Mandibular Nerve Block Chapt. 13 – Flashcards
Unlock all answers in this set
Unlock answersquestion
Mandibular Nerve Anesthesia
answer
• Inferior alveolar nerve block (IA) • Buccal block • Mental block • Incisive block • Mandibular supraperiosteal injection • Gow-Gates mandibular block • Vazirani-Akinosi mandibular block • Periodontal ligament injection (PDL)
question
Unique Traits of the Mandible
answer
• Mandible is denser than the maxilla - Making supraperiosteal injections of the mandible not as successful • Supraperiosteal injections more effective on the mandibular anterior teeth - Can be successfully administered for crossover innervations
question
Inferior Alveolar Nerve Block (IA)
answer
Anesthetizes the IA nerve, lingual nerve, mental nerve, and incisive nerve: - Mandibular teeth to midline - Lingual soft tissue to the midline - Facial periodontium & soft tissue of premolars and anterior teeth - Lower lip to midline - Anterior 2/3 of tongue - Floor of mouth
question
- Re-aspirate every ¼ deposition of local anesthesic
answer
- If negative, rotate the syringe barrel gently toward the operator and re-aspirate - If negative, rotate the syringe barrel gently back to the original position and aspirate again
question
Operator Position for IA, Buccal, mental,incisive, (quad 4)
answer
Quad 4 Right-handed: 8 or 9 o'clock Left-handed: 4 or 3 o'clock
question
Operator Position for IA, Buccal ,mental,incisive, (quad 3)
answer
Quad 3 Right-handed: 10 o'clock Left-handed: 2 o'clock
question
Injection Site for IA
answer
• Needle gauge and length: - 25-27 gauge, LONG • Landmarks: - Anterior border of ramus - Coronoid notch - Pterygomandibular fold (raphe) - Pterygomandibular space - Mandibular occlusal plane - Contralateral mandibular 2nd premolar - Contralateral corner of mouth
question
Needle insertion point of IA
answer
Middle of pterygomandibular space (deepest part of depression) at 6- 10 mm superior to occlusal plane of mandibular molars • At intersection of horizontal line and vertical line using the coronoid notch and the pterygomandibular fold - Syringe barrel over contralateral premolars and in line with contralateral corner of mouth - Bevel of needle toward bone
question
Depth of penetration for IA block
answer
- ~ 2/3 - ¾ the depth of the long needle until bone is contacted
question
• Deposit location for IA block - At mandibular foramen with IA nerve
answer
- At mandibular foramen with IA nerve
question
Amount of anesthetic for IA block?
answer
- ~ 1-1 ¾ cartridge (save ¼ for buccal injection)
question
Length of time to deposit for IA block?
answer
- ~ 1-2 mins.
question
IA Complications:
answer
Lingual Shock-As the needle passes by the lingual nerve, the moving needle shocks the nerve. Injecting slowly will NOT prevent lingual shock
question
IA Complications: Bone Contacted Too Soon
answer
Needle tip too far anterior on ramus • Correction is made by: -Partially or completely withdrawing the needle -Bring syringe closer to mandibular anterior teeth to move the needle tip more posteriorly
question
IA Complications: Bone Not Contacted
answer
Needle tip too far posterior on ramus Correction is made by: -Partially or completely withdrawing the needle -Bring syringe closer to mandibular molars to move the needle tip more anteriorly
question
IA Complications: Inadequate Anesthesia
answer
• Cause: - Depositing solution inferior to mandibular foramen • Technique adjustment: - Re-inject at a more superior injection site
question
IA Complications: Incomplete Anesthesia of Mandibular Central or Lateral Incisors
answer
• Cause: - Depositing solution inferior to mandibular foramen • Technique adjustment: - Re-inject at a more superior injection site • Cause: *** Bifid inferior alveolar nerve (in < 1% of population) • Technique adjustment: - Read radiographs - Administer IA inferior to usual anatomic landmarks for bifid IA nerve
question
IA Complications: Incomplete Anesthesia of Mandibular 1st Molar
answer
• Cause: - Possibly due to innervation by the mylohyoid nerve that is not anesthetized by the IA • Treatment adjustment: - Insert a 25-27 gauge, long needle on lingual border of themandible, at the apex of the mesial root of the mandibular 1st molar, near the mylohyoid line - Insert ¼ the depth of the needle - Aspirate ** Deposit ¼ of cartridge over 20 secs.
question
IA Complications: Transient Facial Paralysis
answer
• Cause: - Administration of anesthetic into the parotid salivary gland containing the facial nerve (VII Cranial Nerve) • Symptoms: - Inability to close the eyelid and the drooping of the lips on the affected side • Prevention:- Always contact bone before depositing solution
question
IA Complications: Paresthesia
answer
• Causes: - Usually trauma to the lingual nerve - Lack of adequate fascia around the lingual nerve - Possible neurotoxicity from the local anesthetic agent - Dental infection from contaminated needle - Problematic surgical extraction of impacted 3rd molars • Symptoms: - Abnormal sensation such as burning or prickling • "Pins-and-needle" feeling
question
Buccal Block
answer
• Indications: - Usually given immediately after IA to complete quadrant anesthesia • Anesthetizes long buccal nerve: -Buccal gingival tissue of mandibular molars
question
Injection Site for Buccal Block
answer
Needle gauge & length: ***- Use 25-27 gauge, LONG immediately after IA block - Use 25-27 gauge, short if buccal block is given alone
question
• Landmark for buccal block
answer
- Most distal mandibular molar - Anterior border of the ramus of mandible - Occlusal plane of mandibular molars
question
• Needle insertion point for Buccal black
answer
• Needle insertion point: - In the vestibule, distal and buccal to last molar, and at the height of the occlusal plane - Syringe parallel to occlusal plane - Bevel of needle toward bone
question
• Depth of penetration for Buccal block
answer
- ~ 1/8 - ¼ of needle
question
• Deposit location for Buccal block
answer
- Close to long buccal nerve as it passes over the anterior border of the ramus
question
• Amount of anesthetic for Buccal block
answer
- ~ 1/8 - ¼ cartridge
question
• Length of time to deposit for Buccal block
answer
- ~ 10-20 secs.
question
Buccal Block Complications
answer
• Leakage of solution at injection site - Cause: • Bevel of needle only partially in the tissue - Technique adjustment: • Deeper penetration on re-insertion • Ballooning of tissue - Cause: • Rapid deposit of solution - Technique adjustment: • Slow down the deposit of solution • Cheek biting - Technique adjustment: • Educate patient
question
Mental Block ONLY includes tissue.
answer
• Deposit location is where the mental nerve enters the mental foramen to merge with the incisive nerve to form the IA nerve. • Location of mental foramen is usually between the apices of the mandibular 1st and 2nd premolars. - Palpate depth of the mucobuccal fold between the apices of the mandibular premolars or at a site indicated by dental images until a depression surrounded by smoother bone is felt on the surface. * The mental foramen could be as far posterior as the mandibular 1st molar or as far anterior as the distal surface of the canine
question
Mental block anesthetizes?
answer
Anesthetizes mental nerve: - Facial gingival tissue of the anterior teeth and premolars - Lower lip - Skin of the chin to the midline
question
Incisive Block
answer
• Anesthetizes incisive nerve and mental nerve: - Anterior teeth and premolars - Periodontium and facial soft tissue of anesthetized teeth * Useful when there is a crossover of the contralateral incisive nerve and there is still discomfort on the mandibular anterior teeth after giving an IA block. ** Useful for nonsurgical perio or routine maintenance of sensitive anteriors
question
Technique Difference Between Mental & Incisive Blocks
answer
• Mental block: -** Do NOT massage the tissue after injection • Incisive block: - Palpate injection area for at least 2 minutes after injection • Helpful to position patient upright or in semiupright position after the injection to help with diffusion of anesthetic solution
question
• Landmarks for Mental and Incisive block?
answer
- Mandibular premolars - Mental foramen - Mandibular mucobuccal fold
question
Needle Penetration for Mental or Incisive
answer
• Needle insertion point: - Depth of mucobuccal fold anterior to mental foramen • Between apices of mandibular premolars or location determined by dental images
question
• Depth of penetration for Mental or Incisive block?
answer
~ ¼ depth of short needle
question
Amount of anesthetic for Mental and Incisive block?
answer
~ 1/3 - ½ of cartridge
question
Length of time to deposit for Mental and Incisive block?
answer
- ~ 30-60 secs. • Lingual infiltration required - Infiltrate through papilla from facial to lingual * deposit solution as needle advances
question
Incisive Block Complications
answer
• Inadequate anesthesia - Causes: • Inadequate volume of anesthetic - Treatment Adjustment: » Re-inject in correct location with additional anesthetic • Inadequate duration of pressure over mental foramen - Treatment Adjustment: » Apply firm pressure to deposition site for minimum of 2 minutes
question
Gow-Gates Mandibular Block
answer
• Recommended for extensive procedures during quadrant dentistry or with failure of the IA block • Nerves anesthetized: - Auriculotemporal nerve - Inferior alveolar nerve - Mylohyoid nerve - Lingual nerve - Long buccal nerve - Mental nerve - Incisive nerve
question
Gow-Gates Mandibular Block structures anesthetized?
answer
- Mandibular teeth to midline - Periodontium of anesthetized teeth - Buccal and lingual gingival tissue to midline - Lower lip to midline - Anterior 2/3 of tongue - Floor of mouth - Skin over zygomatic bone and posterior part of buccal & temporal regions
question
Injection Site for Gow-Gates
answer
• Needle gauge and length: - 25-gauge, long • Landmarks: - Extraoral: • Lower border of the tragus • Labial commissure - Intraoral: • Mesiolingual cusp of maxillary 2nd molar • Soft tissue just distal to maxillary 2nd molar
question
Needle insertion for Gow-Gates
answer
• Needle insertion point: - Oral mucosa on mesial of mandibular ramus, just distal to height of mesiolingual cusp of maxillary 2nd molar
question
Depth of penetration for Gow-Gates
answer
**- ~ ¾ the depth of long needle until bone is contacted. The needle will naturally withdraw from the periosteum when bony contact is made, so there is no need to withdraw further
question
• Deposit location
answer
- Anteromedial border of mandibular condylar neck, just inferior to insertion of lateral pterygoid muscle
question
• Amount of anesthetic for Gow-Gates block
answer
- ~ 1 cartridge
question
• Length of time to deposit for Gow gates block
answer
- ~ 1-2 mins.
question
Which injection is used for patients who have trauma or problem opening?
answer
Vazirani-Akinosi
question
Gow-Gates Mandibular Block
answer
• Advantage: - Higher success rate than IA - Injection lasts longer than IA • Disadvantage: - Anesthesia of the lower lip and temporal area ***• Contraindicated: - Patients with limited ability to open mouth
question
Periodontal Ligament Injection (PDL)
answer
• Advantages: - Absence of lip or tongue anesthesia - Single dose and minimal volume of anesthetic - Alternative when other methods are ineffective - Minimal postinjection discomfort - Postoperative complications are unlikely - Minimizes bleeding in area of treatment - Decreased risk of toxicity
question
Periodontal Ligament Injection (PDL)
answer
• Disadvantages: - Needle placement may be difficult and experience is necessary - Anesthetic may leak into the patient's mouth causing bitter taste - Short duration of pulpal anesthesia ** Contraindicated in areas with infection or severe inflammation - Excessive pressure needed for the injection, which may cause breakage of glass cartridge in standard syringe and may cause tissue damage
question
• Quadrant instrumentation begins with the molars (third, second, then first), followed by premolars (second, then first), followed by anterior sextant in order to allow for complete anesthesia of the core bundles.
answer
• If bone is not contacted during IA block, the anesthetic may be inadvertently deposited in the parotid gland, causing temporary anesthesia of the facial nerve.
question
• For half mouth treatment, give injections in this order: IA and buccal blocks first, the maxillary facial injections, then palatal injections. Begin instrumentation on the maxillary arch and then proceed to the mandibular arch.
answer
• Deposit location of the IA block is slightly superior to the entry point of the IA nerve as it moves inferiorly to enter into the mandibular foramen. In case of anesthesia failure, reattempt at a level slightly superior to the first injection.
question
• Following IA block, incomplete anesthesia could mean presence of bifid inferior alveolar nerve in 1% of population.
answer
• Following IA block, failure of anesthesia of mandibular first molar could be a result of innervation of the mylohyoid nerve.
question
• Bilateral incisive/mental blocks may be useful for sextant, canine to canine, treatment.
answer
• IA block has the highest positive aspiration rate of all block injections. • Recommendation: Aspirate and re-aspirate after every one-fourth cartridge of anesthetic solution.
