EVALUATION OF VIDEO IMAGING PREDICTION IN COMBINED MAXILLARY AND MANDIBULAR ORTHOGNATHIC SURGERY

The purpose of this study was to evaluate the accuracy of the soft tis sue profile ''line drawings'' predicted by Quick Ceph Image in combine d maxillary and mandibular orthognathic surgical procedures. Preoperat ive (mean = 27.7 days presurgical) and posttreatment (mean = 11.5 mont hs postsurgical) lateral cephalograms of 40 white patients (10 males a nd 30 females) who had completed treatment that involved orthodontics, one-piece LeFort I osteotomy, and mandibular advancement by bilateral sagittal split osteotomy with or without genioplasty were used in the study. Forty-five lateral hard and soft tissue landmarks were digitiz ed, using the ''on-screen'' digitizing option, for each cephalogram an d for each computer predicted posttreatment tracing. A customized anal ysis consisting of 24 linear and 4 angular measurements was used to an alyze the differences between the actual posttreatment cephalometric l andmark measurements and computer predicted landmark measurements. Sta tistically significant differences between the posttreatment cephalome tric soft tissue profiles and the computer predicted soft tissue profi les were analyzed for the total sample, patients grouped according to: magnitude and direction of maxillary movements, adjunctive genioplast y procedure, V-Y closure of the LeFort I incision, and gender and age differences. The results indicated that for some of the soft tissue la ndmarks, differences were found between the posttreatment and the comp uter predicted profiles. Differences between the predicted and actual posttreatment soft tissue profiles may be attributed to the inaccuracy of Quick Ceph Image's default soft to hard tissue ratios when predict ing the soft tissue response to combined maxillary and mandibular orth ognathic surgical procedures.