A study on job postures and musculoskeletal illnesses in dentists

Ergonomic Analysis of Dental Work in Different Oral Quadrants: A Motion Capture Preliminary Study among Endodontists

BACKGROUND

Dentists, including endodontists, frequently experience musculoskeletal disorders due to unfavourable working postures. Several measures are known to reduce the ergonomic risk; however, there are still gaps in the research, particularly in relation to dental work in the different oral regions (Quadrants 1-4).

METHODS

In this study (of a pilot character), a total of 15 dentists (8 male and 7 female) specialising in endodontics were measured while performing root canal treatments on a phantom head. These measurements took place in a laboratory setting using an inertial motion capture system. A slightly modified Rapid Upper Limb Assessment (RULA) coding system was employed for the analysis of kinematic data. The significance level was set at p = 0.05.

RESULTS

The ergonomic risk for the entire body was higher in the fourth quadrant than in the first quadrant for 80% of the endodontists and higher than in the second quadrant for 87%. For 87% of the endodontists, the ergonomic risk for the right side of the body was significantly higher in the fourth quadrant compared to the first and second quadrant. The right arm was stressed more in the lower jaw than in the upper jaw, and the neck also showed a greater ergonomic risk in the fourth quadrant compared to the first quadrant.

CONCLUSION

In summary, both the total RULA score and scores for the right- and lefthand sides of the body ranged between 5 and 6 out of a possible 7 points. Considering this considerable burden, heightened attention, especially to the fourth quadrant with a significantly higher ergonomic risk compared to Quadrants 1 and 2, may be warranted.

Prevalence of work-related musculoskeletal disorders among health care professionals: A systematic review

BACKGROUND

Work-related musculoskeletal disorders (WRMSDs) are one of the main causes of morbidity among healthcare professionals. It has various secondary consequences on productivity by diminishing the quantity and quality of work completed by the affected personnel, in addition to having a primary impact on the individual with pain and discomfort.

OBJECTIVE

The study aims to determine the overall prevalence rate of WRMSD among dentists, physiotherapists, and surgeons and also identify the commonly affected regions of the body about specific health care professions among each of the three professions, as recorded by the cross-sectional studies performed in various countries and regions of the world.

METHODS

A systematic search strategy was framed following the PRISMA guidelines based on the present inclusion and exclusion criteria. A critical search of articles was conducted during June 2020 in CINAHL (DOAJ), PubMed, Google Scholar Scopus, PEDro databases and SAGE journals.

RESULTS

Out of the 42 articles that met the eligibility criteria, there were 39 cross-sectional studies, 2 pilot cross-sectional surveys and 1 prospective cohort study with one-year follow-up. All studies included in this review used various survey tools for recording the demographic details and measuring the prevalence of WRMSDs and other outcome factors.

CONCLUSION

We conclude that all three health care professionals (dentists, physiotherapists and surgeons) are highly prone to develop WRMSDs with surgeons and dentists being more vulnerable when compared to physiotherapists. The lower back and neck are identified as the two most commonly affected regions among all three professionals.

Ergonomic risk factors and work-related musculoskeletal disorders in clinical physiotherapy

Objectives

The purpose of this study was to objectively quantify and evaluate the ergonomic risk of clinical physiotherapy practices and evaluate physiotherapists for work-related musculoskeletal disorders and pain.

Methods

Twenty-nine physiotherapists in the rehabilitation department of a large-scale tertiary hospital were recruited in this study. The sampling period lasted for 2 weeks for each physiotherapist and interval sampling was adopted to avoid duplication of cases. Therapist posture during physiotherapy was captured, tracked and analyzed in real time using structured light sensors with an automated assessment program. The quantification of ergonomic risk was based on REBA (Rapid Entire Body Assessment) and the RPE (perceived physical exertion) scores of the therapists were recorded before and after treatment, respectively.

Results

Two hundred and twenty-four clinical physiotherapy cases were recorded, of which 49.6% were high risk and 33% were very high risk, with none of the cases presenting negligible risk. The positioning (p < 0.001) of physiotherapist had a considerable impact on ergonomic risk and pediatric physiotherapy presented a higher risk to physiotherapists than adults (p < 0.001). The RPE score of physiotherapist after performing physiotherapy was greater than before physiotherapy and was positively correlated with the REBA distribution.

Conclusion

Our study creates an automatic tool to assess the ergonomic risk of physiotherapy practices and demonstrates unacceptable ergonomic risk in common practices. The high prevalence of musculoskeletal disorders and pains recommends that rehabilitation assistance devices should be optimized and standard ergonomic courses should be included in physiotherapists' training plans.

Prevalence of musculoskeletal disorders among dental healthcare providers: A systematic review and meta-analysis

Background: Work-related musculoskeletal disorders (MSD) are common in dentistry due to the prolonged static work involved during patient care, making dental health care personnel vulnerable to musculoskeletal complaints. We aimed to pool the prevalence estimates of MSD among various dental healthcare providers, including dentists, dental students, dental hygienists, and auxiliaries. Methods: A systematic search of five databases was performed (Scopus, Embase, CINAHL, Web of Science, Dentistry & Oral Sciences Source). The studies that reported the prevalence of MSD among dental healthcare workers and those written in English were selected. Screening and data extraction were performed by two review authors independently. Discrepencies were resolved by another review author. Risk of bias assessment was done using a nine-item questionnaire developed by Hoy et al. Pooled estimates were calculated using meta-analysis of proportions (random effects model). Results: Among the 3090 publications screened, 234 publications were included for full-text screening. Meta-analysis was performed for 89 estimates from 88 publications. Females showed significantly higher prevalence [OR = 1.42 (95% CI = 1.09-1.84); I ² = 66.02; N = 32]. The analysis yielded a pooled estimate of 78.4% (95% CI = 74.8-82). The meta-regression showed similar prevalence over the years (Coefficient: 0.001; P-value: 0.762). Conclusions: A high prevalence of MSD was noted among dental healthcare providers, with about seven out of ten having experienced MSD in the past. This emphasizes the need for awareness and adoption of appropriate ergonomic postures by dental healthcare providers from early in their careers to minimize work-related MSD.

Prevalence of musculoskeletal disorders among dental healthcare providers: A systematic review and meta-analysis

Background: Work-related musculoskeletal disorders (MSD) are common in dentistry due to the prolonged static work involved during patient care, making dental health care personnel vulnerable to musculoskeletal complaints. We aimed to pool the prevalence estimates of MSD among various dental healthcare providers, including dentists, dental students, dental hygienists, and auxiliaries. Methods: A systematic search of five databases was performed (Scopus, Embase, CINAHL, Web of Science, Dentistry & Oral Sciences Source). The studies that reported the prevalence of MSD among dental healthcare workers and those written in English were selected. Screening and data extraction were performed by two review authors independently. Discrepencies were resolved by another review author. Risk of bias assessment was done using a nine-item questionnaire developed by Hoy et al. Pooled estimates were calculated using meta-analysis of proportions (random effects model). Results: Among the 3090 publications screened, 234 publications were included for full-text screening. Meta-analysis was performed for 89 estimates from 88 publications. Females showed significantly higher prevalence [OR = 1.42 (95% CI = 1.09-1.84); I ² = 66.02; N = 32]. The analysis yielded a pooled estimate of 78.4% (95% CI = 74.8-82). The meta-regression showed similar prevalence over the years (Coefficient: 0.001; P-value: 0.762). Conclusions: A high prevalence of MSD was noted among dental healthcare providers, with about seven out of ten having experienced MSD in the past. This emphasizes the need for awareness and adoption of appropriate ergonomic postures by dental healthcare providers from early in their careers to minimize work-related MSD.

Evaluation of the ergonomic sitting position adopted by dental students while using dental simulators

Background/purpose

Ergonomics in dentistry encourages the work to be in an organized manner, where a dentist achieves highest performance with maximum comfort and minimum physical and psychological effort. The purpose of this study was to evaluate the ergonomic sitting position of dental students from third, fourth and fifth year undergraduate programs while they prepared teeth 46 and 27 as Black Class I preparation for amalgam using dental simulators.

Materials and methods

Ten students were randomly selected from each year for this study. Photos and videos were taken from them to record their sitting position as they performed a Black Class I amalgam preparation in Nissin simulators.

Results

It was found that more students had a poor ergonomic sitting position while working in mandibular area (60%, torso and neck angle; 53% knee-angle; 50% elbow-angle). When comparing the average score between maxilla and mandible within students of the same year, fourth year students had a significant difference in their average, with a better performance in maxilla (P ≤ 0.01). They also showed better performance in maxillary area compared to fifth-year students (P ≤ 0.008). The main reasons that the students presented as justification for their bad posture were little work time, lack of knowledge, not knowing how to use indirect vision, and poor comfort.

Conclusion

Every undergraduate year had a compromised sitting position, with the exception of fourth-year students when working in maxillary area. No correlation between undergraduate year and performance was found.

How Does the Use of an Intraoral Scanner Affect Muscle Fatigue? A Preliminary In Vivo Study

The purpose of this study was to evaluate muscle activation and fatigue in the operator during tooth preparation and intraoral scanning by simulating these tasks in two types of dental unit chair systems (UCS). Six participants were recruited, and the above tasks were simulated. Electrodes were placed on the skin over five types of muscles (arm, neck, and shoulder muscles), and the maximal voluntary contraction (MVC) was measured. Electromyography (EMG) was assessed during the simulation, and EMG values were normalized using MVC. The root mean square (RMS) EMG (%MVC) and muscle fatigue (%) were calculated. Owing to a lack of normal distribution of the data, Mann−Whitney U test and Kruskal−Wallis H test were performed for statistical comparison, and Bonferroni adjustment was performed for multiple comparisons (α = 0.05). There was no significant difference in RMS EMG between the two types of dental UCS (intraoral scanning, p = 0.237; tooth preparation, p = 0.543). Moreover, the RMS EMG and muscle fatigue were not significantly different between the two tasks (p > 0.05). There was significant muscle fatigue after the intraoral scanner use was simulated thrice (p < 0.001). It is necessary to refrain from performing continuous intraoral scanning and tooth preparation and to take appropriate rest to reduce the incidence of musculoskeletal disorders in dentists in clinical settings.

Satisfaction Factors with a Dental Unit Chair System in South Korea: A Dentist's Perspective

This study aimed to survey users’ satisfaction with a dental unit chair in order to highlight the elements affecting the dentist’s satisfaction. The questionnaire items were drawn up with seven components that constitute a dental unit chair, including the light, patient seat, foot controller, water fountain and cuspidor, monitor, bracket table and controller, and dentist chair. With these questionnaire elements, a pilot experiment was conducted to test the reliability, and reliability analysis was conducted. The scale reliability was checked using Cronbach’s alpha coefficient. Bartlett’s test of sphericity, the Kaiser-Meyer-Olkin (KMO) measure, and factor analysis were performed to test whether the items would constitute appropriate questionnaire items for the survey. The survey was conducted with 26 dentists with more than three years of clinical experience. A correlation analysis was conducted using Pearson’s correlation coefficient (PCC) (α = 0.05) to analyze the impact of the factors on the overall satisfaction with the dental unit chair. The items that were strongly correlated with the overall satisfaction score of the dental unit chair were the design and appearance quality of the dental unit chair (PCC = 0.781), its maintenance (PCC = 0.784), and the overall satisfaction with the water fountain and cuspidor (PCC = 0.703) (p < 0.05). Most of the questionnaire items could affect the overall satisfaction with the dental unit chair. Additionally, because the design and appearance quality, maintenance, and overall satisfaction with the water fountain and cuspidor may have the greatest impact on the overall satisfaction with the dental unit chair, the improvement of these elements may bring about the enhancement of the overall satisfaction.

A RULA-Based Comparison of the Ergonomic Risk of Typical Working Procedures for Dentists and Dental Assistants of General Dentistry, Endodontology, Oral and Maxillofacial Surgery, and Orthodontics

BACKGROUND

In general, the prevalence of work-related musculoskeletal disorders (WMSD) in dentistry is high, and dental assistants (DA) are even more affected than dentists (D). Furthermore, differentiations between the fields of dental specialization (e.g., general dentistry, endodontology, oral and maxillofacial surgery, or orthodontics) are rare. Therefore, this study aims to investigate the ergonomic risk of the aforementioned four fields of dental specialization for D and DA on the one hand, and to compare the ergonomic risk of D and DA within each individual field of dental specialization.

METHODS

In total, 60 dentists (33 male/27 female) and 60 dental assistants (11 male/49 female) volunteered in this study. The sample was composed of 15 dentists and 15 dental assistants from each of the dental field, in order to represent the fields of dental specialization. In a laboratory setting, all tasks were recorded using an inertial motion capture system. The kinematic data were applied to an automated version of the Rapid Upper Limb Assessment (RULA).

RESULTS

The results revealed significantly reduced ergonomic risks in endodontology and orthodontics compared to oral and maxillofacial surgery and general dentistry in DAs, while orthodontics showed a significantly reduced ergonomic risk compared to general dentistry in Ds. Further differences between the fields of dental specialization were found in the right wrist, right lower arm, and left lower arm in DAs and in the neck, right wrist, right lower arm, and left wrist in Ds. The differences between Ds and DAs within a specialist discipline were rather small.

DISCUSSION

Independent of whether one works as a D or DA, the percentage of time spent working in higher risk scores is reduced in endodontologists, and especially in orthodontics, compared to general dentists or oral and maxillofacial surgeons. In order to counteract the development of WMSD, early intervention should be made. Consequently, ergonomic training or strength training is recommended.

Poor neck posture and longer working duration during root canal treatment correlated with increased neck discomfort in dentists with <5-years' experience in endodontics

OBJECTIVE

This study investigated the effects of neck posture and working duration during each step of root canal treatment (i.e. opening the canal [OC], length determination, mechanical instrumentation, try main cone, and filling the root canal) on neck discomfort (ND) in dentists with <5-years' endodontic experience.

METHODS

Twenty-four dentists performed a one-visit endodontic treatment of an upper molar in a phantom head model. A video was recorded to evaluate the dentists᾽ neck postures using the Modified-Dental Operator Posture Assessment Instrument (M-DOPAI) and treatment duration. The M-DOPAI divides the dentists᾽ neck postures into three categories: acceptable, compromised, or harmful posture. The participants rated their ND using Borg᾽s CR-10 scale every 10 min. and at the end of each treatment step. The relationships between neck posture/treatment duration and Borg᾽s CR-10 scores were examined using partial correlation.

RESULTS

The number of compromised and harmful neck postures during the endodontic procedure (r = 0.43, P = .04) and treatment duration (r = 0.58 P = .005) significantly correlated with ND at the end of treatment. The number of compromised and harmful neck postures during the OC step (r = 0.75, P < .001) and the duration of the OC step (r = .70, P < .001) significantly correlated with ND at the end of the step.

CONCLUSION

Poor neck postures and long working duration during endodontic treatment correlated with ND among inexperienced dentists. Neck pain interventions should focus on neck postures and work duration during root canal treatment, particularly in the OC step.

A study on musculoskeletal complaints and working postures in pathology specialists in Iran

Background

Musculoskeletal disorders (MSDs) are one of the most common causes of occupational injuries and disabilities among health care workers. This study investigates the relationship between musculoskeletal complaints and pathologist postures in laboratories.

Method

In this cross-sectional study, 40 pathologists were evaluated. MSDs in different body segments of the participants were evaluated by Nordic questionnaire. For postural analysis, 20 min film was recorded while using a microscope by subjects. Posture analysis was done by the Rapid Upper Limb Assessment (RULA) method and their repetitive movements were scored. The data was analyzed by SPSS Version 11.5.

Results

The mean age and duration of employment of subjects was 36.57 ± 7.54 years and 6.50 ± 6.30 years, respectively. Most MSDs were found in neck (65%), wrist (57.5%), upper back (50%) and lower back (47.5%). The mean RULA grand score was higher in participants with upper back and shoulder pain. A statistically significant relationship was found between the mean RULA grand, the upper back pain (P = 0.02) and the wrist pain (P = 0.003), as well as between the mean RULA B, the neck pain (P = 0.02) and the lower back pain (P = 0.05). The results showed a significant relationship between mean weekly working hours and tight (P < 0.001), wrist (p = 0.01) and ankle (P = 0.008).

Conclusion

This study revealed high prevalence of MSDs among the pathologists. Therefore, performing ergonomic corrective actions is essential in order to improve their physical conditions at work.

Influence of design of dentist's chairs on body posture for dentists with different working experience

BACKGROUND

Musculoskeletal disorders (MSD) are a common health problem among dentists. Dental treatment is mainly performed in a sitting position. The aim of the study was to quantify the effect of different ergonomic chairs on the sitting position. In addition, it was tested if the sitting position of experienced workers is different from a non-dental group.

METHODS

A total of 59 (28 m/31f) subjects, divided into two dentist groups according to their work experience (students and dentists (9 m/11f) < 10 years, dentists (9 m/10f) ≥ 10 years) and a control group (10 m/10f) were measured. A three-dimensional back scanner captured the bare back of all subjects sitting on six dentist's chairs of different design. Initially, inter-group comparisons per chair, firstly in the habitual and secondly in the working postures, were carried out. Furthermore, inter-chair comparison was conducted for the habitual as well as for the working postures of all subjects and for each group. Finally, a comparison between the habitual sitting posture and the working posture for each respective chair (intra-chair comparison) was conducted (for all subjects and for each group). In addition, a subjective assessment of each chair was made. For the statistical analysis, non-parametric tests were conducted and the level of significance was set at 5%.

RESULTS

When comparing the three subject groups, all chairs caused a more pronounced spinal kyphosis in experienced dentists. In both conditions (habitual and working postures), a symmetrical sitting position was assumed on each chair. The inter-chair comparisons showed no differences regarding the ergonomic design of the chairs. The significances found in the inter-chair comparisons were all within the measurementerror and could, therefore, be classified as clinically irrelevant. The intra-chair comparison (habitual sitting position vs. working sitting position) illustrated position-related changes in the sagittal, but not in the transverse, plane. These changes were only position-related (forward leaned working posture) and were not influenced by the ergonomic sitting design of the respective chair. There are no differences between the groups in the subjective assessment of each chair.

CONCLUSIONS

Regardless of the group or the dental experience, the ergonomic design of the dentist's chair had only a marginal influence on the upper body posture in both the habitual and working sitting postures. Consequently, the focus of the dentist's chair, in order to minimize MSD, should concentrate on adopting a symmetrical sitting posture rather than on its ergonomic design.

Common errors in selecting and implementing pen-paper observational methods by Iranian practitioners for assessing work-related musculoskeletal disorders risk: a systematic review

Objectives. This study aimed to determine the types and frequency of pen-paper observational methods (OMs) used by Iranian practitioners and to identify their errors in selecting and implementing these methods. Methods. This was a systematic review and analytical study of papers in which the OMs had been used. Scientific databases were analyzed from September 1970 to September 2018. Errors were determined based on a list of wrong practices both in the selection and implementation of methods. Three ergonomists carried out the process of identifying errors independently. Results. The most frequently used methods were rapid upper limb assessment (RULA), quick exposure check (QEC) and rapid entire body assessment (REBA), respectively. Errors in selecting and implementing pen-paper OMs were 53.3 and 36.4%, respectively. Conclusions. Despite the abundant number of pen-paper OMs, Iranian practitioners use few of them. The high rate of errors can indicate a lack of knowledge and skills among practitioners for selecting and implementing OMs. The development of decision-making tools may help practitioners to select appropriate pen-paper OMs for assessing different types of tasks.

Effects of Line of Vision on Posture, Muscle Activity and Sitting Balance During Tooth Preparation

OBJECTIVES

Most dentists maintain awkward and restricted postures for prolonged periods that stress the body while providing direct patient care. Information about working posture must be analysed in a more systematic manner to provide a deeper understanding of the relationship between working posture and work-related musculoskeletal disorders (MSD). Therefore, the present study aimed to clarify the effects of different lines of vision during tooth preparation, such as the direct and the mirror view technique, on-body tilt (angle), muscle activity, and sitting balance, which may correlate with the reduction or prevention of MSD.

METHODS

A mannequin head with a maxillary right first molar embedded in a model was attached to the dental chair headrest. Two different techniques for tooth preparation were selected: direct view and mirror view. Muscle activity, body tilt (angle), and sitting balance were analysed as independent parameters.

RESULTS

Different tooth preparation techniques had a distinct influence on body tilt (angle), muscle activity, and sitting balance. The direct view technique resulted in significantly larger values for all parameters, except for the activity of the spinal column erector muscles than the mirror view technique.

CONCLUSION

Based on these results, the direct view technique for tooth preparation, which is used by most dentists in practice, imposes a burden on the lower back, shoulders, and neck of the dentist.

Prevalence of self-reported musculoskeletal disorders of the hand and associated conducted therapy approaches among dentists and dental assistants in Germany

Background

Dental professionals are subjected to higher risks for musculoskeletal disorders (MSDs) than other professional groups, especially the hand region. This study aims to investigate the prevalence of hand complaints among dentists (Ds) and dental assistants (DAs) and examines applied therapies.

Methods

For this purpose, an online questionnaire analysed 389 Ds (240female/149male) and 406 DAs (401female/5male) working in Germany. The self-reported data of the two occupational groups were compared with regard to the topics examined. The questionnaire was based on the Nordic Questionnaire (self-reported lifetime, 12-month and 7-day MSDs prevalence of the hand, the conducted therapy and its success), additional occupational and sociodemographic questions as well as questions about specific medical conditions.

Results

30.8% of Ds affirmed MSDs in the hand at any time in their lives, 20.3% in the last twelve months and 9.5% in the last seven days. Among DAs, 42.6% reported a prevalence of MSDs in the hand at any time in their lives, 31.8% in the last 12 months and 15.3% in the last seven days. 37.5% of the Ds and 28.3% of the DAs stated that they had certain treatments. For both, Ds and DAs, physiotherapy was the most frequently chosen form of therapy. 89.7% of Ds and 63.3% of DAs who received therapy reported an improvement of MSDs.

Conclusion

Although the prevalence of MSDs on the hand is higher among DAs than among Ds, the use of therapeutic options and the success of therapy is lower for DAs compared to Ds.

Development and validation of an instrument to assess adherence to occupational health protocols in dentistry

OBJECTIVES

The purpose of this study was the creation and validation of an instrument to evaluate adherence to occupational health protocols used in dentistry that arise from official regulations and international recommendations on infection control, biosafety, and occupational health in dentistry. Additionally, in May 2017 the effectiveness of the instrument was documented within the dental care clinics in the postgraduate area.

METHODS

The instrument was developed based on constructs of occupational health, infection control, and biosafety in dentistry, made up of 21 indicators of 5 dimensions called protocols. Using direct observation through 35 measurements during 1 week, adherence to occupational health protocols was evaluated in postgraduate residents within the clinical sections of endodontics/pediatric dentistry, periodontics, prosthodontics, and orthodontics.

RESULTS

The instrument presents an index of 0.88 in Cronbach's alpha analysis. There is a 34.4% adherence within the postgraduate dental clinic to the proposed occupational health protocols. The protocol with the highest adherence at 41.1% was the personal protection protocol. The periodontics section had a 52.9% observance of the proposed protocols and had the highest adherence to occupational health protocols.

CONCLUSIONS

The proposed instrument is valid and reliable to evaluate adherence to the proposed occupational health protocols within dental care clinics. Dental clinics must be inspected and evaluated to ensure adherence to infection control, biosafety, and occupational health protocols within routine dental practice.

Application of the Rapid Entire Body Assessment (REBA) in assessing chairside ergonomic risk of dental students

Introduction High prevalence of musculoskeletal disorders (MSDs) have been reported among operators in dentistry related to prolonged demanding and awkward operative tasks, in which non-neutral vertebral positions and risky joint articulations are adopted. The aim of the study was to investigate the feasibility and reliability of the application of the Rapid Entire Body Assessment (REBA) among dental students utilising three digital photographs of the operator to determine chairside ergonomic risk.Materials and methods Third-year dental students (n = 28) obtained profile, back and frontal digital photographs of student operators in a clinical session. REBA scorings were assigned per student utilising the photographs by student groups and independently by a physiotherapist. Statistical comparisons were done for both scorings.Results There was substantial interrater reliability (kappa = 0.625; p <0.001) and moderate concordance level (Kendall's Tau-b of 0.568; p <0.01) between the scores derived from students and staff. Medium- and high-risk students based on the REBA scores accounted for 64% and 75% of the class as determined by students and staff, respectively.Discussion The high percentage of medium-to-high-risk REBA values matched the prevalence of MSDs reported by dental students in the literature. Compared to staff, students with moderate reliability were able to produce REBA scores adequately.Conclusion REBA utilising digital photographs may be an easily applicable and moderately reliable tool for alerting static ergonomic risk for clinical dental students. Modification of at-risk behaviour early in training may limit the establishment of bad posture habits and aid in the prevention of MSDs during their clinical years and post-graduation.

SOPEZ: study for the optimization of ergonomics in the dental practice - musculoskeletal disorders in dentists and dental assistants: a study protocol

Background

Musculoskeletal disorders (MSD) are common among dental professionals. The most common areas affected are the trunk, neck, shoulders and wrists. Current evidence suggests that the causes of MSD can be found in the physical demands of the profession. Posture and movement during treatment is influenced by the arrangement of the treatment concept (patient chair, equipment and cabinets). It has not been investigated whether the ergonomic risk differs between the treatment concepts.

Methods

To evaluate the prevalence of MSD in dental professionals, 1000 responses will be collected from a nationwide (Germany) online questionnaire (mod. Nordic Questionnaire and mod. Meyer questionnaire). In order to assess the ergonomic risk of the treatment techniques used in the four treatment concepts, 3D movement analyses are carried out with inertial sensors. For this purpose, 20 teams of dentists and dental assistants from four dental fields of specializations (generalists, orthodontists, endodontists and oral surgeons) and a student control group will be recruited. Each team will execute field specific standardized treatments at a dummy head. Measurements are carried out in each of the four treatment concepts. The data will be analyzed using the Rapid Upper Limb Assessment (RULA) which will be modified for the evaluation of objective data.

Conclusions

On the basis of these investigations, a substantial gain of knowledge regarding work-related MSD in the field of dentistry and its potential biomechanical causes is possible. For the first time, objective and differentiated comparisons between the four treatment concepts are possible for different fields of dental specialization. Up to now, statically held positions of the trunk and proximal upper extremities, but also the repetitive movements of the hands have been considered a risk for MSD. Since both are included in the RULA, dental activities can be assessed in a detailed but also global manner with regard to ergonomic risks.

An Overview of REBA Method Applications in the World

The objective of this work is to review literature, worldwide, in which the Rapid Entire Body Assessment (REBA) ergonomic assessment method was applied and count the number of times that REBA was applied together with other methods and subsequent incidence. The database used was the "Web of Science-Core Collection". Only scientific articles and bibliographic reviews were included, analysing a total of 314 documents and selecting only 91. The use of the REBA method is indicated in terms of knowledge, country, year and journal sectors. It was most used in the knowledge areas of "Manufacturing" (24.18%), "Agriculture, forestry and fishing" (21.98%) and in "Other activities" (19.78%). One of the benefits of REBA is that it evaluates different body parts: upper limbs (arm, forearm and wrist), lower extremities, trunk and neck. It is a useful method to identify the forced postures adopted by workers to thus develop improvement measures if necessary. It is concluded that REBA method use has increased over the last decade, probably due to the digitization of knowledge. It is almost always applied in combination with other methods, and its use can be a positive indicator of company sustainability.

The Prevalence of Musculoskeletal Pain of Dental Workers Employed in Slovenia

Work-related musculoskeletal (MS) disorders are considered one of the most frequent occupational diseases among dental workers. Dental work consists of static, demanding tasks that involve repeated gripping of small-sized instruments. The purpose of this study was to investigate the prevalence of MS pain, the areas of pain, and the risk factors for MS pain in dental workers. A self-administrated questionnaire was used as a data collection instrument for dental workers who voluntarily responded to the invitation. To determine the prevalence and severity location of MS pain, the Cornell Musculoskeletal Discomfort Questionnaire was administered among 87 dental workers, with a total of 79.8%, who reported at least one MS complaint. MS pain occurred in 82.6% of general dentists, 75.0% of dental specialists, 66.7% of dental assistants, and 33.3% of dental technicians. Pain most frequently occurred in the neck (60.7%), upper back (52.4%), right shoulder (44.0%), lower back (41.7%), hips/buttocks (29.8%), and the right wrist (23.8%). The prevalence of pain among dental workers could be reduced by ergonomic working environment, regular breaks, maintenance of health, and performing specific exercises designed to dental workers.

Using motion capture technology to measure the effects of magnification loupes on dental operator posture: A pilot study

BACKGROUND

Motion analysis has great potential for quantitatively evaluating dental operator posture and the impact of interventions such as magnification loupes on posture and subsequent development of musculoskeletal disorders.

OBJECTIVE

This study sought to determine the feasibility of motion capture technology for measurement of dental operator posture and examine the impact that different styles of magnification loupes had on dental operator posture.

METHODS

Forward and lateral head flexion were measured for two different operators while completing a periodontal probing procedure. Each was measured while wearing magnification loupes (flip up-FL and through the lens-TTL) and basic safety lenses.

RESULTS

Operators both exhibited reduced forward flexion range of motion (ROM) when using loupes (TTL or FL) compared to a baseline lens (BL). In contrast to forward flexion, no consistent trends were observed for lateral flexion between subjects.

CONCLUSIONS

The researchers can report that it is possible to measure dental operator posture using motion capture technology. More study is needed to determine which type of magnification loupes (FL or TTL) are superior in improving dental operator posture. Some evidence was found supporting that the quality of operator posture may more likely be related to the use of magnification loupes, rather than the specific type of lenses worn.

Musculoskeletal symptoms of the neck and shoulder among dental practitioners

OBJECTIVES

Musculoskeletal symptoms of the neck and shoulder represent a condition whose basic characteristic is pain. These conditions are very often present in dental health professionals. The aim of the paper was to determine presence of discomforts in areas of head, neck, shoulders, upper back and upper limbs at health professionals in area of dentistry, as well as discomfort localisation and methods of treatment.

METHODS

The research included 45 health professionals (dentists, dental assistants and dental technicians) employed at Dental Clinic of Vojvodina. The information was collected via questionnaire for analysis musculoskeletal disorders.

RESULTS

Most of the dentists (75.9%) and the dental assistants (90.9%) as well as nearly half of the dental technicians (40%) experience discomforts in area of the neck, which are occasional, present in all three working positions and this discomforts are a little more frequent at women. The present musculoskeletal disorders are followed by headache, whose presence is statistically more significant compared to the other symptoms. The headache is usually located in the occipital part, it occurs individually or joined with other symptoms. Due to said discomforts the examinees in 59.4% of the cases don't contact the doctor. Medical therapy prevails in opposition to physical therapy.

CONCLUSION

The discomforts deriving from the cervical part of the spine are present at great percentage of our examinees. Considering the fact that the said discomforts affect performing both professional and everyday activities, its prevention is necessary in order to avoid the consequences they carry.

The prevalence of occupational health-related problems in dentistry: A review of the literature

The study was conducted to report on the scope and prevalence of occupational health related-problems experienced by dentists, dental therapists, and oral hygienists in their practice of dentistry.

BACKGROUND

Professional practice and dental training have many risk factors, and the dental team should be able to recognize these factors to protect themselves. The prevalence of conditions related to the musculoskeletal system, stress, percutaneous injuries, ears, and eyes are of concern. The dental team should also not forget hepatitis B, hepatitis C, and HIV as risks in practice. Dental practitioners should protect themselves by self-recognizing risk factors and by maintaining proper working conditions.

METHODS

The study targeted all empirical research, case studies, and systematic literature reviews written in English. All articles selected were subjected to a data analysis process. Data were captured on an Excel spreadsheet and reported in a comprehensive table.

RESULTS

The literature addressing occupational health among dental practitioners included mainly cross-sectional studies and review papers (2001-2016). Forty-nine studies were included in the review. Musculoskeletal disorders remain the most researched occupational health-related problems in dentistry. Eye protection compliance was low among practitioners. Percutaneous injuries especially among young dentists and students were still a concern.

CONCLUSION

Occupational health-related problems are still prevalent in current dentistry practice, despite changes in equipment and surgery design. The reported prevalence of occupational related-health problems and other findings of investigative studies highlight the need for continuous professional education and a need to improve clinical practice aspects of dentistry curricula.

Restricted posture in dentistry - a kinematic analysis of orthodontists

BACKGROUND

This study aims at identifying orthodontic activities with the highest frequency of unfavorable/awkward and static postures held over a period of more than 4 s based on kinematic analysis. Moreover, a separate analysis of static postures for orthodontic and non-orthodontic activities serves to evaluate the duration for which these particular postures are assumed.

METHODS

In total, 21 (13f/8 m) orthodontists (age: 31.5 ± 3.8 years) participated in this study. CUELA, a personal measurement system, was used to collect kinematic data for all orthodontic activities in a working day. Angle values of the head and torso were evaluated in accordance with ergonomic standards. Only those postures that were held statically for 4 s and longer were selected for further analysis. Alongside the kinematic analysis, the activities performed on-site were also subject to a detailed computerized analysis. The synchronization of data collected from both measurements arranges the patterns of posture found chronologically and in conjunction with the orthodontic activities performed ((I) "treatment" (II) "office" and (III) "other activities").

RESULTS

For (I) we observed an anterior inclination of the head and torso area as well as a twist of the head and neck area to the right. We found anterior back inclination and lateral back torsion to the right for (II) and (III). If, furthermore, we differentiate the duration of static postures, there are primarily short to medium-term (4-30s) static postures identified for (I). Also, categories (II) and (III) predominantly demonstrate static back postures with a duration of up to 30 s. With regard to (II) we observed that the back is ventrally inclined for 10.1% of the total activity duration.

CONCLUSIONS

During treatment static strains are observed in the entire head and torso area. On the contrary, static postures prevalent in the torso area are essential for activities of the other categories, particularly office work. These findings allow for a careful selection of unfavorable and static postures for each of the activities performed and help to develop specific preventive measures.

Work-Related Musculoskeletal Disorders in Iranian Dentists: A Systematic Review and Meta-analysis

Background

Work-related musculoskeletal disorders are the most important problems among professions particularly, dentists. This study was conducted to determine the prevalence of musculoskeletal disorders in various parts of the body in Iranian dentists by using systematic review and meta-analysis.

Methods

This systematic review and meta-analysis was based on preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines and searching in national databases such as SID, Magiran, Irandoc, IranMedex, and Medlib, and international databases such as MedLine, Web of Sciences, Scopus, PubMed, ScienceDirect, Cochrane, Embase, Springer, Wiley Online Library, Ebsco, CEBM, and Google Scholar search engine which were published by January 1, 2017. Researched keywords were in Persian and their standard English equivalents were in accordance with their MeSH. The obtained documents were analyzed using Comprehensive Meta-analysis version 2.

Results

According to 23 studies through 2,531 Iranian dentists which took part in this study, prevalence of skeletal disorders in Iranian dentists has been 17.6% [confidence interval (CI) 95%:11.7-25.5] in knees, 33.2% (CI 95%:24.1-43.8) in shoulders, 33.4% (CI 95%: 26.8-40.8) in the thorax, 51.9% (CI 95%:46.7-57.2) in necks, 33.7% (CI 95%:28.2-39.6) in wrists/hands, 12.9% (CI 95%:7.7-20.6) in elbows, 37.3% (CI 95%: 31.5-43.5) in lower back, 11.9% (CI 95%:8.7-16.1) in thighs, 12.9% (CI 95%:3.8-36) in the foot, and 10.5% (CI 95%:7-15.4) in legs.

Conclusion

Considering the high prevalence of musculoskeletal disorders in Iranian dentists, ergonomics should be included as a lesson in preclinic and also, reeducation courses for ergonomics basics should be executed for graduate dentists.

Investigation of musculoskeletal discomfort, work postures, and muscle activation among practicing tattoo artists

Tattoo artists are an understudied worker population with respect to investigation of work-related musculoskeletal (MSK) discomfort and associated risk factors. Results from one discomfort survey has been published; no analysis of worker biomechanics has been published. As such, a study was conducted to begin exposure assessment of tattoo artists to work factors that could result in MSK discomfort. Consistent with the prior survey, the current study showed an elevated prevalence of MSK discomfort. Twelve month discomfort prevalence exceeded 50% in the neck, shoulders, hands/wrists, and upper and lower back (range: 53-94%). Seventy-one percent of postures evaluated during 16 h of observation had total RULA scores of 5, 6, or 7 (investigation and changes are required soon or immediately). Static muscle activity levels in the left, right, or both upper trapezius muscles in each study participant exceeded the 2-5% MVE limit recommended in the literature. Intervention concepts are also discussed.

Do dental students have a neutral working posture?

BACKGROUND

Dentists are susceptible to Musculoskeletal Disorders (MSDs) due to prolonged static postures. To prevent MSDs, working postures of dental students should be assessed and corrected in early career life.

OBJECTIVE

This study estimated the risk of developing musculoskeletal disorders in dental students using Rapid Upper Limb Assessment (RULA) tool.

METHODS

A number of 103 undergraduate dental students from fourth and fifth academic years participated. Postures of these students were assessed using RULA tool while working in the dental clinic. They also answered a questionnaire regarding their knowledge about postural dental ergonomic principles.

RESULTS

The majority of the students (66%) were at intermediate and high risk levels to develop MSDs and their postures needed to be corrected. There was no significant correlation between RULA score and gender, academic year and different wards of dental clinics. There was no significant correlation between knowledge and RULA scores.

CONCLUSIONS

Dental students did not have favorable working postures. They were at an intermediate to high risk for developing MSDs which calls for a change in their working postures. Therefore students should be trained with ergonomic principles and to achieve the best results, ergonomic lessons should be accompanied by practice and periodical evaluations.

Influence of different stool types on muscle activity and lumbar posture among dentists during a simulated dental screening task

Whereas in the past dental stools typically facilitated a 90° hip angle, a number of currently available alternative designs allow for a more extended hip posture. The present study investigated the influence of different stool types on muscle activity and lumbar posture. Twenty five participants completed a simulated dental procedure on a standard stool, a saddle and the Ghopec. The latter stool comprises a seat pan consisting of a horizontal rear part for the pelvis and an inclinable sloping down front part for the upper legs, with a vertically and horizontally adjustable back rest. Lumbar posture was most close to neutral on the Ghopec, whereas sitting on a standard/saddle stool resulted in more flexed/extended postures respectively. Sitting with a 90° angle (standard stool) resulted in higher activation of back muscles while sitting with a 125° angle (saddle and Ghopec) activated abdominal muscles more, although less in the presence of a backrest (Ghopec). To maintain neutral posture during dental screening, the Ghopec is considered the most suitable design for the tasks undertaken.

Opting to wear prismatic spectacles was associated with reduced neck pain in dental personnel: a longitudinal cohort study

Background

The aim of this study was to investigate effects on perceived exertion, work ability self-reported neck pain and clinically diagnosed conditions in the neck, of an intervention with prismatic spectacles among dental personnel.

Methods

In this cohort study a baseline questionnaire including questions about frequency of neck pain, perceived exertion during work and background information was distributed to dental personnel in municipal dental care units. In connection, personnel from 78 out of 110 dental care units underwent a clinical neck examination and rated their perceived work ability with the single-item question from the Work Ability Index. The study population consisted of 564 participants; 366 in the questionnaire group, 321 in the examination group, whereof 123 participated in both assessments. In total 371 belonged to the intervention group and received individually adjusted prismatic spectacles after the baseline assessments (inclusion based on self-selection) and 193 belonged to the reference group. At the 12-month follow-up the clinical examination was repeated and the same questionnaire with additional questions was completed. Fisher’s exact test or the Mann–Whitney U test was used to assess differences between the intervention group and the reference group at baseline. Differences at follow up between the two groups were assessed by means of Linear-by Linear association test for trends.

Results

A significant decrease in neck pain (p = 0.047), clinical diagnoses in the neck (p = 0.025), and perceived exertion (p = 0.003) was observed at follow up for the intervention group compared to the reference group. Moreover, for the intervention group a significantly improved self-rated work ability (p = 0.040) was reported. Finally, opting to wear prismatic spectacles during dental work appeared to have a preventive effect on neck pain.

Conclusions

Dental personnel opting to wear prismatic spectacles reduced their neck pain significantly more at follow up compared with the reference group. These results are worthwhile testing in a randomised design. The practical implication of this study is that recommendations regarding ergonomics for dental professionals may include the use of prismatic glasses, both as primary and secondary prevention of work-related neck pain. Such glasses should also be tested in other working situations where the work tasks include high visual demands in sustained awkward neck postures.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-016-1145-1) contains supplementary material, which is available to authorized users.

Prevalence of and risk factors for low back pain among dentists

[Purpose] The purpose of this study was to determine the prevalence, symptoms of, and risk factors for low back pain among dentists as well as to discover the possible correlation of these factors with working posture and how to reduce their prevalence. [Subjects and Methods] The study was conducted among 60 dentists (28 male and 32 female) with a mean age of 25.7 years. Dentists were evaluated with the self-administered Nordic musculoskeletal evaluation chart, postural discomfort chart, and a self-prepared questionnaire. [Results] The data showed a 70% incidence of back pain among dentists, with low back pain predominating in 47.6% of cases. Most of the subjects (90.5%) had a mild-to-moderate level of severity, and only 9.5% had a severe level of low back pain. The majority of the dentists (57%) treated 1-3 patients per day. Only a few dentists (17%) exercised during their rest period even though 57% of them reported taking a break during their working hours. Although 63% of the dentists were aware of the advantages of assistive tools, only 40% of them used any kind of assistive devices. [Conclusion] Dental professionals demonstrate a high prevalence of low back pain.

Evaluation of ergonomic factors and postures that cause muscle pains in dentistry students' bodies

Background

Work-related musculoskeletal disorders commonly experienced by dental professionals are one of the main occupational health problem affecting their health and well-being.This study was conducted to evaluate ergonomic factors and profession-related postures and also investigate relationship between demographic factors and work condition with pain in dental students.

Material and Methods

60 freshman and sophomore dentistry students were randomly chosen as the subjects of control group, and 60 of 5th and 6th-year students were selected as the members of exposure group. Data related to the subjects such as sex, doing exercise, severity of musculoskeletal pain were obtained through questionnaire. Students’ postures were directly observed while treating patients and they were scored by REBA method. Data were analyzed by SPSS software using Man-Whitney, Kruskal-Wallis, Spearman and Kendall correlation tests.

Results

80.8% of the subjects were not aware of the correct ergonomic postures for dental procedures. Severity of musculoskeletal pain in the exposure group (15.9± 4.2) was significantly higher than the control group (10.5 ±3.2), (p <0.001). Risk of the most subjects (84%) was at the medium level. Students who were more involved in clinical activities experienced more muscular pains.

Conclusions

The musculoskeletal disorders are probable prolonged in working hours in static positions, incorrect work postures, implying more force and even tools and instruments. Therefore, students who are aware of ergonomic principals of their own profession would be able to maintain their health through activities and lifelong.

Key words:Posture, dentistry, students, musculoskeletal pain.