STATEMENT OF PROBLEM: Rhythmic masticatory muscle activity, including sleep 
bruxism (SB), can be induced in healthy individuals by experimental esophageal 
acidification, which plays an important role in the pathogenesis of 
gastroesophageal reflux disease (GERD). However, no robust evidence supports the 
association between SB and GERD.
PURPOSE: The purpose of this study was to investigate the association between SB 
and GERD.
MATERIAL AND METHODS: Forty-five individuals were eligible to participate in 
this observational transversal study at the Gastroenterology Service of the 
Clinical Hospital of Porto Alegre, Brazil. The participants were classified into 
2 groups, those with and without GERD, according to the Montreal Criteria and 
pH-metry/endoscopy findings. The diagnosis of SB was not assessed in a sleep 
laboratory but was based on self-report plus clinical inspection, according to 
the minimal diagnostic criteria of the American Academy of Sleep Medicine. The 
Lipp Stress Symptom Inventory was used to evaluate self-perceived stress. 
Univariate and multiple logistic regression analyses were performed with SB as 
dependent variable and GERD, sex, age, body mass index, and stress as predictors 
(α=.05; 90% power).
RESULTS: The study population included individuals with SB without GERD (13.3%) 
and individuals with SB with GERD (31.1%). In participants with GERD, the 
prevalence of SB was 73.7%. Only the variable GERD was significantly associated 
with SB (P=.017; odds ratio 6.58; 95% confidence interval 1.40-30.98), although 
adjusted for stress and age.
CONCLUSIONS: Sleep bruxism is prevalent in GERD patients, and GERD is highly 
associated with SB.