## 3 Results
### Peculiarities of Ergonomics in the Work of Dental Specialists  
These peculiarities involve the most important ergonomic factors for the health of dental specialists: the working position of the specialists, work chair type, position of the working tools, and breaks during the working day. The majority of dentists (82.8%) were more likely to work while sitting in a reclining chair, while the others (17.2%) chose a standing position while the patient was sitting in a chair. A total of 98.5% of orthodontists usually worked in a sitting position, and only 1.5% preferred to work in a standing position. Dentists and orthodontists who worked in a sitting position were less likely to experience back pain during work (\(p=0.006\)). The most popular work chairs in both groups were individually adjustable with a backrest and saddle type. Dentists and orthodontists who used an individually adjustable chair with a backrest experienced back pain during work significantly less than specialists who used other types of chairs (\(p=0.006\)). They also experienced fewer shoulder girdles (\(p=0.008\)) and neck pain (\(p=0.003\)). In addition, orthodontists experienced less frequent shoulder girdle pain using a saddle-type chair during work (\(p=0.002\)). The use of \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline \multicolumn{1}{c}{**Problem**} & & & & & & & & & & & & \\ \hline Every day. & 38 (12.1) & 48 (15.2) & 51 (16.2) & 4 (1.3) & 32 (10.2) & 12 (3.8) & 12 (3.8) & 10 (3.2) & 9 (2.9) & 62 (19.7) & 64 (20.3) & 20 (6.3) \\ \hline At least once & 103 (22.7) & 95 (02.0) & 112 (35.6) & 13 (4.1) & 67 (21.3) & 34 (10.8) & 30 (9.5) & 19 (6.0) & 95 (30.2) & 92 (29.2) & 129 (4.0) & 12 (3.8) \\ \multicolumn{1}{c}{\(n\) (\%)} & & & & & & & & & & & \\ \hline Less than once & 63 (20.0) & 67 (21.3) & 68 (21.6) & 28 (8.9) & 80 (25.4) & 51 (16.2) & 33 (10.5) & 37 (11.7) & 112 (35.6) & 87 (27.6) & 76 (24.1) & 27 (8.6) \\ \multicolumn{1}{c}{\(n\) (\%)} & & & & & & & & & & & \\ \hline Less than once & 74 (23.5) & 73 (23.2) & 69 (21.9) & 64 (20.3) & 75 (23.8) & 128 (40.6) & 111 (35.2) & 99 (21.4) & 74 (23.5) & 51 (16.2) & 41 (13.0) & 78 (24.8) \\ \multicolumn{1}{c}{\(n\) (\%)} & & & & & & & & & & & \\ \hline Never & 37 (11.7) & 32 (10.2) & 15 (4.8) & 206 (65.4) & 61 (19.4) & 90 (28.6) & 129 (41.0) & 150 (47.6) & 25 (7.9) & 23 (7.3) & 5 (1.6) & 178 (56.5) \\ \multicolumn{1}{c}{\(n\) (\%)} & & & & & & & & & & & \\ \hline \hline \end{tabular} N–number of cases  
\end{table} 
Table 1: Frequency of pain and ailments experienced by dentists and orthodontists during and after work. a non-adjustable chair especially increased the risk of back (\(p=0.002\)) and shoulder girdle (\(p=0.015\)) pain. It was found that respondents who indicated that their office chair moved smoothly in the work area had a lower incidence of back pain (\(p=0.004\)). The majority of dentists (67.9%) and orthodontists (85.5%, \(p=0.027\)) kept their working tools at a distance of 40-50 cm from themselves, whilst 18.1% of dentists and 14.5% of orthodontists held them closer than 20 cm. The other dentists placed the necessary tools more than 70 cm away from them. It was found that both dentists and orthodontists who kept the tools close to themselves were less likely to experience back (\(p=0.016\)) and shoulder girdle pain (\(p=0.039\)). While sitting, 43.3% of dentists and 29% of orthodontists considered the elbow joints to be bent less than 90 degrees at work and more frequently experienced neck (\(p=0.007\)), shoulder girdle (\(p=0.008\)), and lumbar (\(p=0.006\)) pain than those specialists who bent elbow joints at 90 degrees. Only 9.7% of dentists and 11.5% of orthodontists took their rest breaks after each patient, and about 30% of respondents had them several times a day. Others took breaks only occasionally (50.4% of dentists and 58.5% of orthodontists) or even did not take them (10.1% of dentists) at all. Specialists who took breaks between patients had statistically significantly less pain during and after work (\(p=0.003\)).