Introduction. Bruxism is to press or grind teeth against each other in non-physiologic cases, when an individual does not swallow or chew. If not treated, teeth problems, stress, mental disorders, frequent night waking, and headache is expected. This research aimed to study the effect of hydroxyzine on treating bruxism of 2- to 14-year-old children admitted to the clinic of Bandar Abbas Children Hospital.

Methodology. In this clinical trial, 143 children with the ages between 4-12 years were admitted to the Children Hospital and were divided randomly into test and control groups. The test group consisted of 88 hydroxyzine-treated children and the control group consisted of 55 children who used hot towels. Both groups were examined in some stages including the pre-test stages or the stage before starting treatments at two, four, and six weeks and four months after stopping the treatment. The effects of each treatment on reducing bruxism symptoms were assessed by a questionnaire. The data were analyzed by using SPSS in descriptive statistics, t-test, and ANOVA.

Results. As far as bruxism severity was concerned, the results showed a significant difference between the test group members who received hydroxyzine and the control group members who received no medication. T-test results showed a statistically significant difference between the test and the control groups in the second post-test (four weeks later) (p. value ≤ 0.05). Mean of the scores of bruxism severity in the test group has changed significantly in the post-test (at two weeks, four weeks, and six weeks later) as compared to the pre-test. Whereas, as far as the response to the treatment, no significant difference was recorded between the control group and the test group 4 weeks after the treatment.

Discussion. The results showed that prescribing hydroxyzine for 4 weeks had a considerable effect in diminishing bruxism severity between the test groups.