[Analysis of the correlation between chewing side preference and disc displacement types and clinical symptoms in patients with anterior disc displacement of temporomandibular joint].

To analyze the clinical symptoms and types of disc displacement of patients with anterior disc displacement (ADD) of temporomandibular joint (TMJ) and to explore the correlation between chewing side preference (CSP) and the clinical symptoms and types of disc displacement of ADD patients. This was a cross-sectional study of the ADD patients diagnosed by clinical symptoms and MRI findings of TMJ in the Department of Stomatology, General Hospital of Chinese PLA from January 2018 to December 2019. A total of 111 ADD patients [33 males and 78 females, aged(31.0±10.9) years old] were included. The patients were divided into two groups according to whether they had CSP: non-CSP group (=40) and CSP group (=71). The clinical symptoms and types of ADD were observed and recorded. According to the specific side of CSP in the CSP group, the patients were further divided into the ipsilateral side and the contralateral side of CSP. The pain, TMJ sounds and the ADD types were also observed. square test was used to compare the pain, TMJ sounds, limited mouth opening and ADD types of the two groups. Binary Logistic regression model was used to analyze the correlation between CSP and clinical symptoms and ADD characteristics. The incidence of pain in the CSP group [89% (63/71)] was significantly higher than that in the non-CSP group [70% (28/40)] (<0.05). In CSP patients, the incidences of pain and joint sounds on the ipsilateral side of CSP were significantly higher than that on the contralateral side (<0.05). MRI showed that the incidence of bilateral ADD in the CSP group [58%(41/71)] was significantly higher than that in the non-CSP group [37%(15/40)] (<0.05).There were significant differences in the incidences of no disc displacement (DD), anterior disk displacement with reduction(ADDwR) and anterior disk displacement without reduction (ADDwoR) between ipsilateral and contralateral joints of the CSP patients (<0.05). There were no significant differences in the incidences of no DD, ADDwR and ADDwoR between left and right joints of the non-CSP patients (>0.05). The incidence of ADDwoR in ipsilateral side of the CSP patients was significantly higher than that in contralateral side (<0.05). Pain (=3.375) and the side of disc displacement (=2.278) in patients with ADD were positively correlated with CSP (<0.05). The clinical symptoms and types of disc displacement between patients with and without CSP were significantly different. The incidences of pain and bilateral disc displacement in the CSP group were significantly higher than those in the non-CSP group. In addition, the incidences of pain, TMJ sounds and anterior disk displacement without reduction on the ipsilateral side of patients with CSP were significantly higher than those on the contralateral side. The pain symptoms and side of disc displacement were positively related to CSP.