Background: The gold standard for the diagnosis of sleep bruxism (SB) is laboratory polysomnography (L-PSG) recording. However, many clinicians still define SB using patients’ self-assessment and/or clinical tooth wear (TW). The purpose of this cross-sectional controlled study was to compare the prevalence of TW, head-neck muscles sensitivity and Temporomandibular Disorders (TMD) between SB and non-SB patients diagnosed with L-PSG in a cohort of patient with sleep disorders (SD). Methods: 102 adult subjects with suspected SD underwent L-PSG recording to assess the presence of sleep disorder and SB. TW was clinically analyzed using TWES 2.0. The pressure pain threshold (PPT) of masticatory muscles were assessed using a Fisher algometer. Diagnostic criteria for TMD (DC/TMD) were used to evaluate the presence of TMD. SB self-assessment questionnaires were administered. TWES score, PPT, TMD prevalence and questionnaire results were compared between SB and non-SB patients. Results: 22 SB patients and 66 non-SB patients with SD were included. No significant differences emerged between groups in regards to TW, the PPT values, or SB’s self-assessment questionnaires as well the prevalence of TMD. Conclusion: in a SD population, TW is not pathognomonic of active SB and SB self-assessment is not reliable. There seems to be no correlation between SB, TMD and head/neck muscle sensitivity.

This review explores the emerging relationship between obstructive sleep apnea (OSA) and periodontal disease (PD), emphasizing shared inflammatory pathways, overlapping risk factors, and potential systemic health implications. Both conditions are characterized by chronic inflammation and oxidative stress, which independently contribute to cardiovascular disease, diabetes, and other systemic disorders. Evidence suggests a bidirectional relationship, with OSA-related hypoxia exacerbating periodontal tissue breakdown and PD-induced inflammation potentially influencing OSA severity. However, the causative nature of the relationship between OSA and PD remains uncertain, largely due to inconsistencies in diagnostic criteria, methodological variability, and study heterogeneity. This review highlights the essential role of systematic reviews (SRs) in synthesizing current evidence, identifying research gaps, and guiding future studies. To maximize their impact, SRs should adhere to rigorous methodological quality standards, improve transparency in data reporting, and address the heterogeneity of included studies. Future research should focus on longitudinal and interventional designs, standardize diagnostic protocols, and investigate biomarkers, oral microbiome profiles, and inflammatory mediators to elucidate the mechanisms linking OSA and PD. Multidisciplinary collaboration between dental and sleep specialists is crucial to advancing evidence-based strategies that improve patient outcomes and address the broader health implications of these often coexisting conditions.