A Clinical Observation About The Association Between Lasting Mouth Opening And Temporomadibular Joint Disorders

Objective:To expore the assoiation between the lasting passive opening and frequently active opening state and temporomandibular joint dysfunction, by the observation of80cases of oral molar root canal therapy patients (treatment time30-60minutes), which the change of temporomandibular joint function in the state before root canal therapy.after surgery and48hours of its review.Methods:For the survey.we selected80cases of clinical patients need root canal therapy.which temporomandibular joints without clinical dysfunction, the the Helkimo the clinical examination dysfunction index (DI) is0. By measure the jaw functional state of patients at the three time points (before root canal therapy, immediately after and48hours after surgery).including check the open type, bilateral joint snapping and tenderness situation, and draw DI index and record visual analogue scale(VAS) score. DI index and VAS score changes in the observed indicators of the lasting opening-induced temporomandibular joint change. And the samples were divided into gender groups, age groups, the maximum degree of opening group, treated teeth group, duration of treatment group, in order to observe the risk factors associated with the temporomandibular joint dysfunction.Results:7patients in the immediate postoperative period and within48hours after the DI index increased, accounting for8.75%of the total number of80cases observed object/the symptoms include:opening limited, lateral movement is limited, joint snapping, joint tenderness, muscle pain and jaw movement pain.The number of the postoperative VAS increased was17,21.25%of the total sample size, the patient complained of discomfort to muscle aches and headache. Grouped Comparison:DI index and VAS scores increased for the positive cases in a gender group, age group, the maximum opening degree group was not statistically significant:significant difference in VAS scores in the treatment time and treatment of teeth grouping (P <0.05).Conclusion:Molar root canal treatment with lasting mouth opening can induce TMD-related symptoms appear(8.75%). Gender group, age group, and maximum opening group are not reflected to the significant difference. Obtained in the treatment time and treatment of teeth grouping:root canal therapy of open longer easily lead to joint discomfort, and the second molars, root canal therapy than the first molar more likely to induce joint discomfort.