A Melicrative FR-Ⅲ Appliance In Treatment Of ClassⅢ Malocclusion With Mixed Dentition

The treatment is remarkable by FR-â…¢appliance to classâ…¢malocclusion with mixed dentition who are anterposterior dysplasia in the sagittal relationship of maxilla and mandible by hypoplasia of the maxillary or mandible protrusion on configuration and function. The classic FR-â…¢appliance is very complex and the production procedures are cumbersome and error-prone, on the other hand the classic appliance is big and uncomfortable, but the patients all are children, For the two reasons above, there are many cases of failure. Experts from home and aborad are trying to improve the tranditional FR-â…¢appliance for the complex and ragile structure. The meliorative FR-â…¢appliance designed by me carry on a lot of improvement on the basis of Tentis.Objective:The aims of this study were to evaluate the clinical effect of the meliorative FR-â…¢appliance to classâ…¢malocclusion with mixed dentition.Materials and Methods:The meliorative FR-â…¢appliance were used in 38 cases with classâ…¢malocclusion during the metaphase of mixed dentation. All the 38 patients could put their mandibles back to the retruded contact position. After treatment for 6-15 months, All the 38 patients molar and canine relationship was mesio-relationship and the over jet and over bite of anterior teeth was normal. Cephalometric analysiswas performed before and aftertreatment. SPSS Statistics 17.0 software was used for statistical analysis.Results:The SNA angle,ANS-Ptm length and S-Ptm length increased show that the maxilla length increased and the maxilla moved forward. The S-Co length and ANB angle did not changed significantly show that the mandibular bone stayed at the retruded contact position.The U1-NA angle and U1-SN angle increased show that the maxillary incisors lip-side expansion.The L1-NB angle, L1-MP angle decreased and the FMIA angle increased show that lower incisors linguoclination. The Co-Po length increased show that the meliorative FR-â…¢appliance can not limit the growth of the mandibula.The MP-SN angle,MP-FH angle and Y-Aix angle increased show that the mandibula rotated downwards and backward.Conclusions:(1).The prevention and treatment of the meliorative FR-â…¢appliance to classâ…¢malocclusion with mixed dentition are noticeably effective. The meliorative FR-â…¢appliance bring the maxilla length increased and moved forward, the maxillary incisors lip-side expansion, lower incisors linguoclination and the mandibula rotated downwards and backward so that upper side tooth bites behind the lower teeth in mixed dentition could be treated.(2). The meliorative FR-â…¢appliance is simpler, smaller, more comfortable for patients. It also can be used in conjunction with fixed appliances.