Treatment of ClassIII malocclusion with oral modified protracting appliance in mixed dentition

Objective To study a new treatment method of Class Ⅲ malocclusion in mixed dentition.Method Thirteen skeletal ClassⅢ patients with an average age of 9.6 years old were selected and treated with oral modified protracting appliance.Lateral cephalometric radiographs were taken before and after treatment.The data were measured based on X-ray and analyzed.Result After 3 to 6 months protracting and 2 to 3 months retaining.All the patients reestablished fine molar relationship and obtained normal bite overjet.Facial profiles improved greatly.The SNA increased 2.46 degrees;ANB increased 3.73 degrees;Wits value increased 3.43mm;SNB decreased 1.27 degrees (P 0.01).The changes of L1-MP,NLA and ULP also had statistically significant difference (P0.05).But the changes of PP-SN,U1-SN and LLP had no statistically significant difference (P0.05).Conclusion Oral modified protracting appliance with mask protraction could promote maxilla forward development effectively and it is an effetive method of treating ClassⅢ malocclusion in the mixed dentition.