Objective. To characterize the closed-mouth temporomandibular joint (TMJ) disc-condyle relationship in a population of individuals who sought hospital services for temporomandibular disorders (TMD). Methods. Two hundred and twenty-four TMJ magnetic resonance images (MRIs) of 112 patients were assessed in all spatial planes to classify disc position with respect to the condyle in a closed-mouth position. Results. Disc displacement (DD) was present in 62.1 and superior disc position in 29.9 of the patients. Position could not be determined in 8 of the cases. Among DD, pure anteriorized position was the most common condition (34.4), with different combined translational and rotational displacements in all the other joints (27.7). Conclusion. There is a wide biological variability in disc position in closed mouth among patients seeking for TMD advice. Getting deeper into the correlation with clinical symptoms is recommended to refine the potential relevance of any diagnostic and management strategies based on the imaging evaluation of TMJ disc position.

Purpose. A possible relationship between sleep bruxism (SB) and several sleep disorders has been suggested in children, which could influence sleep quality and quality of life. This study aims to assess such correlations in a large sample of school children.Methods. Parents of 741 consecutive children aged between 8 and 12 years filled the Sleep Disturbance Scale for Children (SDSC). It evaluated 45 items grouped in 8 components: duration of night-time sleep, sleep latency, bedtime problems, sleep quality, night awakenings, nocturnal symptoms, morning symptoms, and daytime sleepiness. An item evaluating parental-reported tooth grinding was also included. Correlation analysis was performed between parental-reported tooth grinding and all the other items.Results. A significant correlation between parental-reported tooth grinding and several sleep disorders concerning bedtime problems, night awakenings, nocturnal symptoms, and morning symptoms has been found. In general, correlation strength of significant pairs was low, ranging from 0.092 (sleep apnea) to 0.234 (movement while falling asleep).Conclusions. Parental-reported tooth grinding in children is correlated, even if weakly, with some sleep disorders concerning the sphere of bedtime problems, night awakenings, nocturnal symptoms, breathing symptoms, and morning symptoms. Further studies are needed to confirm these findings, with particular regard to the consistency of correlation outcomes between the parental reports and the sleep laboratory measures.