LAURA J. WEBB
LAURA J. WEBB,
RDH, MS, CDA, is an
educator, and speaker
who founded LJW
( ljweduserv.com). She
consulting services for
allied dental education
programs and CE
courses for clinicians.
Laura frequently speaks
on the topics of local
was the recipient of the
2012 ADHA Alfred C.
Fones Award. She may
be contacted at
Increasing your odds of
success with the IA block
Dental hygienists often rely on the traditional inferior
alveolar nerve block (IANB), also known as the Halsted
approach, plus the addition of the buccal block for mandibular quadrant anesthesia during nonsurgical periodontal therapy (NSPT). This injection duo is the approach
most often taught to clinical competency by dental hygiene
education programs, so it is what many of us are used to
and feel most confident using. A 2014 study revealed that
less than 20% of dental hygiene education programs require
students to demonstrate clinical competency for the Gow-Gates mandibular block technique, which is the next most
popular mandibular block technique practiced during
dental hygiene education.
The IANB anesthetizes (on one side) the inferior alveolar
(IA) nerve, mental nerve, incisive nerve, and lingual nerve.
Structures anesthetized include: the pulps of the mandibular teeth; the associated lingual tissues and periosteum;
and the facial soft tissues and periosteum of the mandibular teeth anterior to the mental foramen. The anterior
two-thirds of the tongue, floor of the mouth, body of the
mandible, and inferior portion of the ramus are also anesthetized. The buccal block injection is required to anesthetize the facial soft tissue in the molar region.
The problem with the traditional IANB is the high failure
rate. Anesthetizing the adult mandible is more challenging
than the maxilla due to the thick cortical bone, especially
in the posterior region; unreliable location of landmarks and
nerves (which are often asymmetrical on individual patients);
potential for accessory innervation; and the depth of soft-tis-sue penetration required to reach the target.
2-5 Careful review of
the basic technique for
providing the IANB is
the first step in increasing one’s success rate.
Dust off your old skull
from hygiene school. If
Figure 1: Landmarks, mandible, left side.
Figure 2: Palpating the coronoid notch, right side.
Figure 3: Example of a position
of the mandibular foramen
relative to lingula, right side.