The inferior alveolar nerve is also known as inferior dental nerve.  it gives of a motor branch that supplies to mylohyoid muscle and anterior Belly of digastric.  then it travels through mandibular foramen and enters the mandible why are the inferior dental canal.  from inferior dental Canal it supplies to mandibular Third molar, second molar, first molar, and second premolar.

From the level of second premolar it moves forward as mental nerve and exits through mental foramen.  the mental nerve supplies sensory nerve fibres to the chin and lower lip of that side. within the mandible after mental foramen it moves forward as incisive nerve and give sensory supply to mandibular incisors and mandibular canine of that side.

Anatomical landmarks of inferior dental nerve block:

  • mucobuccal fold
  • external oblique Ridge
  • anterior border of mandibular ramus
  • internal oblique Ridge
  • retromolar Triangle
  • pterygomandibular ligament
  • buccal pad
  • pterygomandibular space

Nerves anesthetized by inferior dental nerve block:

  • inferior dental nerve and its subdivisions
  • mental nerve
  • incisive nerve
  • lingual nerve
  • buccinator nerve

Area  anesthetized by inferior dental nerve block

  • lower portion of the ramus and body of the mandible
  • mandibular teeth incisors canines premolars and molars
  • Mucous membrane and underlying tissues anterior to the mandibular first molar ( supplied by lingual nerve)

Remark:

To numb the soft tissues posterior to the buccal aspect of first molar the long buccal nerve should be  anaesthetised.

Indications of inferior dental nerve block:

  • root canal treatment, implant  surgery, flap surgery, extraction of teeth or any other surgical procedure on mandibular teeth.
  • surgical procedure on soft and hard tissues anterior to the first mandibular molar.  in this case both inferior alveolar nerve and lingual nerve should be blocked.
  • surgical procedure performed on soft tissues and heart issues posterior to the first mandibular molar.  in this case both inferior dental nerve and long buccal nerve, both should be a anaesthetised.
  • in diagnosing pulp vitality,  Trigeminal Neuralgia et cetera.

Way of the needle during insertion for inferior dental nerve block:

the needle passes through mucosa,  thin sheet of buccinator muscle, loose connective tissue and fat.

Structures in neighbourhood of the needle when it is in final position:

  • inferior alveolar arteries and veins
  • inferior alveolar nerve
  • inferior portion of the internal pterygoid muscle
  • myelohyoid artery and veins
  • mylohyoid nerve
  • the needle is present anterior to the deep part of parotid gland
  • the needle is present medial to the  ramus of the mandible
  • the needle is present lateral to 1. Lingual nerve 2. internal pterygoid muscle. 3. sphenomandibular ligament

Symptoms of anaesthesia in inferior dental nerve block:

Subjective symptoms:

tingling sensation and numbness of the lower lip, and tip of the tongue when lingual nerve is also anaestheised.

Objective symptoms:

instrumentation should be done. Use either the tip of a blunt probe or elevator to check for objective symptoms.   The anaesthetic tissue and teeth should be pressed and tapped as compared to the normal side without anaesthesia.

Complications of inferior dental nerve block:

One or several of the given  below complications may develop  during inferior alveolar nerve block.

  • muscle trismus
  • Hematoma
  • needle breakage
  • mucosal irritation
  • transient hemifacial paralysis

Take the mock test on inferior dental nerve block HERE.

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