Why is infiltration more effective in the maxilla than the mandible?

Why is infiltration more effective in the maxilla than the mandible?

• A. The bone is less dense in the maxilla
• B. The nerves are closer together in the maxilla
• C. The tooth roots are shorter in the maxilla
• D. LA is more potent in the maxilla

Answer: (A)

Bone density and architecture determine how well infiltration works. The maxilla is composed of porous cancellous bone with a thin cortical shell, especially around the teeth, so local anesthetic can diffuse through the bone and reach the nerve fibers near the tooth apex more readily. The mandible, in contrast, has dense, thick cortical bone that resists diffusion, making infiltration far less reliable there. While other factors like how close nerves are, root length, or potency can influence anesthesia in some cases, the primary reason infiltration is more effective in the maxilla is its lighter, more permeable bone structure.

Bone density and architecture determine how well infiltration works. The maxilla is composed of porous cancellous bone with a thin cortical shell, especially around the teeth, so local anesthetic can diffuse through the bone and reach the nerve fibers near the tooth apex more readily. The mandible, in contrast, has dense, thick cortical bone that resists diffusion, making infiltration far less reliable there. While other factors like how close nerves are, root length, or potency can influence anesthesia in some cases, the primary reason infiltration is more effective in the maxilla is its lighter, more permeable bone structure.