Kineziographic research of patients with cross bite

The paper describes the use of an objective method for the quantitative analysis of the relationship between the posterior cross-bite and the occurrence of occlusive interferences and damages to the mandible muscle elevator. Two groups of subjects were selected for the analysis: 10 patients with unilateral cross-bite and 10 students without any symptoms of temporomandibular disorders (TMD). By means of the Robert Jenkelson K5A kinesiograph we measured maximal opening velocity of the mandible (mm/s), maximal-closing velocity (mm/s), first tooth contact velocity and displacement in the vertical plane at the maximal intercuspidation (mm). The following values were obtained: maximal-opening velocity in the first group was 349 mm/s and 380 mm/s in the control group. This difference was incidental. The maximal closing velocity in the study group was 204.9 and 345.2 in the control group (p < 0.05). The first tooth contact velocity in the study group was 75.93 and 325 in the control group (p < 0.01). Displacements in the vertical plane at the maximal intercuspidation in the investigated group was 0.24 +/- 0.01 mm, while in control group that value was 0.12 +/- 0.012 mm.