A procedure for analyzing mandible roto-translation induced by mandibular advancement devices

Background: Sleep-Related Breathing Disorders are characterized by repeated episodes of complete or partial obstruction of the upper airway during sleep. Mandibular advancement devices represent a non-invasive treatment in reducing the number of respiratory events and in decreasing symptoms. The advancement extent of these devices is responsible for the mandibular roto-translation and its effects on the temporomandibular joint. Methods: This study defined a systematic method to assess the mandible roto translation that is caused by MADs according to a scan-to-CAD approach. Starting from a closed mouth position and simulating the oral appliance at different settings it was possible to define a local reference system that is useful for the evaluation of the mandibular roto-translation. This latter was then applied to evaluate the movements of the condyle and the mandibular dental arch. Results: MAD1 resulted in a reduced mouth opening and protrusion, while MAD2 enabled a higher degree of motion of the mandible useful for patients who need an important protrusion. Conclusions: The two devices present different dynamics. Results that are achievable employing this method can be directly used by practitioners in comparing MADs, as well as by researchers in evaluating MADs effects.