Question 3 of 20

Click on the correct answer to the following question:

 After administering a right inferior alveolar nerve (IAN) block to your patient, the first molar is still sensitive, even though the other teeth in the quadrant are numb. What could be the cause of this:

  1. the area of insertion of the needle was too superior
  2. the area of insertion of the needle was too inferior
  3. the local anesthetic agent that was used lacked a vasoconstrictor
  4. innervation of this tooth is being supplied by the mylohyoid nerve
  5. there is cross-over innervation from the inferior alveolar nerve on the opposite side