Identifying predictive factors for sleep bruxism severity using clinical and polysomnographic parameters: a principal component analysis

Is There a Relationship between Salivary Cortisol and Temporomandibular Disorder: A Systematic Review

BACKGROUND

This systematic review examines and evaluates the relationship between salivary cortisol levels and temporomandibular disorder (TMD) in young adult patients.

METHOD

Six databases-PubMed, Scopus, Web of Science, Google Scholar, ProQuest, and Cochrane Library-were utilized to screen eligible studies. A systematic search was performed based on PECO questions and eligibility criteria. The research question for this review was "Do salivary cortisol levels correlate with TMD in individuals aged 18-40?" The risk of bias for quality assessment was determined by the Cochrane tool. PRISMA guidelines were followed while performing this review.

RESULT

A total of fourteen studies were included in this review. Of these, eleven were observational studies (four cross-sectional and seven case-control), and three were randomized control trials. Eleven of the included studies presented a low to moderate risk in the qualitative synthesis. The total sample size of the included studies was 751 participants. The included studies suggest higher salivary cortisol levels in TMD patients than in healthy individuals.

CONCLUSIONS

The findings of this review indicate higher salivary cortisol levels in adult patients with TMD than in healthy controls. Thus, supportive psychological treatment and clinical modalities should be provided to patients with TMD. Moreover, higher-quality studies with low heterogeneity are required to support this finding.

Sleep architecture as a candidate for phenotyping sleep bruxism: A narrative physiological review

BACKGROUND

Sleep bruxism (SB), an oral behaviour in otherwise healthy individuals, is characterised by frequent rhythmic masticatory muscle activity (RMMA) during sleep. RMMA/SB episodes occur over various sleep stages (N1-N3 and rapid eye movement (REM)), sleep cycles (non-REM to REM), and frequently with microarousals. It currently remains unclear whether these characteristics of sleep architecture are phenotype candidates for the genesis of RMMA/SB.

OBJECTIVES

This narrative review investigated the relationship between sleep architecture and the occurrence of RMMA as a SB phenotype candidate.

METHODS

PubMed research was performed using keywords related to RMMA/SB and sleep architecture.

RESULTS

In non-SB and SB healthy individuals, RMMA episodes were most frequent in the light non-REM sleep stages N1 and N2, particularly during the ascending phase of sleep cycles. The onset of RMMA/SB episodes in healthy individuals was preceded by a physiological arousal sequence of autonomic cardiovascular to cortical activation. It was not possible to extract a consistent sleep architecture pattern in the presence of sleep comorbidities. The lack of standardisation and variability between subject complexified the search for specific sleep architecture phenotype(s).

CONCLUSION

In otherwise healthy individuals, the genesis of RMMA/SB episodes is largely affected by oscillations in the sleep stage and cycle as well as the occurrence of microarousal. Furthermore, a specific sleep architecture pattern cannot be confirmed in the presence of sleep comorbidity. Further studies are needed to delineate sleep architecture phenotype candidate(s) that contribute to the more accurate diagnosis of SB and treatment approaches using standardised and innovative methodologies.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

The Scientific Investigation Committee of the American Academy of Restorative Dentistry offers this review of the 2021 dental literature in restorative dentistry to inform busy dentists regarding noteworthy scientific and clinical progress over the past year. Each member of the committee brings discipline-specific expertise to coverage of this broad topical area. Specific subject areas addressed, in order of the appearance in this report, include COVID-19 and the dental profession (new); prosthodontics; periodontics, alveolar bone, and peri-implant tissues; implant dentistry; dental materials and therapeutics; occlusion and temporomandibular disorders; sleep-related breathing disorders; oral medicine and oral and maxillofacial surgery; and dental caries and cariology. The authors focused their efforts on reporting information likely to influence daily dental treatment decisions with an emphasis on future trends in dentistry. With the tremendous volume of dentistry and related literature being published daily, this review cannot possibly be comprehensive. Rather, its purpose is to update interested readers and provide important resource material for those interested in pursuing greater details on their own. It remains our intent to assist colleagues in negotiating the extensive volume of important information being published annually. It is our hope that readers find this work useful in successfully managing the patients and dental problems they encounter.

Circadian preference and its relationship with possible sleep and awake bruxism in adults assisted by the public health system

Modern lifestyle and social demands induce changes in sleep routines that may not meet individual circadian preferences (chronotype). Such changes may be associated with the development of unhealthy lifestyles and the emergence of diseases relevant to public health services, such as obesity, hypertension, and diabetes mellitus, as well as sleep bruxism (SB) and awake bruxism (AB). The present study aimed to assess the relationship between the evening, morning or intermediate chronotypes with the report of possible SB and AB in adult individuals assisted by the Family Health Strategy (FHS). The selection of participants was performed through probabilistic cluster analysis. The sample size (n = 384) was calculated to include a representative sample of the 52,628 adults registered in the FHS of a countryside city located in the Southeast Region of Brazil. The Morningness-Eveningness Questionnaire (MEQ) was used to determine the chronotype, and Questionnaire-Based Self-Reported Bruxism was used for identifying possible SB and AB. The following clinical and social-behavioral variables were also evaluated: age, sex, BMI, income, physical activity, schooling, alcohol consumption and smoking, chronic diseases and depression. Two logistic regression models were used: one for SB and one for AB. Possible SB was associated with female sex, lack of physical activity and income above 2 minimum wages. Regarding chronotype, a 19% reduction in the chance of possible SB was observed in morning individuals compared to evening individuals (p = .017). Possible AB was associated with younger individuals, smoking and depression. In conclusion, compared with the evening circadian preference, the morning circadian preference was associated with greater protection against possible SB in an adult population assisted by the FHS.