Effects of Distal Jet for molar distalization on eruption of second molar

    BAI Yuª²Ming, DUAN Yinª²Zhong, LI Dong, GUO Jun

    Department of Orthodontics, Stomolgocial College, Fourth Military Medical University, Xi¬ðan 710033, China

    ¡¾Abstract¡¿ AIM: To assess the effects of Distal Jet for the first molar distalization on the eruption of maxillary second molar. METHODS: The dental cast and cephalograms of 28 patients with class¢ò malocclusion were analyzed. The group of Distal Jet appliance had 13 patients, and the group of control orthodontics treatment (nonª²extraction) had 15 patients. 9 linear and proportional, angular measurements were made. Analysis of variance was applied in statistical analysis of the two groups. RESULTS: Significant difference was found in the 9 linear and proportional, angulars measurements in the two groups(P<0.01). The mean mesiobuccal rotation of the second molars was 4.2¡ã¡À0.6¡ã. The changes of m2ª²SN (¡ã) (before treatment 54.3¡À3.7, after treatment 48.0¡À3.5) and m2ª²Ptv (mm) (before treatment 12.8¡À1.6, after treatment 9.7¡À1.4) in the second molar region indicated that both expansion and tipping occurred in the second molar. CONCLUSION: Mesiobuccal rotation and vestibular drift of second molars occur with the application of Distal Jet for first molar distalization. ......