What is a hallmark diagnostic finding in necrotizing ulcerative gingivitis (NUG)?

The hallmark diagnostic finding in necrotizing ulcerative gingivitis (NUG) is the presence of ulcerated "punched-out" papillae, along with significant pain and bleeding. This condition is characterized by the rapid onset of necrosis of the gingival tissues, which typically leads to the distinctive appearance of the gingival papillae being necrotized and appearing like they have been "punched out."

The pain associated with NUG is often intense, and bleeding can occur spontaneously or be triggered by touch. These clinical signs are critical for distinguishing NUG from other types of periodontal diseases.

While fever and lymphadenopathy may occur in some cases due to the systemic response to infection, they are not specific findings for NUG. Similarly, loss of periodontal attachment and alveolar bone support can be associated with various periodontal diseases but does not define NUG uniquely. The distinctive appearance of the ulcerated papillae, combined with clinical symptoms, makes it a hallmark finding for this condition.