How Do You Give a Mandibular Nerve Block Injection?

A mandibular nerve block numbs parts of the mouth and face in preparation for surgery.

A mandibular nerve block is a procedure to numb the lower jaw (mandible) and a part of the mouth and tongue. An anesthetic solution is injected adjacent to the mandibular nerve to block the transmission of pain signals from the mandible to the brain.

The mandibular nerve is one of the three major branches of the trigeminal nerve, which is located on either side of the face. The mandibular nerve is responsible for the motor and sensory functions in the mandibular region.

The mandibular nerve block administered on one side of the face is effective in anesthetizing all the mandibular nerve’s branches on that side. The main terminal branches of the mandibular nerve are:

• Temporoauricular nerve
• Inferior alveolar nerve
• Buccal nerve
• Mylohyoid nerve
• Lingual nerve

A mandibular nerve block provides anesthesia to the following areas:

• Mandibular teeth up to the mid-line
• Soft and hard tissue on the inside of the cheek, and on both sides of the teeth
• Floor of the mouth
• Anterior two-thirds of the tongue
• Skin over the lower jaw, posterior cheek and temple
• Ear, including the external ear canal

A mandibular nerve block is given for oral and dental procedures such as the following:

• Surgery on the
  • Lower lip
  • Mandible skin or bone
  • Lower teeth and gums
  • Anterior two-thirds of the tongue
• Treatment of oral cancer
• Treatment of injury or trauma to the mandibular area
• Dental procedures involving the lower teeth
• Chronic pain conditions such as
  • Trigeminal neuralgia
  • Postherpetic neuralgia

Mandibular nerve block is avoided with:

• Acute inflammation at the injection site
• Infection in the cheek or jaw
• Broken lower jaw
• Presence of a tumor
• Anatomical distortion
• Allergy to a local anesthetic

A mandibular nerve block injection is administered as an outpatient procedure, by a dentist, an oral, facial or orthodontic surgeon.

Anesthesia

One of the following three anesthetic solutions is used:

• Lidocaine
• Bupivacaine
• Mepivacaine

Preparation

• The patient is in a semi-reclining position usually in a dental chair.
• The patient’s heart rate, blood pressure and oxygen levels are monitored.

Procedure

The doctor may follow one of the following techniques:

Gow-Gates technique

The doctor

• Places the needle in the inside of the cheek at the second upper molar tooth level, while the patient opens their mouth as wide as possible.
• Inserts the needle parallel to the angle of the mouth.
• Injects the anesthetic slowly.

Vazirani-Akinosi (closed-mouth) technique

The doctor

• Retracts the patient’s cheek, while the patient keeps their mouth closed and bites their teeth gently.
• Places the needle in the inside of the cheek next to the junction of the second and third upper molar.
• Injects the anesthetic slowly.

Coronoid approach

The doctor

• Sterilizes the skin on the cheek in the notch, where the mandible connects to the cheek bone (coronoid process), while the patient lies down with their mouth in a neutral position.
• Inserts the needle perpendicular to the skull base.
• Advances the needle under the bone next to the ear.
• Injects the anesthetic slowly.

A mandibular nerve block is a relatively safe procedure and complications are uncommon. Risks include:

• Needle-track infection
• Hematoma and swelling
• Nerve injury resulting in persistent tingling or numbness
• Injury to blood vessel
• Allergic reaction to the medication
• Systemic toxic response from anesthetic injected into a blood vessel with moderate symptoms such as:
  • Anxiety
  • Numbness
  • Dizziness
  • Weakness
  • Tremors
• Cardiovascular and central nervous system collapse due to local anesthetic systemic toxicity (very rare)