Epidemic Trend Of Temporomandibular Disorders In Mainland China:A Systematic Review And Meta-analysis

Background: Temporomandibular disorders(TMDs)is the fourth largest oral disease and the third chronic painful disease after tension headaches and back pain.TMDs affects the temporomandibular joint and masticatory muscles,which causes harm to the function of maxillofacial system.At present,there is no large-scale epidemiological survey of TMDs in China,and the results of existing surveys are also different.Therefore,it is necessary to carry out a systematic review and quantitative analysis of the existing original literatures to determine the epidemic trend of TMDs,which helps to formulate effective preventive measures and improve national awareness of TMDs.Objective : The study intends to assess the prevalence of temporomandibular disorders and its clinical signs in mainland China,which provides theoretical support on health policy formulation.Materials and methods: Search strategies were conducted in 7 electronic databases and the reference lists from potentially relevant studies were searched manually.Only observational studies that met the eligibility criteria were selected.STROBE statement was used to evaluate the quality of the included studies.Kappa's test was used to test consistency between researchers.Stata12.0 and RevMan5.3 software were used to conduct data analysis.Results:28 articles that met the eligibility criteria were included in this review and meta-analysis.The prevalence of temporomandibular disorders was 31 %(95% confidence interval [CI],25.9-36.7).The most prevalent sign was temporomandibular joint sounds(18%,95% CI: 15.3-21.9)followed by abnormal jaw movements(13.8%,95% CI: 9.9-18)and pain(9.1%,95% CI: 6.5-11.5).The prevalence of TMDs in female was 32.4%(95% CI: 26.5-39),while 30.1%(95% CI: 24.2-36.7)in male and a significant difference was observed between males and females(P<0.05).Compared to male(7.4%,95% CI: 5.6-10.7),female was more vulnerable to pain(9.9%,95% CI: 7.4-13.8),which showed statistical difference(P<0.05).The prevalence of TMDs increased significantly over time from 23.1% up to 37.9%.Meanwhile the detection rate of pain increased continuously from 3.8% to 11.5%.Although joint noise and abnormal mandibular movements showed no continuous changes over time,they generally increased.The detection rate of TMDs in juveniles was 25.4%(95% CI: 11.5-34.2)and 33.8%(95% CI: 23.7-45.9)in adults,with adults more susceptible(P < 0.05).The detection of TMDs showed difference diagnosed by different criteria.Meanwhile,the prevalence of TMDs was highest in central-south China(42.5%),and the lowest in northwest China(28.1%).Conclusions: The prevalence of temporomandibular disorders is as high as 31% in mainland China,which shows an obvious upward trend.The most prevalent sign is joint sound followed by abnormal mandibular movement and pain.And there're differences among sexes,regions,survey times,ages,genders and diagnostic criteria.Therefore,effective measures according to the prevalent characteristics of TMDs are required to enhance the national awareness and oral health care among Chinese.