Brazilian Journal of Oral Sciences Piracicaba Dental School - UNICAMP EISSN: 1677-3225 Vol. 10, Num. 2, 2011, pp. 130-135

Brazilian Journal of Oral Sciences, Vol. 10, No. 2, Apr-Jun, 2011, pp. 130-135

Cumulative trauma disorders, overweight andobesity among Brazilian dentists

Evelyne Pessoa Soriano¹, Marcus Vitor Diniz de Carvalho¹, Ana Beatriz Vasconcelos Lima Araújo², Humberto Gomes Vidal³, Kátia Maria Diniz de Carvalho³, Clóvis César de Mendoza³

¹Adjunct Professor, MSc in Forensic Sciences, Faculty of Dentistry, University of Pernambuco, Brazil
²MSc student in Public Health, Faculty of Dentistry, University of Pernambuco, Brazil
³MSc student in Forensic Sciences, Faculty of Dentistry, University of Pernambuco, Brazil

Code Number: os11026

Abstract

Aim: This study aimed to assess the prevalence of cumulative trauma disorders (CTD), overweight and obesity and the association between them, among public health dentists.
Methods: The study included 150 dentists working at various public health system units in Recife, PE, Brazil. A Brazilian version of the Nordic Musculoskeletal Symptoms Questionnaire was used. Obesity and overweight were observed across the BMI (body mass index) recommended by the World Health Organization. A descriptive analysis was carried out using SPSS 13.0 software.
Results: Among respondents, 79.3% were female with a mean age of 44.42 years. The presence of musculoskeletal symptoms was reported by 138 (92%) of participants, 129 of whom linked the symptoms to their work activity. The cervical region was the most involved, accounting for 104 (14.3%) of the total 723 affected areas. Overweight was observed in 32% of the professionals and obesity in 13%. Of the 150 participants, 30 (20%) received a medical diagnosis of CTD and of these, 13 (43.3%) had a high BMI. The 40-49-year-old age group was most affected by CTD and females were more affected than males, accounting for 22.7% of professionals interviewed. There was no significant association between the presence of CTD and overweight/obesity (p >0.05).
Conclusions: However, given the multifactorial nature of occupational diseases, it is likely that overweight and obesity may act as a predisposing factor in these diseases, interacting and enhancing the effects of other important risk factors for the occurrence of work-related musculoskeletal disorders.

Keywords: occupational health, cumulative trauma disorders, overweight, obesity.

Recently there have been reports of an increase in the prevalence of musculoskeletal conditions among dental professionals, with an etiology of repetitive movements, injuries due to cumulative trauma or work-relatedmusculoskeletal disorders^1-2.

Cumulative trauma disorders (CTD) are a group of diseases that affect muscles, tendons, nerves and vessels of the upper limbs (fingers, hands, wrists, forearms,arms, shoulder, neck and spine) and lower limbs (knee and ankle, especially) that are directly related to the demands of work tasks, physical environments and with the organization of work. They include clinical manifestations characterized by the occurrence of various symptoms, concomitant or not, such as pain, numbness, heaviness and fatigue and are often causes of temporary or permanent employment disability^3-4.

There are several risk factors associated with these disorders, which can be divided into individual risk factors and occupational risk factors. The following are considered to be the most likely individual risk factors: age, gender, body mass index, muscular imbalance, muscle strength, socioeconomic conditions and the presence of other pathologies. Overweight and obesity may act as a permissible factor in musculoskeletal disease, interacting and enhancing the effects of other risk factors, as well as the alignment of the skeleton and the condition of muscles^5-6. In a Swedish study that compared 6,328 obese individuals with 1,135 individuals from the general population of either gender, itwas found that neck pain, along with pain in the back, hip,knee and ankle, was more common in obese people than inthe general population⁷.

Although they are not recent illnesses, CTD are undoubtedly taking on an epidemic character, and some of their pathologies are chronic and recurring, difficult to treatand are creating disability that is not restricted to the workplace but also found in other normal activities of personal life⁸.

A high prevalence of musculoskeletal complaints wasfound in 430 Greek dentists participating in a study where a questionnaire was applied. The survey results showed that 62% reported at least one painful complaint⁹. In another study, 98.6% of dentists of Caxias do Sul, RS, Brazil, had some symptoms of musculoskeletal disorder that were associated with certain demographic, clinical and laboratorial characteristics. Pain was the primary symptom of disorder, affecting mainly theregions of the cervical spine, the elbows, lumbar spine and shoulders¹⁰. In a study carried out with 227 Brazilian dentalstudents in Recife and Camaragibe, PE, Brazil, 176 (76.2%)reported experiencing pain during or after clinical work¹¹.

Musculoskeletal disorders have a major impact on quality of life of the population in many countries, not tomention the financial costs. Although not exclusively caused by work, they represent a third of the occupational diseases in countries such as Japan, the United States and the Scandinavian countries¹². In Brazil, the total of benefits provided by Social Security during the months from January to August 2009 was1,162,818; of these, 18.97% were related to diseases of the musculoskeletal system and connective tissue¹³.

In order to draw attention to occupational health and tocontribute to the quality of the working lives of these professionals, the aim of this study was to assess the prevalence of musculoskeletal symptoms and the association with obesityand overweight among Brazilian public sector dentists.

This is a cross-sectional study that investigates the factor and effect at the same historical moment. The study was carried out from April to July 2010 and included 150 dentists (drawn from a population of 243) who worked in various units that are part of the public health system in the city ofRecife, PE, Brazil, selected by the calculation for finite population, from a list provided by the Municipality of thecity of Recife. Of the 283 professionals who originally appeared in the list, 33 were excluded because they were managers and did not perform clinical activities in healt hunits, two had died and five were removed (two professionals for maternity leave, one for an ongoing long-term out ofstate, and two due to health problems). Thus, the estimated prevalence was 50%, since no data were available concerning the prevalence for this population, and 5% error and confidence interval of 95%, resulting, then, in 150 subjects.

A modified version of the Nordic Musculoskeletal Symptoms Questionnaire (NMSQ) was used, which was validated in Brazil by Pinheiro¹⁴. The aim was to investigate the occurrence of musculoskeletal symptoms in the previous 12 months, the anatomical regions most affected, the frequency of symptoms, the participant’s demographic profile (gender,age, education and marital status) and the characterization of the work process (activity time and work schedule).

Pain intensity was assessed from the clinical stages of CTDas advocated by Oliveira (1989)¹⁵, using an increasing scale of symptoms reported by the interviewee. The questionnaire was given to the dentists in their work environment. After filling it out, their anthropometric measurements were taken to assess ifthey were overweight or obese.

Obesity and overweight were observed across the BMI (body mass index), with the objective of determining if there is an association between this variable and the occurrence of CTD in this sample. To record the BMI, dentists were weighed using a digital scale with a maximum capacity of150 kg and precision of 0.1 kg. Height was measured inmeters, using a flexible measuring tape fixed to the wall.The participants were asked to remove their shoes, their heels and shoulders touching the wall, after which his head waspositioned so that the occlusal plane were parallel to the ground. So, with the help of a frame of wood, the individual’s height was marked on the tape, making it easier to read.

In population studies, the BMI, defined as the weight inkilograms divided by height in meters squared, is a useful measure to assess excess body fat, and it is generally agreed that, regardless of gender and age, adults with a BMI equal to or greater than 30 kg/m² are classified as obese¹⁶.

Data was analyzed through statistical tests, using the Statistical Package for Social Sciences (SPSS 13.0). Initially, a descriptive analysis was carried out to evaluate the frequency of the distribution of variables and to check if there were errors in data entry, seeking thereby to characterize the sample. The bivariate relationships between the dependent and independent variables were examined using tests of association (chi-square and Fisher’s exact test). A statistical significance was considered when p <0.05 and confidence interval was determined at 95%.

This research was duly approved by the Ethics Committee of the University of Pernambuco, according tothe Resolution CNS 196/96, via protocol 212/09.

Data analysis revealed that 119 (79.3%) of the 150 participants were female and their mean age was 44.42 years. Among respondents, 77 (51.3%) reported working an averageof eight hours per day and 78 (52%) reported performing some physical activity.

The presence of musculoskeletal symptoms was reported by 138 (92%) of participants and 129 (86%) of respondents linked these symptoms to their work activity. The cervical region was identified by respondents as the most affected by painful symptoms, accounting for 104 (14.3%) of the totalof 723 affected areas, followed by wrists, hands and fingers(13.4%), lower back (13.4%) and shoulders (13.1%).

Using the BMI calculations, it was found that 48 individuals (32%) were overweight and 20 (13%) were obese.Among the 68 respondents who were overweight, the mostaffected age group was the 50 to 59 years one and the gender had a significant association with overweight/obesity (p<0.05) using the Pearson chi-square test, in which 26 (83.9%) of the total male respondents were overweight. The number of years doing the same activity was also significantly associated with overweight/obesity, and professionals with 21 or more years of activity as dentists had a greater increase in BMI. Physical activity was carried out by 35 (51.4%) of the dentists who were overweight or obese (Table 1).

Of the 150 participants, 30 (20%) were diagnosed with CTD in the previous 12 months. Among these, 14 (46.7%)reported that their pain symptoms corresponded to the firststage of clinical CTD, as described by Oliveira (1989)¹⁵, feeling of heaviness, discomfort or mild and transientlocalized pain and without irradiation, that worsens with work and improves with rest. The most affected age groupby CTD was the 40 to 49 years one and females were more affected than males, accounting for 22.7% of professionals interviewed. Of the 30 professionals diagnosed with CTD,13 (43.3%) were overweight or obese. There was no significant association (p <0.05) between the presence of CTD and overweight/obesity (Table 2).

One of the main objectives of the results of this study was to describe and analyze how dentists are affected by work-related musculoskeletal symptoms. Despite the occurrence of musculoskeletal disorders found in the study group was considered high, 129 of professionals reported some work-related painful symptoms in the previous 12 months, only 30 were diagnosed with CTD. This suggests that even though the presence of musculoskeletal pain corresponding to the first clinical stage of the CTD condition, dentists trend towards minimization of signs pointing to musculoskeletal changes that somehow relate to their laboring. The symptoms of CTD vary during the working activity and tend to relieve through the rest. Over time, they may become frequent throughout the workday, and also in the performance of other activities. People tend to seek medical help only when the pain becomes unbearable ortheir movements are restricted¹⁷. On the other hand, treatment is often based only on prescription of antiinflammatory drugs and physical therapy sessions, which will only mask theproblem without reaching its causes, neglecting the changes in conditions of work¹⁸.

The study of Santos Filho and Barreto¹⁹, which assessed all dentists of the Public Health Service in Belo Horizonte/Brazil (n = 358) also observed a large number of professionals with symptoms (58%). The same situation occurred in theState of Santa Catarina, where Regis Filho et al.²⁰ reported that among 771 dentists registered at the Regional State Council of Dentistry, 437 (56.68%) had some painful musculoskeletal manifestation that was work-related, which is in line with our study. These data reinforce the observationthat the practice of dentistry favors, by its own nature, the occurrence of disorders affecting primarily the musculoskeletal system of dental surgeons.

In this study, the body region that was most affected bythe symptoms was the cervical spine, followed by wrists,hands and fingers, lower back and shoulders. These resultsare similar to those of a study of 421 dentists who graduated between the years 1986 and 1997 in British Columbia,Canada, which revealed that approximately 18% reported experiencing shoulder pain, 24% had pain in the neck and the lumbar region, with 19% in the upper part of the spine, 30% in the middle and 17% in the lower part²¹. In a surveyof 268 Polish dentists²² symptoms were also mainly relatedto the thoracolumbar region (60.1%), neck (56.3%), lowerlimbs (47.8%) and wrist and hand (44.0%). A study that was carried out with all 115 dentists that were members of the Danish Society of Craniom and ibular Disorders²³ also found that two thirds of respondents had some type of problem,such as pain or discomfort in the neck and/or shoulder withsimilar frequency in relation to the problems present in the lumbar region.

With respect to CTD, women were more affected in the present study. This is in accordance with the study by RegisFilho et al.²⁰ in which the statistical analysis indicated thepresence of a significant association between the two gendersfor the presence of CTD, with women showing more pathologies related to CTD than men. The mean age obtainedin this study was 44.42 years, and the most affected agegroup was the 40 to 49 years one. This is in contrast withthe study by Santana et al.²⁴, which surveyed 100 dentists in Salvador, BA, Brazil, and the most affected age group wasthe 27 to 34 years one. However, our study did agree with these authors regarding the higher prevalence of painfulsymptoms of CTD in females and those professionals who worked 8 hours per day.

In the present study, 30 (20%) participants were diagnosed with CTD in recent months. Of these, 14 (46.7%) reported that they had painful symptoms corresponding tothe first clinical stage of the condition as advocated byOliveira (1989)¹⁵. These results are similar to those obtained in the study of 227 dental students from Recife and Camaragibe, PE, Brazil, where 42 (18.5%) had a diagnosis of CTD¹¹, emphasizing the fact that since their academic training, dentists are already prone to work-related risk factors.This fact is of great importance and should be taken into account on the establishment of preventive practices.

Our study also found a prevalence of overweight in 48(32%) professionals and obesity in 20 (13%), similar to the study that measured the prevalence of overweight and obesity in 435 employees of the State University of Feira de Santanain the state of Bahia, Brazil²⁵. The prevalence of overweightand obesity was 31.95% and 10.34%, respectively²⁵.

Among those interviewees who were overweight, the most affected age group was the 50 to 59 years group and 26(83.9%) of the total of male respondents were overweight.This is in contrast with the study by Abrantes et al. (2003)²⁶, in which the prevalence of overweight and obesity was higher among females aged 40 to 79 years. The study that compared estimates of the Household Budget Survey with data from the National Health and Nutrition Survey, found that the prevalence of overweight and obesity is higher in the male population²⁷, as in this study.

As overweight and obesity are consistently identified as risk factors for the development of a number of diseases,evaluation of their prevalence among various population groups is needed, especially when it comes to individuals who develop occupational activities. The illness among workers may lead to dismissal or even partially or totally unable to work, as can occur with people who develop work related musculoskeletal disorders.

Some authors report that given the multifactorial nature of musculoskeletal disorders, it is likely that overweight and obesity may act as a permissible factor in musculoskeletal disease, interacting and enhancing the effects of other riskfactors, as well as the alignment of the skeleton and themuscular condition 6. One study from Sweden, whichcompared 6,328 obese individuals with 1,135 individualsfrom the general population of both genders, found that painin the neck, lumbar region, hip, knee and ankle was more common in obese people than in the general population (oddsratio - OR ranging from 1.7 to 9.9, p<0.001)⁷. In the present study, the statistical analysis showed no significant association between CTD and overweight and obesity.However, although there was no association, one cannot overlook the fact that overweight and obesity are present in these professionals and can cause, in addition to musculoskeletal problems, other health problems, such as hypertension, diabetes and vascular problems, which can interfere with the work quality of these people.

The evaluation of the prevalence of overweight and obesity, which act as risk factors for the onset of work-related diseases, should be continued, since it is known that the population, not only in Brazil but in many countries, has increasingly showing an increase of body mass. Because dentists are part of a category rather prone to developing diseases related to work due to the ergonomic features and overload of dental activity, this study had the scope to contribute to an initial analysis of productive working health professionals to highlight the need for preventive measures that should be implemented since the academic training of dentists. This way, they are less likely to have problems with their working life quality and suffer impediments in exercising their professional activity.

Special thanks to the National Council for Scientificand Technological Development (CNPq) for the financial support.

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