Ace the Iowa RDA Exam 2026 – Smile Your Way to Success!

Understanding these surface abbreviations is about the directions and surfaces used on teeth. M stands for mesial, which is the surface toward the midline of the face. D stands for distal, the surface away from that midline. B stands for buccal, the surface toward the cheek (the outer side). L stands for lingual, the surface toward the tongue (the inner side). O stands for occlusal, the chewing surface on the back teeth (the incisal edge on front teeth is not typically called occlusal). This mapping—M to mesial, D to distal, B to buccal, L to lingual, O to occlusal—follows standard dental terminology, which is why it is the correct choice. The other options mix up these directions or use terms that aren’t surfaces (like molar or deciduous) or swap occlusal with lingual, which isn’t accurate.