Review of Mandibular Nerve Block

Inferior Alveolar Nerve Block (Mandibular Nerve Block)

The inferior alveolar nerve block (also known as the mandibular nerve block) is the most commonly used block in dentistry for the mandibular teeth.

What it numbs: The inferior alveolar nerve block anesthetizes the eight mandibular teeth in the quadrant, from the third molars to the central incisors including buccal soft tissues from mental nerve, tongue and lingual soft tissues from lingual nerve.  

Needle:

A 25 gauge long needle is recommended.  

Positioning:

Patient position is supine.  

For the right inferior alveolar nerve block and right handed operator, sit at an 8 or o'clock position directly facing the patient.

For the left inferior alveolar nerve block and right handed operator, sit at an 10 o'clock position directly facing the patient.   

Landmarks:

The landmark is the inferior alveolar nerve above the mandibular foramen where the nerve inserts into the canal.  

Have the patient open wide.  

Locate the anterior border of the ramus and palpating the coranoid notch of the external oblique ridge, then palpate the internal oblique ridge, slide your thumb laterally pulling soft tissue taut.  

Place the barrel of the syringe in the corner of the mouth on the opposite side.  

Target area:

The target area and injection site is located by placing the needle at the most posterior aspect of the pterygo-mandibular raphe, then move the needle half the distance toward the coranoid notch, then half the distance back to the pterygo- mandibular raphe this is where the needle will be inserted.  

The height of the needle insertion is from at the top of you thumb nail about 1 1/2 centimeters above the occlusal plane.

Advance needle slowly about 25mm or until you hit bone, withdraw slightly, aspirate twice if negative, deposit anesthetic slowly 1.5-1.8 ml over 30-40 seconds.

If you contact bone to soon withdraw the syringe slightly move barrel medially over canines or incisors and advance again until you contact bone.

Document:

Document in patient record, what injection you gave, who gave it, what kind of anesthetic, how much anesthetic, negative aspiration, no complications, ect.  

Remind patients to be careful not to bite their cheeks or tongue if they are still numb upon completion of the treatment.  

 

For More information and References:

Malamed SF. Techniques of mandibular anesthesia. In: Handbook of local anesthesia. 4th ed. Noida, India: Harcourt Brace; 1997:193–219.    

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