To evaluate the effects and clinical application of molar intrusion with a new mandibular molar intrusion appliance.

7 patients who needed mandibular molars intrusion to correct open-bite were selected. To evaluate effects of molar intrusion, clinical examination, dental model analysis and aphalometric analysis by Winceph 7.0 software were used before and after intrusion treatment, SPSS 17.0 software was used for data analysis.

All the mandibular molars were intruded successfully in an average time of 4.0 months. Cephalometric analysis before and after treatment showed that the average amount of mandibular first molars intrusion were (1.92 ± 0.44) mm. The vertical distance to the reference plane (MP plane) per and post treatment was statistically significant (P＜0.05). The average amount of maxillary first molar intrusion was (0.36 ± 0.25) mm, with no significant difference in vertical distances to reference plane (PP plane) (P＞0.05). No signs of root resorption was obsersed in radiograph of the intruded mandibular molars.

The new mandibular molar intrusion appliance has a remarkable clinical effect in correcting anterior open bite without obvious periodontal tissue damage and root resorption. teeth intrusion with the new appliance has a significant effect without apparent destruction of the periodontal tissue and root resorption.

To assess the result of treatment in Class Ⅱ malocclusion subdivision with unilateral Forsus appliance.

23 patients with Class Ⅱ malocclusion subdivision were selected, who were treated with Straight wire fixed appliance in combination with unilateral Forsus appliances while another 27 patients were untreated as control group. Lateral cephalographs were taken before and after the comprehensive treatment, and the indicators of dental, skeletal, and soft tissue profile were measured.

The Forsus appliance can correct Class Ⅱ malocclusion subdivision through distalizing the upper teeth and moving the lower teeth mesially. Midline can be corrected at the same time. There was a statistically significant difference in the amount of tooth movement (P＜0.05).

Forsus appliance is an effective device for treating Class Ⅱ malocclusion subdivision, which can induce significant dental and soft tissue changes.