Objective To explore the effect of osteopontin( OPN) in the temporomandibular joint( TMJ) of rats subjected to chronic sleep deprivation( CSD). Methods Rats were subjected to CSD using the modified multiple platform method( MMPM). A total of 180 male 8-week-old Wistar rats were randomly divided into two groups( n = 90 per group) : the control( CON) group and chronic sleep deprivation( CSD) group. The two groups were equally divided into three subgroups( n = 30 each) according to the observation time points(...