Mental Nerve Block

1. Indication
   1. Regional Anesthesia for anterior Mandible, lower lip and chin
2. Physiology: Landmarks for Mental Nerve
   1. Mental Nerve is a branch of the Trigeminal Nerve V3
   2. Exits Mandible at mental foramen
      1. Located 1 cm inferior and slightly anterior to the second premolar
      2. Exits Mandible in line with the mid-pupil on forward gaze
   3. Located between upper and lower border of Mandible
   4. Overlies medial jaw
      1. Centered below midline of orbit
      2. Line drawn through supraorbital, infraorbital foramen
3. Technique: Mental Nerve Block (extraoral)
   1. Locate mental foramen as above
      1. Palpate for the foramen along the external Mandible
   2. Insert needle
      1. Insert needle at point overlying mental foramen
      2. Advance needle perpendicular to bone until striking periosteum
      3. Withdraw the needle 2-3 mm
   3. Infiltrate at mental foramen
      1. Inject 2-3 ml of Lidocaine 1% near but not in the mental foramen
      2. Redirect needle if Paresthesias or sharp pain
      3. Repeat on the opposite side if the operative region is near the midline
4. Technique: Mental Nerve Block (intraoral)
   1. Locate mental foramen as above
      1. Palpate for the foramen along the external Mandible
   2. Retract the lower lip
      1. Examiner grasps the lip between index finger and thumb
      2. Pull the lower lip outward and downward
   3. Insert needle
      1. Insert needle at junction of mucosa and gum, in line with the second premolar
      2. Direct the needle inferiorly toward the mental foramen
   4. Infiltrate at mental foramen
      1. Inject 1-2 ml of Lidocaine 1% near but not in the mental foramen
      2. Redirect needle if Paresthesias or sharp pain
      3. Repeat on the opposite side if the operative region is near the midline
5. References
   1. Moy in Pfenninger (1994) Procedures, p. 145-55
   2. Latham (2014) Am Fam Physician 89(12): 956-62 [PubMed]
   3. Salam (2004) Am Fam Physician 69(3):585-90 [PubMed]