Inferior Alveolar Nerve Block
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Inferior Alveolar Nerve Block

Local And General Anesthesia

Oral And Maxillofacial Surgery

INFERIOR ALVEOLAR NERVE BLOCK

 

It is commonly also referred as MANDIBULAR NERVE BLOCK.

 

INDICATIONS:

  • Procedures on multiple mandibular teeth in one quadrant
  • Buccal and lingual soft tissues are to be anesthetized

CONTRAINDICATIONS:

  • Acute inflammation or infection at the site of injection
  • A very young child or physically or mentally handicapped person who might bite either lip or tongue

NERVES ANESTHETIZED:

  • Inferior alveolar nerve
  • Incisive nerve
  • Mental nerve
  • Lingual nerve


AREAS ANESTHETIZED:

  • All mandibular teeth pertaining to that side up to midline
  • Body of mandible
  • Inferior portion of ramus
  • Buccal mucoperiosteum and mucous membrane anterior to mandibular 1st molar
  • Lingual soft tissues and periosteum
  • Anterior 2\3rds of tongue and floor of the oral cavity
  • External and internal oblique ridge

 


ANATOMICAL LANDMARKS:

  • External oblique ridge
  • Internal oblique ridge
  • Retromolar pad
  • Buccal fat pad
  • Coronoid notch
  • Pterygomandibular raphe
  • Pterygomandibular space
  • Pterygotemporal depression

TECHNIQUE OF INSERTION:

DIRECT TECHNIQUE: (Halstead approach)(Commonly used)

  • Patient is seated on the dental chair in supine or semi-supine position in such a way that the mandible is parallel to the floor with mouth wide open
  • With the help of index finger or thumb of left hand palpate the external oblique ridge slowly move the finger across retromolar triangle and up-to internal oblique ridge in such a way that pterygomandibular raphe and pterygotemporal depression is clearly visible
  • Now move index finger or thumb extra-orally to asses the width of the mandible
  • A 25 gauge needle is inserted from the opposite side parallel to the mandibular plane bisecting the thumb intra-orally up-to half the distance of palpating finger extra-orally behind the ramus of mandible
  • The needle contacts the bone withdraw 1 mm to prevent sub-periosteal injection , aspirate and inject slowly 1.5ml to 1.8ml of anesthetic solution over 60 secs
  • Withdraw the needle and make it safe, after approx. 20 secs upright the patient and wait for 3 to 5 mins before commencing the dental procedure

 

VIDEO: Youtube Video Link


 INDIRECT TECHNIQUE

Inferior alveolar nerve is anesthetized in 3rdposition hence is known as indirect technique or Fischer 1-2-3 technique

  • 1st position : Long buccal nerve is anesthetized from opposite side
  • 2nd position : Lingual nerve is anesthetized from the same side
  • 3rd position : Inferior alveolar nerve is anesthetized from opposite side

GOW-GATES TECHNIQUE:

 

  • This injection is given with patient positioned in supine position with neck extended and mouth wide open, this position facilitates injection by moving the condyle anteriorly.
  • Palpate the anterior border of ramus and identify tendon of temporalis muscle
  • Penetrate the needle gently into the tissues just distal to maxillary 2nd molar at the height of mesiopalatal cusp
  • The needle should be just medial to the temporal tendon and directed in the direction parallel to an imaginary line drawn from the corner of the mouth to the intertragic notch of the ear and advanced until the fovea region of the condylar neck is connected.
  • With negative aspiration inject slowly 1.5ml to 1.8ml of anesthetic solution over 60 to 90 secs

VIDEO: Youtube Video Link


VAZIRANI-AKINOSI’S CLOSED MOUTH MANDIBULAR BLOCK: 

 

  • This type of injection is given to patients who can not open their mouth.
  • Patient is seated in supine position with the teeth in occlusion
  • Retract the lips to expose mandibular and maxillary teeth, the syringe is directed parallel to the occlusal and sagittal planes at the level of mucogingival junction of maxillary molars.
  • Penetrate the needle medial to the ramus of the mandible 25 to 30mm into the tissues, the tip of the needle lies in the mid portion of pterygomandibular space ,close to the mandibular nerve.
  • With negative aspiration inject slowly 1.5ml to 1.8ml of anesthetic solution over 60 to 90 secs

 VIDEO: Youtube Video Link


SIGNS AND SYMPTOMS:

  • Subjective : Tingling  or numbness of lower lip and side of tongue indicating anesthesia
  • Objective : Loss of pain sensation over the area anesthetized

COMPLICATIONS:

  • Hematoma of the tissues in the medial side of the mandibular ramus
  • Trismus or limited mouth opening
  • Transient facial palsy

REFERENCES:

  1. Hand book of local Anesthesia by Stanley F. Malamed 5th edition
  2. Text book of Oral and Maxillofacial surgery by S M. Balaji 2nd edition

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