No abstract

Background. The aim of this study was to propose and establish the proof of concept of an approach to synchronize 3D Electromagnetic Articulography (3D-EMA) with Surface Electromyography (SEMG) based on the standard components of this equipment. Methods. The appropriate equipment and instruments were selected according to specifications stablished for this study. Once the necessary equipment was gathered, the proper conditions to synchronize the signals were created. Thus, we selected a SEMG with a switch module incorporated to be able to achieve synchronization of the signals. After the system setup was stablished, chewing tasks were recorded on a healthy volunteer, collecting a proof-of-concept database. The variability among recordings of the database were analyzed in terms of its standard deviation in order to detect possible interferences. Results. The analysis of the chewing task recordings obtained with the synchronized 3D EMA and SEMG signals in the present study did not reveal significant distortions, and all values were within those that had been given by the manufacturers of both of the systems. The method presented the advantage of using only components that are already included with the equipment employed. Conclusion. The method of analysis described in this paper is an effective tool that facilitates the investigation of mandibular movements synchronized in two domains: articulatory movements and electromyographic activity. Thus, it seems promising that it can be applied in different clinical situations to improve the analysis of the complexity of masticatory activity in addition to being able to generate new insights on this topic.

Mandibular movement recording is relevant for the planning and evaluation of mandibular function. These movements can include mandibular border movements (MBM) or mastication. Our objective was to characterize the kinematics of MBM and mastication among skeletal classes I, II, and III in the three spatial planes. A descriptive cross-sectional study was conducted with 30 participants. Instructions were provided on how to form Posselt’s envelope and to perform masticatory. After data processing, we obtained numerical values for the areas, trajectories, and ranges of MBM that formed Posselt’s envelope and the values for speed, masticatory frequency, and the areas of each masticatory cycle. Significant differences were found in the area of Posselt’s envelope in the horizontal plane between skeletal classes I and III and in the range of right laterality between skeletal classes II and III. Mastication showed significant differences in the area of the masticatory cycles in the horizontal plane between classes I and III and between classes II and III. In conclusion, there were differences in MBM and mastication between skeletal classes III and I in the horizontal plane. This study supports the need to establish normal values for mandibular kinematics in skeletal class III.