CBCT On The Combined Orthodontic-orthognathic Treatment Of Skeletal â…¢ Deformity In Diagnosis And Therapeutic Evaluation

ObjectiveTo compare measurements from synthesized cone-beam computed tomography (CBCT) cephalograms using orthogonal and perspective projections with those from conventional cephalometric radiographs. And to reseach specific applications of CBCT in Orthodontics-Orthognathic diagnosis and treatment of skeletalâ…¢defor-mity.Materials and methodsThe subjects for this study were 36 patients from the orthodontic and orthog-nathic Department of Tianjin Stomatological Hospital from Oct.2008 to Mar.2010. All patients were diagnosed as having Classâ…¢skeletal deformities and underwent surgical-orthodontic treatment.21 patients with non-deviation were taken lateral radi-ographs,15 patients with mandibular deviation were taken posteroanterior radio-graphs before surgical treatment. CBCT were taken before surgical treatment and measured through Ezimplant software. Two methods generated cephalometrics were measured through Winceph8.0 software for same index. CBCT were taken after treatment and cephalometric radiographs were created from 3D virtual models. 3D-image were reconstrtructed.Statistical analysis were using SPSS 17.0 package .Statistical significance was defined as an alevel of.05.Results1.With the exception of the Frankfort-mandibular plane angle (FMA), angular measurements were not statistically different for any modality.2. Both Cephalometric can be used for skeletal classâ…¢Malocclusion of clinical di-agnosis and preoperative treatment plan design of skeletal classâ…¢Malocclusion. CBCT has broad prospect for clinical application since its lots advantages.3.lateral radiographs(non-deviation):Mandible was backward shift significantly rela-tive to the skull; the relationship between maxilla and mandibular was became nor-mal; counterclockwise rotation was occurred on mandibular. 4. Posteroanterior radiographs(deviation):The width of bilateral mandibular anatomy had not been changed significantly; For the asymmetric rate of anatomical structure, the point Go had been undergone significantly to the normal range; mandibular length and mandibular body length was significantly improved integrated;5.3D-image(deviation):with the exception of the disence of Go point to FH plane, bilateral condylar height, inside diameter width of the condyle, ramus width, ramus length, mandibular body length, the other measurements of the difference was not statistically significant.6.CBCT-3D image:In the subjects of Classâ…¢skeletal deformities with mandibular deviation Go-MS, Go-FH, Co height, et al. were statistically different bilateral sides.Conclusin1.Two methods generated cephalometric have the same diagnostic significance for skeletalâ…¢Malocclusion,and CBCT image was more precise.Only CBCT was scanned in the future clinical in patients with combination therapy;2.CBCT 3D image can provide more information on the skeletalâ…¢malocclusion with mandibular asymmetry;3.CBCT can accurately analyze the characteristics of condylar anatomy for further study of temporomandibular joint; Thus, additional conventional imaging may gener-ally be avoided when CBCT scans are acquired for orthodontic diagnosis;4.Treatment effects can be accurately evaluated by the comparing of the CBCT mesurements before and after treatment. CBCT can clearly show the exact ner ves and blood vessels to avoid the surgical risk, achieve better treatment.