The accuracy of two-dimensional planning for routine orthognathic surgery

Area of Science:

• Orthognathic Surgery
• Craniofacial Surgery
• Orthodontics

Background:

• Two-dimensional (2D) cephalometric planning software is utilized for predicting hard tissue outcomes in orthognathic surgeries like bilateral sagittal split ramus osteotomy (BSSRO) and bimaxillary osteotomy.
• Potential errors can arise from transferring 2D data to 3D for surgical simulation and execution.

Purpose of the Study:

• To retrospectively analyze deviations between predicted and postoperative outcomes using cephalometric analyses.
• To evaluate the clinical applicability of 2D cephalometric planning for routine orthognathic surgeries.

Main Methods:

• Fifty-four patients undergoing BSSRO alone (n=21) or combined with Le Fort I osteotomy (n=33) were included.
• Surgical predictions were generated using cephalometric planning software and physical mock operations with study models.
• Postoperative cephalograms were compared to predicted cephalograms for sagittal (SNA, SNB, ANB) and vertical (ArMeGo, ML-NSL, NL-NSL) measurements.

Main Results:

• Mean differences between predicted and actual outcomes ranged from 1.1° to 2.2° for both BSSRO and bimaxillary osteotomy groups.
• No significant differences were found between measurement types or surgical procedures, indicating prediction accuracy.
• A maximum deviation of 8.5° was observed in a single case.

Conclusions:

• Cephalometric prediction remains an accurate tool for planning sagittal and vertical maxillary movements in routine orthognathic surgeries.
• For procedures requiring significant transversal dimension changes, integration with 3D planning devices is recommended to minimize discrepancies.