II. Indications
- Regional Anesthesia for anterior Mandible, lower lip and chin
III. Physiology: Landmarks for Mental Nerve
- Images
- Mental Nerve is a branch of the Trigeminal Nerve V3
- Exits Mandible at mental foramen
- Located 1 cm inferior and slightly anterior to the second premolar
- Exits Mandible in line with the mid-pupil on forward gaze
- Located between upper and lower border of Mandible
- Overlies medial jaw
- Centered below midline of orbit
- Line drawn through supraorbital, infraorbital foramen
IV. Technique: Preparation
- Lidocaine 1%
- Syringe 3-5 ml
- Needle 25-27 gauge, 0.5 to 1 inch
V. Technique: Mental Nerve Block (extraoral)
- Locate mental foramen as above
- Palpate for the foramen along the external Mandible
- Insert needle
- Insert needle at point overlying mental foramen
- Advance needle perpendicular to bone until striking periosteum
- Withdraw the needle 2-3 mm
- Infiltrate at mental foramen
- Inject 2-3 ml of Lidocaine 1% near but not in the mental foramen
- Withdraw and redirect needle if Paresthesias or sharp pain
- May inject in a fan distribution to disperse the Anesthetic
- Repeat on the opposite side if the operative region is near the midline
VI. Technique: Mental Nerve Block (intraoral)
- Consider topical anesthestic
- Viscous Lidocaine soaked pledget or gauze applied to injection site
- Locate mental foramen as above
- Palpate for the foramen along the external Mandible
- Retract the lower lip
- Examiner grasps the lip between index finger and thumb
- Pull the lower lip outward and downward
- Insert needle
- Insert needle at junction of mucosa and gum, in line with the second premolar
- Direct the needle inferiorly toward the mental foramen
- Infiltrate at mental foramen
- Inject 1-2 ml of Lidocaine 1% near but not in the mental foramen
- Withdraw and redirect needle if Paresthesias or sharp pain
- May inject in a fan distribution to disperse the Anesthetic
- Repeat on the opposite side if the operative region is near the midline
VII. References
- Moy in Pfenninger (1994) Procedures, p. 145-55
- Warrington (2021) Crit Dec Emerg Med 35(1): 11
- Latham (2014) Am Fam Physician 89(12): 956-62 [PubMed]
- Salam (2004) Am Fam Physician 69(3):585-90 [PubMed]