Landmarks:

• Coronoid notch

• Pterygomandibular raphe

• Occlusal plane of the posterior mandibular teeth

Target:

The inferior alveolar nerve in the region of the lingula before it enters the mandibular foramen.

Procedure:

Insert the needle at a point lateral to the pterygomandibular raphe at a height corresponding to a line drawn between the midpoint of the coronoid notch and the pterygomandibular raphe parallel to the occlusal plane of the mandibular teeth. The insertion of the needle lies within the injection triangle. The injection triangle is bound laterally by the anteromedial portion of the ramus, medially by the pterygomandibular raphe, and anteriorly by the retromolar trigone. The retromolar trigone is the area behind the third mandibular molars bounded medially and laterally by the crests of the post-molar alveolar process. The barrel of the syringe lies over the contralateral premolars allowing for the correct anteroposterior angulation of the syringe. The bevel of the needle tip is oriented laterally or such that deflection of the tip during penetration would increase the likelihood of premature bony contact. The needle is then inserted at this angulation until bony contact is made.

Nerves anesthetized:

• Inferior alveolar

• Incisive

• Mental

• Lingual

Areas anesthetized:

• Mandibular teeth to midline

• Body of the mandible and the inferior portion of ramus

• Buccal mucoperiosteum

• Mucous membrane anterior to first mandibular molar

• Anterior two thirds of the tongue and floor of mouth

• Lingual soft tissues and periosteum

Indications:

• Quadrant dentistry

• Buccal soft tissue anesthesia, anterior to first molar, when lingual soft tissue anesthesia is required.

Contraindications:

• Infection or acute inflammation at injection site

• Patients with the potential to bite lip or tongue (children or patients with disabilities)

 Advantages:

• One injection provides wide area of anesthesia

Disadvantages:

• Localized procedures do not require wide area of anesthesia

• Failure rate of 15 to 20 per cent due to variations in anatomy and accessory innervation

• Inconsistent landmarks

• Positive aspiration of 10 to 15 per cent

• Lingual and lower lip anesthesia can be uncomfortable for some patients

• Risk of over insertion into the parotid gland, which may cause facial paralysis (CN VII, facial nerve).