is therefore valid and novel, although a specific virus has yet to be isolated from oral
lesions.
Predisposing factors
Poor oral hygiene and a pre-existing gingivitis invariably reflect the patient's attitude
to oral care. Many young adults with NUG are heavy smokers. The effect of smoking
on the gingiva may be mediated through a local irritation or by the vasoconstrictive
action of nicotine, thus reducing tissue resistance and making the host more
susceptible to anaerobic infection. Smoking is obviously not a predisposing factor in
young children. In underdeveloped countries, however, children are often
undernourished and debilitated, which may predispose to infection. Outbreaks of
NUG in groups of subjects who are under stress has implicated emotional status as an
important predisposing factor. Elevated plasma levels of corticosteroids as a response
to an emotional upset are thought to be a possible mechanism.
It is conceivable that all the predisposing factors have a common action to initiate or
potentiate a specific change in the host such as lowering the cell-mediated response.
Indeed, patients with NUG have depressed phagocytic activity and chemotactic
response of their polymorphonuclear leucocytes.
Key Points
Necrotizing ulcerative gingivitis⎯clinical:
- yellow-grey ulcers;
- fusospirochaetal infection;
- possible viral aetiology;
- well-established predisposing factors.
Treatment
It is important at the outset that the patient is informed of the nature of NUG and the
likelihood of recurrence of the condition if the treatment is not completed. Smokers
should be advised to reduce the number of cigarettes smoked. A soft, multitufted
brush is recommended when a medium-textured brush is too painful.
Mouthrinses may be recommended but only for short-term use (7-10 days). Rinsing
with chlorhexidine (0.2% for about 1 min) reduces plaque formation, while the use of
a hydrogen peroxide or sodium hydroxyperborate mouthrinse oxygenates and
cleanses the necrotic tissues.
Mechanical debridement should be undertaken at the initial visit. An ultrasonic scaler
with its accompanying water spray can be effective with minimal discomfort for the
patient. Further, if NUG is localized to one part of the mouth, local anaesthesia of the
soft tissues can allow some subgingival scaling to be undertaken.
In severe cases of NUG, a 3-day course of metronidazole (200 mg three times a day)
alleviates the symptoms, but the patients must be informed that they are required to
reattend for further treatment.
Occasionally, it is necessary to surgically recontour the gingival margin