3. mandibular anesthesia part 1

largest branch of trigeminal nerve

V3

• Exit via Foramen Ovale and enter the Infratemporal Fossa

• Large sensory root

  • Skin on lower 3rd of the face, lower lip

  • Skin of temporal region

  • Mandibular dentition and gingiva

  • Anterior 2/3rd of the tongue (general sensation)

• Small motor root: Muscles of mastication

• Also carries nerves fibers from other nuclei:

  • Autonomic fibers for salivary glands (CN VII)

  • Special sensory taste fibers (CN VII)

V3

V3 exits (BLANK 1) and enter (BLANK 2)

blank1: foramen ovale blank 2: infratemporal fossa

V3 sensory to

• Skin on lower 3rd of the face, lower lip

• Skin of temporal region

• Mandibular dentition and gingiva

• Anterior 2/3rd of the tongue (general sensation)

V3 motor for

MOM

what two nerve fibers are carried via V3?

VII: chorda tympani taste an 2/3rd tongue + autonomic submand and sublingual glands via lingual sensation ant 2/3rd tongue

(and lesser petrosal postganglionic of CN IX via auriculotemporal parotid gland)

describe motor and sensory anterior division of V3

motor MOM: masseter, deep temporal, medial pterygoid, lateral pterygoid + sensory: long buccal

describe motor and sensory posterior division of V3

motor: mylohyoid sensory: auriculotemporal, lingual, IAN (mental and incisive), mylohyoid

which nerve is both motor and sensory and what division of V3?

mylohyoid posterior

which nerve innervates cheek, buccal mucosa, and gingiva of posterior mandible?

(long) buccal n

which nerve continues to floor of the mouth?

lingual

lingula = bony prominence of mandibular foramen where IAN enters, protects nerve

innervates the skin of the chin, lower lip, and buccal mucosa

mental n

continues within the mandible to supply sensory innervation to the mandibular canine, premolars, and their associated gingiva and pulps, originating from the inferior alveolar nerve

incisive nerve

innervates medial pterygoid, tensor veli paalinin of palate and tensor tympani of ear

medial pterygoid

innervates masseter

masseteric

innervates temporalis muscle

deep temporal

innervates lateral pterygoid

lateral pterygoid

innervates mylohyoid muscle and anterior belly of digastric m

mylohyoid

sensory root of V3 innervates skin of

• Temporal region

• Auricular

• External auditory meatus

• Cheek

• Lower lip

• lower part of the face (chin region)

sensory of V3 also innervates

• Mucous membranes of cheek

• Tongue (anterior two thirds)

• Mucous membrane of mastoid cells and

• parotid glands

• Mandibular teeth and periodontal tissues

• Mandibular bone and TMJ

describe dermatomes

sensory innervation to:

• External auditory meatus

• Skin of anterior aspect of temple

• Skin of the auricle

auriculotemporal

dermatome for auriculotemporal

Location:

• Runs from the medial side and cross the anterior border of the ramus

• Runs anterior to inferior alveolar nerve

• Enters the cheek

(long) buccal

Sensory Innervation :

• Buccal gingival tissue of the molars to the second premolar region

• Skin of the cheek

(long) buccal

(long) buccal

Sensory Innervation:

• Mandibular dentition to midline

• Lingual hard and soft tissue

• Buccal gingiva anterior to mandibular first molar

IAN

Terminal Branches: mental and incisive nerves

IAN

Location

Emerges from the mental foramen Sensory Innervation :

Buccal gingiva from second premolars to midline Lower lip and skin of the chin to midline

mental nerve

mental nerve

Location:

• Remains within the mandibular canal

Sensory Innervation:

• Buccal mucosa anterior to mental foramen from second premolar to midline

• Lower lip and skin of chin to midline

• Dental pulps of premolars, canine, lateral and central incisors

incisive nerve

• mostly motor innervation

• Sensory Innervation: Mandibular dentition accessory innervation

mylohyoid

Communicates with Chorda Tympani (Facial Nerve)

• Parasympathetic fibers to the submandibular/sublingual gland

• Special taste sensory fibers to taste buds on the anterior two thirds of the tongue

lingual nerve

Sensory Innervation :

• Lingual gingiva of lower dentition

• Mucosa of floor of the mouth

• Anterior two thirds of the tongue - general sensation

lingual

lingual

The problem with mandibular anesthesia, in adults, is the density of the cortical plate of the mandibular bone

It precludes the successful administration of supraperiosteal anesthesia

MOM attachments

hat are six mandibular injections?

• Supraperiosteal Injection

• Inferior Alveolar Nerve Block: Standard “classic” technique, Gow-Gates Mandibular technique Akinosi “closed mouth” technique

• Lingual Nerve Block

• (Long) Buccal Nerve Block

• Mylohyoid Nerve Block

• Mental/Incisive Nerve Block

• Indication: Pupal and buccal soft tissue anesthesia for a limited area (single tooth)

• Contraindication: Infection, dense bone covering the apices of teeth

• Nerve Anesthetized: Large terminal branches of the dental plexus

supraperiosteal injection

supraperiosteal injection

supraperiosteal injection

Area of Anesthesia

• All mandibular teeth to midline and surrounding periodontium and alveolar

• Buccal and labial soft tissue anterior to mandibular 1st molar (served by mental nerve)

• All lingual soft tissue, floor of the mouth,anterior two thirds of the tongue

IAN nerve block - standard/Halstead

Nerves Anesthetized

• Inferior alveolar nerve

• Incisive nerve and mental nerve

• Lingual nerve (very commonly)

IAN nerve block

(before mandibular foramen)

IAN nerve block

• Indication:

  • Procedure on multiple mandibular teeth in one quadrant

  • When buccal (anterior to 1st molar) and lingual soft tissue anesthesia is required

• Contraindication:

  • Infection/acute inflammation in area of injection

  • Patient who might bite either the lip or tongue (young pediatric or special needs patients)

IAN nerve block

Advantage:

• One injection provides a wide area of anesthesia - useful for quadrant dentistry

• Bony contact

Disadvantage:

• Lower success rate than maxillary anesthesia (80-85%)

• Density of bone

• Anatomical variations

• Greater distance to target area

• Positive aspiration: 10-15%

• Wide area of anesthesia (vs localized procedure)

• Lingual and lower lip anesthesia, which causes discomfort for many patients

• Inadequate/partial anesthesia (supplemental buccal nerve block or supraperiosteal injections may be needed)

IAN nerve block

IAN nerve block- standard/Halstead

three steps of the IAN standard/classic technique

1. find lamarks

2. establish height of injection

3. determine direction/angulation of injection

what landmarks are you looking for with standard/halstead IAN nerve block technique?

coronoid notch and pterygomandibular raphe

what does the pterygomandibular raphe connect?

superior connector muscle and buccinator muscle

for standard/halstead technique for IAN nerve block needle insertion is slightly (medial/lateral) to the pterygomandibular raphe

lateral

IAN standard/classic/halstead technique

how to establish height for IAN nerve block classic/standard/halstead injection?

• Place thumb at the coronoid notch, parallel to the plane of occlusion

• The imaginary line begin at the midpoint of the notch and terminate at the deepest part of the pterygomandibular raphe

• Place finger in the coronoid notch (greatest concavity on anterior border of the ramus)

• Continue the imaginary line to the deepest part of the pterygomandibular raphe. (In most patients, this line lies 6-10 mm above the mandibular occlusal plane)

• Needle insertion lies 3/4th of the anteroposterior distance of this line

how to determine direction/angulation for IAN nerve block classic/standard/halstead injection?

• Come in from the contralateral side between the premolar area

• Slowly advance until bone is contacted

• Average depth of insertion: 20-25 mm ~ 2/3rd needle size

IAN standard/halstead technique

which IAN standard/halstead issue?

• Needle tip is located too anteriorly

• Withdraw slightly

• Angulate the needle tip more posteriorly (syringe barrel more anteriorly)

• Re-advance to correct depth (20-25 mm)

bone contacted too soon

which IAN standard/halstead issue?

• Needle tip located too posteriorly

• Withdraw slightly

• Angulate the needle tip more anteriorly (syringe barrel more posteriorly)

• Re-advance to correct depth (20-25 mm)

no bony contact

what two nerves are anesthetized with IAN standard/halstead technique?

lingual and IAN

what is in the pterygomandibular space? what if you hit no bone

standard IAN technique

what are the signs and symptoms of a successful IAN nerve block? think tingling and numbness of lower lip and tongue

• Tingling or numbness of lower lip

  • Mental nerve - good indication

  • But not a reliable indicator of pulpal anesthesia depth - means you got mental nerve but maybe not IAN

• Tingling or numbness of tongue

  • Lingual Nerve

  • May be present without anesthesia of the inferior alveolar nerve

Objective: no pain is felt during dental therapy