Quiz 4- Mandibular Blocks & Considerations

What does the mental nerve anesthetize?

Soft tissues of the lower lip, chin, and facial gingiva.

What does the incisive nerve anesthetize?

Pulpal anesthesia of mandibular premolars and anterior teeth.

When is the Mental-Incisive (M-I) nerve block indicated?

Treatment involving more than one mandibular premolar or any mandibular anterior teeth.

Main advantage of the M-I nerve block?

High success rate and atraumatic injection.

Main disadvantage of the M-I nerve block?

Positive aspiration rate of approximately 5.7%.

How is the mental foramen located before an M-I injection?

By reviewing radiographs and palpating the area.

Preferred M-I injection method?

Horizontal method.

Why is the horizontal M-I technique preferred?

Keeps syringe out of patient's view, lowers risk of puncturing the lip, and improves aspiration visibility.

Main disadvantage of the vertical M-I technique?

Greater chance of puncturing the lower lip and poorer ergonomics.

Needle used for the M-I block?

Short needle.

Needle depth for the M-I block?

Approximately 5 mm (¼ of the short needle).

Target of the M-I injection?

Mental foramen.

Amount deposited during an M-I injection?

0.6 mL (⅓ cartridge).

What should be done immediately after depositing anesthetic during an M-I block?

Apply pressure over the mental foramen.

Most common injection in dentistry?

Inferior Alveolar Nerve Block (IA).

Three injections included in the IA/L/B technique?

Inferior alveolar, lingual, and buccal.

Which injection is administered first during IA/L/B?

Inferior alveolar.

Which injection is administered second during IA/L/B?

Lingual.

Which injection is administered last during IA/L/B?

Long buccal.

Together, the IA/L/B injections anesthetize what?

An entire mandibular quadrant.

Which cranial nerve is anesthetized during an IA block?

Mandibular division of CN V (V3).

Why should bilateral IALB injections be avoided?

Increased risk of airway and soft tissue complications.

Target of the IA injection?

Mandibular foramen.

If the needle passes too far posteriorly during an IA block, where can it enter?

Parotid gland.

Possible result of injecting into the parotid gland?

Temporary facial nerve paralysis.

Major landmarks for an IA injection?

Coronoid notch, pterygomandibular raphe, and linea alba.

Needle used for IA block?

Long 25- or 27-gauge needle.

Syringe position for IA block?

Over the opposite mandibular premolars, parallel to the occlusal plane.

Needle depth for IA block?

Until ⅔-¾ of the needle contacts bone.

How much anesthetic is deposited for the IA block?

1.3 mL (¾ cartridge).

What should never be done if bone is not contacted during an IA injection?

Do not inject; reposition the needle.

If bone is contacted too early during IA, how should the syringe be redirected?

Move the syringe more anteriorly.

If bone is not contacted during IA, how should the syringe be redirected?

Move the syringe more posteriorly.

Target of the lingual injection?

Lingual nerve.

Amount deposited during lingual injection?

0.2 mL.

Target of the buccal injection?

Buccal nerve.

Insertion site for the buccal injection?

Distal and buccal to the most distal mandibular molar.

Amount deposited during buccal injection?

0.2 mL.

Most common complication of the IA block?

Inadequate anesthesia (15-20%).

Positive aspiration rate of the IA block?

Approximately 10-15%.

If lingual tissues of mandibular molars remain sensitive after IA block, what nerve may be responsible?

Mylohyoid nerve.

Common complications of IA/L/B injections?

Hematoma, trismus, lingual shock, paresthesia, self-inflicted trauma, facial nerve paralysis.

How do pediatric injection techniques differ from adults?

Mainly by reducing insertion depth.

Needle recommended for most pediatric injections?

Short or extra-short needle.

Needle insertion depth for pediatric supraperiosteal injections?

About 2 mm.

Needle insertion depth for pediatric M-I injections?

About 3 mm.

Where is the mandibular foramen located in children?

More inferior until about age 12.

Syringe height for pediatric IA injections?

At the level of the mandibular occlusal plane.

Primary reason overdose occurs more often in children?

Lower maximum recommended dose due to body weight.

Maximum lidocaine dosage calculation for a 60-lb child?

Approximately 3.5 cartridges.

Maximum articaine dosage calculation for a 60-lb child?

Approximately 2.8 cartridges.

Words to avoid when communicating with children?

Pain, hurt, sharp, needle.

Behavior management techniques for pediatric patients?

Distraction, rapport, communication, nitrous oxide, assistant stabilization.

Which anesthetic should generally be avoided in children?

Bupivacaine.

What reversal agent can reduce soft tissue numbness in children?

OraVerse.

Minimum age for OraVerse?

3 years.

Minimum weight for OraVerse?

33 pounds.

What should parents monitor after pediatric anesthesia?

Lip or cheek biting.

What does the Gow-Gates injection anesthetize?

The entire mandibular division (V3).

Success rate of the Gow-Gates injection?

About 95%.

Positive aspiration rate of Gow-Gates?

Approximately 2%.

Needle used for Gow-Gates?

Long 25- or 27-gauge needle.

Patient instruction during Gow-Gates injection?

Open wide and remain open.

Target of the Gow-Gates injection?

Neck of the mandibular condyle.

Insertion site for Gow-Gates?

Distal to the maxillary second molar at the height of its mesiolingual cusp.

Amount deposited during Gow-Gates injection?

1.7 mL (one cartridge).

What should be done if bone is not contacted during Gow-Gates?

Do not inject; reposition the needle.

Major landmarks for Gow-Gates?

Tragus, intertragic notch, coronoid notch, maxillary second molar.

Advantage of Gow-Gates over IA block?

Lower risk of hematoma and trismus.

Which patients especially benefit from Gow-Gates?

Patients taking anticoagulants.

Contraindication for Gow-Gates?

Patients unable to open wide (such as severe TMD).

Main disadvantage of Gow-Gates?

Longer onset (5-10 minutes).

Which nerves are not consistently anesthetized by the IA block but are with Gow-Gates?

Auriculotemporal and mylohyoid nerves.

Main concern when treating geriatric patients with local anesthesia?

Age-related drug metabolism and medical conditions.

Why are older adults at higher risk for adverse drug reactions?

Polypharmacy and physiologic changes.

General vasoconstrictor recommendation for older adults?

Limit to fewer than three cartridges of 1:100,000 epinephrine.

Most common iatrogenic illness in older adults?

Drug-related illness.

What percentage of adverse drug reactions are preventable?

Up to 40%.

Examples of adverse effects after local anesthesia in older adults?

Lip chewing, bleeding, cardiovascular complications.

Best principle for medication dosing in older adults?

Start low and go slow.

Why should long-acting anesthetics be used cautiously in older adults?

Increased duration and risk of self-injury.

Preferred anesthetic approach for many geriatric patients?

Articaine infiltrations or PDL injections when possible.

Preferred epinephrine concentration for medically compromised geriatric patients?

1:200,000 when appropriate.

Why is aspiration especially important in geriatric patients?

To avoid accidental intravascular injection.

Maximum carpules often recommended for ASA II or III patients?

2-3 cartridges.

Purpose of stepwise palatal injections?

Reduce pain in anxious or cognitively impaired patients.

First step of a stepwise palatal injection?

Administer buccal/labial injection first.

Second step of a stepwise palatal injection?

Allow anesthetic to blanch palatal tissues through the interdental papilla.

Final step of a stepwise palatal injection?

Proceed with palatal injection after blanching.

What should always be documented after local anesthesia?

Type of anesthetic, amount, injection site, and patient response.