Comparison Of Eiffcacy In Patients With Class â…¢ Malocclusion Treated With Single Or Bimaxiltary Orthognathic Surgery

Class Ⅲ skeletal malocclusion is one of the most common types in orthodontic cases.Most persons with Class Ⅲ malocclusions show combinations of skeletal and dentoalveolarcomponents. This kind of malocclusion seriously affect facial appearance, the edentulousfunction and mental health. The usual ways to deal with it are growth modification,orthodontic camouflage and orthognathic surgery. According to the surgical site orthognathictreatment can be divided into single-jaw surgery and Bimaxillary surgery. Differenttreatment options for the treatment process from the guiding role, and will ultimately affectthe treatment outcome.Objective:The purpose of this study was to analyze the hard and soft tissues before and at the endof the treatment and the change of the tissues between them in patients with Skeletal AngleClass Ⅲ malocclusion following single or Bimaxillary orthognathic surgery. According tothe surgical approach it was divided into single-jaw surgery group (mandibular only,18cases)and Bimaxillary surgery group (20cases). The result of this study is useful for preoperativeand postoperative diagnostic design, treatment, and ultimately to obtain the desiredtherapeutic effect to provide a reliable reference.Methods:The author selected38skeletal Class Ⅲ malocclusion patients in OrthodonticDepartment, College of Stomatology,Jilin University. Patients were deviede into single-jawsurgery group and Bimaxillary surgery group. There are18patients in the single-jaw group,with the mean age of19.77±2.56years old and the total course average of19.83±3.93months. There are20patients in the single-jaw group, with the mean age of19.15±2.99years old and the total course average of22.0±3.73months.37hard and soft tissuelandmarks、22angles (angle of16hard tissue,6soft tissue angle) and six linear variables inthe x-ray cephalometric lateral radiographs were selected to analyze the hard and softtissues before and at the end of the treatment and the change of the tissues between them.Alldata were analyzed by SPSS19.O software. Results:1. There are no difference between two groups in patients’ age and course.2. Mandibular surgery patients had better pretreatment SNA-angle、 ANB-angle、G-SN-Pos angle、U1/SN angle、NLA、wits values and overbite than Bimaxillary surgerypatients.3. Bimaxillary surgery patients had better posttreatment SNA-angle、 FH/MP-angle、SN/MP-angle and U1/NA-angle than mandibular surgery patients；Bimaxillary surgery ismore conducive to gain better skeletal relationship and more completely upper incisordecompensation and more mandibular counterclockwise rotation;4. Patients with pretreatment SNA-angle、U1/SN angle and NLA within one standarddeviation and mild maxillary hypoplasia are suggested to accept mandibular surgery only.