ORAL AND MAXILLOFACIAL RADIOLOGY Editor: Stephen R. Matteson Temporomandibular joint: A methodology of magnetic resonance imaging 3-D reconstruction Reza Arbab Chirani, DDS, a Jean-Jose ´ Jacq, PhD, b Philippe Meriot, MD, c and Christian Roux, PhD, d Brest, France U650 UNIT 650 OF THE FRENCH NATIONAL INSTITUTE OF MEDICAL RESEARCH (INSERM), LABORATORY OF MEDICAL INFORMATION TREATMENT (LATIM), UNIVERSITY OF BRETAGNE OCCIDENTALE, GROUPING OF FRENCH SCHOOLS OF COMMUNICATION (GET), ENGINEERING SCHOOL OF TELECOMMUNICATION (ENST) BRETAGNE, AND UNIVERSITY HOSPITAL Objective. The aim of this study was to develop a new method for the 3-dimensional reconstruction of the temporomandibular joint (TMJ) images by means of magnetic resonance imaging (MRI). In a preliminary study, this modality of 3-D representation was tested to evaluate the joint motion. Study design. Sagittal MRI slices were obtained from a healthy subject. Acquisitions were realized by a spin-echo sequence, with a proton-density weighting and a 2-mm slice thickness. A 3-D reconstruction of the TMJ images was performed. Results. Three-dimensional representations of the temporomandibular joint were obtained. The depiction of the principal anatomical elements of this joint was realized. A study of TMJ dynamics was also carried out. In this case, movements of the right and left disks and condyles were measured. Conclusion. This 3-D reconstruction methodology allowed a more understandable anatomical description than 2-D images of the TMJ and offered possibilities for joint functional analysis. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2004;97:756-61) Temporomandibular joint (TMJ) pathology concerns a significant share of the world population and constitutes a problem of public health. A report concerning TMJ pathologies estimates that over 10 million people in USA suffer from disturbances of this joint. 1 Magnetic resonance imaging and 3-D reconstruction of the TMJ images have greatly contributed to the understanding of pathophysiology of this joint. 1-4 Three-dimensional reconstructions of the temporomandibular joint images usually use 2 medical imaging modalities: magnetic res- onance imaging (MRI) and computerized tomography scanning (CT scan). MRI contrary to CT scan enables simultaneous visualization of all tissues and is the most preferred imaging technique in many institutions for the study of the TMJ soft tissue pathology. 5 MRI is also a medical modality which has been used routinely in the evaluation of TMJ abnormalities since 1985. 6-9 MRI has been considered as the prime diagnostic noninvasive modality of choice for the patients with clinical symptoms of TMJ soft tissue disease. 1,2,10,11 Information about the TMJ available from this technique includes the location of the disk in both open and closed positions at multiple levels through the joint. 5 In 1993 a report demonstrated the accuracy of MRI for disk position localization. 8 This modality has a low observer variation and a high diagnostic accuracy. 8,12,13 This imaging technique and the software of MR units have progressed greatly since the last 10 years. However, if there is a low contrast between hard and soft tissues on the slices, image’s interpretation by practitioners can be hard. Thus, the localization and the relationship among the various joint components can be difficult to interpret. a Head, Department of Endodontics and Conservative Dentistry, Faculty of Dentistry, University of Bretagne Occidentale. LATIM, U650 INSERM. b Research engineer, LATIM, U650 INSERM. GET/ENST Bretagne, Department ITI, Brest, France. c Hospital Radiologist, Department of Radiology, University Hospital. d Professor and Head of LATIM, U650 INSERM. Department ITI, GET/ENST Bretagne. Received for publication Jul 25, 2003; accepted for publication Feb 23, 2004. 1079-2104/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.tripleo.2004.02.073 756 Vol. 97 No. 6 June 2004