EXPERIMENTAL OCCLUSAL INTERFERENCES .5. MANDIBULAR ROTATIONS VERSUS HEMIMANDIBULAR TRANSLATIONS

Frontal plane mandibular rotations and corresponding hemimandibular tr anslations were studied in vitro by using direct observations of a hum an cadaver mandible and in vivo by using the indirect observations of rotational electrognathography. A comparison between the two methods s howed that rotational electrognathography erred in measuring the clini cally relevant hemimandibular translations resulting from mandibular r otations having a unilateral molar point (simulated occlusal interfere nce) as the pivot of frontal plane torque. In vitro frontal plane rota tions about a unilateral mandibular molar tooth (simulated occlusal in terference) suggested that the resulting hemimandibular upward transla tions of the lateral portion of the mandibular condyle, contralateral to the molar tooth, would cause considerable compressive loading of th e temporomandibular joint disc.