A descriptive cross-sectional study consisting of 60 dentists who daily practices for more than 8 hours was planned and carried out to determine musculoskeletal work related pain in three major cities Amritsar, Ludhiana and Chandigarh of North India. Ethical clearance was taken from institutional ethical committee for the commencement of the study. The study was undertaken at Ludhiana and authors visited different cities and collected the data. Informed consent was taken from all the study participants. The study was planned in two phases. In the first phase, the subjects were given questionnaire related to the musculoskeletal pain happened over last twelve months. Standardized Nordic Questionnaire (SNQ) [6] [Table/Fig-1] consisted of mainly objectives questions, requiring a simple yes or no reply [Table/Fig-1,2]. The validity of questionnaire was determined by carrying pilot study by asking the 20 subjects to refill the questioner and reliability of the questionnaire was determined by using cronbach’s alpha coefficient test value degree 0.92. Thus, in the first phase musculoskeletal problem was defined, measured and analysed using first three steps of DMAIC methodology. In the second phase of study, fourth step of DMAIC methodology improving was carried out by recommending the subjects to implement ergonomics at their workplace. After three months subjects were again approached and given questionnaire about the MSD.

Data so obtained was analysed using Statistical Package for Social Science (SPSS) Version-16 data analysis software. Chi-square test was used for the analysis. A 95% Confidence Level was used and a p-value of less than or equal to 0.05 was considered statistically significant.

The overall prevalence of musculoskeletal problems in the present study was found to be 68.3%. The mean age of total 60 respondents was 42.4 years. Among them 38 were males and 22 were females. Out of 38 male dentists 23 were suffering from MSD and among 22 females, 18 were affected by this condition. Out of 41 affected dentists, 28 were general dental practitioners and 13 were specialist. Genetic predisposition was found in case of 13 (Male = 5, Female = 8) dentists. Thirteen reported lack of rest, 16 maintenance of same position for more than half an hour and 12 reported both the reasons for the occurrence of this disorder [Table/Fig-3]. The areas affected by musculoskeletal pain and discomfort was neck in 58% cases, shoulder 29%, hands or wrists 52%, elbows 43%, upper back 37%, low back 42%, knees 4%, hips, thighs, ankles and feet 2% each [Table/Fig-4]. Twelve percent respondents had taken self administered medicines for relief and 5% had consulted the orthopaedicians for discomfort. After three months only 23 respondents applied ergonomics at their work place, prevalence of pain was reduced in neck from 11 (47.8%) to 5 (21.7%) out of total 23 respondents, shoulder pain 9 (39.1%) to 4 (17.3%), pain in elbows from 6 (26%) to 5 (21.7%), pain in wrists or hands 8 (34.7%) to 3 (13%), upper back pain 13 (56.2%) to 4 (17.3%), low back pain 7 (30.4%) to 3 (13%), pain in one or both knees 3 (13%) to 1 (4.3%), pain in one or both ankles and feet from 2 (8.6%) to 0%. The p-value was significant with p< 0.05 [Table/Fig-5].

MSD consist of injuries that influence soft tissues mainly muscles, tendons, ligaments, joints, cartilage as well as nervous system and most commonly involve the arms and back. These conditions are also known as cumulative trauma disorders, repeated trauma, repetitive stress injuries, and occupational overexertion syndrome. Such conditions generally develop gradually over weeks, months and years and are usually painful and disabling for the patient [7].

Dentists are more vulnerable to occupational health hazards, their long working hours and maintenance of same postures without microbreaks result in MSDs causing pathologies such as tendinitis, synovitis, tenosynovitis, and bursitis [8,9]. The present study was undertaken to find the prevalence of musculoskeletal conditions in dentists practicing in the major cities of North India which revealed that the overall prevalence of musculoskeletal problems was found to be 68.3%. Similarly, In Southern part of India, Muralidharan D et al., [4] carried a study in the state of Andhra Pradesh and reported an incidence of 78% MSD. Abduljabbar TA [1] studied musculoskeletal disorders among dentists in Saudi Arabia and reported 82.9% of the responding dentists had pain or discomfort from the neck, shoulders, lower back or head. Chowanadisai S et al., [10] carried a cross-sectional study regarding the occupational health problems faced by dentists in Thailand and found that musculoskeletal pain (78%) and percutaneous injury (50%) are the most often disorders faced by the dentists. Al Ali K et al., [11] also carried a similar study among dentists in the United Arab Emirates and reported prevalence of musculoskeletal pain to be 68%. Leggat PA et al., [12] reported 87.2% prevalence; neck being the most prevalent MSD during the previous 12 months followed by lower back and shoulder (53.3 per cent). The present study also showed similar pattern of distribution of musculoskeletal disorders as reported by previous studies [Table/Fig-6].

The female dentists showed higher frequency of pain and discomfort than their male counterparts which was similar to studies carried by Abduljabbar TA [1] and Ayers KMS et al., [13]. Ergonomics is a discipline that includes all aspects of work from the physical stresses it places on joints, muscles, nerves, tendons, bones and the environmental factors which can effect hearing, vision, and general comfort and health of the worker [5]. Repetitive neck movements, long continuous working hours, constant hand and wrist movements affecting the neck and shoulder forms the ergonomic risk factors for dentists resulting in neck MSDs. Dental work is related with greater force and repetitive motions resulting in prolonged increased passive or active pressure in the carpal canal which makes dentist more liable to suffer from Carpal Tunnel syndrome. Discomfort and pain in low back area has been correlated with prolonged tiresome sitting and standing dental work with forward bending postures and dentists experiencing work-related MSDs have been found to be more discontented at work and are more apprehensive, agonized by poorer psychosomatic health and less assured with their future prospectives [14]. Yamalik et al., [15] provided some points to work with good posture which includes use of an adjustable chair with lumbar, thoracic and arm support, maintenance of an erect posture, placement of feet flat on the floor, working close to your body by positioning chair close to the patient, alternate work positions between sitting and standing.

In the present study, after three months only 23 respondents applied ergonomics at their work place and all agreed that ergonomics helped in reduction of musculoskeletal pain and discomfort. The DMAIC technique is a tool of six sigma method that was used by various forums to increase their output to zero defect [16]. The DMAIC technique was taken into account to apply ergonomics in the dental offices in the present study. According to the authors this is the first study in which authors have attempted to reduce MSD among dentists by first analysing the prevalence of musculoskeletal problems among them, then motivating them for implementing ergonomics and then again evaluated the affects of implementation of ergonomics.Approaches for reduction of ergonomic problems in dentists include awareness and adaptation of postural techniques that consists of sustaining a low back curve, utilization of magnification systems, adjusting dental chair, positional and postural strategies that consist of avoiding constant postures, alternating between standing and sitting, positioning patients at the proper height, positioning feet parallel to floor, repositioning the feet, rotating shoulders backwards, usage of backrests, avoiding twisting, regular periodic breaks and stretching that includes chairside directional stretching, stretching during microbreaks, releasing trigger points, clasping hands together and turning inside-out [5,14]. Physiotherapy with a psychosomatic approach and individual ergonomic instruction can help to provide better relief from pain and discomfort [1]. Dentists should try to recognize and identify their own working postures and their way of equipment usage to avoid the risks of experiencing occupational MSD.

Within the limitations of the present cross-sectional study, the results suggested that the prevalence of musculoskeletal symptoms among dentists represents a major occupational health issue for dentists, further research is required to identify risk factors and results so revealed necessitates the need of workshops to create awareness of ergonomics as a effective measures for reducing MSD among dentists.