A magnetic resonance imaging investigation of temporomandibular joint in class II~1 malocclusion treated with Herbst appliance

Objective:To study the remodeling of temporomandibular joint quantitatively.Method:18 patients exhibiting Class II division 1 malocclusion were selected. In each subject, 4 MRI of both temporomandibular joints were taken before and after treatment. On the MRI, the growth of condylar cartilage was measured and Kurita,s analysis method was used to study the relationship changes of condyle,articular disk,and glenoid fossa.Result:①Signs of condylar cartilage remodeling were seen at the posterosuperior border:the maximum thickness of the bright sign was 1.3 mm,the minimum was 0.6 mm and the mean was 0.93 mm.②The relationship of condyle,articular disk,and glenoid fossa changed: concerning TC/TP and TD/TP, there was statistic difference between before and after treatment, concerning TD/TC,there was no statistic difference between before and after treatment.Conclusion:Herbst appliance can stimulate condyle,articular disk,and glenoid fossa to remodel adaptively.