The Epidemiology of Bruxism in Relation to Psychological Factors

The aim of the present study was to establish the prevalence of sleep/awake bruxism among young students in Transylvania and to correlate the presence of this muscle activity with behavioral variations. This analytical, observational, cohort, cross-sectional, and prospective study involved 308 volunteers aged between 19 and 30 years of different nationalities, all students of the “Iuliu Hațieganu” University of Medicine and Pharmacy in Cluj-Napoca, Romania. Subjects were asked to complete an anonymous questionnaire which was structured in five sections. The results obtained from the questionnaires were analyzed separately for sleep bruxism and for awake bruxism. We did not find any statistically significant correlation between awake bruxism or sleep bruxism and age (p = 0.30 and p = 0.37, respectively), sex (p = 0.44 and p = 0.48, respectively), or nationality (p = 0.55 and p = 0.67, respectively). Only a high degree of stress and frustration (p = 0.035 and p = 0.020) was observed in European subjects except for the Romanians and the French, likely related to the difficulties of adapting to the language and lifestyle in Romania. Female sex was statistically significantly associated with an increased level of stress (p = 0.004), duty-related depression (p = 0.006), and duty-related anxiety (p = 0.003). Stress and anxiety can be favorable factors in the appearance of both types of bruxism; however, depression is associated only with awake bruxism.

The Association between Emotional Stress, Sleep, and Awake Bruxism among Dental Students: A Sex Comparison

Psychosocial factors may play an important role in the etiology of sleep and awake bruxism. The purpose of this study was to assess the relationship between emotional stress and bruxism in male and female dental students at various stages of their education. Dental education in Israel is based on a six-year curriculum, divided into three stages: pre-medical studies (yr. 1–2), manual skills (yr. 3–4), and clinical experience (yr. 5–6). Each stage requires different capabilities and skills. Questionnaires regarding psychological state (SCL-90) measuring depression, anxiety, and somatization as well as stress evaluation questioners (Perceived Stress Scale questionnaire 14) were completed by 387 dental students in the 1st to 6th years. Sleep and awake bruxism were evaluated based on the respondent’s awareness. During the manual stage of studies, a significant increase was identified, albeit with weak correlations, between stress scales, depression, anxiety, somatization, and the prevalence of awake bruxism, particularly among males. Only in females was sleep bruxism correlated with emotional parameters, whereas no significant difference in sleep bruxism was observed in males throughout the stages of the study. The manual years of dental education were found to be linked to higher levels of emotional distress and awake bruxism, particularly in men. Sleep bruxism, on the other hand, was not directly linked to emotional factors, implying a distinct etiology.

Is sleep bruxism related to the levels of enzymes involved in the serotonin synthesis pathway?

Objectives This exploratory research aimed to evaluate the levels of tryptophan hydroxylase 1 (TPH1) and aromatic l-amino acid decarboxylase (DDC), which play an important role in the serotonin synthesis pathway, in individuals with sleep bruxism (SB) diagnosed using audio–video polysomnography (vPSG) and compare them with that of individuals not presenting with SB. Materials and methods The study included adult patients hospitalized in the Department and Clinic of Internal Medicine, Occupational Diseases, Hypertension and Clinical Oncology at the Wroclaw Medical University. The participants underwent a single-night vPSG for the evaluation of the SB parameters. Peripheral blood samples were also collected from them for estimating the serum levels of TPH1 and DDC. Results A total of 105 patients (80 women and 25 men) were included in the study. All the patients were Caucasians and aged 18–63 years (mean age: 33.43 ± 10.8 years). Seventy-five patients (71.43%) presented with SB, of which 50 (47.62%) had severe SB, while the remaining 30 patients (28.57%) did not. No statistically significant differences in TPH1 and DDC levels were observed between the individuals with SB and without SB. A significant negative correlation was found between tonic SB episodes and DDC levels (p = 0.0012). Other correlations between the SB parameters and the levels of the studied enzymes were statistically insignificant (p > 0.05 for all comparisons). Conclusions The levels of the enzymes that are crucial for serotonin synthesis (TPH1 and DDC) did not seem to influence SB. Clinical relevance This study provides important insights for further research on the relationship between the serotonin pathway and SB, which should take into account not only the process of serotonin synthesis but also the effect of serotonin-dependent neurotransmission on SB.

Variability of sleep bruxism—findings from consecutive nights of monitoring

Objectives To determine sleep bruxism (SB) behavior during five consecutive nights and to identify correlations between SB episodes per hour (SB index) and sleep-time masseter-muscle activity (sMMA). Material and methods Thirty-one participants were included in the study. Of these, 10 were classified as sleep bruxers (group SB-1) and nine as non-sleep bruxers (group non-SB). The bruxism status of these 19 patients was identified by means of questionnaires, an assessment of clinical symptoms, and electromyographic/electrocardiographic data (Bruxoff® device). The remaining 12 participants were also identified as bruxers, but based exclusively on data from the Bruxoff device (group SB-2). Data analysis included descriptive statistics and Spearman’s correlation to assess the relationship between the SB index and sMMA. Results Participants in group SB-1 showed an overall mean SB index of 3.1 ± 1.6 and a mean total sMMA per night of 62.9 ± 38.3. Participants in group SB-2 had an overall mean SB index of 2.7 ± 1.5 and a mean total sMMA of 56.0 ± 29.3. In the non-SB group, participants showed an overall mean SB index of 0.8 ± 0.5 and a mean total sMMA of 56.8 ± 30.3. Spearman’s correlation yielded values of − 0.27 to 0.71 for the correlation between sMMA and SB index. Conclusions The data revealed variable SB activity and the absence of a reliable correlation between sMMA and the SB index. Clinical relevance The high variation in SB activity and lack of correlation between sMMA and the SB index should be considered when diagnosing SB. Trial registration Clinical Trials [NIH], clinical trial no. NCT03039985.