Time Course of Phenobarbital and Cimetidine Mediated Changes
2020 Self Study #4 Course - College of Dentistrycimetidine, and those with hepatic diseases Patients...
Transcript of 2020 Self Study #4 Course - College of Dentistrycimetidine, and those with hepatic diseases Patients...
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2020Course#4Self‐Study
Course
ContactUs:Phone
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TheOhioStateUniversityCollegeofDentistry305W.12thAvenueColumbus,OH43210
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CourseInstructions:
Readandreviewthecoursematerials.
Completethe15questiontest.Atotalof12questionsmustbeansweredcorrectlyforcredit.
Submityouranswersonlineat:http://dentistry.osu.edu/sms‐continuing‐education
CheckyouremailforyourCEcertificationofcompletion(pleasecheckyourjunk/spamfolderaswell).
AboutSMSCEcourses: TWOCREDITHOURSareissued
forsuccessfulcompletionofthisself‐studycoursefortheOSDB2019‐2021bienniumtotals.
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ALLOW2WEEKS forprocessingofyourcertificate.
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A:YourSMSnumbercanbefoundintheupperrighthandcornerofyourmonthlyreports,or,imprintedonthebackofyourtestenvelopes.TheSMSnumberistheaccountnumberforyourofficeonly,andisthesameforeveryoneintheoffice.Q:Howoftenarethesecoursesavailable?
A:Fourtimesperyear(8CEcredits).
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Learning Objectives:
a. Discuss neurophysiology and action potentialb. List and describe the composition of local anesthetic agents c. Discuss the properties, precautions, and contraindications
for the following local anesthetics: lidocaine, mepivacaine, prilocaine, articaine, bupivacaine
d. Discuss the importance of obtaining patient’s medical/dental history
e. List the steps to administering successful local anesthesia f. Correlating the maxillary and mandibular injections to the
teeth and areas anesthetized
2020Course#4
OriginalAuthors:IrinaNovopoltseva,RDH,
MS
ReleaseDate:December7,2020
8:30amEST
LastDaytoTakeCourseFreeofCharge:January7,2021
4:30pmEST
LocalAnesthesia:RefresherfortheDental
Professional
ThisisanOSDBCategoryB:Supervisedself‐instructioncourse
About the AuthorIrina Novopoltseva, RDH, MSAssistant Professor- Clinical
College of Dentistry Division of Dental Hygiene
Neither I nor my immediate family have any financial interests that would create a conflict of interest or restrict my judgement with regard to the
content of this course.
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One of the most important skills required of dental practitioners is the ability to provide
safe and effective local anesthesia. The agents and armamentarium available today
provide the clinician with an array of options to effectively manage the pain associated
with dental procedures. We came a long way from the time when the numbing
properties of the cocaine were first recognized, to the development of the amide
anesthetics implemented today into the dental care of our patients.1
Local anesthetics work by diffusing into a nerve and blocking Na+ channels, preventing
nerve impulses from reaching the brain. As long as the concentration of local
anesthetic outside of the nerve is greater than that inside, the drug will diffuse into the
nerve. Once the equilibrium is achieved, the diffusion stops. Blood vessels inside and
outside the nerve continue to ‘carry away’ local anesthetic.2 The concentration of local
anesthetic inside the nerve exceeds the concentration of it outside the nerve, thus the
diffusion of the drug reverses. Consequently, the local anesthetic diffuses out of the
nerve. As the local anesthetic concentration in the nerve decreases, a point is reached
at which nerve impulses begin to propagate and reach the brain.2,3
Local anesthetics used in dentistry are manufactured in a single-use cartridge. The
cartridge is a glass cylinder containing the local anesthetic drug, along with other
ingredients.3 In the United States, each cartridge of local anesthetic is designed to
contain 2.0ml of solution. However, by the time the silicone rubber stopper is added to
the cartridge, it can contain anywhere between 1.7ml-1.76 ml.2
Local anesthetics are vasodilators, regardless of the rate of absorption, the blood
vessels around injection side will immediately begin to absorb the anesthetic by
causing vasodilation of the blood vessels. This physiological process results in the
increased blood flow to the injection site.3 Consequently causing higher blood levels of
local anesthetic, increasing the risk of systemic toxicity, and rate of anesthetic
absorption into the bloodstream. The anesthetic solution is carried away from the
injection site, causing decrease in duration and rapid rate of diffusion. This chemical
process increases bleeding at the injection site.2,3
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In addition to the local anesthetic drug, the dental cartridge contains several other
ingredients: vasoconstrictor, preservative, reducing agent, and fungicide.2
Vasoconstrictors are combined with the anesthetic solution to counteract the vasodilating
properties of local anesthetics. The vasoconstrictor function includes constricting the
blood vessels leading to a decrease in blood flow to the injection site.4 All while
supporting the increased duration of action, and reduction of bleeding at the injection site.3
Since vasoconstrictors are unstable with a short shelf life, the addition of a preservative
delays these properties. Thus, only the local anesthetic agents with vasoconstrictors
contain the preservatives. Sodium bisulfite, metabisulfite, or acetone sodium bisulfite are
the vasoconstrictor preservatives only added to the local anesthetic agents with
vasoconstrictors.3 As a chemical property, sodium bisulfite dissociates in water into
bisulfite and sodium ions, decreasing the pH of the agent.5
Local anesthesia is the temporary loss of sensation or pain in one part of the body
produced by a topically applied or injected agent without depressing the level of
consciousness. Dental anesthetics fall into two groups: amides (lidocaine, mepivacaine,
prilocaine and articaine), which are metabolized in the liver, and esters (procaine,
benzocaine), metabolized in the blood.2 Due to the high degree of hypersensitivity to
injectable esters, all injectable local anesthetics manufactured in a single-use dental
cartridge are of amide group. Procaine is available in the multidose vials and is used in
medicine.3 Typically, procaine and the longer-acting related compound, procaine amide,
have been most widely employed for the treatment of the various ventricular arrhythmias
occurring during cardiac operations.6 Benzocaine is one of the most commonly used
topical anesthetics available in various forms (i.e. gel, spray, ointment, and patch). It is
preferred due to rapid onset, slow absorption into circulation, therefore having a desired
low systemic toxicity. However, methemoglobinemia has been reported with higher
concentrations of 14% to 20% spray.3,7
Supraperiosteal injection anesthetizes a small area by depositing anesthetic near the
terminal nerve endings and is referred to as infiltration.3 Whereas with a nerve block, an
injection of local anesthetic is in the area of a nerve trunk.2,3
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Available Formulations
Lidocaine 2% plain Lidocaine 2% 1:50,000 epinephrine
Lidocaine 2% 1:100,000 epinephrine
ADA Color coding band
Light Blue Green Red
Onset of action (in minutes)
2‐3 2‐3 2‐3
Duration category Very short Intermediate IntermediateDuration pulpal tissues (in minutes)
5‐10 60 60
Duration soft tissues (in minutes)
60‐120 180‐300 180‐300
Precautions with Vasoconstrictors
N/A Patients with significant cardiovascular disease, elderly patients with sensitivity to epi.Patients taking non‐selective beta‐blockers, CNS stimulants, tricyclic antidepressants, and/or allergic to sodium bisulfite
Patients with significant cardiovascular disease, elderly patients with sensitivity to epi.Patients taking non‐selective beta‐blockers, CNS stimulants, tricyclic antidepressants, and/or allergic to sodium bisulfite
Precautions with Local Anesthetic
Patients taking non‐selective beta‐blockers, central nervous system depressants, cimetidine, and those with hepatic diseases
Patients taking non‐selective beta‐blockers, central nervous system depressants, cimetidine, and those with hepatic diseases and renal dysfunction
Patients taking non‐selective beta‐blockers, central nervous system depressants, cimetidine, and those with hepatic diseases and renal dysfunction
Helpful Tips Not commonly used Low risk of systemic toxicityBest choice for bleeding control (infiltrate small amnt. into area requiring hemostasis)
Most used anestheticLow risk of systemic toxicity Best choice for pregnancy (category B)Can be used for significant cardiovascular disease at decreased dose of 0.04mg (2.2 cartridges) per appt.
The tables that follow describe the properties, precautions, and contraindications of each
amide group local anesthetic mentioned above.
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Available Formulations
Mepivacaine 3%Plain
Mepivacaine 2% 1:20,000 levonordefrin
ADA Color coding band
Tan Brown
Onset of action (in minutes)
2‐4 1.5‐2
Duration category Short IntermediateDuration pulpal tissues (in minutes)
20 (Supraperiosteal)40 (Block)
60
Duration soft tissues (in minutes)
120‐180 180‐300
Precautions with Vasoconstrictors
N/A Patients with significant cardiovascular disease, elderly patients with sensitivity to epi.Patients taking non‐selective beta‐blockers, CNS stimulants, tricyclic antidepressants, and/or allergic to sodium bisulfite
Precautions with Local Anesthetic
Patients taking beta‐blockers, central nervous system depressantsSevere renal dysfunctionHepatic diseaseRisk of systemic toxicity Use with caution in pediatric patients
Patients taking non‐selective beta‐blockers, central nervous system depressantshepatic diseases renal dysfunction
Helpful Tips Good choice when a vasoconstrictor is contraindicated utilizing nerve block
Low risk of systemic toxicityCan be used for patients with significant cardiovascular disease at 0.2 mg (2.2. cartridges) per appt.
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Available Formulations
Prilocaine 4% Plain Prilocaine 4% 1:200,000 epinephrine
ADA Color coding band
Black Yellow
Onset of action (in minutes)
2‐4 2‐4
Duration category Short (Supraperiosteal) Intermediate (Block)
Intermediate
Duration pulpal tissues (in minutes)
10‐15 (Supraperiosteal)
40‐60 (Block)
60‐90
Duration soft tissues (in minutes)
90‐120 (Supraperiosteal)
120‐240 (Block)
180‐480
Precautions with Vasoconstrictors
N/A Patients with significant cardiovascular disease, elderly patients with sensitivity to epi.Patients taking non‐selective beta‐blockers, CNS stimulants, tricyclic antidepressants, and/or allergic to sodium bisulfite
Precautions with Local Anesthetic
Risk for systemic toxicity
Avoid using on patients with sickle cell anemia
Risk of methemoglobinemia
Patients taking central nervous system depressants
Avoid using on patients with sickle cell anemia
Risk of methemoglobinemiaHelpful Tips Least vasodilatory properties of all
amide anesthetics
Metabolizes in lungs and liver, ؞patients with hepatic disease less of a concern
Best choice for pregnancy (category B)
Least toxic of all amide local anesthetics
Good choice for elderly patients, hyper‐sensitive to epinephrine
Best choice for patients with significant cardiovascular disease, or those needing modifications due to epinephrine
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Available Formulations
Articaine 4% 1:100,000 epinephrine
Articaine 4% 1:200,000 epinephrine
Bupivacaine 0.5% 1:200,000 epinephrine
ADA Color coding band
Gold Silver Blue
Onset of action (in minutes)
1‐2 (Supraperiosteal)
2‐2.5 (Block)
1‐2 (Supraperiosteal)
2‐3 (Block)
6‐10
Duration category Intermediate Intermediate LongDuration pulpal tissues (in minutes)
60‐75 45‐60 90‐180
Duration soft tissues (in minutes)
180‐360 120‐300 240‐540
Precautions with Vasoconstrictors
Patients with significant cardiovascular disease, elderly patients with sensitivity to epi.Patients taking non‐selective beta‐blockers, CNS stimulants, tricyclic antidepressants, and/or allergic to sodium bisulfite
Patients with significant cardiovascular disease, elderly patients with sensitivity to epi.Patients taking non‐selective beta‐blockers, CNS stimulants, tricyclic antidepressants, and/or allergic to sodium bisulfite
Patients with significant cardiovascular disease, elderly patients with sensitivity to epi.Patients taking non‐selective beta‐blockers, CNS stimulants, tricyclic antidepressants, and/or allergic to sodium bisulfite
Precautions with Local Anesthetic
Patients taking central nervous system depressants
Patients with myasthenia gravis
Patients taking central nervous system depressants
Patients with myasthenia gravis
Patients taking non‐selective beta‐blockers
Patients taking central nervous system depressants
Patients prone to self‐mutilation (special needs/young children)
Helpful Tips Safer choice for patients with hepatic disease
Safer drug to re‐administer later in the appointment
Best choice when mandibular supraperiosteal injection is needed
Safer choice for patients with hepatic disease
Good choice for elderly patients hyper‐sensitive to epinephrine
Safer drug to re‐administer later in the appointment (due to short half‐life)
Best choice when mandibular supraperiosteal injection is needed
Procedures requiring long duration of anesthesia
Greater risk of systemic toxicity
Good alternative when profound anesthesia cannot be achieved with other anesthetics
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Over time, the administration of local anesthesia can become mundane to the clinician, as
the patient is often viewing it as a stressful experience and part of their dental visit. For
many of our patients, the anxiety and anticipation of receiving a ‘shot’ could generate an
emergency situation.3 Syncope, is the most common medical emergency observed in the
dental office, and it is most frequently linked to the administration of local anesthesia.6
Dental professionals must be mindful of not allowing the administration of the local
anesthesia to become mundane and repetitive. Therefore, establishing effective
communication and psychological support is essential in developing patient rapport and
instilling confidence thus reducing the likelihood for an emergency. Implementing the
following steps will assist each provider to administer safe, effective, and will provide a
comfortable patient experience.
The dental provider must evaluate a patient by completing a thorough medical and dental
history, including physical and psychological evaluations. If necessary, a medical clearance
evaluation should be requested and before any dental treatment rendered the vital signs
should be taken and recorded.7 The care plan must be tactfully developed in collaboration
with the patient involving their risk assessments and expectations. It should be viewed as a
mutual road map for the clinician and the patient. The benefits and risks of all the
treatments should be discussed including the administration of local anesthesia. One
cannot overlook the importance of discussing the risk associated with not receiving
treatment. The clinician in detail should discuss the treatment including the type of
anesthetic, injection(s), and any post-operative instructions.8 Prior to treatment, the
informed consent should be presented, and any questions need to be addressed, after
which, the treatment can be accepted by the patient. The written agreement of the care
plan becomes a legal binding contract between the patient and the provider.4 Based on the
care plan, the clinician should select the appropriate injection(s) and the agent(s). In this
selection process, the dental provider ought to determine the need for pulpal and/or soft
tissue anesthesia and select an anesthetizing agent taking into consideration the
medical/dental history, hemostasis, duration of the procedure, and a potential for self-
mutilation.6
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Ideally, the preparation of all the equipment and supplies should be completed prior to
patient arriving to the operatory. The selection of the syringe is important, considering
the clinician’s hand size, as it relates to be able to properly aspirate. The view of the
syringe, needle, and cartridges can be unsettling for a patient, therefore, assembled
armamentarium along with any additional supplies should be kept out of patient’s
sight. The supine position, with the patient’s feet slightly elevated, is the recommended
position for the administration of local anesthesia. This is the best position to treat
vasodepressor syncope, the most common dental emergency due to local
anesthesia.3,4 The injection site should be evaluated for any anatomical abnormalities
and/or trauma and dried prior to the application of a topical anesthetic. Topical
anesthetics are designed to provide soft tissue anesthesia prior to the needle insertion.
They do not contain vasoconstrictors, therefore rapidly absorb when applied to the
mucous membrane. You would want to follow the manufacturers recommendations
and guidelines for usage, but typically the application of the topical anesthetic is
indicated anywhere between 1 – 2 minutes.12
During this window of time, it is advised to provide supportive communication to the
patient, to help elevate any anxiety. Following the application of topical anesthetic,
redry the injection site to remove any excess and offer a dry area effective for
visualization of the injection site. Palpate the anatomical landmark to determine the
insertion site.2-4
As the clinician picks up the syringe, the following stipulations must be evaluated. The
orientation of the bevel, should be oriented toward the bone to ensure the proximity to
the periosteum. The dental professional should hold the syringe palm up, with the
large window facing upward. It is suggested to expel few drops of the local anesthetic
to guarantee a free flow of the solution, and ensure the harpoon is fully engaged in the
rubber stopper. The clinician should double check the safety protocol such as the
needle sheath protector, patient protective eyewear.2,3
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Establishing a fulcrum is essential in administering safe and comfortable injections. This is
also critical during the aspiration in two planes, as it will ensure the minimum movement
of the needle. Retracting the tissue taut at the injection site serves two purposes, it allows
for greater clinical visibility, and less trauma with needle insertion. Concurrently, the
clinician has to provide encouraging and reassuring words to the patient while observing
the facial expressions and overall well-being.13
Aspiration is one of the most critical steps in the prevention of administrating the local
anesthetic directly into the blood vessel. Once the desired location is reached, aspirate by
pulling back on the thumb ring gently for about 1-2mm. Following the successful negative
aspiration, rotate the barrel of the syringe 45° and aspirate the second time.2-4 Aspirating
in two planes ensures that the needle is not located in the blood vessel, and that first
aspiration is not a false negative. A negative aspiration is when there is no blood in the
cartridge, rather a clear air bubble. Whereas a positive aspiration of a slight reddish
discoloration at the diaphragm indicated venous penetration. The clinician should
reposition the needle, re-aspirate, and proceed if aspiration is negative. The bright red
blood rapidly filling the cartridge is indicative of arterial penetration. Thus, the clinician
needs to remove the syringe, replace the cartridge, and repeat the procedure.2
Once the clinician successfully aspirated in two planes, the anesthetic solution should be
deposited at a slow rate of 1 mL per minute. Therefore, a cartridge of 1.8mL should be
deposited in approximately 2 minutes for patient comfort, and most importantly the safety.
The slow injection prevents the solution from tearing the tissue at the injection site.2,3
Some studies have linked the slow deposition of the anesthetic solution for the Inferior
Alveolar Block providing a faster onset with greater efficacy.14 Following the completion of
the injection, the clinician should slowly withdraw the needle from the tissue. The needle
must be recapped following safety protocol to prevent needle punctures by the clinicians.
Succeeding, the proper safety protocol, the clinician should monitor the patient for
possible adverse reactions to the anesthetic. Under no circumstance, the patient should
be left unattended after administration of local anesthetic. The delivery of the local
anesthesia must be documented and becomes a part of the patient’s permanent record.6
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Maxillary Anesthesia In effort to provide patients with successful anesthesia, dental professionals must
determine how the trigeminal (V) nerve along with its branches can be anesthetized in
various ways with clinical effectiveness.2 The local anesthesia on the maxillary arch is
typically more effective due to the anatomical considerations. The facial cortical plate of the
maxillae is less dense and more porous in comparison to the mandible. In addition, the
maxillae presents with less variations in relations of anatomical structures and nerves
associated with the local anesthesia landmarks.2
Maxillary nerve blocks anesthetize various maxillary nerve branches and have high level of
clinical effectiveness when administered correctly. To accomplish the highest level of
patient comfort with the maxillary facial nerve blocks, a clinician must avoid any bony
contact with a needle during the injection. The exception to this concept is the infraorbital
block. In addition, a clinician is required to establish a stable fulcrum in effort to minimize
the needle movement within the tissue during a deposition. There is no significant evidence
supporting the shaking motion of the upper lip during the administration of a local
anesthetic as a patient management strategy.2,5 During patient evaluation, a dental
professional must access the patient’s anatomy. For example, the site of deposition for the
maxillary facial nerve blocks is superior to the apex of each target tooth. The topical
anesthetic is yet another means to increase patient comfort during the administration of the
local anesthetic. It should be applied in the vestibule at the height of the maxillary
mucobuccal fold, with the focus on the redder, soft tissue of the superior alveolar mucosa.2
The following set of charts will discuss maxillary facial and palatal nerve blocks including
areas anesthetized, landmarks, and potential complications for each injection.
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INJECTION Middle Superior Alveolar Block (MSA)
Branch of Trigeminal Nerve Middle Superior Alveolar branch of infraobital nerve. (V2)
Area Anesthetized (Teeth &/orSoft Tissue)
Field block that includes maxillary premolars & MB root of Max. 1stmolar, periosteum and buccal soft tissue of same area. Absent in a large % of the population.
Needle 25, 27 or 30 short
Landmarks Apex Max 2nd premolar
Insertion/ Penetration Site Height of muccobuccal fold over Max. 2nd premolar.
*Approximate Depth of Penetration
4‐10mm 1/4 – 1/2”
Deposition/ Target Site Para‐periosteal through the mucous membrane over apex of 2ndpremolar.
*Volume of Anesthetic 1.0‐1.2 (1/2‐2/3 cartridge)Potential Complications/ Additional Considerations
Pain if periosteum is scraped. Ballooning of tissue possible.Some patients do not have MSA.
INJECTION Posterior Superior Alveolar Block (PSA)
Branch of Trigeminal Nerve Posterior Superior Alveolar Max. Division (V2)
Area Anesthetized (Teeth &/or Soft Tissue)
3rd, 2nd, 1st max. molars (except mesio‐buccal root of 1st perm. molar if MSA is present) periosteum, and buccal soft tissue of same area.
Needle 25 or 27 short
Landmarks Maxillary Tuberosity Alveolar canal openings Zygomatic Process of maxilla
Insertion/ Penetration Site Height of mucobuccal fold in concavity distal to zygomatic buttress, distal of 2nd molar, 45° angle from occlusal plane
*Approximate Depth of Penetration
(3/4”) 16mm(3‐4mm from hub of short needle)
Deposition/ Target Site Posterior, superior, & medial to max. tuberosity; 45° angle to occlusal plane; 45° angle to midsaggital plane
*Volume of Anesthetic 1‐1.8ml (3/4 –1 cartridge)
Potential Complications/ Additional Considerations
Mandibular anesthesia if anesthetic is deposited too far laterally.No bony landmark, risk of hematoma; hemorrhage, may be problem for some patient. May require 2nd injection for MB root of 1st molar.
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INJECTION Infraorbital Block (IO)
Branch of Trigeminal Nerve Infraorbital is a branch of the Maxillary nerve (V2)Area Anesthetized (Teeth &/orSoft Tissue)
Field block that includes maxillary central, lateral, canine, periosteum, and facial/labial soft tissue of same area (to midline).
Needle 27 or 25 gauge needle is recommended ‐ 27 gauge short most commonly used
• if larger individual, may need a long needleLandmarks Extraoral: IO rim, IO foramen, zygomaticomaxillary suture
Intraoral: Maxillary first premolar, maxillary mucobuccal fold
height of IO foramen varies based on facial size, vestibular depth, and age
• adult 8‐10 mm below the IO ridge
• children ‐ shorter distanceInsertion/ Penetration Site height of the mucobuccal fold directly over the first premolar*Approximate Depth of Penetration
16mm or ¾ of a short needle or ½ of a long needle
Deposition/ Target Site Depth adequate to reach the foramen
*Volume of Anesthetic 0.9‐1.2 ml or ½ ‐ 2/3 of a cartridge
Potential Complications/ Additional Considerations
Pain if periosteum is scraped. Ballooning of tissue possible.
INJECTION (Anterior Superior Alveolar Block) ASA
Branch of Trigeminal Nerve Anterior Superior Alveolar branch of infraorbital n. (V2)
Area Anesthetized (Teeth &/or Soft Tissue)
Field block that includes maxillary central, lateral, canine, periosteum, and facial/labial soft tissue of same area (to midline).
Needle 25, 27, or 30 short
Landmarks Canine fossae, located between lateral and canine.Infraorbital foramen vs. Apex of canine
Insertion/ Penetration Site Height of MB fold mesial to root of canine at canine fossa.*Approximate Depth of Penetration
4‐6mm 1/4”
Deposition/ Target Site Para‐periosteal through the mucous membrane mesial to the apex of max. canine.
*Volume of Anesthetic 1.0‐1.2 (1/2‐2/3 cartridge)Potential Complications/ Additional Considerations
Pain if periosteum is scraped. Ballooning of tissue possible.Often central innervation overlap; may require additional infiltration over central.
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INJECTION Nasopalatine Nerve Block (NP)
Branch of Trigeminal Nerve Nasopalatine nerve, branch of pterygo‐palatine nerve (V2)
Area Anesthetized (Teeth &/orSoft Tissue)
No teeth.
Anterior 1/3 of hard palate, lingual tissues from cuspid to cuspid.
Needle 25, 27 or 30 short
Landmarks Max. centrals, incisive papilla
Insertion/ Penetration Site Para‐periosteal through the mucous membrane next to incisive papilla at 45 degree angle
*Approximate Depth of Penetration
1/8 – 1/4 “ (usually 3‐6mm)
Deposition/ Target Site At the incisive foramen. One injection will anesthetize both right & left NP nerves.
*Volume of Anesthetic .2‐.45 ml 1/8‐1/4 cartridge Potential Complications/ Additional Considerations
Necrosis of soft tissue from vasoconstrictor is possible.
No hemostasis except in injection area, traumatic injection
INJECTION Greater Palatine Nerve Block (GP)
Branch of Trigeminal Nerve Greater (or Anterior) Palatine, branch of pterygopalatine n. (V2)
Area Anesthetized (Teeth &/orSoft Tissue)
No teeth
Hard palate & lingual tissue posterior to 1st premolar & medial to midline
Needle 25, 27 or 30 short
Landmarks Vertical and horizontal processes of maxillae & palatine bones.
Insertion/ Penetration Site Anterior to Greater Palatine foramen & junction of Max. alveolar process and palatine bone.
*Approximate Depth of Penetration
1/8 – 1/4 “
(usually 3‐6mm)Deposition/ Target Site Slightly anterior to greater (anterior) palatine foramen.
*Volume of Anesthetic 0.45 to 0.6 ml (1/4 to 1/3 cartridge)Potential Complications/ Additional Considerations
No hemostasis except in injection are
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Mandibular Anesthesia
Local anesthesia on the mandibular arch is achieved by anesthetizing the mandibular
nerve of the trigeminal or cranial nerve (V) along with its branches. The mandible is less
porous and dense than the maxillae, this anatomical difference can be evaluated on the
panoramic radiograph. Therefore, nerve blocks are favored to supraperiosteal injections
on the mandibular arch.2,3
The following set of charts will discuss mandibular nerve blocks including areas
anesthetized, landmarks, and potential complications for each injection.
INJECTION Inferior Alveolar Nerve Black (IA/LINGUAL)
Branch of Trigeminal Nerve Inferior Alveolar nerve: branch of posterior root of Mandibular (V3)
Lingual nerve: branch of posterior root of Mandibular (V3).Area Anesthetized (Teeth &/or Soft Tissue)
I.A. nerve: Mandibular teeth to midline (molars, premolars, cuspid, central, lateral); body of mandible, all buccal soft tissue except buccal area of molars
Lingual nerve: No teeth; lingual gingival of mandibular quadrant (Central to 3rdmolar), anterior 2/3 of tongue, floor of mouth.
The lingual nerve is commonly anesthetized during the IA injection but can be done separately.
Needle 25 or 27 longLandmarks Coronoid notch, lingula, pterygomandibular raphe, occlusal plane of MN premolar
teeth & commissure on contralateral side.
Insertion/ Penetration Site Medial to internal & external oblique ridges. Height of coronoid notch. Lateral to pterygomandibular raphe. The syringe barrel placed at the corner of the mouth, usually corresponding to the contralateral premolars.
The lingual nerve will be anesthetized during the same insertion for IA injection*Approximate Depth of Penetration IA: 20‐25 mm 2/3‐3/4 length of long needle.
Lingual: 1/2 distance of IA.Deposition/ Target Site IA: Directly above mandibular foramen.
Lingual: Half the distance to mandibular foramen at lingual nerve.
*Volume of Anesthetic IA: 1.5‐1.8ml (3/4 ‐ 1 cartridge)
Lingual: 25‐.5ml (1/8 cartridge)Potential Complications/ Additional Considerations
Too far medially: medial pterygoid muscle; trismus. Too deep: facial nerve paralysis if anesthetic is deposited in parotid gland. Wide area anesthesia; lower lip anesthesia. Warn patients to not bite lip or tongue. Shocking pain if lingual nerve touched.
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INJECTION Buccal Nerve Block (B)
Branch of Trigeminal Nerve Long buccal nerve, branch of anterior root of Mandibular (V3)Area Anesthetized (Teeth &/orSoft Tissue)
No teeth.
Soft tissues & periosteum buccal to MD molars
Needle 25 or 27 long because it follows IALandmarks External oblique ridge and 2nd molar; retromolar fossa.
Insertion/ Penetration Site Mucobuccal fold distal & buccal to last molar; parallel with occlusal plane
Border of ramus / External oblique ridge / distal & buccal to last molar*Approximate Depth of Penetration
3 ‐ 6mm (1/8 – 1/4”)
Deposition/ Target Site Medial to external oblique ridge; distal and buccal to last molar.
*Volume of Anesthetic .25‐.5ml (1/8 cartridge)Potential Complications/ Additional Considerations
Uncomfortable if needle contacts periosteum
INJECTION MENTAL BLOCK
Branch of Trigeminal Nerve Terminal branch of the inferior alveolar nerveArea Anesthetized (Teeth &/orSoft Tissue)
No teeth.
Buccal soft tissues from mental foramen to midline and the soft tissues of the lower lip and chin.
Needle 25 or 27 shortLandmarks Mental foramen‐usually located between the two premolars.
However, it may be either anterior or posterior to this site.
Insertion/ Penetration Site Mental foramen usually between apices of 1st and 2nd premolars, Mucobuccal fold
*Approximate Depth of Penetration
4‐6mm (1/8‐1/4”)
Deposition/ Target Site Directly over the mental foramen*Volume of Anesthetic .5‐1.0ml (1/3‐1/2 cartridge)Potential Complications/ Additional Considerations
Possibility of hematoma
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Since 1884, when cocaine was first used by William Halsted as a nerve block, local anesthetics came a long way.15 With the improved efficacy and safety for our patients, dental providers can administer these anesthetics in effort to provide painless procedures. Nevertheless, the medical and dental histories, along with the patients’ previous exposures and procedures at hand must be carefully evaluated in the selection of the local anesthetic. Successfully administered local anesthesia can elevate the anxiety of the procedure and create an overall positive experience for the patient, leading to a trustworthy relationship between the patient and healthcare provider.
End
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References
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2. Malamed S: Handbook of local anesthesia, ed 7, St Louis, 2020, Elsevier. 3. Logothetis, DD: Local Anesthesia for the Dental Hygienist, ed 2, St Louis, 2017,
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Saunders.5. Sodium Bisulfite https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-bisulfite6. Malamed SF: Medical emergencies in the dental office, ed 7, St Louis, 2015, Mosby. 7. Becker, D. E., & Reed, K. L. (2006). Essentials of local anesthetic
pharmacology. Anesthesia progress, 53(3), 98–110. https://doi.org/10.2344/0003-3006(2006)53[98:EOLAP]2.0.CO;2
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9. Frank, S. G., & Lalonde, D. H. (2012). How acidic is the lidocaine we are injecting, and how much bicarbonate should we add?. The Canadian journal of plastic surgery = Journal canadien de chirurgie plastique, 20(2), 71–73. https://doi.org/10.1177/229255031202000207
10. Orrett E. Ogle DDS and Ghazal Mahjoubi DMD Dental Clinics of North America, 2012-01-01, Volume 56, Issue 1, Pages 133-148, Copyright © 2012 Elsevier Inc
11. The Antiarrhythmic Properties of Lidocaine and Procaine Amide Clinical and Physiologic Studies of Their Cardiovascular Effects in Man By DONALD C. HARRISON, M.D., J. HENRY SPROUSE, M.D., AND ANDREW G. MORROW, M.D. https://www.ahajournals.org/doi/pdf/10.1161/01.CIR.28.4.486
12. Nusstein JM, Beck M. Effectiveness of 20% benzocaine as a topical anesthetic for intraoral injections. Anesth Prog. 2003;50(4):159-63. PMID: 14959903; PMCID: PMC2007446.
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14. Kanaa MD, Meechen JG, Corbett IR, Whitworth JM. Speed of injection influences efficacy of inferior alveolar nerve blocks: a double-blind randomized controlled trial in volunteers. J Endod. 2006;32:919-923.
15. Redman M. Cocaine: What is the Crack? A Brief History of the Use of Cocaine as an Anesthetic. Anesth Pain Med. 2011 Fall;1(2):95-7. doi: 10.5812/kowsar.22287523.1890. Epub 2011 Sep 26. PMID: 25729664; PMCID: PMC4335732.