Techniques of Mandibular Anesthesia including Inferior Alveoar Nerve Block

Mandibular Anesthesia

• Lower success rate than Maxillary anesthesia (approx. 80-85 %)
• Related to bone density
• Less access to nerve trunks  

Mandibular Nerve Blocks

1. Inferior alveolar
2. Mental - Incisive             
3. Buccal
4. Lingual
5. Gow-Gates
6. Akinosi

Mandibular Anesthesia

• Most commonly performed technique
• Has highest failure rate (15-20%)
• Success depends on depositing solution within 1 mm of nerve trunk

Inferior Alveolar Nerve Block

Not a complete mandibular nerve block.

Requires supplemental buccal nerve block

May require infiltration of incisors or mesial root of first molar

Nerves anesthetized

• Inferior Alveolar
• Mental
• Incisive   
• Lingual

Areas Anesthetized

• Mandibular teeth to midline
• Body of mandible, inferior ramus   
• Buccal mucosa anterior to mental foramen
• Anterior 2/3 tongue & floor of mouth
• Lingual soft tissue and periosteum

Indications of inferior Alveolar nerve block

• Multiple mandibular teeth
• Buccal anterior soft tissue
• Lingual anesthesia

Contraindications of inferior Alveolar nerve block

• Infection/inflammation at injection site
• Patients at risk for self injury (eg. children)

10%-15% positive aspiration

Alternatives for inferior Alveolar nerve block

1. Mental nerve block
2. Incisive nerve block
3. Anterior infiltration
4. Periodontal ligament injection (PDL)
5. Gow-Gates
6. Akinosi  
7. Intraseptal

Technique for of inferior Alveolar nerve block

Apply topical anaesthesia

Area of insertion:

• Medial ramus, mid-coronoid notch,
• Level with occlusal plane (1 cm above),
• 3/4 posterior from coronoid notch to pterygomandibular raphe
• Advance to bone (20-25 mm)

Target Area

    Inferior alveolar nerve, near mandibular foramen

Landmarks

    Coronoid notch

    Pterygomandibular raphe

    Occlusal plane of mandibular posteriors

Inferior Alveolar Nerve Block

Precautions

    Do not inject if bone not contacted

    Avoid forceful bone contact

Failure of Anesthesia in inferior Alveolar nerve block

    Injection too low

    Injection too anterior

    Accessory innervation

        -Mylohyoid nerve

        -Contra lateral Incisive nerve innervation

Complications of inferior Alveolar nerve block

1. Hematoma
2. Trismus
3. Facial paralysis

Mandibular nerve block

Other Techniques of Manidilar nerve block

Long Buccal Nerve Block

• Anterior branch of Mandibular nerve (V3)
• Provides buccal soft tissue anesthesia adjacent to mandibular molars
• Not required for most restorative procedures

Buccal Nerve Block

Indications

    Anesthesia required - mucoperiosteum buccal to mandibular molars

Contraindications

    Infection/inflammation at injection site

Advantages

    Technically easy

    High success rate

Disadvantages

    Discomfort

Alternatives

    Buccal infiltration

    Gow-Gates

    PDL

    Intraseptal

Technique

Apply topical

Insertion distil and buccal to last molar

Target - Long Buccal nerve as it passes anterior border of ramus

•    Insert  approx.  2 mm, aspirate
•    Inject 0.3 ml of solution, slowly
•    25-27 gauge needle

Area of insertion:- Mucosa adjacent to most distal

Landmarks

    Mandibular molars

    Mucobuccal fold

Complications

    Hematoma (unusual)

    Positive aspiration-0.7 %

Mental Nerve Block

Terminal branch of IAN as it exits mental foramen

Provides sensory innervation to buccal soft tissue anterior to mental foramen, lip and chin

Indication

    Need for anesthesia in innervated area

Contraindication

    Infection/inflammation  at injection site

Advantages

    Easy, high success rate

    Usually atraumatic

Disadvantage

    Hematoma

Alternatives

    Local infiltration

    PDL

    Intraseptal

    Inferior alveolar nerve block

    Gow Gates

Complications

    Few

    Hematoma

    Positive aspiration-5.7 %

Incisive Nerve Block

Terminal branch of IAN         

Originates in mental foramen and proceeds anteriorly

Good for bilateral anterior anesthesia               

Not effective for anterior lingual anesthesia  

Nerves anesthetized

    Incisive

    Mental

Areas Anesthetized

    Mandibular labial mucous membranes

    Lower lip / skin of chin

    Incisor, cuspid and bicuspid teeth

Indication

    Anesthesia of pulp or tissue required anterior to mental foramen

Contraindication

    Infection/inflammation at injection site

Advantages

    High success rate

    Pulpal anesthesia w/o lingual anesthesia

Disadvantages

    Lack of lingual or midline anesthesia

Complications

    Hematoma

    Positive aspiration-5.7 %

Mandibular nerve block (other techniques)