Anatomical Considerations

Mental nerve location in relation to the mental foramen.

Mental foramen location relying on a panoramic

Mental foramen location in relation to the 2nd PM radiographic apex.

Mental block should enter soft tissue posterior-superior to mental foramen along the long axis of the 2nd premolar and be advanced anterior-inferior until mental foramen guides the needle
Vertical releasing incisions should be avoided around the MD second premolar to avoid mental nerve damage

Distances from sinus floor will dictate the size of the crypt during surgical endodontics
Lateral thickness of bone may indicate location of access with consideration of soft tissue reflection, hemorrhage control, and visibility