Prevalence of musculoskeletal muscle disease and its correlation with workload among dentists

  Objective  To investigate the prevalence of musculoskeletal disorders (MSDs) among dentists, and explore its association with their workload.

  Methods  In April 2020, a cross-sectional survey was conducted with the musculoskeletal disorders questionnaire. The survey included the basic information of dentists, the prevalence of MSDs in the main parts of the body, the degree of subjective fatigue and possible factors related to workload. The possible influencing factors of MSDs were analyzed by χ² test and logistic regression.

  Results  A total of 656 dentists from 27 provinces or municipalities completed the questionnaire. Among them 614 questionnaires were valid and the effective response rate was 93.6%. In the past 12 months, the prevalence of MSDs in any part of the dentists' body was 82.4%, with the highest in neck (75.2%), followed by wais(t 50.8%). The average weekly working days of dentists in the past 12 months, the past 7 days and March 2020 were(5.3 ±0.8)d, (4.8 ±1.6)d and(3.3 ±1.9)d, respectively. The prevalence of MSDs in any part of the body in the past 12 months(82.4%)was higher than that in the past 7 days(67.8%) and that in March(48.9%). Multivariate logistic regression analysis showed that the risk of MSDs increased to 1.45 times (P < 0.01)at any part and 1.55 times in the neck(P < 0.01) respectively with increment of working hours by 1 day per week. The manpower shortage(OR=1.82) and old age (OR=1.7, aged 36-45 years vs. aged 35 years)were also the risk of MSDs at any part (P < 0.05). Work break was a protective factor, compared with the dentists without break, with the risk of MSDs of dentists with 1-2 times break only 0.57 and 0.55 in neck and waist, respectively (P < 0.01 or 0.05), and the risk of the dentists with more than 2 times break was only 0.40 times, 0.46 times and 0.55 times in any part, neck and waist, respectively (P < 0.05). The dentists who had sometimes or frequently overtime work weekdays and weekends had higher risk of MSDs in the waist, and the OR was 1.59 and 2.07, respectively (P < 0.01). The dentists who had no assistant while operating had higher risk of MSDs in the waist(OR=1.80), compared with whom having assistant(P < 0.01). The prevalence of MSDs was positively associated with the degree of fatigue of dentists at end of work(P < 0.01).

  Conclusions  The dentists had higher prevalence of MSDs. Measures should be taken to reduce their workload and working hours, and increase the number of work break. In addition, we should pay attention to the training of dentists and their assistants.