Analysis of mandibular movements and chewing cycles in patients with Skeletal Class III: a preliminary study using 3D electromagnetic articulography

Background. Study of mandibular movements (MM) was introduced into oral physiology to increase knowledge of the stomatognathic system and achieve better results in treatments. Electromagnetic Articulography (EMA), specifically the most recent equipment, AG501, plays an important role in these objectives, since it permits description of movements in 3 dimensions by recording the position of body parts at a high sampling frequency. Aim. The aim of the present study was to report an exploratory analysis of the geometrical characteristics (area, trajectory, ranges) and the velocity of border and functional MM in patients with Skeletal Class III by the use of EMA AG501. Material and methods. Two individuals with skeletal class III, patients at the Dental Teaching Clinic of the Dental Faculty of Universidad de La Frontera, Chile, were assessed and the results were processed with computer scripts developed specifically for this study. Results. The result produced from border MM was Posselt's envelope in the frontal and sagittal planes, allowing analysis of the morphology and area. The result obtained from the mastication movements was an assessment of the area of each chewing cycle, which was compared with the area of the envelopes in the various planes. We also analysed the number, frequency and velocity of cycles, comparing them with available data.