Statistics show up a significant pourcentage of musculoskeletal disorders (MSD) : 64 % to 93 % of dental surgeons complain of pain in various parts of the body (HAYES, 2009), and 28 % of occupational illnesses in this profession are MSD, whereas doctors suffer for only 4,5 % (CARCDSF, 2009).
The operator's stool is too often accused of being the cause of these disorders, whereas this is in fact rarely the case.
OUR DENTAL EQUIPMENT IS NOT ADAPTED TO OUR WAY OF WORKING
Facing the huge prevalence of our musculoskeletal disorders, it's time to re-question everything.
AT WHICH DISTANCE SHOULD WE WORK ?
The ergonomical approach consists of adjusting the surroundings and the tools we use, thereby minimizing human stress factors and increasing the quality of our work and our efficiency. What we call ergonomical is therefore what has been adjusted. Too often, in a contrary approach, we let the patient sit down on the dental chair, we then tilt the backrest at random, and we finally try to adapt ourselves. This way, we create a paradoxical situation in which the patient, the dental nurse and the dental surgeon, are all in a bad position. For evident reasons of precision, in ergonomics it is always the distance « eye-task » which dictates the working position, particularly in dental surgery. This distance, set at 25cm., is a compulsory preliminary and conditions our posture and all our movements. We have to learn how to settle our patients in a way which bears in mind this working distance. This is the whole challenge of dental ergonomics.
At the end of the nineteen fifties, a whole new work concept was elaborated by Dr. Daryl Beach, DDS. He found a favourable echo to his concept in Japan after the second World War, where huge needs instigated the development of equipment capable of producing mass quality treatment with a minimum of fatigue. Nowadays, this concept is very widespread in Japan, India and Thailand, where it is lectured in the dental schools. Dr. Beach used his proprioception to develop what he calls the « concept zero ». He sits down and positions himself comfortably, puts his fingers at the shortest working distance allowing him to see the smallest details, and defines this as the zero position. He then positions the patient and the instruments around him, placing them where he feels the most at ease, with the help of his proprioception. This seems to correspond to the definition of ergonomics, where the equipment is adjusted to suit the practioner and not the contrary.
INDUSTRY HAS LONG SINCE ADJUSTED THEIR EQUIPMENT. IT IS HIGH TIME WE APPLY THIS NOTION TO OUR OWN PROFESSION. WE NEED TO RETHINK OUR WAY OF WORKING AND FORGET OUR PRECONCEPTIONS
We have to replace the old-fashioned methods which lead to our aches and pains and to our stress, and instigate avant-garde strategies based on proof. This is called Evidence Based Dentistry.