The effect of chewing gum on the rate of en-masse space closure: A randomised controlled trial.

AIM: To evaluate the effect of chewing gum on the rate of space closure, oral hygiene, pain during space closure and appliance breakage in patients undergoing fixed appliance therapy. DESIGN: A prospective, single-centre, two-arm, parallel, double-blinded randomised controlled trial. SETTING: Orthodontic unit of a privately funded hospital, Chennai, India. PARTICIPANTS: In total, 28 participants were randomly allocated into a chewing gum group (CGG) (n = 14) or a control group (CG) (n = 14). METHODS: Baseline data were collected at the start of retraction (T0), at 4 weeks (T1), 8 weeks (T2) and 12 weeks (T3) after the start of retraction. Rate of space closure, pain, oral hygiene and appliance breakage were assessed at T1, T2 and T3. Data were analysed using an independent t-test with P < 0.05 considered to be statistically significant. RESULTS: The mean rate of space closure in the CGG was 0.9 +/- 0.2 mm/month and 0.8 +/- 0.2 mm/month in the CG (mean difference 0.1mm/month +/- 0.16; 95% confidence interval -0.055-0.26). In both the groups, oral hygiene became worse between T0 and T3. At T0 and T1, participants in the CGG reported less pain at 24 h and 7 days when compared to the CG (P < 0.05). At T2 and T3, participants in the CGG reported less pain at 0 h, 24 h and 7 days when compared to the CG (P < 0.05). Appliance breakage in both groups was minimal, with an odds ratio of 0.7 (95% CI 0.1-3.8) and was similar (P = 0.66). CONCLUSION: There was a minimal increase that was clinically not significant in the rate of space closure with chewing gum. Chewing gum ensured better oral hygiene, helped alleviate pain and had no effect on appliance breakage during space closure.