A novel 3D image analysis leading to different treatment planning and outcome in orthognathic surgery

  • 林 廷宣

Student thesis: Master's Thesis

Abstract

Two basic problems have been associated with traditional 2D cephalometry First 2D cephalometry is a 2D representation of 3D structures and is subjected to systematic errors such as magnification and projection error Second conventional cephalometry is difficult to evaluate patients with facial asymmetry 2D image could not give us sufficient information to diagnose and determine a suitable treatment plan especially to identify the mandibular angle of facial asymmetry patients even though it has combined with 3D dental casts This is due to the above-mentioned limits of 2D image and poor connection between 2D image and dental casts The development of 3D CT not only made us more understand the 3D nature of facial structures but also improved the insufficiency of 2D image In addition 3D CT navigation system software enables 3D reconstruction and provides a more accurate facial symmetry image analysis and prediction Our department also developed a software system of 3D image analysis and prediction The aim of the study is to know how 2D and 3D image analysis affect the treatment plans and outcome of orthognathic surgery patients The samples in the study are patients who had orthognathic surgery in NCKUH The study is divided into two parts The first part is to compare the treatment plans derived from 2D and 3D image analysis simultaneously in the same patient The second part is to compare the post treatment photographs PA cephalometry and lateral cephalometric radiographs to identify the different treatment outcome of facial asymmetry patients with treatment plans derived from 2D or 3D image analysis individually In first part 18 patients were collected Significant differences were observed in vertical movement of maxilla and sagittal movement of mandible between conventional and novel 3D treatment plans In second part 10 patients in each group were collected Evaluation of post-surgical symmetry made in PA cephalograms the Ag plane angle could be corrected better by using novel 3D method The evaluation of postoperative facial symmetry in photographs the faces were symmetrical in both groups There was almost no statistical significant difference of postoperative skeletal stability between conventional and novel 3D groups In conclusion significant differences were observed in vertical movement of maxilla and sagittal movement of mandible between conventional and novel 3D treatment plans and there was a significant difference in postoperative symmetry of Ag plane angle between conventional and novel 3D treatment outcome
Date of Award2014 Sep 4
Original languageEnglish
SupervisorDung-Yau Wang (Supervisor)

Cite this

A novel 3D image analysis leading to different treatment planning and outcome in orthognathic surgery
廷宣, 林. (Author). 2014 Sep 4

Student thesis: Master's Thesis