PRECISION OF ORTHOGNATHIC SURGERY - A COMPUTERIZED CEPHALOMETRIC ANALYSIS OF 27 PATIENTS

The precision of orthognathic surgery was evaluated in 27 patients. Ri gid internal skeletal fixation was used without intermaxillary fixatio n. A computerized cephalometric program package (TIOPS) was utilized i n the preoperative analysis, surgical planning, and postoperative exam ination. The mean positional difference of the cephalometric landmarks between planned and observed outcome ranged from -0.4 to 0.7 mm. Only one reference point (pm) differed statistically significantly from th e plan (P=0.02). Ail other mean differences in point location were of a magnitude that was not statistically different from zero (P>0.05). I t was concluded that no systematic sources of error could be demonstra ted. However, the range of random variation in the individual cases le ft room for considerable improvement.