Objective:
Since bruxism is related to respiratory events and RPE increases respiratory capacity, the objective of this study is to evaluate the possible reduction of bruxism after RPE therapy.
Method:
This prospective randomized controlled clinical pilot study is in progress, with 6 children who completed their RPE and 23 children currently in treatment (8-14 years old, 8 boys, 21 girls). These patients were seeking treatment for transverse maxillary deficiency (5 mm or more) at the orthodontics department of the University of Montreal. Patients underwent an ambulatory polysomnography before (T0) and after expansion (T1). All patients answered behavorial, anxiety and diagnotic sleep questionnaires at those visits.
Result:
The preliminary results show a significant interaction between groups (control/bruxers) and before/after treatment (p=0.02, ANOVA repeated measures), where the mean rhythmic masticatory muscle activity index of bruxers decreased from 2.4 ±0.3 before to 0.9±0.1 after rapid palatal expansion (p=0.059, paired t-test). There is no difference between groups and before/after treatment for sleep and respiratory variables (Snoring index, apnea/hypopnea index, total sleep time, sleep efficiency, sleep stage 1,2 and REM sleep), however, sleep stage 3 increased for bruxers after treatment (p=0.02, paired t-test).
Conclusion:
These preliminary results, though promising, require additional subjects to support the link between the reduction of bruxism following RPE therapy.