Which index modification is used when it is unclear whether missing teeth were lost due to decay?

• A. DFT/DFS
• B. DMFT
• C. DEFT/DEFS
• D. Root Caries Index

Answer: (A)

When caries experience is being measured, you don’t want to misattribute tooth loss to decay if you’re not sure that loss was caused by caries. In the standard DMFT index, missing teeth (M) are counted as due to caries, which can overestimate caries experience if the reason for extraction isn’t clear. Using a modification that excludes missing teeth and focuses on teeth that are decayed or filled (DFT) or, in some versions, also counts sound teeth (DFS), avoids this misclassification. This approach is particularly useful when the cause of tooth loss is uncertain, so decayed and filled teeth are tracked without assuming all missing teeth resulted from caries. Thus, DFT/DFS is the best choice in this scenario.