Where is the injection site for a dental block procedure?

Dental Block Injection Sites

For dental block procedures, the injection site depends on the specific nerve block being performed: inferior alveolar nerve blocks are administered at the pterygomandibular space targeting the mandibular foramen, while maxillary blocks utilize various approaches including buccal infiltration, palatal injections, or the palatal approach anterior superior alveolar (P-ASA) block at the anterior palate.

Mandibular (Lower Jaw) Block Injections

Inferior Alveolar Nerve Block (IANB)

• The traditional IANB targets the mandibular foramen in the pterygomandibular space, typically using 1.8-3.6 mL of local anesthetic 1
• This injection anesthetizes the mandibular teeth, floor of mouth, ipsilateral tongue, and all but the buccal gingiva 2
• For enhanced anesthesia in mandibular molars with irreversible pulpitis, combining an IANB (1.8 mL) with a buccal infiltration (1.8 mL) provides significantly better success rates (65.4%) compared to IANB alone (14.8%) 1

Incisive Nerve Block

• The incisive nerve block is administered at the mental foramen region 3
• This block alone successfully anesthetizes first and second premolars for approximately 30 minutes, but fails to provide adequate pulpal anesthesia for central incisors, lateral incisors, and molars 3
• Combining an IANB with an incisive nerve block enhances anesthesia for lateral incisors and first molars, and improves success in premolars 3

Alternative Mandibular Infiltration

• For implant placement posterior to the mental foramen, mandibular infiltration (buccal approach) can be used instead of IANB to allow patients to sense potential nerve damage 2

Maxillary (Upper Jaw) Block Injections

Palatal Approach Anterior Superior Alveolar (P-ASA) Block

• The P-ASA block uses a single palatal injection site to anesthetize all six maxillary anterior teeth, the anterior third of the palate, and facial gingiva 4
• This technique requires only 0.9-1.4 mL of anesthetic, significantly less than traditional supraperiosteal approaches 4
• The primary advantage is avoiding collateral anesthesia to lips, face, and muscles of facial expression, preventing smile line distortion 4, 5

Traditional Maxillary Approach

• Traditional maxillary anesthesia combines buccal infiltration with palatal injections 5
• The palatal injection is typically the most uncomfortable for patients 5

Key Technical Considerations

Needle Selection and Technique

• Use a 25- or 27-gauge needle for dental injections 6
• Always aspirate before injection to avoid intravascular administration 7

Common Pitfalls to Avoid

• Inadequate anesthesia in mandibular molars with irreversible pulpitis is common with IANB alone; supplemental buccal infiltration significantly improves success 1
• The incisive nerve block should not be relied upon as a sole technique for anterior teeth or molars 3
• When using computerized delivery systems (e.g., Wand) with palatal approaches, patients exhibit significantly fewer disruptive behaviors during injection compared to traditional palatal injections 5

Volume Recommendations

• Standard IANB: 1.8 mL 1
• Enhanced IANB: 3.6 mL (provides 39.3% success vs. 14.8% with standard volume) 1
• Supplemental buccal infiltration: 1.8 mL 1
• P-ASA block: 0.9-1.4 mL 4