Three-dimensional virtual planning in orthognathic surgery enhances the accuracy of soft tissue prediction

doi:10.1016/j.jcms.2015.04.006

Journal of Cranio-Maxillofacial Surgery

Volume 43, Issue 6, July 2015, Pages 918-925

https://doi.org/10.1016/j.jcms.2015.04.006 Get rights and content

Abstract

Introduction

Throughout the history of computing, shortening the gap between the physical and digital world behind the screen has always been strived for. Recent advances in three-dimensional (3D) virtual surgery programs have reduced this gap significantly. Although 3D assisted surgery is now widely available for orthognathic surgery, one might still argue whether a 3D virtual planning approach is a better alternative to a conventional two-dimensional (2D) planning technique. The purpose of this study was to compare the accuracy of a traditional 2D technique and a 3D computer-aided prediction method.

Methods

A double blind randomised prospective study was performed to compare the prediction accuracy of a traditional 2D planning technique versus a 3D computer-aided planning approach. The accuracy of the hard and soft tissue profile predictions using both planning methods was investigated.

Results

There was a statistically significant difference between 2D and 3D soft tissue planning (p < 0.05). The statistically significant difference found between 2D and 3D planning and the actual soft tissue outcome was not confirmed by a statistically significant difference between methods.

Conclusions

The 3D planning approach provides more accurate soft tissue planning. However, the 2D orthognathic planning is comparable to 3D planning when it comes to hard tissue planning. This study provides relevant results for choosing between 3D and 2D planning in clinical practice.

Introduction

Evolution in medical imaging has produced an emerging trend of 3D virtually assisted computer planning programs. Virtual 3D computer-aided planning is becoming more and more important in orthognathic surgical treatment planning. It not only embodies a powerful communication tool between the surgeon, the orthodontist, and the patient, but it is also considered to have an added value in diagnosis and planning of orthognathic surgery. As the terminology implies, classical 2D planning is a profile planning which does not sufficiently control the third dimension (Chabanas et al., 2004). The third dimension is often of crucial importance, such as when treating facial asymmetry. Face bow registration combined with anthropometrical analysis generates additional control of the third dimension, but theoretical errors and inaccuracies easily occur (Olszewski and Reychler, 2004). There are scientific literature reports on the accuracy of 3D computer-aided planning, but this has not yet led to widespread use of 3D virtual planning of orthognathic surgery in common clinical practice (Chabanas et al., 2004, Kaipatur and Flores-Mir, 2009, Marcheti et al., 2011, Mollemans et al., 2007, Shafi et al., 2013, Westermark et al., 2005, Xia et al., 2009, Zinser et al., 2013).

In this study, we focused on the accuracy of the hard and soft tissue profile predictions and the time-consuming aspects of both planning approaches in routine daily practice, which we consider important from a clinical perspective. The design of this study was set up to compare the accuracy of 2D and 3D orthognathic planning in their 2 common directions (depth and height).

Section snippets

Materials and methods

The study protocol was approved by the local ethics committee (Dirsec/EC/134The, AZ Monica, Antwerp, Belgium). The study included 66 patients (29 males, 37 females) who were operated on by the same surgeon. 58 patients had an Angle Class II malocclusion, and 8 patients had an Angle Class III malocclusion. 46 Patients underwent a bimaxillary osteotomy, of which 21 patients also received a genioplasty. 17 Patients underwent a bilateral sagittal split osteotomy of the lower jaw, of which 6

Results

A comparison between the demographic characteristics of 2D and 3D patients showed that both groups were similar. No significant differences were observed. For hard tissue measurements, the mean differences between the postoperative clinical results and the planned hard tissue cephalometric points for 2D and 3D planning were 1.71 mm and 1.42 mm in the horizontal (depth) direction and 1.69 mm and 1.44 mm in the vertical (height) direction, respectively (Fig. 5). The combined mean difference

Discussion

Skeletal dysgnathia often results in facial disharmony. However, it can also pose some dysfunctional problems. Orthognathic not only improves basic functions like chewing, speech, and swallowing, but it is also part of a complete treatment for improving quality of life (Rustemeyer and Gregersen, 2012). Continuously striving for the highest quality standards in the execution of this type of surgery is essential. Among other factors, the success of a complex orthognathic surgical procedure is

Conclusion

The 3D planning approach provides more accurate soft tissue planning. However, the 2D orthognathic planning can be comparable with 3D planning when it comes to hard tissue planning. Possible disadvantages of 3D are the cost of the CBCT scans and software packages, the learning curve, and the greater amount of time required. We believe that 3D planning can only fully replace conventional 2D planning when these issues are dealt with.

The accuracy can offer strong guidance to a surgeon during the

Conflict of interest statement

There are no conflicts of interest.

Acknowledgments

We would like to thank Prof. M. Elseviers for the statistical analysis of our data.

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Citation Excerpt :
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Of a total of 642 eligible subjects in both centers, 5.8% used alternatives to OS-CAOP. 78.4% of these were due to reasons that may have affected outcomes (P < .001), representing 4.5% of all cases. The frequency of the need for OS-CAOP alternatives was identical in both centers (5.8%), but the specific reasons varied, with KNU having mostly plan-related changes (38.1% of alternatives), and UIC with more access and education-related reasons (68.8% of alternatives). At KNU, 71.4% of all alternatives were by repeat OS-CAOP, whereas at UIC, all were by in-house CAOP (IH-CAOP).
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Three-dimensional virtual planning in orthognathic surgery enhances the accuracy of soft tissue prediction

Abstract

Introduction

Methods

Results

Conclusions

Introduction

Section snippets

Materials and methods

Results

Discussion

Conclusion

Conflict of interest statement

Acknowledgments

Int J Oral Maxillofac Surg

Int J Oral Maxillofac Surg

J Oral Maxillofac Surg

JADA

Med Image Anal

Int J Oral Maxillofac Surg

Rev Stomatol Chir Maxillofac