Comparison of the Effects of Modified Jones Device and Face Bow in Molar Distalization

Objective To explore the clinical effects of modified Jones device and face bow in molar distalization.Methods 18 patients with mild-to-moderate Angle class Ⅱ malocclusion caused by crowded front teeth were selected in this study,and they could be treated by tooth extraction or non- extraction correction. The selected patients were randomly divided into two groups,and were treated by molar distalization with modified Jones device and face bow,respectively. X-ray cephalometric and model measurement was performed in patients in two groups before and after treatment.Result Both modified Jones device and face bow had obvious effects in molar distalization, but had statistically significant differences in the molar moving speed, anterior overjet and the inclination of the first molar.Conclusions Both methods can effectively push the maxillary molar to far,but face bow method needs good cooperation of patients and can't continue to work,so the clinical curative effect is not very stable. By modified Jones device can more quickly and effectively promote maxillary molar move far,and does not depend on the patient's coordination,so it is worth clinical popularizing.