Anesthisa

Ten minutes after administering 2% lidocaine with 1:100,000 epinephrine to a healthy female adult, she starts to become very talkative and agitated. You immediately take her vitals and note that her blood pressure and pulse have increased substantially. What is occurring to her: a. a mild overdose reaction b. a severe overdose reaction c. syncope d. an allergic reaction

This patient is experiencing a mild overdose reaction to the local anesthetic. The symptoms she experienced - talkativeness, agitation and an increase in vital signs - are indicative of this condition. It will usually occur between 5 and 10 minutes following completion of the injection.

Your patient requires anesthesia for multiple teeth in the mandibular left quadrant. Which length needle should be used: a. a short needle b. a long needle c. it doesn't matter - both will work equally well

This patient will need a long needle. Injections such as an IAN that pass through substantial amounts of tissue require a long needle.

If a hematoma appears after the posterior superior alveolar injection (PSA), it is most likely due to: a. anesthetic agent was injected too quickly b. lack of a vasoconstrictor in the anesthetic agent c. needle inserted too far posteriorly into the pterygoid plexus of veins d. a 25 gauge needle was used instead of a 27 gauge needle

A hematoma produced from a PSA injection is due to inserting the needle too far posteriorly into the pterygoid plexus of veins. Perforation of the maxillary artery may also occur. To minimize the chance of this occurring, be certain to use a short needle. Also, remember to insert the needle at the height of the mucobuccal fold above the maxillary second molar and advance slowly in an upward, inward and backward direction.

The concentration of the local anesthetic drug (for example, lidocaine) found in topical anesthetics is usually greater than if that same agent were administered by injection. a. True b. False

A. The concentrations found in topical anesthetics are usually greater than if that same agent were administered by injection. That is because a higher concentration is needed for the active ingredients to diffuse through the mucous membranes. This quick diffusion to the nerve endings helps with a faster onset of the topical anesthetic. This, however, can lead to a greater potential for toxicity not only topically, but also systemically. A comparative example is Lidocaine which is used at 2% concentrations for injection, but at 5% for topical application.

When a stimulus excites a nerve, the following sequence of events occurs: a. slow depolarization, followed by rapid depolarization, and then reversal of the electrical potential across the nerve membrane leaving the interior of the nerve electrically positive in relation to the negative exterior b. slow depolarization, followed by a neutralization of the interior and the exterior of the nerve c. rapid depolarization resulting in the nerve achieving its resting potential

A. When a stimulus excites a nerve, the following events occur in this sequence: slow depolarization whereby the electrical potential in the nerve becomes slightly less negative when this electrical potential reaches a critical level, there is then a rapid phase of depolarization called threshold potential or firing threshold this depolarization brings about a reversal of the electrical potential across the nerve membrane - the interior of the nerve is now positive in relation to the negative exterior

The periodontal ligament injection (PDL) is contraindicated for deciduous teeth because: a. the injection technique is too painful for children b. innervation of the deciduous teeth is unpredictable, therefore the PDL injection is unreliable c. it can cause enamel hypoplasia in the permanent tooth that is developing just beneath the deciduous tooth d. the decreased density of the bone surrounding deciduous teeth will not allow diffusion of the anesthetic solution

Administering a PDL injection for a deciduous tooth can cause enamel hypoplasia in the permanent tooth that is developing just beneath the deciduous tooth.

The process of saltatory conduction: a. is the manner in which impulse conduction occurs in myelinated nerves b. produces faster and more energy-efficient conduction c. is more rapid in a thicker axon d. progresses from one node to the next in a stepwise fashion e. all of the above

All of the answers provided are correct. In a myelinated nerve, the impulse leaps from node to node - this is called saltatory conduction. When the nerve is myelinated, this conduction is more rapid and energy efficient than in an unmyelinated nerve. And the greater the diameter of the axon, the thicker is the myelin sheath, therefore saltatory conduction occurs more rapidly in thicker axons.

What is an advantage of using a larger gauge needle (such as a 25 gauge) over a smaller gauge needle (such as a 30 gauge): 1. there is less deflection of the needle with the larger gauge 2. greater accuracy of injecting at the proper site of deposition with a larger gauge 3. needle breakage is less likely to occur when a larger gauge is used 4. it is easier to perform aspiration with a larger gauge needle a. 1, 3 and 4 only b. 1, 2 and 3 only c. 2 and 4 only d. all of the above e. none of the above

All of the choices were correct. there is less deflection of the needle with the larger gauge - particularly when the depth of soft tissue being penetrated is significant as in the IAN less deflection leads to greater accuracy at reaching your target site - once again, particularly when the depth of soft tissue being penetrated is significant as in the IAN while needle breakage is not a problem with disposable needles, it is less likely to occur with larger gauge needles aspiration is easier and more reliable with a larger gauge needle, particularly since it takes more pressure to aspirate when a narrower, smaller gauge needle is being used

What are the most likely cause(s) of an overdose from a local anesthetic: patient positioned in a supine position during the injection solution was administered too rapidly solution was inadvertently injected intravascularly solution contained a vasoconstrictor a. all of the above b. 1 and 2 only c. 2 and 3 only d. 3 and 4 only

An overdose from a local anesthetic is most likely due to the solution being administered too rapidly and also inadvertent injection intravascularly. Some other factors that can lead to overdose include: the concentration of the anesthetic: A 4% solution contains more drug than does a 2% solution. It is advised to use the lowest concentration of a local anesthetic that is clinically effective. the dose of the drug: Use the recommended amounts of anesthetic solution to achieve pain control. The smallest dose that is clinically effective should be administered. The correct response: c

In areas of inflammation and infection, what can be done to maximize the effectiveness of the local anesthetic agent: a. move away from the area of inflammation and inject further up the nerve branch b. deposit a larger amount of anesthetic agent than normal c. deposit a smaller amount of anesthetic agent than normal d. avoid using topical anesthetic e. both a. and b.

Answers a. and b. were both options to employ when local anesthetic needs to be administered in areas of inflammation and infection. In this situation, it is recommended to: move away from the area of inflammation and inject further up the nerve branch deposit a larger volume of anesthetic into the region than what would normally be injected

After applying topical anesthetic to an injection site for 4 minutes, the clinician notices that the epithelium is sloughing in the area where the topical was applied. This can be due to: a. presence of vasoconstrictor in the topical anesthetic b. topical anesthetic was held too long in the area c. the high degree of water solubility of the topical anesthetic d. the low degree of water solubility of the topical anesthetic

Applying topical anesthetic at an injection site for 4 minutes can cause sloughing of the epithelium. It is recommended that topical anesthetic contact the mucous membranes for only 1 - 2 minutes, and then the excess should be wiped off. Other factors that may cause sloughing of tissues can be sensitivity of the tissues to the topical or a reaction to the topical anesthetic. Remember that a vasoconstrictor is NOT found in topical anesthetic.

The most common topical anesthetic, benzocaine, falls under which drug classification: a. amide b. ester

Benzocaine is an ester. While it is poorly soluble in water, it also has a poor absorption into the cardiovascular system. The benefits of this are that it will be absorbed slowly which provides a long duration of effects with an absence of toxic effects. The onset of action for benzocaine is under one minute. Contraindications for its use would be patients with a known allergy to the ester-type of local anesthetic agents. Some common brand names include: Cetacaine, Gingicaine, Hurricaine and Topicale.

Bubbles of approximately 1 - 2 mm found in anesthetic cartridges are: a. an indication that the cartridge has been contaminated b. an indication that the cartridge has been dropped c. unsafe to use as it indicates that oxygen has seeped into the cartridge d. not a concern

Bubbles approximately 1 - 2 mm in diameter found in the cartridge are not of concern. The bubbles are composed of nitrogen gas which has been added to the cartridge during its manufacturing process to prevent oxygen from being trapped inside the cartridge. The oxygen could potentially destroy the vasoconstrictor which may be in the solution. However, if bubbles larger than 1 - 2 mm in diameter are found in the cartridge and it appears the stopper is extruded, this may indicate that the solution in the cartridge has been frozen. Since asepsis cannot be guaranteed, their use is not advised. The correct response: d

The contents of an anesthetic cartridge may include which of the following: 1. local anesthetic drug 2. vasoconstrictor 3. preservative for the vasoconstrictor 4. distilled water 5. sodium chloride 6. methylparaben a. all of the above b. 1, 2, 4, 5, and 6 c. 1, 2, 3, 4 and 5 d. 1, 2 and 5 e. 1, 2, 3 and 4

C An anesthetic cartridge can contain the following: local anesthetic drug: for example, lidocaine vasoconstrictor: Also called a vasopressor, these will lower the pH of the solution and are only found in cartridges that indicate that a vasoconstrictor is present preservative for the vasoconstrictor: This serves as an antioxidant for the vasoconstrictor to prevent it from being biodegraded by oxygen. Sodium bisulfite is used for this purpose. distilled water: This provides volume to the solution. sodium chloride: Sodium chloride helps to make the solution isotonic (similar) with the body's tissues Methylparaben has NOT been added to dental cartridges since 1984

Using the same patient experiencing an overdose reaction to a local anesthetic agent, what could be done to prevent this from occurring: -deposit the solution slowly -deposit the solution in a quick manner -use a vasoconstrictor to slow the absorption of the local anesthetic agent a. none of the above b. 2 and 3 only c. 1 and 3 only d. 2 only

C, To prevent this situation from occurring, the anesthetic solution should always be deposited slowly and whenever possible, a vasoconstrictor should be used to slow the absorption of the local anesthetic agent. Also, aspiration must always be done to assure that the solution is not being deposited intravascularly.

When administering the ___ injection, there is risk of traumatizing the lateral pterygoid muscle; whereas, when administering the ___ injection, there is risk of trauma to the medial pterygoid muscle. a. MSA...Buccal b. PSA ...Buccal c. PSA... IAN d. IO ...Incisive

C. When giving the PSA injection, there is risk of inserting the needle into the lateral pterygoid muscle which is located more superiorly and inserts onto the mandibular condyle. When administering the IAN injection, there is risk of trauma to the medial pterygoid muscle, which is located more inferiorly and inserts onto the angle of the mandible.

For the same patient as in the preceding question (a 56-year old woman who is allergic to PABA), you notice that she is experiencing pain as you are administering her last injection. She has received a PSA, MSA, ASA, GP and you are about to administer the NP. What are some things you should confirm prior to the next injection: 1. is the needle dull? 2. is there a barb on the end of the needle? 3. is she allergic to the local anesthetic you are using? 4. is she allergic to the topical anesthetic you are using? a. 1 and 2 only b. 3 and 4 only c. 1, 3 and 4 only d. all of the above should be checked

Check to see if the needle is dull or if there is a barb on the end of the needle. Since it appears the same needle was used for the PSA, MSA, ASA and GP on this patient, the needle is most likely dull. Three penetrations are usually the limit before a needle loses its sharpness. The needle should be changed prior to any other injections. Also, there could be a fishhook-type barb on the end of the needle. The clinician can place the needle on a sterile 2 x 2 gauze and draw it backward to see if it catches or snags. If it does, the needle should be discarded as it will cause pain upon insertion. This can usually be found out prior to any injection being given with the needle. You should know whether the patient is allergic to the local anesthetic or topical anesthetic PRIOR to administering the injection, and an allergy would not cause this type of pain reaction. The correct response: a

A local anesthetic can be injected into areas of inflammation and infection, and adequate anesthesia will be achieved. a. This statement is true b. This statement is false

Correct! The statement is false.

Your patient, a 35-year old healthy female, indicates on her medical history that she is allergic to penicillin and is 4 months pregnant. Her chief complaint is that she is noticing blood on her toothbrush when she brushes her teeth and that her "gums hurt." Upon clinical examination, you observe that she has a pyogenic granuloma between her maxillary central incisors and there is moderate to advanced gingival inflammation throughout her mouth, accompanied by large deposits of supra- and sub-gingival calculus. Your treatment plan includes full-mouth root debridement, to be performed in quadrants in 4 subsequent appointments. Your plan is to use lidocaine 2% with epinephrine 1:100,000. Is the use of this anesthetic contraindicated? a. yes, epinephrine should not be used on pregnant women b. yes, lidocaine should not be used on pregnant women c. no, there are not any contraindications to the use of local anesthetic agents on pregnant women d. no, however the clinician should be conservative in using any drugs on pregnant women

D, Yes, that answer is correct. Local anesthetics and vasoconstrictors are not contraindicated in the treatment of pregnant women. However, only conservative amounts of any drug should be administered to a pregnant woman. It is wise to consult with the patient's physician prior to performing dental/dental hygiene therapy on a pregnant woman to determine if there are any problems with this pregnancy or past pregnancies.

For a pediatric patient, in which of the following situations may it be difficult to achieve anesthesia: a. inferior alveolar nerve block b. nasopalatine nerve block c. buccal nerve block d. infiltration of maxillary first molars e. infiltration of maxillary central incisors

D. Infiltration of maxillary first molars poses special challenges in a pediatric patient. This is because in some children the zygomatic process is very prominent and lies close to the alveolar bone, hindering local anesthesia administration. In these cases, it is acceptable to either: administer a posterior superior alveolar nerve block, or administer buccal infiltrations at both the mesial and distal of the maxillary first molar

One key to obtaining an atraumatic injection is to: a. stretch the tissues taut prior to inserting the needle b. jiggle the lip as the needle is inserted c. pull the soft tissues over the needle tip for insertion d. all the above are good techniques

Distraction techniques such as jiggling the lip as the needle is inserted or pulling the soft tissues over the needle tip for insertion will obscure your view of the needle tip as you are inserting it, which is less than ideal. The best answer is to stretch the tissues taut prior to inserting the needle. In this manner, the sharp needle will cut through the mucosa rather than being torn through the tissues which can happen when the tissues aren't taut.

Generally speaking, due to the thinner bone found in the maxilla, clinically adequate anesthesia is easier to achieve here than in the mandible. a. True b. False

Due to the thinner bone found in the maxilla, it is easier to achieve successful anesthesia here than in the mandible.

For this same patient with the hematoma from the PSA injection, how would you recommend that she treat the area: a. apply ice immediately to the area b. hot, moist towels for 20 minutes every hour on affected side c. open and close her mouth for 5 minutes every hour for 6 hours d. warm salt water rinses on the affected side

Ice should be applied to the area immediately. If possible, digital pressure can be applied to the affected soft tissues in the mucobuccal fold. Heat should not be applied to the area for at least 4 - 6 hours as it produces vasodilation which can further exacerbate the region. After 4 - 6 hours, warm, moist towels may be applied to the area for 20 minutes every hour. Additionally, advise your patient that the area will probably be sore and will have discoloration that will last for 1 - 2 weeks. The correct response: a

For this same patient, what would you recommend as a treatment to alleviate his trismus: 1. Aspirin 2. Cold pack every 20 minutes for 2 hours on affected side 3. Hot, moist towels for 20 minutes every hour on affected side 4. Warm, salt water rinses on affected side 5. Opening and closing the mouth for 5 minutes every 3 - 4 hours, including lateral movements 6. Muscle relaxants if necessary a. all of the above b. 1 and 2 only c. 1, 2, 3 and 5 only d. 1, 3 and 5 only e. 1, 3, 4, 5 and 6 only

Improvement will usually be noted within 48 - 72 hours. The correct response: e

Which three injections have the highest rates of positive aspiration, which could lead to intravascular injection: a. PSA, MSA, IAN b. PSA, GP, IAN c. IAN, MSA, Mental/Incisive d. IAN, Mental/Incisive, PSA

In descending order, the injections with the highest rate of positive aspiration are: IAN mental/incisive PSA While positive aspiration can occur with any injection, it is more likely with the above-listed injections. Therefore, it is recommended that with these injections, a 25-gauge needle be used since aspiration of blood will be easier and more reliable with the larger diameter (lumen). The correct response: d

After administering a right inferior alveolar nerve (IAN) block to your patient, the first molar is still sensitive, even though the other teeth in the quadrant are numb. What could be the cause of this? a. insertion of the needle was too superior b. insertion of the needle was too inferior c. the local anesthetic agent that was used lacked a vasoconstrictor d. innervation of this tooth is being supplied by the mylohyoid nerve e. cross-over innervation from the inferior alveolar nerve on the opposite side

In some individuals, the mylohyoid nerve provides accessory innervation to the first molar, usually the mesial portion of the tooth. In this situation, there are two options to obtain anesthesia to the first molar: administer a PDL injection to the first molar using a 25-gauge needle, administer local anesthesia on the lingual side of the mandible to the apex of the tooth just posterior to the tooth in question, in this case to the apex of the second molar

In the unlikely event that an anesthetic needle breaks within the patient's tissues, the following steps should be taken: 1. Keep the patient's mouth open either by keeping your fingers in the patient's mouth or by using a bite block 2. Have the patient close her mouth immediately to avoid having the needle migrate 3. If the broken needle is visible, try to remove it with a hemostat 4. If the broken needle is not visible, have the dentist incise the area to locate the needle for easy removal a. 1, 3 and 4 only b. 2, 3 and 4 only c. 1 and 3 only d. 2 and 4 only

In the unlikely event that an anesthetic needle should break within the patient's tissues, the following steps should be taken: keep the patient's mouth open either by leaving your fingers in the mouth or by using a bite block if the broken needle is visible, try to remove it with a hemostat if the broken needle is not visible, DO NOT have the dentist incise the area to locate the needle - in this instance, referral to an oral and maxillofacial surgeon for a consultation is recommended

Immediately after applying a lidocaine topical anesthetic and administering 3% mepivacaine to your patient, he loses consciousness and begins to convulse. What is the most likely cause of this: a. epinephrine overdose b. local anesthetic overdose c. reaction to using two different types of anesthetic d. allergic reaction to the topical anesthetic e. allergic reaction to the local anesthetic

In this instance, the patient is experiencing a severe overdose to the local anesthetic, most likely from a rapid intravascular injection.

In this instance where the patient is experiencing a severe overdose reaction to a local anesthetic and is experiencing convulsions, what is the recommended management of the situation: a. 911, basic life support, administer IV anti-convulsant if seizure lasts longer than 4 - 5 minutes with no signs of terminating b. position patient in sitting position, monitor vitals for 5 minutes, summon 911 if vitals remain at high levels over 5 minutes c. position patient in supine position, monitor vitals for 5 minutes, summon 911 if vitals remain at high levels over 5 minutes d. administer oxygen, administer epinephrine via aerosol inhaler

In this situation, protect the patient if he is having convulsions, call 911, administer basic life support and administer an anti-convulsant IV, such as diazapam, if the seizure lasts longer than 4 - 5 minutes with no signs of terminating. It is essential that the patient have an adequate airway and oxygenation during a local anesthetic-induced seizure. The correct response: a

It is an acceptable practice when giving an injection to penetrate the tissues up to the hub of the needle: a. True b. False

It is NOT an acceptable practice to "hub" the needle. The hub is the weakest point of the needle - if it is inserted to the hub and then breaks, the tissues will cover the needle and it will be difficult at best to remove the needle from the patient's tissues.

Why is it critical to aspirate prior to depositing any anesthetic solution into a patient's tissues: a. to determine if the operator has reached the correct depth b. to verify that the operator isn't in a blood vessel prior to depositing the solution c. to verify that the operator isn't in connective tissue prior to depositing the solution d. it isn't critical to aspirate prior to depositing anesthetic solution

It is critical to aspirate prior to depositing any anesthetic solution into a patient's tissues to verify that the operator isn't in a blood vessel prior to depositing the solution. Aspiration must be performed prior to any injection.

Name the nerve which provides sensory innervation to the lingual gingiva of the mandibular molars: a. inferior alveolar b. lingual c. mental d. incisive

It is the lingual nerve that provides sensory innervation to the gingiva on the lingual side of the mandible, as well as the anterior 2/3 of the tongue and the mucous membranes of the floor of the mouth. The correct response: b

Name the nerve which provides sensory innervation to the buccal gingiva of the mandibular molars and the mucobuccal fold in that region: a. inferior alveolar b. incisive c. massateric d. long buccal e. lingual

It is the long buccal nerve (LB) which provides sensory innervation to the buccal gingiva of the mandibular molars and the mucobuccal fold in that region.

Name the nerve which provides sensory innervation to the pulp of the maxillary 1st molar: a. posterior superior alveolar b. anterior superior alveolar c. infraorbital d. mental

It is the posterior superior alveolar (PSA) nerve which provides sensory innervation to the pulps of all the maxillary molars, as well as the buccal periodontium and bone overlying these teeth. However, in some cases, the mesiobuccal root is not innervated by the PSA. In that situation, the mesiobuccal root can be infiltrated or a middle superior alveolar nerve block can be given.

Which of the following vasoconstrictors is found in topical anesthetic agents: a. Epinephrine b. Neo-Cobefrin c. Levophed d. none of the above

None of the options provided were correct, as vasoconstrictors are not found in topical anesthetic agents. Additionally, since anesthetics by themselves are vasodilators, this can speed the absorption of the anesthetic by the cardiovascular system. Combined with the fact that there is no vasoconstrictor present to slow absorption, this can increase possible overdose reactions and decrease the duration of action of the topical anesthetic. The correct response: d

A major difference between overdose and allergic reactions is that allergic reactions are not dose related. a. True b. False

Overdose reactions are dose related and allergic reactions are NOT dose related. When overdose reactions develop, there is a large enough amount of the drug administered to the patient leading to excessive blood levels in the target organ or tissues. On the other hand, a patient with an allergy to a local anesthetic can have an allergic reaction with an extremely small amount of the drug.

Your patient indicates that he has congenital methemoglobinemia. Because of this, which anesthetic is relatively contraindicated in his case?: a. Prilocaine b. Lidocaine c. Mepivacaine d. Bupivacaine

Prilocaine, commonly available as Citanest®, can produce methemoglobinemia when administered in large doses. This condition can be congenital or acquired*, and produces a cyanosis-like state where the oxygen-carrying capacity of the blood is reduced. Respiratory depression, syncope and even death can result when the condition is severe. While methemoglobinemia should not develop in otherwise healthy patients who are given doses of prilocaine within the recommended limits, the condition is nevertheless a relative contraindication for the use of prilocaine. *An example of acquired, drug-induced methemoglobunemia is seen in people who take frequent, large doses of acetaminophen.

Signs of anaphylaxis include: -intense itching -severe abdominal cramps -nausea and vomiting -substernal tightness or pain in the chest -hypotension -convulsion a. all of the above b. 1, 2, 3 and 4 only c. 2, 3, 4, 5 and 6 only d. 1, 2, 3, 4 and 5 only

Signs and symptoms of anaphylaxis include: intense itching severe abdominal cramps nausea and vomiting substernal tightness or pain in the chest hypotension Convulsions would not be a sign of anaphylaxis. The correct response: d

Because the mandible consists of denser cortical bone than the maxilla, the incidence of clinically adequate anesthesia is higher in the mandible. a. Both parts of the statement are true b. Both parts of the statement are false c. The first part is true, the second part is false d. The first part is false, the second part is true

Since the maxilla consists of more porous bone than the mandible, this leads to a higher incidence of clinically adequate anesthesia in the maxilla than what is attained in the mandible. The denser cortical bone present in the mandible accounts for this. Answer: C

Immediately after administering a left IAN to your patient, the left side of his face droops. In addition, the area did not become anesthetized. What most likely occurred: a. the needle was inserted too deep b. the needle was not inserted deep enough c. the needle traumatized the lingual nerve d. anesthetic solution was inadvertently deposited while the needle was advancing

The answer is that the needle was inserted too deep. In this situation, solution was injected into the parotid gland where terminal portions of the facial nerve extend. This resulted in the facial nerve paralysis. For an IAN injection, the appropriate depth of penetration is 2/3 to 3/4 the length of a long needle, which is approximately 20 - 25 mm. In this case, the clinician penetrated almost to the hub, thus creating this complication.

Your patient is a 56-year old woman who informs you that she is allergic to PABA (para-aminobenzoic acid). Which of the following topical anesthetics could you use when treating her: 1. benzocaine 2. tetracaine 3. lidocaine 4. lidocaine/prilocaine mixture a. 1 and 4 only b. 2 and 3 only c. 3 and 4 only d. 1, 2 and 3 only e. all the above are acceptable

The correct answers are both lidocaine andlidocaine/prilocaine mixture. PABA is found in esters. Lidocaine is an amide, therefore it could be used for a patient with an allergy to esters. The lidocaine/prilocaine mixture is also an amide, and can be used for patients with known sensitivities to esters. The lidocaine/prilocaine mixture is commercially available as Oraqix, but is contraindicated for people with congenital or idiopathic methemoglobinemia due to the prilocaine content. The correct response: c

What is the deposition site for the IAN injection in relation to the mandibular foramen: a. slightly inferior to the foramen b. slightly superior to the foramen c. distal to the foramen d. medial to the foramen

The deposition site for the IAN injection in relation to the mandibular foramen is slightly superior to the foramen. The correct response: b

What is the deposition site for the PSA injection in relation to the pterygoid plexus of veins: a. posterior and superior to the pterygoid plexus of veins b. anterior and superior to the pterygoid plexus of veins c. anterior and inferior to the pterygoid plexus of veins d. posterior and inferior to the pterygoid plexus of veins

The deposition site for the PSA injection is anterior and inferior to the pterygoid plexus of veins. The correct response: c

Name the nerve which provides sensory innervation to the palatal gingiva of the maxillary first molar: a. nasopalatine b. greater palatine c. anterior superior alveolar d. middle superior alveolar e. lingual

The greater palatine nerve (GP) innervates the palatal gingiva of the maxillary first molar, as well as the palatal gingiva of the other molars and both premolars.

The ideal rate at which to deposit anesthetic solution is: a. 1 ml. in approximately 15 seconds b. 1 ml. in approximately 20 seconds c. 1 ml. in approximately 25 seconds d. 1 ml. in approximately 60 seconds

The ideal rate at which to inject anesthetic solution is 1 ml. in approximately 60 seconds. Remember that a cartridge holds 1.8 ml., so it should take approximately 2 minutes to inject an entire cartridge. This may seem unrealistic, however, to most clinicians. While it is the time frame recommended by Malamed, he also acknowledges that in actual clinical practice this may not occur. Consequently, he recommends at least 1 minute for 1 cartridge of solution. The correct response: d

The ideal seating position for a patient about to receive an injection is: a. sitting upright b. sitting upright with feet slightly elevated c. placed so entire body is parallel to floor d. placed with the head and heart parallel to the floor with the feet slightly elevated

The ideal seating position for a patient about to receive an injection is placed with the head and heart parallel to the floor with the feet slightly elevated. This supine position will help decrease the incidence of vasodepressor syncope (common fainting).

When administering local anesthesia to a pediatric patient, the following is true: 1. maxillary and mandibular bones are less dense than in an adult patient, therefore the anesthetic solution will diffuse through the bone more rapidly 2. maxillary and mandibular bones are more dense than in an adult patient, therefore the anesthetic solution will not diffuse readily through the bone 3. an increased depth of penetration is necessary than in an adult patient 4. a decreased depth of penetration is necessary than in an adult patient a. 1 and 3 b. 2 and 4 c. 1 and 4 d. 2 and 3

The maxillary and mandibular bones in a child are generally less dense. This will allow the anesthetic solution to diffuse more rapidly to the site. Additionally, since children are smaller than adults, a decreased depth of penetration is necessary to reach the correct deposition site. The correct response: c

For the preceding question, what was the most likely technique error that created this hematoma from the PSA injection: a. the needle was inserted too far mesially b. the needle was inserted too far distally c. the needle was inserted at the height of the mucobuccal fold above the maxillary second molar d. the bevel was turned toward bone

The needle was inserted too far distally. To correct this, insert the needle at the height of the mucobuccal fold above the maxillary second molar. It is recommended to use a 25-gauge short needle, although a 27-gauge short is also acceptable.

The optimal temperature for the local anesthetic solution prior to injection is: a. room temperature b. warmed a few degrees above room temperature c. cooled a few degrees below room temperature d. any temperature for the solution is fine

The optimal temperature for the local anesthetic solution prior to injection is room temperature. Solutions do not need to be heated, nor do they need to be cooled prior to injection. Hot or cold solutions can cause patient discomfort and can create adverse effects on the contents of the anesthetic cartridge. Some clinicians may chose to slightly warm the metal syringe prior to using it on a patient as it may help the patient psychologically. This can be accomplished by merely holding the metal syringe in one's palm for 30 seconds.

The phase of conduction affected by local anesthetics is the repolarization phase. a. This statement is true b. This statement is false

The phase of conduction affected by local anesthetics is the depolarization phase, not the repolarization phase. The correct response: b

The posterior superior alveolar nerve provides sensory innervation to: 1. pulp of the maxillary teeth to the midline 2. palatal gingiva to the midline 3. pulp of the maxillary molars excluding the mesiobuccal root of the maxillary first molar 4. buccal gingiva overlying the maxillary molars 5. anterior 2/3 of the tongue a. 1 and 2 only b. 2, 3 and 4 only c. 3 and 4 only d. 1, 2 and 3 only

The posterior superior alveolar nerve (PSA) provides sensory innervation to: pulp of the maxillary molars excluding the mesiobuccal root of the maxillary first molar buccal gingiva overlying the maxillary molars Additionally, the PSA innervates the buccal periodontium overlying the maxillary molars. The correct response: c

The primary factor influencing the ability to aspirate successfully is: a. the length of the needle b. whether the injection requires bone to be contacted prior to the injection of solution c. the gauge of the needle d. all the above

The primary factor influencing the ability to aspirate successfully is the gauge of the needle. Aspiration is easier and more reliable when the diameter (lumen) of the needle is larger. Consequently, it would be easier to aspirate using a 25-gauge needle than when using a 30-gauge needle. The correct response: c

Which cranial nerve provides sensory innervation to the teeth, bone and soft tissues of the oral cavity a. Oculomotor b. Trochlear c. Trigeminal d. Facial e. Hypoglossal

The right and left trigeminal nerve provides the sensory innervation to the teeth, bone and soft tissues of the oral cavity. This nerve is the fifth cranial nerve.

Which gauge needle has the smallest diameter? a. 30 gauge needle b. 27 gauge needle c. 25 gauge needle

The smallest diameter is the 30 gauge needle. The higher the number, the smaller is the diameter of the lumen of the needle. Therefore, between a 25, 27 or 30 gauge needle, the 30 gauge would have the smallest diameter.

For adequate aspiration, the thumb ring on the syringe must be pulled back: a. 1 - 2 mm b. 3 - 5 mm c. 5 - 7 mm d. 7 - 9 mm

The thumb ring on the syringe must be pulled back from 1 - 2 mm for a reliable aspiration. This will create negative pressure inside the cartridge which will draw whatever is lying at the needle tip into the cartridge. The clinician must observe whether blood enters the cartridge during aspiration, indicating a positive aspiration. If that occurs, local anesthetic solution should not be given at that site. The correct response: a

Name two injections in which pressure anesthesia is used to enhance patient comfort: a. PSA and MSA b. MSA and GP c. GP and NP d. NP and ASA e. ASA and GP

The two injections in which pressure anesthesia is used are the GP (greater palatine) and NP (nasopalatine). The correct response: c

You have begun providing therapy to your patient, and you notice that he is sweating profusely and appears pale. Additionally, his face feels cool to your touch and he isn't responding to your questions about how he is feeling. What is the probable complication: a. an allergic reaction b. an overdose reaction c. syncope d. infection from the anesthetic

These are the symptoms of syncope, or fainting, which is the most common medical emergency seen either before, during or after administration of anesthesia. Other symptoms include light-headedness, dizziness, tachycardia and palpitations. The correct response: c

Your HIV positive patient presents with severe gingivitis on #18, 19, 20 and 21. These teeth bleed profusely upon gentle probing. You decide to administer an IAN using lidocaine 2% with epinephrine 1:50,000 for hemostasis. After administering the nerve block, your patient tells you he has a throbbing headache, he becomes dizzy and also perspires profusely. He also states that his heart is pounding. What appears to have happened? a. overdose of lidocaine b. allergic reaction to the lidocaine c. overdose of epinephrine d. allergic reaction to the epinephrine e. syncope

These symptoms indicate that this patient is experiencing an overdose reaction to the epinephrine which was probably delivered intravascularly. Other symptoms of epinephrine overdose include tenseness, restlessness, respiratory difficulty and an elevated heart rate. The correct response: c

After administering a left inferior alveolar nerve (IAN) block to your patient, #23 and #24 are still sensitive, even though the other teeth in the quadrant are numb. It appears these teeth have not received adequate anesthesia. What could be the cause of this? a. overlap of sensory fibers from the right side b. a long buccal injection is needed to anesthetize #23 and #24 c. inadequate volume of anesthetic was administered d. insertion of the needle was too superior e. insertion of the needle was too inferior

This problem arose because in this patient there was partial anesthesia caused by the overlap of sensory fibers from the opposite side. While this situation rarely occurs, the mandibular incisors may need to be infiltrated (supraperiosteal injection) in order to be anesthetized. Alternately, a PDL injection can be given to each of these teeth.

How would you treat the patient in the previous question who is experiencing a mild overdose reaction to a local anesthetic agent: a. immediate basic life support b. IM injection of epinephrine c. administer oxygen d. no treatment is necessary - the patient will recover in a few minutes

To treat a mild overdose reaction to a local anesthetic agent, administer oxygen after reassuring the patient that everything will be OK. Monitor vital signs and allow the patient to recover for as long as necessary. However if the patient experiences a slower onset of the same symptoms (occurs 15 minutes or more after completion of the injection), the situation may be due to abnormal biotransformation of the drug and/or renal dysfunction. In this situation, reassure the patient, administer oxygen, monitor vital signs and administer an anti-convulsant such as Diazepam (valium). Medical assistance should be summoned. Do not allow the patient to leave the dental office unattended. The correct response: c

What would be the course of treatment for the preceding patient experiencing an epinephrine overdose: a. recline the patient so his head and heart are parallel to the floor with his feet slightly inclined b. no treatment is necessary; this episode is transitory and will be over quickly c. administer CPR d. position the patient in a sitting position to minimize any cardiovascular effects

To treat a patient experiencing an epinephrine overdose, position them so that they are comfortable and in a sitting position to minimize any cardiovascular effects which could raise the blood pressure. As with any medical emergency, monitor the patient's vitals and administer oxygen if necessary, but not if the patient is hyperventilating. This emergency should pass shortly, however allow the patient to fully recover as long as necessary. According to the Handbook of Local Anesthesia by Malamed, 1:50,000 epinephrine should only be used in very small volumes infiltrated directly into a surgical site for hemostasis. You will remember that is what was used for this patient. It was given as an IAN block, and most likely it was inadvertently administered intravascularly. The correct response: d

Upon reviewing your patient's medical history, you note that he has indicated he has "atypical pseudocholinesterase." Would this affect your decision to use a local anesthetic agent on him: a. no, there would be no contraindications to using a local anesthetic b. yes, he would not be able to tolerate a vasoconstrictor c. yes, he would not be able to tolerate the amide classification of local anesthetics d. yes, he would not be able to tolerate the ester classification of local anesthetics

When a patient has atypical pseudocholinesterase, it represents a relative contraindication to the use of esters. Plasma pseudocholinesterase is primarily responsible for the hydrolysis of esters to para-aminobenzoic acid (PABA). Patients who have atypical pseudocholinesterase may not be able to biotransform esters at the usual rate. This could lead to higher levels of the ester drug in their blood. These patients should receive amides when administration of local anesthetics are necessary. The correct response: d

In the previous question involving facial nerve paralysis, what technique modification needs to be made to avoid this problem in the future: a. when administering an IAN, be certain to contact bone prior to depositing any solution b. when administering an IAN, avoid contacting bone prior to depositing any solution c. use a short needle for an IAN injection to avoid going too deep with the needle

When administering an IAN, be certain to gently contact bone prior to depositing any solution. This will prevent over-insertion and assure that the needle is not in the parotid gland. However, remember that the correct depth is 2/3 to 3/4 the length of a long dental needle. If the clinician hasn't contacted bone and is advancing the needle deeper than this, the needle should be withdrawn until only approximately 1/4 its length remains in tissue. Then the syringe barrel should be repositioned more posteriorly so it is over the mandibular molars. The needle should be advanced until it gently contacts bone. If, on the other hand, the clinician contacts bone prior to being at least 2/3 the length of the needle into the tissue, the needle should be withdrawn slightly, the syringe barrel should be repositioned more anteriorly (over cuspid or lateral incisor, but keeping the syringe on the same side of the mouth as it originally was), and then advancing until bone is contacted.

What significance does the coronoid notch have when administering the inferior alveolar nerve block: a. the operator places their index finger or thumb in the coronoid notch to help determine the height of the injection b. the operator places their index finger or thumb in the coronoid notch to help determine the penetration depth of the injection c. the coronoid notch helps determine the site to administer the lingual nerve block if that is to follow the inferior alveolar nerve block d. the coronoid notch has no importance in determining anything of significance for the inferior alveolar nerve block

When administering an inferior alveolar nerve block (IAN), the operator should place their index finger or thumb in the coronoid notch. They then should draw an imaginary line extending posteriorly from their finger tip to the pterygomandibular raphe as it turns upward toward the maxilla. This imaginary line will be approximately 6 - 10 millimeters above the occlusal plane.

At which point does automatic aspiration occur while using a self-aspirating syringe: a. when the thumb ring is depressed and then released b. when pressure is released on the thumb ring c. when the needle contacts resistance during an injection d. when the needle is redirected during an injection

While using a self-aspirating syringe, aspiration occurs whenever the clinician depresses and then releases the thumb ring. In order for aspiration to occur, pressure must first be applied on the piston and then released! The correct response: a

After administering a left PSA injection to a patient, swelling becomes evident on the left side of her face within a few minutes. What has most likely occurred to this patient: a. the nerve has been damaged during the injection b. contaminated anesthetic solution has been administered c. the anesthetic solutions were administered too quickly d. the needle inadvertently nicked the pterygoid plexus of veins

Yes, the needle inadvertently nicked the pterygoid plexus of veins, causing this hematoma. The maxillary artery is also at risk of being penetrated in this area. Diffuse bruising may appear on her face, progressing downwards and forwards toward the lower portion of her cheek.

After 3 attempts, you achieved anesthesia with a left IAN block on your patient, and then spent 1 hour scaling and root planing that quadrant. As he got up to leave, he informed you that he couldn't open his mouth very wide at this time without experiencing pain. What is this condition called: a. hematoma b. trismus c. paresthesia d. facial nerve paralysis

Yes, this condition is called trismus and may have been caused by the repeated attempts to administer this injection. Multiple insertions can cause this post-injection discomfort. Factors that can cause trismus include: -trauma to muscles or blood vessels in the infratemporal fossa -using a local anesthetic agent which has been contaminated by alcohol or other disinfectant or sterilizing agents -using a barbed needle -an excessive amount of local anesthetic solution deposited into a restricted area

How would you manage the patient described in the previous question who has fainted: a. seat the patient in an upright position and administer oxygen b. recline the patient in a supine position and administer oxygen c. administer CPR immediately d. Call 911 immediately

Yes. To manage a patient who has just fainted, you would recline the patient in a supine position and administer oxygen. Additionally, you would monitor their vitals and administer ammonia smelling salts if necessary. It is best to prevent this from occurring to begin with, however. To do so, when administering local anesthesia it is advisable to have the patient reclining so the head and heart are even and parallel to the floor with the feet slightly elevated. This position enhances the delivery of oxygenated blood to the brain.

The myelin sheath and the nodes of Ranvier on a myelinated nerve fiber enable a nerve's impulse to: a. conduct impulses at a much faster rate than an unmyelinated nerve of equal size b. conduct impulses at a much slower rate than an unmyelinated nerve of equal size c. the myelin sheath and nodes of Ranvier have no effect on a nerve's impulse

a The myelin sheath and the nodes of Ranvier (gaps) on a myelinated nerve fiber enable a nerve's impulse to conduct impulses at a much faster rate than an unmyelinated nerve of equal size.

How can the clinician easily determine the gauge of a needle? a. 30 gauge is blue, 27 gauge is yellow and 25 gauge is red b. 30 gauge is yellow, 27 gauge is red and 25 gauge is blue c. 30 gauge is red, 27 gauge is blue and 25 gauge is yellow d. 30 gauge is green, 27 gauge is yellow and 25 gauge is red

a 30 gauge needle is blue, a 27 gauge needle is yellow, and a 25 gauge needle is red The correct response: a