3D motion analysis of cervical spine joints of dental hygiene students and dental hygienists during scaling operation / 대한구강보건학회지

Objectives@#This study aimed to objectively evaluate factors associated with musculoskeletal disorders by measuring the range of motion of the cervical spine. Using three-dimensional motion analysis, the degree of flexion, lateral flexion and rotation were compared between dental hygiene students and dental hygienists during dental scaling. @*Methods@#Muscle activity in the range of motion of the cervical vertebrae was measured in 35 dental hygiene students and 15 dental hygienists while scaling. Data were collected and processed using the biofeedback exercise function of the 2EM (4D-MT, Relive, Gimhae, Korea), an electromyography measuring device. A three-dimensional motion analysis sensor was attached to the subject’s right external auditory canal, and the joint angle was measured at 20 Hz. @*Results@#Cervical flexion (15°-45°) was measured higher in dental hygienists than in students.Cervical flexion within 15° of the normal range was higher in students than in dental hygienists. For cervical lateral flexion of 15°-45° and >45°, dental hygienists measured higher than students. In contrast, cervical lateral flexion within 15° of the normal range was higher among students than dental hygienists. Cervical rotation (15°-45°) was measured higher in dental hygienists than in students. No dental hygienist’s cervical rotation measured over 45°, and more students reached the 45° measurement than dental hygienists. @*Conclusions@#Flexion, lateral flexion, and rotation were measured higher in dental hygienists then dental hygiene students. The results indicated that the range of motion of the cervical spine in the two groups exceeded the average scores for normal flexion, lateral flexion, and rotation by more than 15°, thereby increasing the risk of musculoskeletal disorders.

3D motion analysis of cervical spine joints of dental hygiene students and dental hygienists during scaling operation / 대한구강보건학회지

Objectives@#This study aimed to objectively evaluate factors associated with musculoskeletal disorders by measuring the range of motion of the cervical spine. Using three-dimensional motion analysis, the degree of flexion, lateral flexion and rotation were compared between dental hygiene students and dental hygienists during dental scaling. @*Methods@#Muscle activity in the range of motion of the cervical vertebrae was measured in 35 dental hygiene students and 15 dental hygienists while scaling. Data were collected and processed using the biofeedback exercise function of the 2EM (4D-MT, Relive, Gimhae, Korea), an electromyography measuring device. A three-dimensional motion analysis sensor was attached to the subject’s right external auditory canal, and the joint angle was measured at 20 Hz. @*Results@#Cervical flexion (15°-45°) was measured higher in dental hygienists than in students.Cervical flexion within 15° of the normal range was higher in students than in dental hygienists. For cervical lateral flexion of 15°-45° and >45°, dental hygienists measured higher than students. In contrast, cervical lateral flexion within 15° of the normal range was higher among students than dental hygienists. Cervical rotation (15°-45°) was measured higher in dental hygienists than in students. No dental hygienist’s cervical rotation measured over 45°, and more students reached the 45° measurement than dental hygienists. @*Conclusions@#Flexion, lateral flexion, and rotation were measured higher in dental hygienists then dental hygiene students. The results indicated that the range of motion of the cervical spine in the two groups exceeded the average scores for normal flexion, lateral flexion, and rotation by more than 15°, thereby increasing the risk of musculoskeletal disorders.

Assessment of risk factors for work-related musculoskeletal disorders of the neck in dental hygienists using video recording / 대한구강보건학회지

OBJECTIVES: Work-related musculoskeletal disorder (WMSD) of the neck is a frequent health problem in dental hygienists. This study was conducted to assess the risk factors of neck musculoskeletal disorder (neck MSD) using video recording. METHODS: The subjects were 50 currently working dental hygienists who agreed to participate in this study. A standardized questionnaire about WMSD (NIOSH/KOSHA) was distributed and video recording for neck posture and motion was performed between August and October 2012. The video recording was performed for 5 minutes using the reflective marker attachment on the 7th cervical vertebra. Major observation points included neck flexion angle, number of flexions, and length of static work when performing scaling and prosthetic procedures. Data were analyzed using MedCalc (ver 12.3.0, Mariakerke, Belgium), and the risk factors for neck MSD were assessed using simple and multiple variate analysis. RESULTS: The mean age and work experience of the subjects were 27.9 years and 5 years respectively. The prevalence of neck MSD symptoms that met NIOSH/KOSHA's criteria was 48%. The mean angle of neck flexion was 54.6°, mean maximum angle of flexion was 64.8°, and the mean time of static posture was 4.8 minutes during the 5 minutes recording interval. In the multiple logistic regression analysis adjusted by career, daily work time, and posture, the prevalence of neck MSD symptoms increased by 1.47 times (95% CI=0.24–9.48) with flexion >45°, and by 4.90 times (95% CI=0.91–26.4) when a static posture was preserved for >4.8 minutes CONCLUSIONS: The measured angle of flexion and time of preserved static posture identified further serious than expected. Therefore, to reduce the risk of neck MSD, reasonable and practically applicable guidelines to correct neck bending and tilting, especially to relax the long static posture associated with flexion, should be prepared.

Bactericidal Effect of Electrolyzed Oxidized Water Generated by WATRIX(R)-10G against Clinical Isolates / 병원감염관리

Background: Disinfection is essential for the prevention of hospital infection. The electrolyzed oxidized water generated by WATRIX(R)-10G(Microbank co., Korea) was recently developed as a disinfectant. This is not costly and does not cause any clinical problems and environmental pollution. We evaluated bactericidal activity of the electrolyzed oxidized water generated by WATRIX(R)-10G against several clinical isolates of bacteria and yeasts. Methods: 23 strains of bacteria and four strains of yeast were exposed to the electrolyzed oxidized water(40&50ppm HOel) generated by WATRIX(R)-10G for the various periods (0.5, 1, 2, 4, 10, 15, 30, 60minutes). After the exposure to electrolyzed oxidized water, 0.01mL of mixture of microorganisms and electrolyzed oxidized water was inoculated into brain-heart infusion broth or onto Sabouraud dextrose agar and incubated at 35degrees C for 48 hours. Results: All strains of bacteria and yeast were killed within 30 seconds after an exposure to 40 ppm of electrolyzed oxidized water. All vegetative forms of Bacillus subtills were killed within 10, 4 and 2 minutes in 30, 40 and 50 ppm of electrolyzed oxidized water. respectively. But, all spore forms of Bacillus subtilis were killed within 30, 15 and 10 minutes in 30, 40 and 50 ppm of electrolyzed oxidized water respectively. Conclusions: This study showed that the electrolyzed oxidized water generated by WATRIX(R)-10G was effective not only for the disinfection of commonly isolated bacteria and yeast from hospital but also against spore-forming bacteria. It may be recommended that WATRIX(R)-10G should be used for the effective disinfection of skin, instruments ,hospital floors and hand-washing.

Bactericidal Effect of Electrolyzed Oxidized Water Generated by WATRIX(R)-10G against Clinical Isolates / 병원감염관리

Background: Disinfection is essential for the prevention of hospital infection. The electrolyzed oxidized water generated by WATRIX(R)-10G(Microbank co., Korea) was recently developed as a disinfectant. This is not costly and does not cause any clinical problems and environmental pollution. We evaluated bactericidal activity of the electrolyzed oxidized water generated by WATRIX(R)-10G against several clinical isolates of bacteria and yeasts. Methods: 23 strains of bacteria and four strains of yeast were exposed to the electrolyzed oxidized water(40&50ppm HOel) generated by WATRIX(R)-10G for the various periods (0.5, 1, 2, 4, 10, 15, 30, 60minutes). After the exposure to electrolyzed oxidized water, 0.01mL of mixture of microorganisms and electrolyzed oxidized water was inoculated into brain-heart infusion broth or onto Sabouraud dextrose agar and incubated at 35degrees C for 48 hours. Results: All strains of bacteria and yeast were killed within 30 seconds after an exposure to 40 ppm of electrolyzed oxidized water. All vegetative forms of Bacillus subtills were killed within 10, 4 and 2 minutes in 30, 40 and 50 ppm of electrolyzed oxidized water. respectively. But, all spore forms of Bacillus subtilis were killed within 30, 15 and 10 minutes in 30, 40 and 50 ppm of electrolyzed oxidized water respectively. Conclusions: This study showed that the electrolyzed oxidized water generated by WATRIX(R)-10G was effective not only for the disinfection of commonly isolated bacteria and yeast from hospital but also against spore-forming bacteria. It may be recommended that WATRIX(R)-10G should be used for the effective disinfection of skin, instruments ,hospital floors and hand-washing.