Enjoying a long career in clinical dental hygiene can be a challenge with the high incidence of musculoskeletal disorders (MSDs) faced by dental hygienists. Dental hygienists continue to experience up to a 92% prevalence rate of MSDs despite extensive research on and coverage of work-related MSDs.1-3 The majority of MSD symptoms in dental hygiene occur in the upper extremities and neck region.
Signs and Symptoms
Signs of MSDs include a decrease in range of motion, protection of body area, decreased grip strength, and the eventual loss of muscle function and most often appear in the upper extremities. The most pervasive manifestation is related to either nerve compression or musculotendinous (tendon) overuse. Nerve symptoms include pain, tingling, numbness, and burning in the nerve distribution that may lead to weakness over a period of time. Tendon involvement may cause pain, inflammation, swelling, tenderness, and weakness due to pain. Musculoskeletal areas of concern for the dental hygienist include the neck, shoulder, arm, hand, wrist, fingers, thumbs, and back. MSDs are not the result of a single event but occur from gradual or chronic development over weeks, months, or years.4
Musculoskeletal health can be affected by the design of the workstation and instruments, work process, environment, organization of work, and characteristics of the individual.5 Work factors are categorized into three etiological groups of risk factors: biomechanical, psychosocial, and personal. Biomechanical risk factors caused by work tasks are identified as repetitive motion, awkward and static posture, force, and vibration. Psychosocial factors include precision work, high perceived workload, time pressures or schedules, lack of job control, and lack of teamwork. Psychosocial factors encompass the clinician’s interpersonal skills in presenting a pleasant, friendly, caring, and professional environment while maintaining patient comfort.6 Physical work conditions consist of the work station, work space, lighting, noise, and equipment used during work (including instruments). Personal factors include size and medical history as well as personal stress, family responsibilities, personal work style, and previous exposures.
Problem Solving Approach
The problem solving approach is a systematic method in developing an ergonomic plan. This approach includes identifying factors to be analyzed, ranking factors, summarizing and recommending solutions, and implementing and evaluating the plan.7,8 Ideally, an ergonomic plan is a proactive endeavor, rather than a reactive course of action based on musculoskeletal discomfort. Risk factors can be identified via checklists, data collections sheets (click here to see Figure 1 for an example), videotapes, and observations. Risk factors and interventions then need to be prioritized to control or eliminate the risk factors. Solutions need to be selected, implemented, and evaluated continuously to create a successful ergonomic plan. This approach requires assessing the outcome of interventions and, if not effective, identifying and implementing an alternative solution to the problem until the risk factor is controlled or eliminated.
Individual factors such as worker size, stress, role overload, and work-family responsibilities may contribute to the development of MSDs. Some risk factors may not be modifiable, such as previous exposure and medical history, therefore, the focus needs to remain on modifiable risk factors. The first step in developing an ergonomic plan is identifying any awkward postures and MSD risk factors such as force or vibration, and musculoskeletal symptoms of pain, numbness, or tingling. The clinician’s posture should be assessed by another hygiene coworker. Psychosocial factors should also be considered such as job satisfaction, endurance, work hours, and career growth
Stress has a strong correlation with MSDs and should be addressed by each dental hygienist. Self-reflection can reveal personal factors of emotions, stresses, and thoughts that influence work performance. Muscle tension and pain in the neck and shoulder areas associated with daily stressors may contribute to musculoskeletal disorders such as tension neck syndrome or trigger points among other MSDs.9 Dental hygienists are often frustrated by the lack of time to adequately complete their jobs.10
Many dental hygienists report difficulty in managing multiple home and family roles, which may contribute further to personal stress levels.9-11 Role overload is when stress from a job spills over into stress at home. Hall and Gordon9 suggest that married women with part-time jobs may be more susceptible to role overload than women who are employed full time because they are trying to fulfill tasks of both a mother and worker. These difficulties may be exacerbated by having young children and little spousal support.12
Clinicians with hobbies like knitting, latch hooking, crocheting, carpentry, quilting, and gardening use similar muscles groups as those used during dental tasks. Engaging in such hobbies may contribute to the musculoskeletal strain of dental hygienists’ work from the accumulation of risk exposures throughout the day particularly when hobbies are performed without adequate time for recovery.
Workstation Design and Work Process Factors
Some risk factors cannot be totally eliminated in the delivery of dental hygiene services, such as repetitive hand motions for debridement and polishing. Technology and computer integration require additional repetitive motion of fingers. Ultrasonic scalers minimize force needed for debridement but can add to the risk factor of repetition and awkward posture. Finger motion and a continuous brush-like stroke used during ultrasonic scaling increases repetitive motion of specific body parts, such as the finger and arm. The biomechanics of dental hygiene require precision work and high neck muscle activity with head/neck flexion. Hand muscle activity and pinch force can be reduced with the use of fulcrums during instrumentation. Therefore, hygienists should use various fulcrums to gain access and effective instrumentation while maintaining neutral posture.14
Dental hygienists will jeopardize good posture and work practices to provide quality care. Clinicians need to be self-aware of postures that are not neutral, which contribute to musculoskeletal disorders.14 Dental hygienists without assistants are not able to effectively use the suction, mirror, and instruments like an ultrasonic scaler, curing light, or sealant applicator. Dry environment sealant application necessitates suction during application and curing, eliminating indirect vision as an option, causing the hygienist to work in an awkward posture to maintain visibility. Dental hygiene assistants can contribute to the musculoskeletal health of dental hygienists by providing suction and maintaining a clear field during ultrasonic scaling and sealant application.
Dental instrument, equipment, and supply manufacturers have been making adjustments and redesigns to better fit dental professionals’ needs to reduce MSD symptoms in dental professionals. Wet environment sealants, magnification loupes, and various hand instrument designs provide interventions to an ergonomic problem. For example, clinicians need to select instruments that not only fit their hand size but that can also be effectively manipulated in the patient’s oral cavity.
Dental hygienists need to reveal the basis of their awkward posture and subsequent MSD symptoms or awkward posture in order to develop an effective ergonomic plan. For instance, a clinician may identify an awkward wrist posture caused by difficulty adapting instruments to the posteriors. If an area cannot be accessed due to the patient’s anatomy or inability to open wide, the clinician may choose a smaller diameter instrument or use a different instrument, such as a Gracey 15/16 or a Gracey 17/18, to gain access for effective instrumentation. Each patient has different anatomical and oral access issues. Through continuous problem solving and self-assessment, the hygienist may need to alter techniques on individual patients by identifying the risk factor of awkward posture, finding and implementing a solution, and evaluating for neutral posture and effective instrumentation.
Posture can be enhanced through the selection of properly adjusted magnification loupes. Adjustments should meet the dental hygienist’s physical needs including working distance, declination angle in which the eyes are declined, depth of field (the ability to see near and far working objects), and field size. With proper adjustments, the hygienist who typically flexes the neck extensively will decrease the amount of flexion and possibly reduce musculoskeletal symptoms. There are a variety of loupes with different powers of magnification and lenses on the market including through-the-lens and flip-up-capability.
- Anton D, Rosecrance J, Merlino L, Cook T. Prevalence of musculoskeletal symptoms and carpal tunnel syndrome among dental hygienists. Am J Ind Med. 2002;42:248-257.
- Lalumandier JA, McPhee SD. Prevelance and risk factors of hand problems and carpal tunnel syndrome among dental hygienists. J Dent Hyg. 2001;75:130-134.
- Werner RA, Hamann C, Franzblau A, Rodgers PA. Prevalence of carpal tunnel syndrome and upper extremity tendonitis among dental hygienists. J Dent Hyg. 2002;76:126-132.
- Atwood MA, Michalak C. The occurrence of cumulative trauma disorders in dental hygienists. Work. 1992;2(4):17-31.
- Ylipaa V, Szuster F, Spencer J, Preber H, Benko SS, Arnetz BB. Health, mental well-being, and musculoskeletal disorders: a comparison between Swedish and Australian dental hygienists. J Dent Hyg. 2002;76:47-57.
- Shenkar O, Mann J, Shevach A, Ever-Hadani P, Weiss P. Prevalence and risk factors of upper extremity cumulative trauma disorders in dental hygienists. Work.1998;11:263-275.
- Kroemer KHE, Grandjean, E. Fitting the Task to the Human. London: Taylor and Francis; 2001.
- Warren N. Work stress and musculoskeletal disorder etiology: The relative roles of psychosocial and physical risk factors. Work. 2001;17:221-234.
- Westgaard RH, Aaras A. Postural muscle strain as a causal factor in the development of musculoskeletal illness. Appl Ergons.1984;15:162-174.
- Anderson MA . EADS: Ergonomics Affinity Design System. Work. 2000;15:113-119.
- Michalak-Turcotte C. Controlling dental hygiene work-related musculoskeletal disorders: the ergonomic process. J Dent Hyg. 2000;74:41-48.
- Rolander B, Bellner A. Experience of musculo-skeletal disorders, intensity of pain, and general conditions in work—the case of employees in non-private dental clinics in a county in southern Sweden. Work. 2001;17:65-73.
- Hall DT, Gordon GV. Career choices of married women: Effects of conflict, role behavior, and satisfaction. J Appl Psychol. 1973;58:42-48.
- Greenhaus JH, Beutel NJ. Sources of conflict between work and family roles. Acad Manage Rev. 1985;10(1):76-88.
From Dimensions of Dental Hygiene . September 2005;3(9):18, 20-21.