Comprehensive Study Guide Flashcards
Label water the following ions are intra- or extra-cellular:
- K+
- Na+
- Cl-
- proteins
- HCO3-
- ICF
- ECF
- ECF
- ICF
- ECF
Intracellular ions=
K+ & proteins (More negative)
Extracellular ions=
Na+, Cl-, HCO3-
Where do local anesthetics exert their pharmacological action on the nerve?
nerve membrane
How do local anesthetics work?
Specific receptor theory- local anesthetic binds to specific receptors on the Na+ channel
What does the specific receptor theory state?
The local anesthetic binds to a specific receptor on the Na+ channel to prevent the channel from opening (therefore no action potential & no pain)
Which ion channel do local anesthetics bind to?
Specific receptors on the Na+ channel
Speed of conduction of a myelinated nerve:
Speed of conduction of an unmyelinated nerve:
myelinated: 120 m/s
unmyelinated: 1.2 m/s
Where do local anesthetics work at the myelinated nerve?
Local anesthetics work at the nodes of ranvier (abundance of sodium channels here)
In order for local anesthetic to work on a myelinated nerve it needs to block:
2-3 nodes (8-10mm of the nerve)
Drug: Lidocaine
Onset:
Half-Life:
Mg/Kg of max dose:
Onset: 2-3 min
Half-life: 1.6 hrs
(1 hr of pulpal, 3-5 hrs of soft tissue for 2% solution)
Mg/Kg of max dose: 4.4 mg/kg (300mg)
Drug: Prilocaine
Onset:
Half-Life:
Mg/Kg of max dose:
Onset: 2-4 min (slightly slower)
Half-Life: 1.6 hrs
Mg/Kg of max dose:6.0 mg/kg (400mg)
Drug: Mepivacaine
Onset:
Half-Life:
Mg/Kg of max dose:
Onset: 1.5-2 min (rapid!)
Half-Life:1.9 hr
(20-40 min of pulpal. 2-3 hrs of soft tissue anesthesia)
Mg/Kg of max dose: 4.4mg/kg (300 mg)
Bupivacaine:
Onset:
Half-Life:
Mg/Kg of max dose:
Onset: 6-10 min (longer)
Half-Life:2.7 hrs (long!)
Mg/Kg of max dose: 1.3 mg/kg (90 mg)
What drug would be used when more than 90 min of pulpal anesthesia is needed and is also used to reduce post-op pain?
Bupivacaine
Drug: Articaine
Onset:
Half-Life:
Mg/Kg of max dose:
Onset: 1-2 min (rapid!)
Half-Life: 0.5 hrs (short!)
(0.5 hrs of pulpal and 3-5 hrs of soft tissue for 4%)
Mg/Kg of max dose: 7 mg/kg (500 mg)
Drug: Cocaine
Onset:
Half-Life:
Onset: immediate-1 min
Half-Life: 1-1.5 hours
Drug: Procaine
Onset:
Onset: 6-10 min
List the following anesthetics in order of fastest to slowest onset:
-Bupivacaine
-Articaine
-Prilocaine
-Procaine
-Cocaine
-Mepivacaine
-Lidocaine
(Fastest)
1. Cocaine
2. Articaine
3. Mepivacaine
4. Lidocaine
5. Prilocaine
6. Bupivacaine
7. Procaine
(Slowest)
List the following anesthetics in order of longest to shortest duration:
-Bupivacaine
-Articaine
-Prilocaine
-Procaine
-Cocaine
-Mepivacaine
-Lidocaine
(Longest)
1. Bupivacaine
2. Mepivacaine
3. Lidocaine = Prilocaine
4. Cocaine
5. Articaine
For maximum recommended dose (MRD) what guidelines do we follow?
ADA & USPC guidelines (NOT manufacturer)
How does low tissue pH influence local anesthesia?
Low tissue pH (high acidity (H+) is harder to anesthetize (usually associated with inflamed or infected tissues)
How does low anesthetic pH influence local anesthesia?
Low anesthetic pH leads to higher effective shelf life
What is the average pH of local anesthetics?
5.5-7.0
If the pH of the environment does not allow the ________ of anesthetic to exist, numbing will NOT occur
free base form
In order for the local anesthetic to work, the pH of the environment:
must allow the free base form to exist
What is the free base form of the local anesthetic?
what enters the nerve membrane
The further the pH is from the ideal for that specific anesthetic, the:
lower the percentage of that local anesthetic will be present in free base form
Is local anesthetic hydrophilic or hydrophobic?
amphipathic (both hydrophilic and hydrophobic)
What is an exception to local anesthetic being amphipathic?
Benzocaine; doesn’t have hydrophilic group - good for topical but not good for injections)
_____ determines the ease for the nerve blockade
extracellular pH
Inflamed or infected tissue is much more difficult to get adequate anesthesia because:
of increased H+ or lower pH
RNH+ —> RN + H+ describes:
The dissociation of local anesthesia
RNH+ —> RN + H+
What does the RN represent?
Free base
RNH+ —> RN + H+
What does the RNH+ represent?
Cation
RNH+ —> RN + H+
In this reaction, if there’s excess H+, the equilibrium will shift to the _____
What is the significance of this?
Left (RNH+ side)
this means that if there is an acidic environment (example- really infected tooth with lots of bacteria is very acidic) it will be harder to anesthetize because there is less of the free base form (RN) which is what actually enters the nerve membrane
Only the _______ of the anesthetic can enter the nerve, which is important because the sodium channel must be blocked ________
free base form (ninja); from the inside
Anesthesia is injected as an ______ that _______
ionized cation; cannot cross the nerve cell membrane
(until broke down into free-base form)
The anesthesia that is injected must break down from its _____ form into ______ form in order to diffuse into the nerve cell membrane
ionized cation; non-ionized free-base
Once in the nerve, the free base can become the ionized version again and bind to the specific receptor to:
prevent sodium channel from opening
Once the free base form of the local anesthetic is diffused. it must ____ in order to bind to the receptor
dissociate back into the cationic form
Once the free base form of the local anesthetic is diffuse, it must dissociate back into the cationic form in order to bind to the receptor- what does this binding to the receptor cause?
Prevents Na channel from opening
Describe the following relationships between pKA vs local anesthesia:
- High pKA:
- Low pKA:
- slow onset (few free bases available)
- rapid onset
Local anesthesia are _______- They combine with acids to form local anesthetic salt (HCl)
weak basic compounds
pKA influences _______
onset (inverse relationship)
Describe why a high pKA would have a slower onset:
because there are fewer free bases to diffuse (fewer ninjas without their backpack that can get through- most ninjas still have their backpack on so they cannot cross inside the nerve cell membrane)
How does lipid solubility influence local anesthesia?
With increased lipid solubility, the drug is more potent
With decreased lipid solubility, the drug is less potent
The relationship of pKA to onset is ______
The relationship of lipid solubility to local anesthesia potency is _____
inverse
direct
The nerve membrane is ____% lipid
90%
- What influences the ONSET of local anesthesia?
- What influences the POTENCY of local anesthesia?
- What influences the DURATION of local anesthesia?
- pKA
- Lipid solubility
- protein binding
With increased protein binding the drug has _________
longer duration
With decreased protein binding the drug has ______
shorter duration
The nerve membrane is _____% protein
10%
With increased lipid solubility, the drug is:
more potent
With decreased lipid solubility, the drug is:
less potent
With a high pKA the onset of local anesthesia is:
slow (less free base form available)
With a low pKA the onset of local anesthesia is:
rapid
Most local anesthetics have a ______ effect
vasodilation
Which local anesthetic has the most profound vasodilator effect?
Procaine
The only local anesthetic with a vasoconstrictor effect?
Cocaine
What is used with local anesthetics that has a vasoconstrictive effect?
epinephrine
Cocaine is a vasoconstrictor (meaning its alpha-1) and works by:
inhibition of catecholamine re-uptake
Alpha-1 =
vasoconstriction
Beta-2 =
vasodilation
What agent has the most potent vasodilation properties?
Procaine
“I” comes before the “Caine”if the agent is:
an amide
_____ agents are easily hydrolyzed in aqueous solutions
esters
List some examples of local anesthetics that belong to the ester class: (6)
- Procaine
- Propoxycaine
- Tetracaine
- Cocaine
- Benzocaine
- Dyclonine
____ agents resist hydrolysis & get excreted in urine as an unchanged form
amides
List some examples of local anesthetics that belong to the amide class: (6)
- Lidocaine
- Etidocaine
- Mepivocaine
- Bupivocaine
- Prilocaine
- Articaine
what are the two different classes of local anesthesia?
amides & esters
How do amides metabolize in the body?
The liver is the primary biotransformation site
Metabolism of what class of local anesthetic may lead to cirrhosis/CHF or hypotension?
Amide metabolism
How do esters metabolize in the body?
Hydrolyzed in the plasma by pseudocholinesterase into paraaminobenzoic acid (PABA)
What is a substance in local anesthetics that individuals commonly have a reaction to? Is this in amide anesthetics or ester anesthetics?
PABA; Esters
What is the relationship between cirrhosis patient and metabolism of local anesthetics?
Liver function/hepatic perfusion influence biotransformation
(1) cirrhosis –> late stage of scaring (fibrosis) of the liver
When is local anesthetics a contraindication for patients with liver issues?
ASA IV to V for patients with liver dysfunction (or heart failure)
How do cirrhosis and/or CHF interfere with the amounts of your local anesthesia injection?
Amide LAs are chemically modified (metabolized in the body in the liver, so since the liver is not functioning well (doesn’t have full metabolic capacity) then less LA should be administered
If a patient has cirrhosis and/or liver failure, do you give them more or less anesthetic when injecting?
less
Does a patient who has cirrhosis and/or liver failure increase or decrease the availability of the amide local anesthetic? Explain:
Increases Thea availability because the amide is not being metabolized as quickly more is left in the body for longer periods of time
Which organ in the body has the greatest concentration of local anesthesia?
skeletal muscle
What is tachyphylaxis?
the increase in tolerance to drug after repeated administration
Explain how you calculate elimination half-life:
Take percentage of leftover, divide that in half, them add it on to what has been eliminated thus far
what does elimination half life describe?
the amount of time needed for 50% reduction in the blood level
list the percentages of elimination of the following elimination half-lifes:
1st half life: 50% eliminated
2nd half life:
3rd half life:
4th half life:
1st half life: 50%
2nd half life: 75%
3rd half life: 87.5%
4th half life: 94%
Do all local anesthesia readily cross the BBB and placenta?
yes
What is the cause of local anesthesia overdose/toxicity?
over injection or repeated injections in the blood stream & systemic circulation
To prevent local anesthesia overdose/toxicity it is important to:
aspirate
What are the initial signs of local anesthesia overdose/toxicity?
Initially causes excitatory response (numbness of tongue and circumoral region slurred speech, shivering AV disturbances. tremor, etc.)
If you ignore the initial signs of local anesthesia overdose/toxicity, what may occur?
patient an go into a seizure and if you continue loading them up with more local anesthesia they will stop breathing
What are the later signs/stages of local anesthesia overdose/toxicity?
Depressive response on CNS with a lesser CV effect as well as agitation, confusion, dizziness, drowsiness, dysphoria, auditory changes, tinnitus, perioral numbness, metallic taste, etc.
Causes excitatory response (numbness of tongue and circumoral region slurred speech, shivering AV disturbances. tremor, etc.)
Initial stage of local anesthesia overdose/toxicity
Depressive response on CNS with a lesser CV effect as well as agitation, confusion, dizziness, drowsiness, dysphoria, auditory changes, tinnitus, perioral numbness, metallic taste, etc.
Later stage of local anesthesia overdose/toxicty
The initial clinical signs/symptoms of CNS toxicity are:
excitatory
Higher levels of toxicity from local anesthesia may result in:
tonic-clonic convulsion (seizure)
In the later stages of toxicity, or where there is further increases in anesthetic beyond the initial symptoms, there will be:
cessation of seizure activity –> respiratory depression –> respiratory arrest
Catecholamines include:
epinephrine, norepinephrine, dopamine
Non-catecholamines include:
amphetamine, ephedrine, methamphetamine
Epinphrine, norepinephrine & dopamine are all categorized as:
natural catecholamines
Isoproterenol & levonordefrin are both categorized as:
synthetic catecholamines
Contain hydroxyl group on benzene ring and work directly on adrenergic receptors (alpha 1,2 and beta 1,2)
Catecholamines
Do not contain hydroxyl group on benzene ring:
Non-catecholamine
Catecholamines work directly on:
adrenergic receptors (alpha 1,2 and beta 1,2)
What is more concentrated?
1:100000 or 1:200000
1:10000 because this is equal to 1G or 1000mg/100000 ml
whereas 1:200000 is equal to 1G or 1000mg/200000 ml of solution
Calculate the mg/ml of solution for a 1:300000 dilution:
1G = 1000 mg
1000mg/ 300000 ml = 0.0033 mg/ml
The maximum dose of epinephrine in a healthy patient is:
0.20 mg (200 mcg)
The maximum dose of epinephrine in an unhealthy/cardiac patient is:
0.04. mg (40 mcg)
If you have a 1.7ml solution of the 1:100000 dilution of epinephrine, how much epi is present per ml?
(1.7 x .01) = 0.017 mg/ml
Which agent (catecholamine) lacks significant b2 actions thus produces intense peripheral vasconstriction with possible dramatic elevation of blood pressure and is associated with a side effect ratio 9x higher than that of epinephrine
(a big reason that this agent is NOT available in the U.S)
Norepinephrine (EXCESSIVE Vasoconstriction)
Closely resembles norepinephrine:
Levonordefrin
Contraindication for vasoconstrictor administration includes: (6)
- Blood pressure in excess of 200mmHg systolic or 115 mmHg diastolic
- uncontrolled hyperthyroidism
- severe cardiovascular disease
- undergoing general anesthesia with halogenated agents
- Patients receiving nonspecific B-blocker, MAOi, tricyclic antidepressants
- patients in categories 1-3a through 3d are classified as ASA 4 RISKS and NOT normally considered candidates for elective or emergency dental treatment in the office
Contraindication for vasoconstrictor administration includes patients with severe cardiovascular disease such as: (6)
- acute MI within past 6 months
- cerebrovascular accident within past 6 months
- cardiac dysrhythmias despite appropriate therapy
- daily exposure of angina pectoris or unstable angina
- post-coronary artery bypass surgery within last 6 months
Do patients overdose if you exceed MRD?
No- remember bell-shaped curve, multiple factors involved, but does increase chances of overdose
What are contributing factors to local anesthetic overdose?
- accuracy of deposition
- tissue status
- anatomical variation
- type of injection
Can a patient overdose if given under the MRD?
yes
What categories of patients might you want to decrease the MRD on? Why?
Medically compromised, debilitated & elderly patients; these disadvantaged patients are slower in metabolizing these drugs
Do we need to decrease the MRD on medically compromised, debilitated and elderly patients? Why or Why not?
Yes because they are unable to metabolize anesthetic as efficiently
What is the most common cause of failure to achieve adequate anesthesia?
Anatomic variation & faulty technique
Articaine is _____% concentration
4%
What are contraindications for Articaine use?
- patient allergic to amide anesthesias
- sulfite sensitivity
- hepatic disease
- patient with impairments in cardiovascular function
- children under age of 4
Why should you not use Articaine on children under age of 4 years old?
due to insufficient data
Has the potential for neurotoxicity, resulting in more nonsurgical paresthesias than all of local anesthetics (despite fewer injections given)
Articaine
The smaller the gauge:
The bigger the diameter
Which has a greater internal diameter?
25 gauge or 30 gauge
25 gauge
A ____ gauge needle results in less deflection, greater accuracy in injection, and less chance for the needle to break along with easier aspiration
30 gauge
Name four positive qualities of a 30 gauge needle:
- less deflection
- greater accuracy
- less chance of needle break
- easier aspiration
A total of 4ml of 3% mepivacaine without epinephrine has been used. What is the total mg used in this case?
The MRP for Mepivacaine is 4.4 mg/kg
4ml x 0.03% = 0.12
0.12 x 1000 = 120 mg
3% is = to 30mg/ml
Billy Jean is going through a special diet, and after two months she only weighs 20kg. She is at UMKC for some dental work. You pick 2% Lidocaine with epinephrine 1:100,000 as your anesthetic agent (because it has red label on it). What is the maximum mg that you. can give for her?
We know that MRD for lidocaine is 4.4mg/kg
4.4 mg/kg x 20kg = 88 mg
Can a needle be used on more than one patient?
No
When not in use the needle should be:
Covered with protective sheath
T/F: You should use both hands to recap the needle
False- use scoop technique
What technique should be used to recap the needle?
scoop technique
T/F: The needle should be bent for difficult access blocks due to curves and different contours of the facial skeleton
False- absolutely not
Where should you dispose of the needle after use?
Sharps and in biohazard containers
Which agent is bacteriostatic and was removed fro local anesthesia cartridge in 1984 due to reported allergic reactions?
Methyparaben
_______ was replaced by lidocaine (back in the day)
Novacaine
When discussing the “care & handling of cartridge” there is no manufacturer claim of:
sterility of the exterior surface of cartridge
(bacterial culture test failed to produce growth)
When discussing the “care & handling of cartridge” it cannot:
withstand extreme temperatures
Due to a cartridges inability to withstand extreme temps, no ______ especially with plastic cartridge
autoclaving
Due to a cartridges inability to withstand extreme temps, when heated _____ are _____
Vasopressors are destroyed
How should you store cartridges?
At room temp in a dark space
T/F: studies showed benefits of using a cartridge warmer
False- studies showed NO BENEFITS of using a cartridge warmer
in regards to cartridges, do NOT soak in:
alcohol or “cold sterilizing solution”
Why should you NEVER soak cartridges in alcohol or “cold sterilizing solution”?
The semipermeable diaphragm permits diffusion of these solutions
What should you read in regards to cartridges?
Drug insert
What can you wipe the rubber diaphragm of a cartridge with?
Alcohol wipes moistened with undiluted 91% isopropyl alcohol or 70% ethyl alcohol - but do NOT soak
What are some problems that can occur with cartridges? (6)
- bubble in cartridge
- corroded cap
- rust on cap
- leakage during injection
- broken cartridge
- burning on injection
What is the size considered a “small bubble” in cartridge and what is the cause?
Small bubble = (1-2mm)
Usually just nitrogen gas
What is the size considered a “large bubble” in a cartridge and what is the cause?
Large bubble= greater than 2mm
Occurs due to extruded stopper or frozen cartridge
When might the cap of cartridge become corroded?
If immersed in disinfection solution
The only sterilization needed for a cartridge is to rub the rubber diaphragm only with:
91% isopropyl alcohol or 70% ethyl alcohol
Why might the cap of a cartridge rust?
From “tin” container
Leakage from the cartridge during injection may occur if:
eccentric needle puncture of diaphragm
What should you do with a broken cartridge?
return damaged box upon receiving
when might a cartridge shatter?
shatter cartridge occurs due to improper loading & bent harpoons
A bent harpoon may result in:
a shatter cartridge
Why might burning on injection occur?
Due to mishandled or defective cartridges
1. pH
2. Alcohol
3. heat
4. expired
What are the most common psychogenically induced reactions people have upon local anesthesia injection?
most common: Vasodepressor syncope & hyperventilation
Others (less common) include: Tonic clonic convulsions, bronchospasm, and angina pectoris
What does relative contraindication to local anesthetic mean?
Means that caution should be used when two drugs or procedures are used together (it is acceptable if the benefits outweigh the risk)
What does absolute contraindication to local anesthetic mean?
Means that event or substance can cause a life-threatening situation
List the RELATIVE contraindications to local anesthetic administration: (5)
- pregnant women in first trimester
- Malignant hyperthermia
- Cimetidine + ASA III CHF patient
- ASA III or IV + CHF
- Methemoglobinemia to Prilocaine
Why is an ASA III CHF patient taking cimetidine a relative contraindication to local anesthetic?
Because cimetidine increases the half life of circulation LA
Why is an ASA III or IV patient with CHF considered an relative contraindication to local anesthetic?
Because this patient may demonstrate decreased liver perfusion and increase half-life
List the ABSOLUTE contraindication to administration to local anesthesia: (3)
- ASA IV Cardiovascular risk patient
- Tricyclic antidepressant (TCAs)
- Cocaine abuser
Why is an ASA IV cardiovascular risk patient an ABSOLUTE contraindication to local anesthetic?
Because an ASA IV cardiovascular risk patient is not a candidate for vasopressors or elective dental care
Specifically recent MI (less than 6 months ago) or repeated MIs increase risk during dental care or local injection
Specifically what classifies someone as an ASA IV cardiovascular risk patient (Making them an ABSOLUTE contraindication to local anesthetic)
Specifically recent MI (less than 6 months ago) or repeated MIs increase risk during dental care or local injection
Why are patients taking Tricyclic antidepressants (TCAs) an ABSOLUTE contraindication to local anesthetic?
TCAs enhance cardiovascular action to exogenously administered vasopressors
List the statistical risks associated with TCAs enhancing cardiovascular action to exogenously administered vasopressors:
(a) 5-10x increase with levonordefrin and norepinephrine
(b) 2x increase with epinephrine
(c) hypertensive crisis –> death
List the reasons a cocaine abuser is an ABSOLUTE contraindication to local anesthesia: (3)
- cocaine stimulates norepinephrine release and inhibits reuptake
- 72 hours is needed for cocaine clearance
- epinephrine-impregnated gingival retraction cord is absolutely contraindicated
What should you do if you suspect cocaine usage within 24 hours of dental treatment?
Postpone
Since cocaine stimulates norepinephrine release and inhibits reuptake, what may occur to the patient?
Tachycardia/HTN leading to increased myocardial oxygen requirement leading to cardiac ischemia and eventually myocardial infarction
What is ABSOLUTELY contraindicated for a cocaine user?
Epinephrine-impregnated gingival retraction cord
How long do you need to topical in the mouth to be effective?
Apply topical for 2 min
Where should the bevel of the needle be placed during a LA injection?
Place the bevel of the needle on the tissue in the direct you want to go (towards bone)
When MUST you aspirate when giving local anesthetic injections?
For PSA and inferior alveolar nerve blocks
What does aspirating when giving an injection do?
Makes sure you are not in a blood vessel
When giving an LA injection you should: (technique)
twist the needle as you insert it to keep the needle from deflection in one direction
How do you avoid deflection in one direction when giving LA injections?
Twist the needle as you insert
Finger rest or chest/body rest?
finger rest
What are the three branches of the trigeminal nerve?
V1: opthalmic
V2: Maxillary
V3: Mandibular
Where do the following branches of the trigeminal were enter/exit the cranium?
- V1- opthalmic:
- V2- maxillary
- V3: mandibular
- V1- opthalmic: superior orbital fissure
- V2- maxillary: foramen rotundum
- V3: mandibular: foramen ovale
Name whether each branch of the trigeminal nerve is sensory or motor:
- V1- opthalmic:
- V2- maxillary
- V3: mandibular
- V1- opthalmic: sensory
- V2- maxillary: sensory
- V3: mandibular: sensory & motor
One of the branches of the V2 (trigeminal nerve) upon exiting cranial base makes a quick 180 degree turn back into the cranium. This nerve provides sensory innervation to the dural mater. Its the _____ nerve
middle meningeal nerve
Which division of the trigeminal nerve is sensory and/or motor?
Mandibular branch (V3)
Type of injection that numbs one tooth:
local infiltration
Type of injection that numbs about two teeth:
field block
Type of injection that numbs the entire area as you are injection the nerve bundle:
nerve block
When you inject a nerve bundle, you are performing a:
nerve block
What type of LA injection is seen in the photo below?
Local infiltration
What type of LA injection is seen in the photo below?
Field block
What type of LA injection is seen in the photo below?
Nerve block
Infiltration is considered a _____ injection
supraperiosteal
Infiltration is performed if you are numbing:
one tooth
How is the needle entered when performing infiltration injections?
Adjacent to bone, apical to apex
Describe how infiltration kind of works:
Maxillary labial bone is porous and allows infiltration of anesthetic (anesthetic diffuses into bone)
Infiltration is commonly done with:
premolars
List the areas anesthetized by infiltration:
- single tooth
- buccal periodontium & bone
- labial/buccal bucosa
PSA:
Posterior superior alveolar nerve block
What type of LA injection is seen in the following photos?
Posterior superior alveolar nerve block (PSA)
How is the needle entered for a posterior superior alveolar nerve block (PSA)?
Needle is entered into the height of the vestibule at a 45 degree angle to the occlusal plane
Needle is inserted about 16mm and you MUST aspirate
How far is the needle inserted in a posterior superior alveolar nerve block?
16mm
What is the aspiration rate for a posterior superior alveolar nerve block?
3%
If there is a positive aspiration with a PSA what may occur?
hematoma
List the areas anesthetized with a PSA:
- Maxillary molar tooth pulps
- MB root of 1st molar (72%)
- buccal periodontium & bone (NOT palatal)
During an infiltration injection (supraperiosteal) the syringe is held ______ and the anesthetic is placed ______
parallel to the long axis of the tooth; apical to apex of tooth
Given the anesthetized areas, what type of injection was given?
-tooth
-buccal periodontium
-labial/buccal mucosa
Infiltration (supraperiosteal)
What tooth root has special innervation?
1st molar MB root
What injection is most likely to give you an ugly hematoma?
PSA
Given the anesthetized areas, what type of injection was given?
-maxillary molar tooth pulps
-MB root of 1st molar (72%)
-buccal periodontite and bone
Posterior superior alveolar nerve block (PSA)
What type of injection was given if the yellow portion is the area anesthetized?
PSA
What type of injection was given if the yellow portion is the area anesthetized?
MSA
Describe the position of the needle when injecting a middle superior alveolar nerve block (MSA):
Needle is injected well above premolar apices; bevel facing the bone
List the areas anesthetized during an MSA:
- Maxillary premolars
- MB root of 1st molar (20%)
- Buccal periodontal & bone (NOT palatal)
According to the image, what type of injection is being given?
Middle superior alveolar nerve block (MSA)
Given the anesthetized areas, what type of injection was given?
-maxillary premolars
-MB root of 1st molar (28%)
-Buccal periodontite & bone
MSA
Describe the needle placement in an anterior superior alveolar nerve block (ASA):
- Needle contacts roof of infraorbital Forman (which is located about 16mm above vestibule)
- Insert needle about 1/2 length
- orient bevel towards bone and insert until bone is contacting needle
- maintain pressure during injection and about 1 min after
In an ASA nerve block, the anesthetic is directed:
into canal
List the areas anesthetized by an ASA:
- maxillary central incisor through canine
- premolars
- MB root of first premolar (28%)
- buccal periodontite & bone
- Lower eyelid, side of nose, upper lip
Given the following anesthetized areas, what type of injection was given?
-maxillary central incisor through canine
-premolars
-MB root of first molar in 28%
-Buccal periodontite & bone
-lower eyelid, side of nose, upper lip
Anterior superior alveolar nerve block (ASA)
The following images depict what type of injection?
ASA
An anterior superior alveolar nerve block (ASA) may also be called:
infraorbital nerve block
What should be located before an ASA and how?
Locate foramen by palpation
For a greater palatine injection, where is the needle aiming?
Needle is aiming for greater palatine foramen area & contacts bone (not into the foramen)
What type of injection is seen in the following images?
Greater palatine
What type of injection is seen in the following images?
Nasopalatine
List the areas anesthetized with a greater palatine infection:
- posterior portion of hard palatine (canine to last molar)
- overlying soft tissue
(NO anesthesia of teeth)
Where is the boundary of anesthesia for greater palatine vs. nasopalatine on the palate?
Greater palatine is distal to 2nd maxillary molar
How can the greater palatine foramen be located?
Can be identified by finding the junctions of molars 2&3 and then moving the needle 1cm medially
Can be identified by finding the junctions of molars 2&3 and then moving the needle 1cm medially:
Greater palatine foramen
If the following areas are anesthetized what type of injection was given?
-posterior portion of hard palate
-overyling soft tissues
(no teeth anesthetized)
Greater palatine
Where is the injection area of a greater palatine injection?
Midway between midline and free gingival border (10mm from palatal midline)
Where does the needle need to contact with a nasopalatine injection?
Needle contacts bone lateral to incisive papilla
Given the image, what type of injection was given?
Greater palatine
Given the image, what type of injection was given?
Nasopalatine
Describe the steps to giving an nasopalatine injection:
- needle contacts bone lateral to incisive papilla
- bevel against tissue and bow the needle
- straighten needle and advance
What is an alternative approach for a nasopalatine injection?
Trans-papillary
Insert needle through papilla between 8&9 towards palate
List the areas anesthetized during a nasopalatine injection:
- anterior portion of hard palate (canine to canine)
- both hard and soft tissues
(no anesthesia of teeth)
The following image depicts what type of injection?
Buccal nerve block
The following image depicts what type of injection?
Mental nerve block
The following image depicts what type of injection?
Inferior alveolar nerve block
The following image depicts what type of injection?
Tow-gates block (true mandibular nerve block)
The following image depicts what type of injection?
Vazirani-akinosi nerve block (closed mouth mandibular nerve block)
Use a 25 gauge long needle, stretch tissue, and contact periosteum. (Large area of nerve coverage, just need to aim in general area)
buccal nerve block
What gauge of needle should be used for a buccal nerve block?
25 gauge
What is the only block to anesthetize the buccal mucosa of molars?
Buccal nerve block
T/F: a lot of anesthetic is needed to anesthetize the buccal mucosa of molars (buccal nerve block)
true
List the areas anesthetized with a buccal nerve block:
- gingival buccal to molars
- retromolar pad mucosa
- buccal mucosa in molar areas
(no hard tissue anesthetized)
Given the following image, what type of injection was given?
Buccal nerve block
The mental nerve (targeted in a mental nerve block) exits out of the:
mental foramen
How should you locate the site of injection for a mental nerve block?
Palpate the mental foramen (near the premolars) to determine site of injection
Inject into tissue over foramen
There is risk of possible _____ with a mental nerve block
What is the aspiration rate?
Hematoma; 5.7%
List what becomes anesthetized with a mental nerve block:
- mucosa anterior to foramen
- skin of the lower lip
- chin
If the following areas are anesthetized, what injection was given?
-mucosa anterior to foramen
-skin of lower lip
-chin
mental nerve block
The largest branch of the posterior division protected by the sphenomandibular ligament:
Inferior alveolar nerve
The inferior alveolar nerve is protected by:
sphenomandibular ligament
What injection is being given in the following scenario:
Syringe is directed across the arch (from contralateral side) at level of coronoid notch. Place finger on notch to locate it and determine height of injection. Needle penetrated buccinator muscle and it is lateral to pertygomadibular raphe- contacts bone and must aspirate
Inferior alveolar nerve block
At what level is an inferior alveolar nerve block given?
Level of the coronoid notch
With an inferior alveolar nerve block, the needle penetrates _____ and is lateral to ____
buccinator muscle; pterygomandibular raphe
Do you contact bone in an inferior alveolar nerve block?
yes
What nerves are anesthetized with an inferior alveolar block?
- inferior alveolar
- incisive
- mental
- lingual (usually)
What areas and nerves are anesthetized with an inferior alveolar nerve block?
- Nerves- inferior alveolar, incisive, mental, lingual
- entire unilateral side from midline
- lingual mucosa
- tongue
- teeth
According to the following image, what injection was given?
Inferior alveolar nerve block
Considered a “true mandibular nerve block”
Gow-gates block
What injection is being described:
Needle contacts neck of condyle, patient opens wide so condyle moves forward; must aspirate:
Gow-gates block
What are the extra oral landmarks for a Gow-gates block:
Intertragic notch & corner of mouth
When doing a Gow-gates block, what should you have the patient do?
Open wide so condyle moves forward
What nerves are anesthetized with a Gow-gates block?
- inferior alveolar
- lingual
- mylohyoid
- auriculotemporal
- buccal (75%)
A closed mouth mandibular nerve block may also be called:
Vazirani-akinosi nerve block
The height of injection of a Vazirani-akinosi nerve block is:
maxillary muco-gingival line
How far is the needle inserted in a Vazirani-akinosi nerve block?
35 mm
When giving a Vazirani-akinosi nerve block, the path of insertion is:
Parallel to ramus
Should you contact bone with a Vazirani-akinosi nerve block?
No
What nerves are anesthetized with a Vazirani-akinosi nerve block?
- inferior alveolar
- lingual
- mylohyoid