1
|
Nadjmi N, Defrancq E, Mollemans W, Hemelen GV, Bergé S. Quantitative validation of a computer-aided maxillofacial planning system, focusing on soft tissue deformations. Ann Maxillofac Surg 2015; 4:171-5. [PMID: 25593866 PMCID: PMC4293837 DOI: 10.4103/2231-0746.147112] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
AIM The aim of this study was to evaluate the accuracy of 3D soft tissue predictions generated by a computer-aided maxillofacial planning system in patients undergoing orthognathic surgery. METHODS AND MATERIALS Twenty patients with dentofacial dysmorphosis were treated with orthognathic surgery after a preoperative orthodontic treatment. Fourteen patients had an Angle Class II malocclusion; three patients had an Angle class III malocclusion, and three patients had an Angle Class I malocclusion. Skeletal asymmetry was observed in six patient. The surgeries were planned using the Maxilim software. Computer assisted surgical planning was transferred to the patient by digitally generated splints. The validation procedures were performed in the following steps: (1) Standardized registration of the pre- and postoperative Cone Beam CT volumes; (2) Automated adjustment of the bone-related planning to the actual operative bony displacement; (3) Simulation of soft tissue changes; (4) Calculation of the soft tissue differences between the predicted and the postoperative results by distance mapping. STATISTICAL ANALYSIS AND RESULTS Eighty four percent of the mapped distances between the predicted and actual postoperative results measured between -2 mm and +2 mm. The mean absolute linear measurements between the predicted and actual postoperative surface was 1.18. Our study shows the overall prediction was dependent on neither the surgical procedures nor the dentofacial deformity type. CONCLUSION Despite some shortcomings in the prediction of the final position of the lower lip and cheek area, this software promises a clinically acceptable soft tissue prediction for orthognathic surgical procedures.
Collapse
Affiliation(s)
- Nasser Nadjmi
- Department of Cranio-Maxillofacial Surgery, AZ MONICA, Harmoniestraat 68, B-2018 Antwerp, Belgium University Hospital Antwerp, Belgium
| | - Ellen Defrancq
- Department of Cranio-Maxillofacial Surgery, AZ MONICA, Harmoniestraat 68, B-2018 Antwerp, Belgium University Hospital Antwerp, Belgium
| | - Wouter Mollemans
- Medical Image Computing (Radiology - ESAT/PSI), Faculties of Medicine and Engineering University Hospital Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium
| | - Geert Van Hemelen
- Department of Cranio-Maxillofacial Surgery, AZ MONICA, Harmoniestraat 68, B-2018 Antwerp, Belgium University Hospital Antwerp, Belgium
| | - Stefaan Bergé
- Department of Oral and Maxillofacial Surgery, Radboud University Nijmegen, Medical Centre, Nijmegen, The Netherlands
| |
Collapse
|
2
|
Swennen G, Van Leemput P, Mollemans W, Schutyser F, De Clercq C. A new ‘surface to Cone-beam CT’ registration method to obtain an appropriate 3D virtual patient model for orthognathic surgery planning. Int J Oral Maxillofac Surg 2013. [DOI: 10.1016/j.ijom.2013.07.588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
3
|
Swennen GRJ, Mollemans W, Schutyser F. Three-dimensional treatment planning of orthognathic surgery in the era of virtual imaging. J Oral Maxillofac Surg 2009; 67:2080-92. [PMID: 19761902 DOI: 10.1016/j.joms.2009.06.007] [Citation(s) in RCA: 252] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2009] [Revised: 06/25/2009] [Accepted: 06/30/2009] [Indexed: 11/25/2022]
Abstract
PURPOSE The aim of this report was to present an integrated 3-dimensional (3D) virtual approach toward cone-beam computed tomography-based treatment planning of orthognathic surgery in the clinical routine. MATERIALS AND METHODS We have described the different stages of the workflow process for routine 3D virtual treatment planning of orthognathic surgery: 1) image acquisition for 3D virtual orthognathic surgery; 2) processing of acquired image data toward a 3D virtual augmented model of the patient's head; 3) 3D virtual diagnosis of the patient; 4) 3D virtual treatment planning of orthognathic surgery; 5) 3D virtual treatment planning communication; 6) 3D splint manufacturing; 7) 3D virtual treatment planning transfer to the operating room; and 8) 3D virtual treatment outcome evaluation. CONCLUSIONS The potential benefits and actual limits of an integrated 3D virtual approach for the treatment of the patient with a maxillofacial deformity are discussed comprehensively from our experience using 3D virtual treatment planning clinically.
Collapse
Affiliation(s)
- Gwen R J Swennen
- Department of Surgery, General Hospital St-Jan Bruges, Bruges, Belgium.
| | | | | |
Collapse
|
4
|
Nadjmi N, Mollemans W, Daelemans A, Van Hemelen G, Schutyser F. O.104 Virtual occlusion planning for orthognathic surgery. J Craniomaxillofac Surg 2008. [DOI: 10.1016/s1010-5182(08)71228-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
5
|
Roose L, Loeckx D, Mollemans W, Maest F, Suetens P. Adaptive boundary conditions for physically based follow-up breast MR image registration. Med Image Comput Comput Assist Interv 2008; 11:839-46. [PMID: 18982683 DOI: 10.1007/978-3-540-85990-1_101] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
This paper presents an algorithm for non-rigid registration of breast MRI follow-up images that compensates for differences in patient positioning while maintaining real anatomical and pathological changes. The proposed method uses a biomechanical model to constrain the deformation of the internal breast tissue according to elastic continuum mechanics, which is driven by suitable boundary conditions that align the breast surfaces in the images to be registered. Typically, such boundary conditions impose one-to-one surface point correspondences that are established a priori. We investigate alternative, more flexible boundary conditions that do not depend on fixed point correspondences and do not assume completely accurate breast surface segmentation in both images. More specifically, we allow for sliding motion of one surface over the other during deformation as well as for restricted motion perpendicular to the initially segmented boundary surface, based on the internal elastic forces and local intensity information. We evaluate the impact of different boundary conditions on registration quality from the subtraction images obtained for repeated scans of healthy volunteers with intermediate repositioning, using rigid body and free form whole volume intensity based registration for comparison, and also present initial results for actual patient data. Our results demonstrate a drastic reduction in subtraction artifacts using our model, without compromising the biomechanical validity of the deformation field such as unrealistically large local volume changes as with traditional voxel intensity based registration.
Collapse
Affiliation(s)
- Liesbet Roose
- Katholieke Universiteit Leuven, Faculty of Medicine, Medical Image Computing (Radiology - ESAT/PSI), University Hospital Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium.
| | | | | | | | | |
Collapse
|
6
|
Mollemans W, Schutyser F, Nadjmi N, Maes F, Suetens P. Predicting soft tissue deformations for a maxillofacial surgery planning system: From computational strategies to a complete clinical validation. Med Image Anal 2007; 11:282-301. [PMID: 17493864 DOI: 10.1016/j.media.2007.02.003] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2006] [Revised: 08/03/2006] [Accepted: 02/15/2007] [Indexed: 11/24/2022]
Abstract
In the field of maxillofacial surgery, there is a huge demand from surgeons to be able to pre-operatively predict the new facial outlook after surgery. Besides the big interest for the surgeon during the planning, it is also an essential tool to improve the communication between the surgeon and his patient. In this work, we compare the usage of four different computational strategies to predict this new facial outlook. These four strategies are: a linear Finite Element Model (FEM), a non-linear Finite Element Model (NFEM), a Mass Spring Model (MSM) and a novel Mass Tensor Model (MTM). For true validation of these four models we acquired a data set of 10 patients who underwent maxillofacial surgery, including pre-operative and post-operative CT data. For all patient data we compared in a quantitative validation the predicted facial outlook, obtained with one of the four computational models, with post-operative image data. During this quantitative validation distance measurements between corresponding points of the predicted and the actual post-operative facial skin surface, are quantified and visualised in 3D. Our results show that the MTM and linear FEM predictions achieve the highest accuracy. For these models the average median distance measures only 0.60 mm and even the average 90% percentile stays below 1.5 mm. Furthermore, the MTM turned out to be the fastest model, with an average simulation time of only 10 s. Besides this quantitative validation, a qualitative validation study was carried out by eight maxillofacial surgeons, who scored the visualised predicted facial appearance by means of pre-defined statements. This study confirmed the positive results of the quantitative study, so we can conclude that fast and accurate predictions of the post-operative facial outcome are possible. Therefore, the usage of a maxillofacial soft tissue prediction system is relevant and suitable for daily clinical practice.
Collapse
Affiliation(s)
- W Mollemans
- Medical Image Computing (Radiology - ESAT/PSI), Faculties of Medicine and Engineering, University Hospital Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium.
| | | | | | | | | |
Collapse
|
7
|
Nadjmi N, Mollemans W, Schutyser F, Suetens P. P.162 3D soft tissue predictions for a computer-aided maxillofacial surgery planning system. J Craniomaxillofac Surg 2006. [DOI: 10.1016/s1010-5182(06)60670-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
8
|
De Greef S, Claes P, Vandermeulen D, Mollemans W, Suetens P, Willems G. Large-scale in-vivo Caucasian facial soft tissue thickness database for craniofacial reconstruction. Forensic Sci Int 2006; 159 Suppl 1:S126-46. [PMID: 16563680 DOI: 10.1016/j.forsciint.2006.02.034] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
A large-scale study of facial soft tissue depths of Caucasian adults was conducted. Over a 2-years period, 967 Caucasian subjects of both sexes, varying age and varying body mass index (BMI) were studied. A user-friendly and mobile ultrasound-based system was used to measure, in about 20min per subject, the soft tissue thickness at 52 facial landmarks including most of the landmarks used in previous studies. This system was previously validated on repeatability and accuracy [S. De Greef, P. Claes, W. Mollemans, M. Loubele, D. Vandermeulen, P. Suetens, G. Willems, Semi-automated ultrasound facial soft tissue depth registration: method and validation. J. Forensic Sci. 50 (2005)]. The data of 510 women and 457 men were analyzed in order to update facial soft tissue depth charts of the contemporary Caucasian adult. Tables with the average thickness values for each landmark as well as the standard deviation and range, tabulated according to gender, age and BMI are reported. In addition, for each landmark and for both sexes separately, a multiple linear regression of thickness versus age and BMI is calculated. The lateral asymmetry of the face was analysed on an initial subset of 588 subjects showing negligible differences and thus warranting the unilateral measurements of the remaining subjects. The new dataset was statistically compared to three datasets for the Caucasian adults: the traditional datasets of Rhine and Moore [J.S. Rhine, C.E. Moore, Tables of facial tissue thickness of American Caucasoids in forensic anthropology. Maxwell Museum Technical series 1 (1984)] and Helmer [R. Helmer, Schädelidentifizierung durch elektronische bildmischung, Kriminalistik Verlag GmbH, Heidelberg, 1984] together with the most recent in vivo study by Manhein et al. [M.H. Manhein, G.A. Listi, R.E. Barsley, R. Musselman, N.E. Barrow, D.H. Ubelbaker, In vivo facial tissue depth measurements for children and adults. J. Forensic Sci. 45 (2000) 48-60]. The large-scale database presented in this paper offers a denser sampling of the facial soft tissue depths of a more representative subset of the actual Caucasian population over the different age and body posture subcategories. This database can be used as an updated chart for manual and computer-based craniofacial approximation and allows more refined analyses of the possible factors affecting facial soft tissue depth.
Collapse
Affiliation(s)
- S De Greef
- Katholieke Universiteit Leuven, Faculty of Medicine, School of Dentistry, Oral Pathology and Maxillo-Facial Surgery, Forensic Dentistry, Kapucijnenvoer 7, B-3000 Leuven, Belgium
| | | | | | | | | | | |
Collapse
|
9
|
Verstrynge A, Carels C, Verdonck A, Mollemans W, Willems G, Schoenaers J. [Dentomaxillary and -facial problems in cleidocranial dysplasia]. Ned Tijdschr Tandheelkd 2006; 113:69-74. [PMID: 16509515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
A 14-year old boy with cleidocranial dysplasia was referred because of an almost complete presence of the deciduous dentition. Diagnostics by means of a panoramic radiograph, lateral headfilm, CT scan and 3D computer images of the dentomaxillary complex showed 7 supernumerary permanent teeth: 13', 11', 21', 23', 28', 35' and 45'. A combined orthodontic-surgical treatment was started. The supernumary teeth were removed surgically and the impacted teeth are exposed. The closed eruption technique was used to extrude these teeth orthodontically.
Collapse
Affiliation(s)
- A Verstrynge
- Orthodontie, ESAT en Radiologie, School voor Tandheelkunde, faculteit Geneeskunde, Katholieke Universiteit Leuven, België
| | | | | | | | | | | |
Collapse
|
10
|
Roose L, De Maerteleire W, Mollemans W, Maes F, Suetens P. Simulation of Soft-Tissue Deformations for Breast Augmentation Planning. Biomedical Simulation 2006. [DOI: 10.1007/11790273_22] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
11
|
Mollemans W, Schutyser F, Nadjmi N, Maes F, Suetens P. Parameter Optimisation of a Linear Tetrahedral Mass Tensor Model for a Maxillofacial Soft Tissue Simulator. Biomedical Simulation 2006. [DOI: 10.1007/11790273_18] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
|
12
|
Roose L, Mollemans W, Loeckx D, Maes F, Suetens P. Biomechanically Based Elastic Breast Registration Using Mass Tensor Simulation. Medical Image Computing and Computer-Assisted Intervention – MICCAI 2006 2006; 9:718-25. [PMID: 17354836 DOI: 10.1007/11866763_88] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
We present a new approach for the registration of breast MR images, which are acquired at different time points for observation of lesion evolution. In this registration problem, it is of utmost importance to correct only for differences in patient positioning and to preserve other diagnostically important differences between both images, resulting from anatomical and pathological changes between both acquisitions. Classical free form deformation algorithms are therefore less suited, since they allow too large local volume changes and their deformation is not biomechanically based. Instead of adding constraints or penalties to these methods in order to restrict unwanted deformations, we developed a truly biomechanically based registration method where the position of skin and muscle surface are used as the only boundary conditions. Results of our registration method show an important improvement in correspondence between the reference and the deformed floating image, without introducing physically implausible deformations and within a short computational time.
Collapse
Affiliation(s)
- Liesbet Roose
- Medical Image Computing (Radiology - ESAT/PSI), Faculties of Medicine and Engineering, University Hospital, Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium.
| | | | | | | | | |
Collapse
|
13
|
De Greef S, Claes P, Mollemans W, Loubele M, Vandermeulen D, Suetens P, Willems G. Semi-automated ultrasound facial soft tissue depth registration: method and validation. J Forensic Sci 2005; 50:1282-8. [PMID: 16382819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
A mobile and fast, semi-automatic ultrasound (US) system was developed for facial soft tissue depth registration. The system consists of an A-Scan ultrasound device connected to a portable PC with interfacing and controlling software. For 52 cephalometric landmarks, the system was tested for repeatability and accuracy by evaluating intra-observer agreement and comparing ultrasound and CT-scan results on 12 subjects planned for craniofacial surgery, respectively. A paired t-test evaluating repeatability of the ultrasound measurements showed 5.7% (n = 3) of the landmarks being significantly different (p < 0.01). US and CT-scan results showed significant differences (p < 0.01) using a Wilcoxon signed rank test analysis for 11.5% (n = 6) of the landmarks. This is attributed to a difference in the volunteer's head position between lying (CT) and sitting (US). Based on these tests, we conclude that the proposed registration system and measurement protocol allows relatively fast (52 landmarks/20 min), non-invasive, repeatable and accurate acquisition of facial soft tissue depth measurements.
Collapse
Affiliation(s)
- Sven De Greef
- Katholieke Universiteit Leuven, Faculty of Medicine, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Forensic Dentistry, Kapucijnenvoer 7, B-3000 Leuven, Belgium
| | | | | | | | | | | | | |
Collapse
|
14
|
Roose L, De Maerteleire W, Mollemans W, Suetens P. Validation of different soft tissue simulation methods for breast augmentation. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/j.ics.2005.03.126] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
15
|
De Greef S, Claes P, Mollemans W, Vandermeulen D, Suetens P, Willems G. [Computer-assisted facial reconstruction: recent developments and trends]. Rev Belge Med Dent (1984) 2005; 60:237-49. [PMID: 16370439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Three-dimensional (3D) craniofacial reconstruction can be a useful tool in the identification of an unknown body. The progress in computer science and the improvement of medical imaging technologies during recent years has had a significant impact on this domain. New facial soft tissue depth data have been obtained. New guidelines for facial feature properties such as nose projection, eye protrusion or mouth width, have been suggested, but also older theories and "rules of thumbs" have been critically evaluated based on digital technology. New fast, flexible and objective 3D reconstruction computer-based programs are in full development. Employing the newer technologies and permanently evaluating the obtained results will hopefully lead to more accurate reconstructions.
Collapse
Affiliation(s)
- Sven De Greef
- Katholieke Universiteit Leuven, Faculté de Médecine, Ecole de Médecine Dentaire, Stomatologie et Chirurgie Maxillo-Faciale, Service d'Odontologie légale, Kapucijnenvoer 7, B-3000 Louvain
| | | | | | | | | | | |
Collapse
|
16
|
Mollemans W, Schutyser F, Van Cleynenbreugel J, Suetens P. Tetrahedral Mass Spring Model for Fast Soft Tissue Deformation. Surgery Simulation and Soft Tissue Modeling 2003. [DOI: 10.1007/3-540-45015-7_14] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|