Mandibular Nerve and Local Anesthesia Quiz

A dentist needs to perform a procedure on the lingual soft tissue to the midline and the facial soft tissue anterior to the mandibular first molar. Which anesthetic technique should be used?

• Inferior Alveolar (IA) block

• Maxillary infiltration

• Palatal block

• Buccal infiltration

Answer explanation

The Inferior Alveolar (IA) block provides anesthesia to the lingual and facial soft tissues in the mandibular region, making it the appropriate choice for procedures near the midline and anterior to the mandibular first molar.

Which of the following is recommended if bone is contacted too soon during an IA block?

• Bring the syringe more closely superior to mandibular molars

• Bring the syringe more closely superior to mandibular anterior teeth

• Use a shorter needle

• Inject more anesthetic

Answer explanation

If bone is contacted too soon during an IA block, repositioning the syringe closer to the mandibular anterior teeth helps avoid the bone and ensures proper placement for effective anesthesia.

What is the cause of "lingual shock" during an IA nerve block procedure?

• The needle passing by and shocking the lingual nerve

• The anesthetic solution being too cold

• The patient moving suddenly

• The use of an incorrect needle size

Answer explanation

Lingual shock occurs when the needle inadvertently contacts the lingual nerve during the IA nerve block, causing a sudden, sharp sensation. This is why the correct answer is the needle passing by and shocking the lingual nerve.

What is a common cause of inadequate anesthesia during an IA nerve block?

• Depositing solution inferior to the mandibular foramen

• Depositing solution superior to the mandibular foramen

• Depositing solution in the maxillary sinus

• Depositing solution in the parotid gland

Answer explanation

Depositing solution inferior to the mandibular foramen can lead to inadequate anesthesia because it may not effectively reach the target nerve, resulting in insufficient pain control during procedures.

Which nerve is labeled as running anteriorly from the mental foramen in the provided diagram?

• Incisive nerve

• Lingual nerve

• Buccal nerve

• Maxillary nerve

Answer explanation

The incisive nerve runs anteriorly from the mental foramen, supplying sensation to the anterior teeth. The other options, such as the lingual and buccal nerves, have different pathways and functions.

What is a possible cause of incomplete mandibular first molar anesthesia when using an IA nerve block?

• Innervation by the mylohyoid nerve that is not anesthetized by the IA nerve block

• Overuse of anesthetic solution

• Incorrect patient positioning

• Use of a short needle

Answer explanation

The mylohyoid nerve can provide sensation to the mandibular first molar. If it is not anesthetized during an IA nerve block, this can lead to incomplete anesthesia, making it the correct choice.

Which of the following is a recommended remedy for incomplete mandibular first molar anesthesia due to mylohyoid nerve innervation?

• Using a 27-gauge, long needle, insert at apex of selected tooth at 3 to 5 mm or one-fourth the depth of the needle, aspirate, and deposit one-fourth of cartridge over 20 seconds

• Increase the dose of anesthetic by half

• Use a 30-gauge, short needle for all injections

• Apply topical anesthetic only

Answer explanation

The recommended remedy involves using a 27-gauge, long needle to ensure proper depth and accuracy in delivering anesthetic, which is crucial for addressing incomplete mandibular first molar anesthesia due to mylohyoid nerve innervation.

Which alternative block can be used as a remedy for incomplete mandibular first molar anesthesia?

• Gow-Gates mandibular block

• Infraorbital nerve block

• Maxillary nerve block

• Mental nerve block

Answer explanation

The Gow-Gates mandibular block provides a more complete anesthesia of the mandibular molars, including the first molar, by targeting the mandibular nerve more effectively than other blocks listed.

What needle gauge and length are recommended if a buccal block is given immediately after an IA block?

• 30-gauge, short

• 25-gauge, long

• 27-gauge, extra long

• 22-gauge, short

Answer explanation

The recommended needle gauge for a buccal block after an IA block is 25-gauge, long. This size provides adequate strength and length to reach the target area effectively, ensuring proper anesthesia.

List all the nerves that are anesthetized by the Gow-Gates mandibular block.

• Auriculotemporal, Inferior alveolar, Mylohyoid, Lingual, Long buccal, Mental, Incisive

• Facial, Glossopharyngeal, Hypoglossal, Vagus

• Trigeminal, Optic, Oculomotor, Trochlear

• Maxillary, Zygomatic, Nasopalatine, Greater palatine

Answer explanation

The Gow-Gates mandibular block anesthetizes several nerves including the Auriculotemporal, Inferior alveolar, Mylohyoid, Lingual, Long buccal, Mental, and Incisive nerves, making the first answer choice correct.