## 4 Discussion  
This is the first study that has investigated a comprehensive comparison of MSD and occupational parameters between dentists and dental assistants. Previous studies focused either on MSD occurrence in dentists or general dentistry or conducted limited comparisons between dentists and dental assistants with regard to evaluated body regions or sample size [1; 4; 7; 16; 17; 25; 26]. The comparison of the prevalence of MSD in this study revealed that more dental assistants reported complaints than dentists in all queried body regions. Significant differences in the most affected body regions (neck, shoulders, wrist/hands, upper back, lower back and feet/ankles) were found for all time periods (Figure 1). Furthermore, the weekly prevalence revealed that almost 90.0% of the dental assistants work while in pain, whereas more than 30.0% of the dentists reported no complaints. In total, these results show that dental assistants are significantly more affected by MSD than dentists. In total, the comparison of the current findings show that dental professionals have higher 7-day, 12-month and lifetime prevalence in MSD than the general population in Germany [27]. The results are partly in line with comparable studies [6; 18; 25; 26]; for example, [PERSON] et al. [18] only found significant higher prevalence rates in the lower limb (knee, leg and foot), while the prevalence of MSD in the shoulder and scapula were fewer in dental assistants than dentists. Similarly, in the current study, significant differences were found in the foot, while, in the knee, a non-significant trend with a 4.0% higher prevalence in dental assistants was revealed (Figure 1). In contrast to the abovementioned study [18], however, the dental assistants stated that they experienced significantly more frequent annual shoulder pain than dentists. Other studies that have investigated differences in MSD between dentists and dental assistants either did not meet scientific criteria, due to small sample sizes [25; 26], or queried different time intervals and used different comparison groups [6]. As the proportion of women among dental assistants is known to be significantly higher than among dentists [11] and evidence exists showing that women report pain more frequently than men [8; 9; 10], the prevalence analysis was additionally conducted with a homogeneous gender group (only female participants). The reported gender distribution in the field of dentistry is also represented in the current study; only two dental assistants were men (99.4% female), while 149 men worked as dentists (61.7% female). When applying the analysis to only the female participants, the differences in pain prevalence were still present but reduced (Figures 1 and 2). This is in accordance with [PERSON] et al. [6], who analyzed only female dental professionals and determined that dental assistants had the significantly highest prevalence of low back pain of all dental occupations. In summary, gender may have a slight effect on the prevalence of MSD as the differences did narrow when considering only female dental workers. Potential influencing factors can be differences in the work requirements and habits, since ergonomically different work routines and physical activity can have an impact on the occurrence of MSD [28; 29; 30; 31]. In this sense, dentists manage to integrate preventive measures into their professional routine more frequently. As can be seen in Table 2, the dentists indicated significantly more often that they take \"regular breaks between treatments\", perform \"corrective exercises between treatments\" and engage in \"participation in an ergonomics training course\". In addition, the proportion of dentists who perform physical activities, for example, strength training, on a regular basis is significantly higher than the proportion of dental assistants who perform these activities. Further reasons could be that dental treatment units are predominantly denti-oriented.