What occurs in a class III furcation compared to a class II furcation?

In a class III furcation, the probe passes completely through the furcation area, indicating involvement of the interradicular region between the roots of a multi-rooted tooth. This classification signifies a significant loss of periodontal attachment in the furcation area, allowing for a complete passage of the probe, which reflects the extent of periodontal disease.

In contrast, a class II furcation indicates partial loss of bone support, where the probe can enter the furcation area but does not pass completely through. This distinction is crucial for diagnosing the severity of periodontal disease and planning appropriate treatment. The presence of a class III furcation denotes more advanced periodontal damage compared to a class II furcation, leading to different clinical approaches for management and therapy.