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In the early years of my general dentistry practice I recall that on one occasion after twisting over in an awkward position while sitting and treating a maxillary posterior tooth in a reclined patient I was unable to sit up without severe pain in my lower back. In fact, I could not get up and had difficulty continuing work the rest of the day.

The web documentation suggests that this type of back pain experience is not unique to dental clinicians. The practice of dentistry is often associated with back problems as evidenced by the number of reports of dentists and hygienists that have pain at some point in their careers. And this is not a trivial problem. Work burnout and disability are associated with musculoskeletal disorders and back pain. (Gorter RC. Work stress and burnout among dental hygienists. Int J Dent Hyg. 2005 May;3(2):88-92.)

But what is the actual scientific literature with respect to the incidence and prevalence of back pain of clinicians practicing dentistry (e.g. hygienists, dentists, and assistants)? And what are the precipitating or predisposing factors (such as age, gender, and ergonomics, workload, time in practice, etc.) that may contribute to musculoskeletal problems? To review the research addressing this problem this author systematically assessed the available literature via pubmed and medscape with the search terms ‘dentists with back pain’, ‘dentistry with backpain’, ‘musculoskeletal disorders with dentists’, ‘musculoskeletal disorders with hygienists’, and ‘dental with ergonomics’.

What was found were a number of studies from different countries (e.g. Iran, Sweden, Poland, and Australia, South Africa, Nigeria) that addressed these and other questions related to the problem of musculoskeletal disorders in dentistry.

One such study comes out of Australia. In 2006, Leggat and Smith reported in the Australian Dental Journal on dentists in Queensland who completed a self-report questionnaire on musculoskeletal pain. (Leggat PA, Smith DR. Musculoskeletal disorders self-reported by dentists in Queensland, Australia. Aust Dent J. 2006 Dec;51(4):324-7) This study, which included a total of 285 subject questionnaires, revealed that the problem of pain from work related musculoskeletal disorders or MSD was significant for the respondents that returned the survey (73%). As reported, in the prior 12 months approximately 87% of subjects reported at least one MSD symptom. The most prevalent problem was neck pain (57.5%), followed by lower back pain (53.7%), and pain in the shoulder (53.3%).

All of these pain problems were reported to have interfered with the clinicians daily activities. In fact, one in 10 dentists had taken leave because of the MSD in the prior 12 months and over 37% had sought medical advice or treatment for an MSD during that time. The average sick time related to an MSD was 11.5 days. These data underscore the serious nature of musculoskeletal disorders and their effect on the practice of dentistry.

Comparative studies assessing differences between dental hygienists and dentists are very limited and there are virtually no quality studies addressing dental assistants, either directly or via comparative analysis with the other professionals involved in dental treatment.

However, in a systematic review of the literature by Hayes, Cockrell, and Smith published in the International Journal of Dental Hygiene, 2009 (Hayes M, Cockrell D, Smith DR. A systematic review of musculoskeletal disorders among dental professionals. Int J Dent Hyg. 2009 Aug; 7(3):159-65) the authors looked at studies where dentists were compared with hygienists for work related musculoskeletal disorders. What they found was that the prevalence of general musculoskeletal pain reports (including back, neck, hand and wrist) varied widely (64% to 93%) and that differences in the type of pain reported depended on the discipline of the practitioner (i.e. hygienist or dentist). For example, back (36-60%) and neck (19-85%) pain was mostly reported by dentists while hand and wrist regions were the most prevalent regions of pain reported by dental hygienists (60-69%).

As suggested above, studies that have looked at potential gender differences in the reporting of musculoskeletal disorders suggest that female dentists and hygienists experience different pain problems than dentists. Further, there may be gender differences related to the intensity of reported pain. In at least one study female dentists complained of pain more frequently than their male counterparts. (Memarpour M, Badakhsh S, Khosroshahi SS, Vossoughi M. Work -related musculoskeletal disorders among Iranian dentists. Work. 2012 Sep 13. [Epub ahead of print]) Memarpour and colleagues also report that a significantly higher rate of pain and the number of MSDs were found to be related to the number of years worked and the degree of ergonomic exercise the clinician experienced during their work time. In their study the most common type of pain reported was for the shoulder (44.2%) followed by neck (31.8%) and the back (29.9%). And dentists who worked ‘inclined’ had much greater pain than those who did not.

Memarpour’s findings are consistent with those of another study that also assessed the number of years in practice and work position in relation to MSDs. Kierkio and colleagues from the Department of Dentistry Propaedeutics, Medical University of Białystok, Białystok, Poland, assessed 220 dentists via questionnaire for work related musculoskeletal disorders (Kierklo A, Kobus A, Jaworska M, Botuliński B. Work-related musculoskeletal disorders among dentists - a questionnaire survey. Ann Agric Environ Med. 2011 Jun;18(1):79-84). They report that 92 percent of surveyed dentists experienced an MSD with neck problems being the most commonly reported pain (47%) followed by the back. Interestingly about 29% of dentists reported that they had also experienced finger problems with 23% hip, 18% knee pain, and 15% elbow pain. The number of years in practice was significantly associated with the onset of MSDs. In this case a standing work position (versus an ‘inclined’ position, see above) was also found be significantly associated with an MSD. The lack of rest breaks was also found to be significantly related to report of an MSD.

Valachi and Valachi provide a general review of studies addressing the ergonomic mechanisms that may lead to musculoskeletal disorders (Valachi B, Valachi K. Preventing musculoskeletal disorders in clinical dentistry: strategies to address the mechanisms leading to musculoskeletal disorders. J Am Dent Assoc. 2003 Dec;134(12):1604-12). They report that the studies that have been reported include those that have investigated the relationship between biomechanics associated with the seated working posture, twisting of the trunk, and working in one position for prolonged periods.

They conclude that there are some studies that have confirmed the importance of operator flexibility and core strength in reducing MSDs and that successful strategies to prevent these problems may include those that address deficiencies in the clinician’s position, posture, flexibility, strength, and ergonomics.

Given this, one would think that there would be a number of efficacious therapies available for managing MSDs associated with dental practice. As noted by at least one author, interventions that have been suggested and utilized have focused on including static muscle activities such as postural modification, exercise, and equipment designed to facilitate ‘neutral’ posture. However, as these authors: Books and Klemm note, most of these approaches have not demonstrated significant reductions in the reported rates of pain. They conclude that elimination of static muscle activity rather than modification of posture is the critical issue in preventing pain, fatigue, and injury.

This author was not able to identify any randomized controlled trials of interventions (such as those listed above) aimed at reducing back pain in dental personnel. However an excellent resource for therapies that may be helpful in managing MSDs can be found on the Web at the following: http://www.dentistrytoday.com/ergonomics/1114. In this article published in ‘Dentistry Today’, authors T Delopez, D Pompile, and R Delopez present an excellent overview (titled: ‘Open up and relieve back pain) of the many exercises that dental personnel can utilize to relieve back pain (accessed 1/31/13). There are excellent descriptions of treatments with accompanying pictures.

What is now necessary is for researchers to provide randomized controlled trials evaluating different interventions that have been recommended for improving MSDs in dental personnel. This type of research has been completed in other technical fields, for example in assessing upper body pain and the incident of MSDs among computer operators and therapies, with the exercises showing significant effectiveness (Rempel DM, Krause N, Goldberg R, Benner D, Hudes M, Goldner GU. A randomised controlled trial evaluating the effects of two workstation interventions on upper body pain and incident musculoskeletal disorders among computer operators. Occup Environ Med. 2006 May;63(5):300-6). Dentistry needs this type of validation of exercises for MSDs as well.

Submitted by Jeff Burgess DDS MSD