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

Effect of fence tray matching care on excess adhesive and bracket placement accuracy for orthodontic bonding: an in vitro study

OBJECTIVE

This study aimed to evaluate the effect of fence tray matching care (FTMC) in bracket bonding by measuring excess adhesive, as well as linear and angular deviations, and by comparing it with the half-wrapped tray (HWT).

MATERIALS AND METHODS

An intraoral scanner was used to acquire data on the maxillary dental arch of a patient with periodontitis.Furthermore, 20 maxillary dental arch models were 3D printed. Using 3Shape, PlastyCAD software, and 3D printing technology, 10 FTMC (method I) and HWT (method II) were obtained. By preoperative preparation, intraoperative coordination, and postoperative measurement, the brackets were transferred from the trays to the 3D-printed maxillary dental arch models. Additionally, the bracket's excess adhesive as well as linear and angular deviations were measured, and the differences between the two methods were analyzed.

RESULTS

Excess adhesive was observed in both methods, with FTMC showing less adhesive (P< 0.001), with a statistical difference. Furthermore, HWT's vertical, tip and torque, which was significantly greater than FTMC (P< 0.05), with no statistical difference among other respects. The study data of incisors, canines, and premolars, showed that the premolars had more adhesive residue and were more likely to have linear and angular deviations.

CONCLUSIONS

The FTMC had higher bracket bonding effect in comparison to HWT, and the adhesive residue, linear and angular deviations are smaller. The fence tray offers an intuitive view of the precise bonding of the bracket, and can remove excess adhesive to prevent white spot lesions via care, providing a different bonding method for clinical applications.

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.

Ergonomic interventions and endodontic treatment outcomes: An analysis of dentist working posture and error rates

Purpose

Dentists spend a long time the day in the position. It is possible that this leads to discomfort that may translate to procedural errors during treatment, such as root canal treatment. This study aims to investigate the relationship of working posture and procedural errors in endodontic manipulations.

Materials and Methods

32 dentists (17 men, 53.13%, and 15 women, 46.88%) from the University Dental Polyclinic of Uzhhorod National University (Uzhhorod, Ukraine) were included in the study. REBA, RULA, frequency of procedural errors were analysed using regression.

Results

This study revealed a surprising trend where a decrease in errors during endodontic treatment was associated with higher RULA and REBA scores, contrary to the expected increase in errors with higher ergonomic stress. Additionally, the research highlighted the significant impact of a dentist's handedness and tooth position in the dental arch on treatment ergonomics and efficiency, as observed and analyzed through ergonomic assessments and statistical methods.

Conclusions

The study conclusively demonstrated that optimal positioning and alignment during dental procedures significantly contribute to a reduction in procedural errors, underscoring the importance of ergonomics in clinical dentistry.

Wearables for Monitoring and Postural Feedback in the Work Context: A Scoping Review

Wearables offer a promising solution for simultaneous posture monitoring and/or corrective feedback. The main objective was to identify, synthesise, and characterise the wearables used in the workplace to monitor and postural feedback to workers. The PRISMA-ScR guidelines were followed. Studies were included between 1 January 2000 and 22 March 2023 in Spanish, French, English, and Portuguese without geographical restriction. The databases selected for the research were PubMed®, Web of Science®, Scopus®, and Google Scholar®. Qualitative studies, theses, reviews, and meta-analyses were excluded. Twelve studies were included, involving a total of 304 workers, mostly health professionals (n = 8). The remaining studies covered workers in the industry (n = 2), in the construction (n = 1), and welders (n = 1). For assessment purposes, most studies used one (n = 5) or two sensors (n = 5) characterised as accelerometers (n = 7), sixaxial (n = 2) or nonaxialinertial measurement units (n = 3). The most common source of feedback was the sensor itself (n = 6) or smartphones (n = 4). Haptic feedback was the most prevalent (n = 6), followed by auditory (n = 5) and visual (n = 3). Most studies employed prototype wearables emphasising kinematic variables of human movement. Healthcare professionals were the primary focus of the study along with haptic feedback that proved to be the most common and effective method for correcting posture during work activities.

Measuring ergonomic interventions and prevention programs for reducing musculoskeletal injury risk in the dental workforce: A systematic review

PURPOSE

Pain from musculoskeletal disorders (MSD) is experienced by all types of dental clinicians, leading to forced reduction of work capacity and premature retirement. Prolonged static posture is a major contributor to MSD in dentistry. Currently, there is no uniform ergonomic training in dentistry to prevent MSD. This systematic review explored and summarized methods and technologies for baseline and ongoing measurements of ergonomic intervention and prevention programs for reducing postural risk and for prevention of MSDs.

METHODS

The review was conducted in accordance with PRISMA guidelines. The literature search included PUBMED, Embase, CINAHL and the Cochrane Library, and identified relevant observational, experimental, quasi-experimental, research, and intervention studies. Quality was rated using a validated standardized instrument.

RESULTS

A total of 20 studies were included, of which 4 were rated as being of the high quality. Methods ranged from observers to motion sensors. Ten studies focused used established measuring tools (PAI, RULA, REBA), while nine studies focused on effectiveness of alternative methods of measurement. One study identified ISO standard 11226 for baseline comparisons. Evolving technologies were found to be suitable for baseline measurements of posture, and for feedback for developing sustainable postural behaviors. No studies measured ongoing postural performance improvement.

CONCLUSIONS

This systematic review adds to current evidence for the expanded and improved use of early training and testing of postural competence to reduce MSD risk among dental professionals. Further studies using technologies to assess the impacts of ergonomic training and testing among dental professionals are warranted.

Transparency as a Means to Analyse the Impact of Inertial Sensors on Users during the Occupational Ergonomic Assessment: A Systematic Review

The literature has yielded promising data over the past decade regarding the use of inertial sensors for the analysis of occupational ergonomics. However, despite their significant advantages (e.g., portability, lightness, low cost, etc.), their widespread implementation in the actual workplace has not yet been realized, possibly due to their discomfort or potential alteration of the worker's behaviour. This systematic review has two main objectives: (i) to synthesize and evaluate studies that have employed inertial sensors in ergonomic analysis based on the RULA method; and (ii) to propose an evaluation system for the transparency of this technology to the user as a potential factor that could influence the behaviour and/or movements of the worker. A search was conducted on the Web of Science and Scopus databases. The studies were summarized and categorized based on the type of industry, objective, type and number of sensors used, body parts analysed, combination (or not) with other technologies, real or controlled environment, and transparency. A total of 17 studies were included in this review. The Xsens MVN system was the most widely used in this review, and the majority of studies were classified with a moderate level of transparency. It is noteworthy, however, that there is a limited and worrisome number of studies conducted in uncontrolled real environments.

Assessment of dental ergonomics among dental students: A retrospective study

INTRODUCTION

Musculoskeletal (MSK) disorders account for 11%-98% of occupational health issues for dental professionals, with an onset as early as in dental school. Dental ergonomics is among the risk factors; thus, a prompt assessment is crucial in preventing future MSK pain. The aim of this study was to retrospectively assess dental ergonomics of second-year dental students after dedicated lectures were introduced in the predoctoral curriculum.

METHODS

Three cohorts of second-year dental students were evaluated during preclinical activity in July 2019, January 2022, and December 2022 by an Occupational Therapy (OT) faculty and calibrated OT students. Dental ergonomics was assessed with the Rapid Upper Limb Assessment (RULA). Dental student cohorts were compared with one-way analysis of variance (ANOVA).

RESULTS

The average RULA final score of 409 participants was 5.1 ± 0.9, with no difference between the three cohorts (p = 0.676). The January 2022 cohort scored significantly lower in wrist-arm score than that of 2019 (p = 0.001) and December 2022 (p = 0.046). Neck and lower limb posture were significantly higher in January 2022 cohort than in 2019 (p = 0.001 and 0.013) and December 2022 (p = 0.001 and 0.005) cohorts. The December 2022 cohort revealed a medium, high and extremely high risk of developing MSK of 40.2%, 37.1%, and 21.6%, respectively, with no difference between sexes.

CONCLUSION

The risk of developing MSK pain was medium-high in predoctoral dental students and was not related to sex. The overall dental ergonomics required attention and rapid change. Further implementation of varied forms of teaching and monitoring of dental ergonomics from the early years of education is recommended to prevent development of MSK pain at young age and foster better postural habits.

Evaluating the Dental Hygienists' Exposure to the Risk of Musculoskeletal Disorders

OBJECTIVES

 The aim of the study was to evaluate dental hygienists' exposure to the risk of musculoskeletal disorders (MSDs), by the worksheets compatible with the Rapid Entire Body Assessment (REBA).

MATERIALS AND METHODS

 The research included 272 dental hygienists aged 23 to 52 years from the two administrative regions of Poland.

STATISTICAL ANALYSIS

 STATISTICA 12 and Microsoft Excel were used to analyse the results. The level of significance was p<0.05. The normality of the distribution was tested with the Shapiro-Wilk test. The relationships between the variables were assessed with the χ2 test. Due to the lack of "normality" of the REBA risk distribution, the Mann-Whitney test was used to verify the hypotheses.

RESULTS

 Overall, 48.5% of the examined showed a neck flexion >20, torsion of 80.1%, and 37.5% declared the presence of both types of loads. Also, 14.3% of the examined kept a vertical position, 53.7% flexion to the torso up to 20degrees, 31.4% to 60degrees, and 2.1% to >60degrees. Further, 78.3% of people indicated that they twist the torso. Then, 7% marked the low load's arms position, 45.6% marked the range from 20 to 45degrees, and 39.7% marked the range from 45 to 90degrees. Over 55% showed additional load related to the raising or abduction of the shoulders. Overall, 43% showed a wrong position of forearms. Also, 62.9% showed wrists flexed <15° and the rest showed >15degrees. Again, 79% showed additional twisting and flexion of the wrists. Almost 75% of the examined are exposed to overloads associated with the static load. The examined are not exposed to excessive loads resulting from sudden exertion. REBA scores indicate that the negligible MSDs risk concerns 0.7% examined; low risk, 5.5%; medium risk, 33,1%; high risk, 49.3%; and very high risk, 11.4%. The correlation coeffcients analysis showed that exposure risk is strongly correlated with the overloads on the tested parts of the body in both groups.

CONCLUSION

 The levels of MSDs risk indicate that hygienists more often should be subjected to periodic check-ups in the workplace. They also need ergonomic interventions (education, preventive technique, physical activity, and improvement of the working environment) and modifications of hygienist's college programs in the field of work ergonomics can be also considered.

Testing the Level of Agreement between Two Methodological Approaches of the Rapid Upper Limb Assessment (RULA) for Occupational Health Practice-An Exemplary Application in the Field of Dentistry

BACKGROUND

The Rapid Upper Limb Assessment (RULA) is used for the risk assessment of workplace-related activities. Thus far, the paper and pen method (RULA-PP) has been predominantly used for this purpose. In the present study, this method was compared with an RULA evaluation based on kinematic data using inertial measurement units (RULA-IMU). The aim of this study was, on the one hand, to work out the differences between these two measurement methods and, on the other, to make recommendations for the future use of the respective method on the basis of the available findings.

METHODS

For this purpose, 130 (dentists + dental assistants, paired as teams) subjects from the dental profession were photographed in an initial situation of dental treatment and simultaneously recorded with the IMU system (Xsens). In order to compare both methods statistically, the median value of the difference of both methods, the weighted Cohen's Kappa, and the agreement chart (mosaic plot) were applied.

RESULTS

In Arm and Wrist Analysis-area A-here were differences in risk scores; here, the median difference was 1, and the agreement in the weighted Cohen's kappa test also remained between 0.07 and 0.16 (no agreement to poor agreement). In area B-Neck, Trunk, and Leg Analysis-the median difference was 0, with at least one poor agreement in the Cohen's Kappa test of 0.23-0.39. The final score has a median of 0 and a Cohen's Kappa value of 0.21-0.28. In the mosaic plot, it can be seen that RULA-IMU had a higher discriminatory power overall and more often reached a value of 7 than RULA-PP.

CONCLUSION

The results indicate a systematic difference between the methods. Thus, in the RULA risk assessment, RULA-IMU is mostly one assessment point above RULA-PP. Therefore, future study results of RULA by RULA-IMU can be compared with literature results obtained by RULA-PP to further improve the risk assessment of musculoskeletal diseases.

Preventing work-related musculoskeletal injuries among oral and maxillofacial surgeons

BACKGROUND

Oral and maxillofacial surgeons (OMS) are continually required to adjust position and posture to access the limited surgical field in and around the head and neck, oral cavity, and oropharynx. Very limited data exists that quantifies the burden of musculoskeletal disorders (MSD) among OMS.

OBJECTIVE

This exploratory study seeks to address these literature gaps by assessing the prevalence of MSD among OMS.

METHOD

A 12-question survey was designed to investigate the prevalence of MSD for OMS, including residents in training, actively practicing surgeons, and retired surgeons. Seventy-six surveys were distributed and completed in person by surgeons attending professional conferences from September 2018-September 2019. Survey questions included the Baker-Wong Faces pain scale, years in practice, number of hours worked per week, job tenure, pain attributable to work, and age. The Nordic scale identified and delineated anatomic site of musculoskeletal complaints, duration and treatment sought.

RESULTS

The most frequently cited sources and locations of pain attributable to occupation were shoulders, neck, and lower back. The risk of MSD symptoms was relatively two-fold [PR = 2.54, 95% CI = 0.90, 7.22] among OMS in practice for more than ten years compared to those in practice less than ten years. After adjusting for age and hours worked per week as potential confounders, the risk of MSD symptoms was higher among OMS in practice for more than ten years compared to those with less than ten years of experience, despite no statistically significant association.

CONCLUSION

OMS are impacted by a high prevalence of MSD. The neck, shoulder, and lower back are the most frequently affected with discomfort and pain. This study found that practicing oral and maxillofacial surgery for more than 10 years is a potential risk factor for experiencing MSD.

Home office versus ergonomic workstation - is the ergonomic risk increased when working at the dining table? An inertial motion capture based pilot study

Background

In order to reduce the risk of infection with Sars-Cov-2, work practices have been shifted to the home office in many industries. The first surveys concerning this shift indicate an increase in musculoskeletal complaints of many employees. The aim of this study was to compare the ergonomic risk in the upper extremities and trunk of working in a home office with that of working in an ergonomically optimized workplace.

Methods

For this purpose, 20 subjects (13w/7m) aged 18–31 years each performed a 20-minute workplace simulation (10 min writing a text, 10 min editing a questionnaire) in the following set up: on a dining table with dining chair and laptop (home office) and on an ergonomically adjusted workstation (ergonomically optimized workplace). The subjects were investigated using a combined application of a motion capture kinematic analysis and the rapid upper limb assessment (RULA) in order to identify differences in the ergonomic risk.

Results

Significantly reduced risk values for both shoulders (left: p < 0.001; right: p = 0.02) were found for the ergonomically optimized workstations. In contrast, the left wrist (p = 0.025) showed a significantly reduced ergonomic risk value for the home office workstation.

Conclusion

This study is the first study to compare the ergonomic risk between an ergonomically optimized workplace and a home office workstation. The results indicate minor differences in the upper extremities in favor of the ergonomically optimized workstation. Since work-related musculoskeletal complaints of the upper extremities are common among office workers, the use of an ergonomically optimized workstation for home use is recommended based on the results.