Frequency of temporomandibular disorders and their correlation with improper operating posture in Iranian dentists

Abstract Objectives This study aimed to assess the frequency of temporomandibular disorders (TMDs) and their correlation with improper operating posture in Iranian dentists. Materials and Methods This cross-sectional study was conducted on 59 dentists practicing in Yazd city, Iran with improper operating posture according to the rapid upper limb assessment (RULA) tool (level 2 or higher). Neck pain and disability were evaluated by the neck disability index (NDI), and neck flexion and rotation were assessed by the flexion rotation test-active (FRT-A). The frequency of TMDs was evaluated by clinical examination and Fonseca’s questionnaire. Data were analyzed by the Fisher’s exact test and Spearman’s correlation test (alpha = 0.05). Results A significant correlation was noted between improper posture and TMDs in 23-28-and 29–34-year-old age groups, males and females, in dentists with less than 4 years of work experience, in general dentists, in participants working for a maximum of 38 hours/week and a minimum of 39 hours/week, those visiting a maximum of 3 patients or a minimum of 4 patients per shift, those not using a dental loupe, and those with a suitable dental unit according to their dominant hand (P < 0.05). A significant correlation was found between the RULA level and severity of TMDs in dentists (r = 0.476, P < 0.001). The NDI score had a significant direct correlation with the TMD score (r = 0.476, P < 0.001) while a significant inverse correlation was found between the FRT-A and TMD scores (r=-0.414, P = 0.023). Conclusion The frequency of TMDs and neck disability was higher in dentists with improper operating posture.