of the second molar, which will be the
landmark for injection.
2. Orient the needle with the bevel angled
toward the bone, and advance at at 45degree angle medially, superiorly, and
posteriorly.
3. Advance the needle approximately 2cm or 2/3 the length of the needle.
There should be no resistance or bony contact.
4. Aspirate, and inject one cartridge slowly over one minute.
Nasopalatine block
Used with supraperiosteal infiltrations or IO block to anesthetize the lingual
aspect of the tooth and gums.
1. Identify the incisive papilla and apply local
anesthetic to the area.
2. Orient the needle with the bevel toward
the palate and advance just lateral the
papilla and advance until bony contact.
3. Aspirate and inject ¼ of the cartridge into the
area over 30 seconds.
4. The area will blanch, and also there will be a
significant amount of resistance since the palate
is adherent to the bone at this point.
Greater palatine block
Provides lingual anesthesia posterior to the canine.
1. With the help of your finger or a q-tip, palpate the greater palatine foramen
at the junction of the soft and hard palate and generally medial to the 2nd
or 3rd molar.
2. Orient the needle perpendicular to the injection site, which is
approximately 2mm anterior to the foramen.
3. Advance until bony contact, aspirate, and inject approximately ¼ of the
syringe into the area while keeping pressure on the foramen with the qtip.
4. The tissue will blanch, and resistance is normal.
MANDIBLE ANESTHESIA
Infra-alveolar (IA) nerve block
1. Apply topical anesthetic to the target
area, which is the interior aspect of the
mandibular ramus just anterior to the
pterygomandibular raphe.
2. Place the thumb of your nondominant
hand on the coronoid notch (most
concave portion of the mandible) and the
index finger just anterior to the ear
3. Orient your syringe with the barrel over the premolars on the OPPOSITE
side.
4. Aim toward your index finger, approximately 5-10mm above the occlusal
plane of the lower molars.
5. Advance the needle until bone is contacted, which should be
approximately 2.5cm or ¾ of the needle length.
a. If bone is contacted superficially or not contacted at all, reorient the
syringe more laterally and repeat.
6. Withdraw slightly and aspirate. If no blood is aspirated, inject 1.5-2mL of
anesthetic (1-2 carpules).
a. If blood is aspirated, pull needle back and redirect slightly, then repeat
aspiration attempt.
7. Do not use 4% lidocaine with this injection as it can cause permanent
parasthesias.
(Long) Buccal Nerve Block
This block should be done following the IA when attempting to provide
anesthesia to the molars to anesthetize the buccal aspect.
1. Identify the target area located distal
and buccal to the most distal molar in
the arch on the anterior border of the
ramus.
2. Orient the bevel of the needle toward
the bone and insert parallel to the
occlusal plane to approximately 13mm of depth.
3. Aspirate, and if no blood is aspirated,
inject approximately 0.2mL of anesthetic over 10 seconds.
Mental/incisive nerve block
Often used in combination with the IA for anesthesia of the teeth and/or skin
anterior to the molars, but can be used alone.
1. Identify the landmarks by palpating for the mental foramen either
intraorally or over the chin just inferior to the premolars.
2. Orient the needle vertically, parallel to the second premolar and insert into
the mucobuccal fold approximately 5mm.
3. Aspirate, and inject 0.5-1.0cc of anesthetic.
4. Massage over the foramen for approximately
1 minute to help manipulate the anesthetic
into the mental foramen.
5. Alternatively, you can enter the mucobuccal
fold at the level of the first premolar, angling
slightly posterior to reach the mental foramen
and inject as above.
VIDEO
Maxillary injections: https://www.youtube.com/watch?v=GXuF_KUgfGg
Mandibular injections: https://www.youtube.com/watch?v=Tkcx32iHxh0
Local infiltration: https://www.youtube.com/watch?v=0kOukYPGVmM
Maxillary infiltrations: https://www.youtube.com/watch?v=px1zQh7HJpM
Syringe setup: https://www.youtube.com/watch?v=saEdrJyzusw
DEEP DIVE
! Further Reading
o Roberts & Hedges’ Clinical Procedures in EM. 6th edition. Ch. 30,
Pg. 541-553
! Pearls
o Anesthesia of the upper anterior teeth is generally the most painful,
so topical anesthesia is recommended prior to injection
o Pulling the mucosa taught during injections will help with pain and
ease of puncturing the mucosa
o Nerve blocks will take longer to become numb than infiltration
techniques (approx 3-5 minutes)
o If the intraalveolar block fails, you can try a Gow-Gates block (not
discussed here but can be found in the “mandibular injections”
video