Objective: The analysis of potential discrepancies in condyle position among different occlusal relations (centric relation and maximum intercuspidation) is a key diagnostic component when treating children with unilateral posterior crossbite. Due to strict requirements imposed by ethics committees, and new regulations regarding the use of X-rays, radiological examinations (axial cephalometric radiographs or postero-anterior cephalometric radiographs) are not feasible. Thus the aim of this study was to apply an alternative procedure for the assessment of condylar deviations.
Probands and methods: : We employed ARCUS digma, a measuring system based on ultrasound technology, to record condylar differences occurring in 65 children (6.9+/-2.0 years of age) with functional unilateral posterior crossbite in late deciduous and early mixed dentition. After randomization, 31 patients underwent early orthodontic treatment (bonded palatal expansion appliance and U-bow activator), whereas 34 patients remained untreated. Examinations were carried out at the beginning (T1) and after 12 months of treatment (T2). A three-dimensional (3D) assessment of deviations between maximum intercuspidation and centric position was carried out. Statistical analysis was performed using the SPSS 12.0 software program.
Results: Initially, the electronic position analysis revealed no significant differences between the control and therapy groups. A mean condylar deviation of > 2 mm was noted at T1 in the sagittal, frontal and transversal planes for crossbite and the noncrossbite sides. This difference was reduced in the therapy group, a finding that proved statistically highly significant (p<0.001). We also observed a highly significant (p<0.001) difference between the control and therapy groups at T2.
Conclusion: The Münster concept for early treatment of functional unilateral posterior crossbites in late deciduous and early mixed dentition significantly improved the treated patients' occlusion in comparison to a randomized control group, which exhibited no spontaneous self-healing tendencies.