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A Postoperative Evaluation Guideline for Computer-Assisted Reconstruction of the Mandible
Published on: January 28, 2020
Computer prediction of hard tissue profiles in orthognathic surgery
1Department of Orthodontics, National Dental Centre, Second Hospital Avenue, Singapore 168938.
Summary
Computer-Assisted Simulation System for Orthognathic Surgery (CASSOS) 2001 software accurately predicts hard tissue changes for orthognathic surgery. This study found minimal clinical differences between predicted and actual surgical outcomes.
Area of Science:
- Oral and Maxillofacial Surgery
- Medical Imaging
- Biomedical Engineering
Background:
- Orthognathic surgery planning relies on accurate prediction of hard tissue changes.
- Computer-assisted simulation systems aim to improve surgical predictability.
- Evaluating the accuracy of these prediction tools is crucial for clinical application.
Purpose of the Study:
- To assess the accuracy of the Computer-Assisted Simulation System for Orthognathic Surgery (CASSOS) 2001 software in predicting postsurgical hard tissue changes.
- To compare predicted outcomes with actual results in adult patients undergoing orthognathic surgery.
Main Methods:
- Retrospective analysis of 40 adult patients who underwent orthognathic surgery.
- Digitization of 71 landmarks from pre- and postsurgical lateral cephalographs.
- Customized cephalometric analysis with 14 measurements.
- Comparison of predicted and actual hard tissue landmarks using Student's t-test.
Main Results:
- Good correlation between repeated landmark digitization, indicating reliability.
- No statistically significant differences in 10 out of 14 cephalometric measurements.
- Statistically significant differences observed in angular measurements (SNA, U1-MxP, U1-L1, U1-SN), but clinically insignificant.
- The largest mean difference was in the interincisal angle (U1-L1), deemed clinically insignificant.
Conclusions:
- CASSOS 2001 software demonstrates accuracy in predicting hard tissue outcomes for orthognathic surgery.
- The software provides reliable predictions, supporting its use in surgical planning.
- While some angular differences were statistically significant, they did not impact clinical outcomes.

