The line extended through all the central developmental grooves of the maxillary and mandibular posterior teeth is called which line?

• A. Plane of occlusion
• B. BO line
• C. LO line
• D. CF line

Answer: (D)

The line through the central developmental grooves of the posterior teeth is the central groove line (CF line). These grooves are the primary occlusal pathways on the chewing surfaces of the back teeth, and when you imagine extending them across the arch, they align to form a single, straight reference line that runs through the centers of the occlusal table. This line provides a useful landmark for assessing occlusal relationships and planning restorations, because it reflects how the grooves—key functional pathways for mastication—are positioned across both arches.

The plane of occlusion is a broader concept describing the overall spatial relationship of the maxillary and mandibular dentitions in centric relation, not a single line through grooves. The other lines mentioned aren’t standard references for this groove-based axis, so the central groove line best fits the description.