The aim of the investigation was to study the frequency of pain, ache and discomfort in the musculoskeletal system among dentists, above all concerning headache, cervical and shoulder pain and further, to find possible correlations between these symptoms and various working positions and different working actions. A questionnaire was answered by 359 dentists (90.8%). Of those who answered the questionnaire 72% had pain and discomfort from either the neck, shoulders or headaches. Only 60 dentists had no pain or discomfort. Concerning the male dentists, the investigation revealed that younger dentists had pain and discomfort in the neck, shoulders and headaches to a greater extent than the older dentists. Younger female dentists had a significantly higher frequency of pain and discomfort in the neck and headaches than older colleagues. The results showed that dentist who positioned the patient carefully so that a direct view gained had a significantly lower frequency of headaches. Of the 359 dentists 55% mostly used the mirror to facilitate a direct view. From the answers it was clear that those dentists who did not have discomfort in the upper locomotor system used the mirror more often than those who did suffer discomfort.