The prevalence of TMD in orthodontic patients prior to treatment at NCKUH in southern Taiwan. National Cheng Kung University Hospital.

Orthodontic treatment is considered one of the risk factors for temporomandibular disorders (TMD). However, TMD may occur before orthodontic treatment. The purpose of this study was to investigate the prevalence of TMD in orthodontic patients prior to treatment. The samples consisted of 508 patients (214 males and 294 females) at the National Cheng Kung University Hospital (NCKUH) in southern Taiwan. Ages ranged from 6 to 56 years. TMD signs were recorded by clinical examination prior to treatment. The overall prevalence of TMD was 26.6%. The prevalence was slightly higher in females (27.2%) than males (24.8%). However, the difference was not statistically significant. The prevalence of TMD in children (ages 6-17) and adults (ages 18-56) was 16.5% and 43.6%, respectively. The difference was statistically significant. Distribution of TMD signs was joint sounds (32.3%), muscle or joint pains (32.3%), muscle or joint pains (32.3%), mouth opening less than 35 mm (18%), combination of two signs (16.5%) and combination of three signs (0.8%).