An innovative method to analyse the range of border mandibular movements using 3D electromagnetic articulography (AG501) and MATLAB

Mandibular movements have been investigated for decades in dentistry to diagnose problems related to the masticatory system and temporomandibular joint. This study proposes a novel method for analysing the border movements of the mandible using 3D electromagnetic articulography and scripts developed in MATLAB software, which has the advantages of free and accurate assessment of movements in three dimensions from different angles. Methods: Mandibular border movements of six patients were recorded using a magnetic articulograph AG501 with 5 sensors (4 static and 1 dynamic) in the protocols: 1. maximum mouth opening associated with noncontact laterality movements; 2. border movement in the frontal plane; and 3. border movement in the sagittal plane. Results: The means of the parameters evaluated were 39.9 ± 4.7 mm for mouth opening (displacement on the vertical axis); 61.6 ± 6.5 mm for opening along the three-dimensional trajectory; 11.3 ± 2.1 mm and 11.6 ± 2.5 mm for displacement of non-contacting right and left laterality, respectively; (Posselt’s envelope of motion-frontal view) 481.5 ± 110 mm2 frontal border movement polygon area; and 65.3 ± 31.6 mm2 sagittal border movement polygon area (Posselt’s envelope of motion-sagittal view). Conclusion: The method for analysing border mandibular movement proposed in this study using EMA AG501 and MATLAB scripts generate graphical data similar to classic studies and provided high precision data in a systematic, easy and intuitive way, allowing for further analysis with patients in different clinical conditions as well as the possibility of association with different analysis modalities.