A Grade II furcation defect, as exhibited by tooth #14, is characterized by all EXCEPT which one of the following?

A Grade II furcation defect, as exhibited by tooth #14, is characterized by all EXCEPT which one of the following?

• A. It is a through-and-through defect.
• B. It is a two-wall infrabony defect.
• C. The furcation area can be probed entering but not passing through.
• D. Radiographic appearance may show two-wall involvement.

Answer: (A)

Grade II furcation involvement means there is horizontal bone loss into the furcation area that does not extend all the way through to the opposite side. You can probe into the furcation, but you cannot pass the probe completely through to the other side. This pattern often corresponds to a two-wall infrabony defect in the furcation, and radiographs may show involvement of two walls. It is not a through-and-through defect; that would be characteristic of a Grade III furcation, where the defect communicates from one side to the other. So the statement describing it as a through-and-through defect does not fit Grade II, making it the exception.

Grade II furcation involvement means there is horizontal bone loss into the furcation area that does not extend all the way through to the opposite side. You can probe into the furcation, but you cannot pass the probe completely through to the other side. This pattern often corresponds to a two-wall infrabony defect in the furcation, and radiographs may show involvement of two walls. It is not a through-and-through defect; that would be characteristic of a Grade III furcation, where the defect communicates from one side to the other. So the statement describing it as a through-and-through defect does not fit Grade II, making it the exception.