Which characteristic is NOT associated with Stage III and IV periodontitis?

In the context of Stage III and IV periodontitis, a clinical attachment level of less than 5 mm is not characteristic of these advanced stages of the disease. In fact, Stage III and IV periodontitis typically involve significant clinical attachment loss, often exceeding 5 mm. The hallmark features of these stages include substantial progression of tissue destruction, resulting in notable loss of attachment, with attachment levels usually much lower than 5 mm.

Stage III is defined by the presence of significant attachment loss of 3 mm or more, while Stage IV may involve even greater loss and often results in tooth mobility due to structural support issues. The other characteristics mentioned—such as tooth loss from periodontal disease, probing depths greater than 6 mm, and greater than 33% bone loss—are indeed representative of the severe destruction and instability seen in advanced periodontitis stages. These features reflect the severity of the disease, emphasizing the substantial tissue damage and loss of bone support that occurs as periodontitis progresses.