A CAD/CAM Maxillary Guiding for Osteotomy, Drilling and Maxillary Positioning in Orthognathic Surgery: Accuracy Analysis.

Abstract

Resin CAD/CAM guides for the maxilla are widely used and differ from custom miniplates essentially in that they do not have drill guides for screw fixation and use miniplates that must be modeled in surgery. To solve this problem, we have developed a new Maxillary guide bone-supported indicated for osteotomy, drilling, and maxillary positioning in orthognathic surgeries using standard modeled miniplates. In this study were included sixteen patients who had bimaxillary orthognathic surgery. The technique for its manufacturing is described, and its surgical accuracy was analyzed using the planning image (CT0) superimposed on the computed tomography scan post-treatment (CT1). The mean positional differences between pre-treatment and post-treatment were obtained Tri-dimensionally on the X, Y, and Z axes using four landmarks points: one bone (SNA), and three dentals (CI, RM, and LM). At Sixty-four points analyzed on the X axis of the four landmarks, only eight points were greater than 1 mm; 87.5 % of the deviations were <1 mm. For the Y-axis 78.12% of the deviations were <1 mm and for Z-axis, 76.56 %. The mean and standard deviation of the error was 0.36 (0.28) mm, 0.93 (1.07) mm, and 0.73 (0.86) mm on the X, Y, and Z axes, respectively. The X-axis demonstrated the best results among the three axes. The results of the accuracy and reliability tests were satisfactory and support the use of the proposed technique.

Keywords:
Orthognathic Surgery; Osteotomy; Le Fort; Splints; Surgical Fixation Devices; Computer-Aided Design

HIGHLIGHTS

• Proposal of a new CAD/CAM guide technique for osteotomy, drilling, and maxillary positioning.

• Standard miniplate modeled on 3D print was used similarly a custom miniplate.

• Cutting and drill resin guide was modeled virtually using a 3D scan of the drilled model surface.

• The surgical accuracy test of the proposed technique supports its use.