What are some landmarks to look for in local infiltration?

• A. Mucobuccal fold, crown of tooth, root contour of tooth
• B. Zygomatic arch, nasal alae
• C. Mandibular lingula, coronoid process
• D. Mental foramen, alveolar crest

Answer: (A)

For local infiltration in the maxilla, you rely on surface landmarks that point you to the tooth’s apex so the anesthetic can spread near the root tip. The mucobuccal fold directly over the tooth is the key guide for where to insert the needle; you place the entry just above the apex in that fold. Using the crown of the tooth helps you identify which tooth you’re treating, and the contour of the root gives spatial clues about where the root apex sits inside the bone, allowing you to estimate depth and position the anesthetic near that apex.

The other landmarks listed don’t support this specific technique. The facial features like the zygomatic arch and nasal alae aren’t used to pinpoint a tooth’s apex for maxillary infiltration. Landmarks on the mandible, such as the lingula or coronoid process, belong to techniques for the lower jaw and won’t guide a maxillary infiltration. Mental foramen and the alveolar crest relate more to mandibular injections or general jaw anatomy, not the maxillary infiltration approach.