Inflammatory complications following third molar surgery are a concern of patients. Dexamethasone, one of
the corticosteroids, possesses an anti-inflammatory property that can reduce inflammation. However, there is no consensus
on an appropriate administration. This study evaluated the anti-inflammatory outcomes of 4 mg dexamethasone given
by pre-operative submucosal injection after the surgical removal of third molars. A split-mouth, randomized, triple-blind,
placebo-controlled study was carried out with 17 participants (34 impacted teeth) having bilateral identical lower third
molar impaction. Submucosal injection of either 4 mg dexamethasone or placebo was given after anesthetization
of the inferior alveolar nerve according to random assignment. The time interval between the first and second operation
was a 4week period. Single surgeon, assessor, and data analyst were arranged and they did not know of drug use.
Onset and duration of local anesthetic were collected. On postoperative days 1, 2, 3 and 7, pain intensity was
recorded using a visual analog scale. At baseline and postoperative days 1, 3 and 7, swelling and maximal mouth
opening were measured. No effect of dexamethasone on swelling and mouth opening was detected when compared
to control. However, dexamethasone injection group showed significantly less pain than control at every time points,
p<0.05. The quality of life in the physical domain was better in dexamethasone injection group than control. For third
molar surgery, 4 mg dexamethasone did not demonstrate a benefit in anti-swelling or improve mouth opening.
However, it significantly reduced pain and improved quality of life.