Which access shape is least typical for a mandibular molar?

Which access shape is least typical for a mandibular molar?

• A. Trapezoidal
• B. Circular
• C. Oval
• D. Rhomboid

Answer: (B)

A circular access is least typical because the canals in mandibular molars are spread across multiple locations rather than concentrated in a single central point. Endodontic access aims to expose all canal orifices and provide straight‑line access to each canal while preserving tooth structure. Mandibular molars usually have two mesial canals and one or more distal canals that are offset buccolingually and mesiodistally, so outlines like trapezoidal, rhomboid, or oval fit the anatomy better and allow locating and instrumenting all canals efficiently. A circular opening centered on one spot would miss additional canals and hinder access, making it the least suitable choice.

A circular access is least typical because the canals in mandibular molars are spread across multiple locations rather than concentrated in a single central point. Endodontic access aims to expose all canal orifices and provide straight‑line access to each canal while preserving tooth structure. Mandibular molars usually have two mesial canals and one or more distal canals that are offset buccolingually and mesiodistally, so outlines like trapezoidal, rhomboid, or oval fit the anatomy better and allow locating and instrumenting all canals efficiently. A circular opening centered on one spot would miss additional canals and hinder access, making it the least suitable choice.