Purpose : The purpose of this study was to analyze some factors that can cause incidence of the muscle and skeletal system trouble, by which Dental Hygiene Students examine the pain and the inconvenient feeling according to kinds in manual implements and the usability in the level of manipulating and maintaining the manual implement, in the actual training of the intra oral cavity along with mannequin given the scaling practice. Methods : Targeting 18 female juniors for the department of dental hygiene, who had directly practiced oral prophylaxis for 2 years, the questionnaire research was carried out right after the mutual practice in the intra oral cavity along with mannequin. Results : It was indicated that there is no big difficulty both in intra oral cavity and mannequin in terms of manipulating implement with a method of maintaining the rightly hand fixing or of grasping the trans formative pencil and of controlling force given manipulating the implement. How to grasp a trans formative pencil was indicated to be more difficult in the intra-oral manipulation(p<.05). Pain and inconvenient-feeling level, which occur in muscle and skeletal system during practicing the scaling in mannequin, were indicated to be in order of shoulder, wrist, neck, waist, elbow, and headache. Conclusion : There was no big difference in the pain and the inconvenient feeling in muscle and skeletal system according to mannequin and intra-oral environment given manipulating tile manual implement. However, there was difference in manipulating the implement with a method of grasping transformative pencil. The pain and inconvenient feeling in muscle and skeletal system were the highest both in shoulder and wrist.