Nerve Block: Mental

Background

• Mental nerve innervates the skin of the chin and mucous membranes of the lower lip (from lip anteriorly to alveolar process and to the mid body of the mandible) - by blocking this nerve you can have adequate anesthesia for complicated laceration closures
• NOTE: this block does NOT anesthetize the teeth or mandibular soft tissue (see Nerve Block: Inferior Alveolar)

Indications

• Trauma or need to perform painful procedure on area innervated by mental nerve

Contraindications

• Infection overlying injection site
• Previous allergic reaction to local anesthesic used
• Distortion of anatomic landmarks

Equipment Needed

1. topical anesthesia
   1. viscous lidocaine
   2. LET
2. local anesthesia
   1. lidocaine 1% (lasts 30-60 minutes or longer if given with epinephrine, rapid onset)
   2. Mepivacaine 3% (lasts 45-90 minutes, slower onset)
   3. Bupivacaine 0.5% (lasts 2-4 hours, slowest in onset)
3. 18 gauge needle to draw up anesthetic
4. 25 or 27 gauge needle
5. 6 cc syringe
6. gauze pads
7. good light source

Procedure

1. Place patient in semi-recumbent position
2. apply topical anesthesia
3. draw up 2-5cc of anesthetic into syringe
4. locate the mental foramen by retracting the cheek laterally and palpating between the 2 lower premolar teeth
5. insert the needle along the lower gum into the buccal fold between the premolar teeth without placing the needle directly into the foramen
6. aspirate; if no blood inject a few cc's of anesthetic slowly (avoid injecting directly into the foramen as to prevent damage to the neurovascular bundle)

Complications

• Bleeding
• Infection
• Pain
• Needle fracture
• Neurapraxia

See Also

• Nerve blocks (main)
• Local anesthetic systemic toxicity