What finding explains the Type III classification in the 50-year-old patient with deep pockets and furcation involvement?

• A. Presence of furcations
• B. Pulp vitality
• C. Mobility 0
• D. No furcation involvement

Answer: (A)

The key idea is furcation involvement in a multirooted tooth and how advanced defects are classified. Type III furcation involvement means there is bone loss that creates a through-and-through pathway between the roots of the tooth within the furcation area. In other words, the destruction has progressed to connect the buccal and lingual (or palatal) aspects, indicating an advanced defect. This state can occur with deep pockets and true furcation involvement, and it’s the presence of a furcation defect that allows this classification.

Pulp vitality and mobility are not what define this category, and having no furcation involvement would rule out this being Type III. So the finding that best explains the Type III classification is the presence of furcations with through-and-through bone loss.