REPRODUCIBILITY AND CONDYLAR POSITION OF A PHYSIOLOGICAL MAXILLOMANDIBULAR CENTRIC RELATION IN UPRIGHT AND SUPINE BODY POSITION

Better understanding of the physiologic features of the masticatory sy stem has led to the evolution of the concept of maxillomandibular cent ric relation from the mechanical to physiological bases, However, the reproducibility of physiologic methods for centric relation determinat ion has been criticized, In this clinical study the swallowing techniq ue was modified to establish a physiologic centric relation in a repro ducible manner, Condylar and disk positioning and reproducibility of t he proposed modified swallowing technique (MST) were compared with the same parameters of a traditional technique, namely, the chin point gu idance technique (CGT), Both techniques were studied with the patient in the upright and supine positions, Three interocclusal records were obtained for each technique-position combination for each of the 30 pa tients, The recorded maxillomandibular relations were analyzed on the three-dimensional analyzer, MST positioned the condyles in a more supe roanterior position than did CGT, which was interpreted as a better se ating of the condyles and disk in the articular fossae, There was no s ignificant difference in reproducibility between MST and CGT on x, y, or z axes (p > 0.05), indicating that it is possible to establish a ph ysiologic centric relation in a reproducible manner, The term ''functi onal centric area'' was proposed in this study to define a neuromuscul arly determined centric occlusal scheme.