Anatomy of Local Anesthesia

type of injection that anesthetizes a small area - one or two teeth and associated structures/tissues

Local infiltration

Local infiltration injection is deposited near

apices or terminal nerve endings

Type of injection that anesthetizes a larger area than the local infiltration

Nerve block

the nerve block injection is deposited near

large nerve trunks

Abnormal sensation from an area such as burning or prikcling

Parasthesia

Management of pain requires thorough knowledge of anatomy of

- skull
- Trigeminal Nerve
- and related tissue

the skull bones involved in the local anesthetic administration are the

- maxilla
- palatine bone
- mandible

avoid infection contamination by not injecting into

- abscess
- cellulitis
- osteomyelitis

True or False:
The nerve block has more degrees of success than that of local infiltration

True

the reason for local anesthesia being more successful on the maxilla over the mandible is due to

-the bone over the facial surface of the maxillary teeth is less dense than that of the mandible over similar teeth
- and less variation also exists in the anatomy of the maxillary and palatine bones and associated nerves with respect to local anesthetic landmarks as compared with similar mandibular structures

Maxilla or Mandible
Less bone density, less anatomical variation

Maxilla

Maxilla or Mandible
greater density, greater anatomical variation

Mandible

Maxillary anesthesia is more/less consistent than mandibular anesthesia

more

pulpal anesthesia is achieved through anesthesia of

each tooth's dental branches as they extend into the pulp tissue by way of apical foramen

the hard and soft tissues of the periodontium are anesthetized by way of

interdental and interradicular branches for each tooth

the local anesthetic block that is recommended for anesthesia of the maxillary molar teeth and associated buccal tissues in one quadrant is the

Posterior Superior Alveolar Block (PSA)

The local anesthetic block that is recommended for anesthesia of the maxillary premolars and associated buccal tissues in one quadrant is the

Middle Superior Alveolar Block (MSA)

The local anesthetic block that is recommended for anesthesia of the maxillary canine and incisors and their associated facial tissues in one quadrant is the

Anterior Superior Alveolar Block (ASA)

The local anesthetic block that is recommended for anesthsia of the maxillary anterior and premolar teeth and associated facial tissues in one quadrant is the

Infraorbital block (IO)

_____________ usually involves anesthesia of the soft and hard tissues of the periodontium of the palatal area such as the gingiva, periodontal ligament, and alveolar bone

Palatal Anesthesia

True or False
Palatal Anesthesia usually does not provide any pulpal anesthesia to the maxillary teeth or associated facial or buccal tissues

True

the local anesthetic block that is recommended for anesthesia of the palatal tissues distal to the maxillary canine in one quadrant is the

Greater Palatine Block (GP)

The local anesthetic block that is recommended for anesthesia of the palatal tissues between the right and left maxillary canines is the

Nasopalatine block (NP)

the local anesthetic block that is recommended for anesthesia of most of the maxillary teeth and their associated tissues in one quadrant, except for those innervated by the Posterior superior Alveolar nerve

Anterior Middle Superior Alveolar Block (AMSA)

The posterior superior alveolar block (PSA) is used to provide anesthesia in

- maxillary third, second, & first molar with the exception of the Mesial Buccal root of the maxillary first molar
- buccal periodontium overlying maxillary third, second and first molars including the associated gingiva, periodontal ligament and alveolar bone

the Posterior Superior Alveolar block (PSA) is indicated when procedure involves

2 or more maxillary molars

In some instances, the _______ root of first molar is innervated by the _____ nerve rather than the PSA nerve and therefore the PSA block would require an additional injection to anesthetize.

- Mesial buccal
- MSA

True or False
the PSA block also provides anethesia to the lingual tissues of the first, second and third molars

FALSE
- if anesthesia of the lingual tissues is desired, the greater palatine block also may be necessary

The target area for the PSA block is the

PSA nerve as it enters the maxilla through the posterior superior alveolar foramina on the maxilla's infratemporal surface

The injection site for the PSA block is

into the tissues at the height of the mucobuccal fold at the apex of the maxillary second molar, distal to the zygomatic process of the maxilla

When administering the PSA block a complication may arise if the needle is overinserted and may penetrate the ____________ possibly causing a hematoma in the infratemporal fossa

pterygoid plexus

If the needle of the PSA block is nonsterile, a possible complication could be spread of infection into the

cavernous sinus

Inadvertent and harmless anesthesia of the _________ may occur with a PSA block due to the close proximity of structures

- lingual nerve (branch of V3)

The Middle Superior Avleolar Block is indicated when the procedure invloves

- maxillary premolars and the Mesial Buccal root of the maxillary 1st molar (if innervated by MSA nerve)
- and assoiciated buccal periodontal tissues including the gingiva, periodontal ligament, and alveolar bone

The symptoms of the PSA block includes

- teeth feel dull during procedure
- lack of pain / discomfort during dental procedure

The symptoms of the Middle Superior Alveolar Block include

- Tingling / numbness of upper lip
- lack of pain/discomfort during dental procedure

Complications from the Middle Superior Alveolar Block include

- overinsertion with hematoma (rare)

Target are for the MSA block is

the MSA nerve at the apex of the maxillary second premolar

The injections site of the MSA is

tissues at the height of the mucobuccal fold at the apex of the maxillary second premolar

The _____ block and the _____ block are commonly used in conjuction with each other instead of using the infraorbital block

- MSA
- ASA

The Anterior Superior Alveolar Nerve Block (ASA) is indicated when the procedure involves

maxillary central incisors, lateral incisors, and canines

The Anterior Superior Alveolar Nerve Block anesthisizes the

- pulp tissue of the maxillary canine and incisor teeth as well as the associated facial periodontal tissues including the gingiva, periodontal ligament, and alveolar bone
- if lingual tissue of these teeth needs to be anesthitized then a Nasopalatine block may be necessary

What anesthetic block would be given in order to anesthetize the lingual tissues of the anterior teeth

Nasopalatine Block

The target area for the Anterior Superior Alveolar Nerve Block (ASA) is the

ASA nerve at the apex of the maxillary canine

The site of injection for the Anterior Superior Alveolar Nerve Block (ASA) is the

tissues at the height of the mucobuccal fold at the apex of the maxillary canine, just anterior to and parrallel with the canine eminence

Symptoms of Anterior Superior Alveolar Nerve Block (ASA) include

- tingling / numbness of upper lip
- Lack of pain / discomfort during dental procedure

Complications of Anterior Superior Alveolar Nerve Block (ASA) include

Overinsertion with complications (hematoma) rare

True or False
many times the ASA nerve crosses over the midline to the opposite side in a patient and should be considered when giving anesthesia in this area

True

The Infraorbital block (IO) is indicated when procedure involves

2 or more maxillary premolars or anterior teeth

The infraorbital block (IO) is a useful nerve block becuase it anesthetizes both the _____ & ______ nerves

- MSA
- ASA

The Infrarobital block (IO) is used for anesthesia of the

- maxillary premolars, maxillary canine, and maxillary incisors
- overlying facial periodontium including the gingiva, periodontal ligament and alveolar bone

Symptoms of the Infraorbital Block (IO) include

- tingling / numbness of eyelid, side of nose, upper lip (due to IO branches)
- Lack of pain / discomfort during dental procedure

Complications of the Infraorbital (IO) block include

- overinsertion with complications (Hematoma) rare

The target are for the Infraorbital block (IO) is the

- ASA and MSA nerves as they ascend to join the IO nerve after it enters the infraorbital foramen
- Branches of the IO nerve to the lower eyelids, side of nose, and upper lip are also inadvertently anesthitized

The injection site for the Infraorbital Block (IO) is the

tissues at the height of the mucobuccal fold at the apex of the maxillary first premolar

The Greater Palatine (GP) block is indicated when procedure involves

2 or mor maxillary posterior teeth or palatal soft tissue distal to maxillary canine

The Greater Palatine (GP) block is used for anesthesia of

the posterior portion of the hard palate, anteriorly as far as the maxillary first premolar and medially to the midline

Because the Greater palatine (GP) block does not provide pulpal anesthesia of the area teeth the use of the ____, _____, and _____ blocks or the _____ block may also be indicated

- ASA
- PSA
- MSA
- IO

Soft tissue anethesia in the palatal area of the maxillary first premolar may prove inadequate because of overlappping nerve fibers from the nasopalatine nerve, so this lack of anesthesia may be corrected by additional administration of the

Nasopaltine Block (NP)

Because the overlying palatal tissues are dense and adhere firmly to the underlying palatal bone, what is used to help reduce patient discomfort

pressure anesthesia posterior to the injection site before and during the injection to blanch the tissues

What does pressure anesthesia of the tissues do

produces a dull ache that blocks pain impulses that aries from needle penetration

In addition to pressure anesthesia, what will also help reduce patient discomfort

slow deposition of the local anesthetic agent

The target site for the Greater Palatine (GP) block is

anterior to where the GP nerve enters the greater palatine foramen from its location between the mucoperiosteum and bone of the hard palate

The site of injection of the Greater Palatine (GP) block is

in the palatal tissues anterior to the depression created by the greater palatine foramen

Symptoms of the Greater Palatine (GP) block include

- Numbness in posterior portion of palate
- patient may indicate gagging / discomfort during injection or after if the soft palate inadvertently gets anesthitized due to close proximity
- lack of pain / discomfort during dental procedure

Complications of Greater Palatine (GP) block includes

Hematoma (rare)

The Nasopalatine (NP) block is indicated when procedure involves

palatal soft tissue of 2 or more maxillary anterior teeth

The Nasopalatine (NP) block is used for anesthesia of

- bilateral anterior portion of hard palate (Mesial of right PM1 to Mesial of left PM1)
- no pulpal anesthesia

The Nasopalatine (NP) block does not provide pulpal anesthesia of teeth, so additional anesthesia such as ______ & _______ or _______ may be indicated

- MSA block
- ASA block
- IO block

Because the dense overlying palatal tissues adhere firmly to the underlying maxillary bone, the use of _______ on the _________ side of the injection site of the incisive papilla before and during the injection to blanch the tissues will reduce patient discomfort

- pressure anesthesia
- contralateral

The target area for the Nasopalatine (NP) block is

both the right and left NP nerves as they enter the incisive foramen from the mucosa of the anterior hard palate beneath the incisive papilla

The injection site of the Nasopalatine (NP) block is

the palatal tissues lateral to the incisive papilla which is located at the midline about 10 mm lingual to the maxillary central incisor teeth

Symptoms of the Nasopalatine (NP) block include

- Numbness in anterior portion of palate
- lack of pain / discomfort during dental procedure

Complications of the Nasapalatine (NP) block include

Hematoma (rare)

The Anterior Middle Superior Alveolar (AMSA) Block is indicated when procedure invloves

palatal soft tissue of 2 or more maxillary anterior teeth

The Anterior Middle Superior Alveolar (AMSA) block is use for anesthesia for

soft tissue and pulpal anesthesia of the large area covered by the ASA, MSA, GP, and NP blocks in the maxillary arch

True or False
The single-site palatal injection of the AMSA can anesthetize multiple teeth, without causing usual collateral anesthesia to the soft tissues of the patients lips and face

True

_________ is commonly used in aesthetic / cosmetic dentistry because after the procedures are completed the clinician can immediately and accurately assess the patient's smile line

Anterior Middle Superior Alveolar Block (AMSA)

The AMSA block together with the ______ block will anesthetize a maxillary quadrant for other dental procedures

PSA

True of False
The AMSA injection is best accomplished with a computer controlled delivery device because it regulates the pressure and volume ratio of agent delivered which is not readily attained with a manual syringe

True

Target site of the Anterior Middle Superior Alveolar (AMSA) Block is the

tissues of the hard palate

The injection site of the Anterior Middle Superior Alveolar (AMSA) block is

an area bisecting the apex of the maxillary premolars, as well as being midway between the lingual gingival margin and the median palatal suture

The symptoms of the Anterior Middle superior Alveolar (AMSA) block include

- Numbness
- lack of pain / discomfort during dental procedures

The complications of the Anterior Middle Superior Alveolar (AMSA) block include

- Blanching on palatal and buccal tissues after AMSA block, if excessive may lead to ischemia/sloughing
- hematoma (rare)

True or False
There is only one technique used to anestheszie the Mandibular nerve and its branches

False
- there are many different techniques used

True or False
The infiltration anesthesia on the mandible is not as successful as on the maxilla due to the overall denseness of the mandible, especially in the area of the posterior teeth

True

The ________ is generally recommended for anesthesia of the mandibular teeth and their associated lingual tissues to the midline, as well as the facial tissues anterior to the mandibular first molar

Inferior Alveolar (IA) block

the ________is generally recommended for anesthesia of the tissues buccal to the mandibular molars

Buccal Block

The ______ is generally recommended for anesthesia of the facial tissues anterior to the mental foramen (usually the mandibular premolars and anterior teeth)

Mental Block

The ________ is generally recommended for anesthesia of the teeth and associated facial tissues anterior to the mental foramen (usually the mandibular premolars and anterior teeth)

Incisive block

The _______ is the most commonly used injection in dentistry

Inferior alveolar (IA) block

The inferior alveolar (IA) block is indicated when procedure involves

mandibular teeth and pulpal anesthesia (corresponding tissue)

The inferior alveolar (IA) block is used for anesthesia for

lingual periodontium of all mandibular teeth, as well as anesthesia of the facial periodontium of the mandibular anterior and premolar teeth

________ may be used in addition to the inferior alveolar (IA) block if anesthesia of the buccal perodontium of the mandibular molars is necessary

Buccal Nerve block

When troubleshooting the Inferior alveolar (IA) block, if the bone is contacted to soon that means

that the needle tip is too far anterior on the ramus

When troubleshooting the Inferior Alveolar (IA) block, if bone is not contacted, then that means

the needle tip is too far posterior

If the insertion / depostion of the Inferior alveolar (IA) is too shallow and bone is not contacted, then

the medially locted sphenomandibular ligament can become a physical barrier that stops the important diffusion of the local anesthetic agent to the mandibular foramen and IA nerve

Bilateral inferior Alveolar (IA) blocks are usually avoided unless absolutely necessary because

bilateral mandibular injections produce complete anesthesia of the body of the tongue and floor of mouth, which can cause difficulty with swallowing and speech, especially in patients with full or partial removable mandibular dentures

Sometimes there is an overlap of the left and right incisive nerves, in this case an _______ block or local infiltration at the apices of the mandibular teeth that fail to achieve initial pulpal anesthesia of the tissues would be used in addition to the Inferior Alveolar block

Incisive block

True or False
The IA block is the most commonly used dental injection, but it is not always initially succesful. Therefore the patient mus be reinjected to achieve the necessary anesthesia of the tissues

True

The lack of constant success in the inferior alveolar (IA) block is due in part to

anatomical variation in the height of the mandibular foramen on the medial side of the ramus and the great depth of soft tissue penetration required to achieve pulpal anesthesia

Other techniques to achieve mandibular anesthesia and may also be employed with failure of the IA block is the

Gow-Gates mandibular nerve block

It is important not to deposit Inferior alveolar (IA) block if bone is not contacted on intial insertion of the needle because

the needle tip may be too posterior and thus resting within the parotoid salivary gland near the seventh cranial or facial nerve resulting in facial nerve paralysis

If anesthesia is not achieved with the inferior alveolar (IA) block there may be ___________ of the mandibular teeth

- accessory nerve innervation (mylohyoid nerve)

Whenever a bifid IA nerve present (double mandibular canal) then

a second IA block may be necessary and is injected inferiorly to the first one

Symptoms of the Inferior Alveolar (IA) block include

- numbness in lower limb (mental nerve), tongue and floor of mouth (lingual nerve)
- patient may indicate lingual shock during injection
- lack of pain/discomfort during dental procedure

Complications of the Inferior Alveolar (IA) block include

- facial paralysis (facial nerve)
- hematoma - muscle soreness/ limited jaw movement
- lip bitting
- parasthesia - "pins and needles" due to trauma to lingual nerve, lack of adequate fascia, neurotoxicity from local anesthesia

target area for the IA block is

slightly superior to the entry point of the IA nerve into the mandibular foramen, overhung anteriorly by the lingula

The injection site for the IA block is

the mandibular tissues on the medial border of the mandibular ramus at the correct height and anteroposterior direction for injection

The buccal block is indicated when

anesthesia of buccal periodontium of mandibular molars is needed

the buccal block is used for anesthesia for the

buccal periodontium of the mandibular molars including the gingiva, periodontal ligament, and alveolar bone.

True or False
The buccal block is a successful injection because the buccal nerve is readily located on the surface of the tissue and not within bone

True

the target area for the buccal block is the

buccal nerve (or long buccal nerve) as it passes over the anterior border of the ramus and through the buccinator muscle before it enters the buccal region

The injection site for the buccal block is

the buccal tissues distal and buccal to the most distal molar tooth in the arch, on the anterior border of the ramus

Symptoms of the buccal block included

- lack of pain / discomfort during dental procedure
- patient rarely feels symptoms

Complications of the buccal block include

- cheek biting
- Hematoma (rare)

the mental block is used to anesthetize the

facial periodontium of the mandibular premolars and anterior teeth on one side, including the gingiva, periodontal ligament, and other alveolar tissues

True or False
The mental block provides anesthesia to the lingual tissue of the teeth involved

FALSE
the mental block DOES NOT provide any lingual tissue anesthesia of the involved teeth

the target area for the mental block is

anterior to where the mental nerve enters the mental foramen to merge with the incisive nerve and form the IA nerve

the insertion site for the mental block is

anterior to the depression created by the mental foramen at the height of the muccobuccal fold

Symptoms of the mental block include

- tingling or numbness of lower lip
- lack of pain/discomfort during dental procedure

Complications of the mental block include

- hematoma (rare)

the incisive block anesthetizes the

pulp tissue and facial tissues of the mandibular teeth anterior to the mental foramen (usually the mandibular premolars and anterior teeth)

If lingual anesthesia is necessary on mandible, an ______ block would be administered instead of incisive block, because the incisive block does not provide lingual anesthesia

IA block

target are for the incisive block is

the same as the mental block; anterior to where the mental nerve enters the mental foramen to merge with the incisive nerve and form the IA nerve

The injection site for the incisive block is

anterior to the depression created by the mental foramen

symptoms of the incisive block include

- tingling or numbness of lower lip
- lack of pain / discomfort during dental procedure

Complications of the incisive block include

hematoma (rare)

The nerves anethetized by the Gow-Gates Mandibular Nerve block include

the inferior alveolar, mental, incisive, lingual, mylohyoid, auriculotemporal, and buccal

The Gow-Gates mandibular nerve block is considered a true nerve block because

it anesthetizes almost the entire V3

A Gow-Gates mandibular nerve block is indicated for use in

quadrant dentistry in which the buccal soft tissue anesthesia from most distal molar to midline and lingual soft tissue is necessary and in some cases when a conventional IA block is unsuccessful

the target area for the Gow-Gates mandibular nerve block is the

anteromedial border of the mandibular condylar neck, just inferior to the insertion of the lateral pterygoid muscle

the injection site of the Gow-Gates mandibular nerve block is

located intraorally on the oral mucosa on the mesial of the mandibular ramus, just distal to the height of the mesiolingual cusp of the maxillary second molar, following a line extraorally from the ipsilateral intertragic notch of the ear to the ipsilateral labial commisure

Symptoms of the Gow-Gates mandibular nerve block include

- Mandibular teeth to midline, buccal mucoperiosteum and mucous membranes and lingual soft tissues and periosteum are anesthetized
- inadvertent anesthesia of anterior 2/3 of tongue, floor of mouth, body of mandible, inferior ramus, skin over zygoma, and posterior cheek and temporal region
- lack of pain/discomfort during dental procedure

Complications of the Gow-Gates mandibular nerve block include

- trismus (rare)
- hematoma (rare)

The Gow-Gates mandibular nerve block is contraindicated in patients with

limited jaw movement