Abstract: PURPOSE: To explore the electroencephalogram (EEG) changes after occlusal trauma in rats. METHODS: Health Wistar rats were divided into 2 groups: traumatic occlusion group (1-day, 3-day, 7-day, 14-day, 28-day group) and control group. The electrodes were inserted in the hippocampus of anesthetized rats guided by stereotaxic apparatus of brain and then the hippocampal EEG were recorded during sleep. Data were analysed by SPSS 17.0 software package for ANOVA. RESULTS: The δ waves were increased and the frequency and amplitude of EEG were significantly reduced in 1-day traumatic group(P<0.05); The waves were decreased and the frequency and amplitude of EEG were significantly increased in 3-day traumatic group(P<0.05). There was no significant difference compared with the control group. The δ waves were decreased in 7-day and 14-day traumatic group and the frequency and amplitude of EEG were significantly increased (P<0.05). The indexes in the 28-day traumatic group returned to normal. CONCLUSIONS: Occlusal trauma can change the EEG of the rat during sleep. It mainly affects the deep sleep, and reduces sleep quality.

Key words: Occlusal trauma, Hippocampus, Electroencephalogram