Why are supraperiosteal injections less successful on the mandible?

Supraperiosteal injections tend to be less successful on the mandible primarily due to the density of the bone. The mandible is composed of a dense cortical bone layer that can impede the diffusion of the anesthetic agent. This density requires that the anesthetic solution reach the nerve through a relatively smaller area of porous bone, as compared to the maxilla, where the bone is less dense and more porous, allowing for easier diffusion of the anesthetic.

In addition, the positioning of the mandible presents challenges, as the mental foramen and the location of branches of the inferior alveolar nerve can lead to variations in the effective site for the administration of anesthesia. This factor, while also impactful, does not overshadow the inherent difficulty posed by the density of the mandible’s bony structure.

Other options such as the location of the mandibular foramen or variability in nerve anatomy can complicate anesthesia administration, but it is primarily the dense nature of the mandibular bone that accounts for the challenges faced with supraperiosteal injections on this structure.