Condylar asymmetry in children with functional unilateral posterior crossbite and changes in condylar position after treatment

Objective To examine condylar asymmetry in children with functional unilateral posterior crossbite and to study the changes in condylar position after correction of the crossbite by maxillary expansion.Methods Twenty-two children aged from 6.0 to 8.5 years(mean,7.5 years) with unilateral posterior crossbite were compared with 22 children aged from 6.5 to 9.0 years(mean,7.5 years) with normal occlusion.Pretreatment panoramic radiographs were used to study condylar asymmetry and condylar asymmetry indices were analyzed.In addition,the anterior,superior,and posterior joint spaces were measured to determine differences of relative condylar position before and after crossbite correction with the use of TMJ transcranial lateral cephalometric radiographs.All data were analyzed with SPSS 12.0 software.Results The patients with unilateral posterior crossbite had more asymmetrical condylar relationship.Compared with the controls,anterior joint space was smaller,whereas,upper and posterior spaces were greater on the noncrossbite side before treatment.Relative condylar position was more anterior on the noncrossbite side,compared with the crossbite before treatment,but similar on both sides after treatment.There were no statistically significant differences in condylar for the variables describing skeletal asymmetry of the condyles in crossbite group.Conclusion Children with unilateral posterior crossbite have asymmetrical relative condylar position,but they have symmetrical condylar shape.The correction of posterior crossbite results in a more symmetrical condylar position.