This cross sectional study examined the prevalence of, and some factors associated with MSDs among dental students, by means of an online questionnaire. To our knowledge, this is the first study to report on MSDs among dental students in UAE. The main limitation of this type of research is that participant’s answers may not reflect their actual actions; which may possibly introduce some level of response bias. Nevertheless, this bias was limited as much as possible by utilizing a survey proven to be valid and reliable tool for measuring the prevalence of MSDs.15 Additionally, only two dental colleges in the UAE out of four were included, this might have an impact on the generalizability of the findings. In this study, the dental students were asked to note the occurrence of musculoskeletal pain over the past 12 months, and the previous 7 days. The pain intensity and frequency were not evaluated in this study.
The results of this study showed that (68.3%) of the students reported symptoms of musculoskeletal disorders on the last year. This percentage is comparatively lower than studies reported by Khan and Chew,9 and Rabiei with his team;16 and higher than other studies reported by Marshall and his team,17 and Ahmadi Motemayel and her team.18 While similar percentage was reported by Finsen and co-workers,19 and Al-Ali and Hashim11 who found that the prevalence of musculoskeletal pain in the past 12 months was (68.9%) and (68.0%) respectively. In the current study, only dental students on their clinical stage of practice were recruited, that might explain the high prevalence of MSP among them due to the work posture of clinical-year's students.
Low-back pain occurrence in the past 12 months was the highest as stated by more than half of the students, whereas the incidence of pain in this region in the past 7 days was reported by more than one third. The high level of back pain might be due to holding a static load for long period of time, which in return might create more strain on dentists’ spine while delivering the dental care.2 This clearly indicates that there is not adequate support of the lumbar region when students rest on the dental stool and in fact ergonomic principles are underestimated. Therefore, adequate support of the lumbar region is very critical since it helps preserve the lumbar curve. As a result, muscle activity, disc pressure, in addition to the back and leg pain will be decreased.20
The neck pain in the past 12 months with prevalence of (52.5%) was the second most common reported anatomical region. This result supports the findings of similar previous studies in other countries like the findings of Al Wazzan and co-workers,21 and Varmazyar and co-workers,22 who suggested that pain were mainly localized in the back and in the neck. The substantial prevalence of pain in the neck in this study could be associated with repetitive work performed with a flexed neck and elevated and abducted arms.23 Even with their very short clinical experience, the high prevalence among undergraduate students suggests that the progression and deterioration of MSDs starts from the very beginning of the dentists' career life.20 Therefore, practicing dentistry while maintaining a proper working posture cannot be underestimated as it greatly reduces the risk of work-related musculoskeletal disorders.
According to this research, it is crucial to implement ergonomic rules in the clinics in order to adapt the students to the correct working position. Some examples of dental ergonomics are modifying the patient’s chair accordingly when working on different quadrants, keeping the instruments and the materials within a short distance for easy access, sitting straight with feet touching the floor, keeping the elbows below the level of the shoulders. These precautions reduce the fatigue and probability of developing MSDs.9 If not taken seriously, students will develop serious symptoms overtime which will interfere with their career negatively.
In this study, there were no statistically significant relation between gender, family history with trauma and MSP, which contradicts the findings of previous study conducted by Waersted and co-workers.24 The significant association between history of trauma and MSP in the current study is understandable. Individuals who experienced a traumatic injury to the neck, shoulder and lower-back were at risk to develop MSP.25 The insignificant association between other variables such as coffee consumption, exposure to smoking, and the use of computer is in agreement with Algarni and co-workers.25
Self-awareness and benefits of regular exercise are the needs of the hour. Around one-fifth of the participants do not exercise at all. This behavior might be a direct cause of MSP being more prevalent among clinical-years' students in this study. This finding was also supported by Hashim and Al-Ali26 who suggested that most of the dentists did not find as much time as they would like for exercise. According to a research done by de Carvalho and co-workers,27 which showed that regular exercise can help prevent work related musculoskeletal disorders and those who participate in any kind of sports activity experience less severe symptoms compared to those who are not physically active. Regular exercise may provide dental students with the required break from their heavy workload, which will recharge and strengthen their bodies. It will also provide mental relaxation from high psychosocial demands of the job.23 These effects probably interact to contribute to a better health status and in return will decrease the risk of MSP.28
According to this study, the time spent in the clinic significantly related to experiencing musculoskeletal problems, which is in accordance with previous studies conducted among dental professionals.3,21,29,30 This might be attributed the fact that dentistry demands high level of precision and it is often preferred with the arms unsupported and the cervical spine rotated and flexed forward.31 Additionally, holding static load for long duration may cause symptoms associated with the mask system.32 In a study carried out by Melis and co-workers,33 data suggest that MSD is prevalent in dental students of Italy as quickly as they start their clinical practice in the clinics. For this reason, it is highly recommended to educate the students about ergonomics throughout their clinical training periods in order to avoid the complications of MSD.33
The results of this study suggested a significant relationship between BMI and the prevalence of MSP, and this is consistent with the findings of Ahmadi Motemayel and co-workers,18 and Betterworth and co-workers.34 It’s worth noting that work related musculoskeletal disorders not only have negative psychological and social outcomes but also can become very extreme to the point that it is going to have a direct effect on work capacity and might even lead to an early job retirement.27 As a result, the evaluation of dental students’ knowledge about work related musculoskeletal disorders is very crucial.