Sandbox: Reddy

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Aravind Kuchkuntla, M.B.B.S[2]

Pathophysiology

Pathogenesis

• Necrotizing ulcerative gingivitis causes necrosis of the gingival crest which is described as "punched out" ulcerated papillae resulting in gingival bleeding and pain.
• NUG affects the interdental and marginal soft tissue and has minimal osseous involvement when compared to periodontitis.

Microscopic Pathology

• The features characteristic of NUG on microscopic examination include neutrophil rich, necrotic, and spirochetal infiltration zones are unique to NUG.
• The biopsy of the gingiva under the electron microscopy demonstrate four zones and include:
  • Bacterial zone: This zone demonstrates many different morphological types of high bacterial load, including the presence of spirochetes.
  • Neutrophil rich zone: Below the bacterial zone, a neutrophil rich zone is demonstrated.
  • Necrotic zone: This zone demonstrates disintegrated cells, with the presence of spirochetes and fusiform bacteria.
  • Spirochete infilteration zone: The zone demonstrates tissues infiltrated by spirochetes which are present in high number. Absence of other other bacteria is characteristic.

Causes

NUG is a polybacterial infection and the exact causative organisms are not identified, however the following organisms have been identified in most of the patients. The following is a list of organisms are associated with NUG, the presence of these organisms doesnot always help to make the diagnosis of NUG.

• Prevotella intermedia
• Fusobacterium sp
• Treponema - T. vincentii and T. buccalis
• Selenomonas sp.

Risk Factors

The following risk factors predispose patients to develop NUG:

• Acute psychological stress
• Immune suppression
• Smoking
• Malnutrition
• Pre-existing gingivitis
• Trauma
• Poor oral hygiene

Diagnosis

History and Symptoms

To make the diagnosis of NUG the traid of interproximal necrosis, bleeding, and pain must be present. Absence of any one of the features rules out the diagnosis of NUG.

More common symptoms

• Gingival bleeding
• Severe gingival pain

Less common symptoms

• Lymphadenopathy
• Bad breath-halitosis
• Fever
• Malaise