Osseous abnormalities related to the temporomandibular joint

3D Morphology Analysis of TMJ Articular Eminence in Magnetic Resonance Imaging

Purpose

The objective of this study was to evaluate the computational reconstruction of the articular eminence of the temporomandibular joint (TMJ) based on magnetic resonance imaging (MRI) and semiautomatic volumetric segmentation techniques for morphological classification of the TMJ structure.

Materials and Methods

A total of 36 MRI scans of TMJ individuals were selected and formatted by using the ITK-SNAP software, consisting of MRI segmentation and generation of 3D models. The TMJ articular eminences were also classified according to the morphology analysis of the articular eminence in 3D reconstructions. Two independent trained and calibrated investigators performed the image analysis, which was repeated after thirty days.

Results

There was no association between sex and eminence shape (p = 0.456). Fisher's test revealed no statistically significant association between disc classification and eminence shape on both sides (p = 0.629). Chi-square test showed a significant statistically association between disc classification and disc displacement (p = 0.000). Intra- and interrater correlation coefficients showed excellent reproducibility values.

Conclusions

Anatomical variability of the sample investigated was found, with predominantly round shape and presence of correlation between this shape and normal disc position. The correlation of flattened and convex shapes with disc position reduction indicated that type of disc derangement is more prevalent.

Contrast-enhanced microCT (EPIC-μCT) ex vivo applied to the mouse and human jaw joint

OBJECTIVES

The temporomandibular joint (TMJ) is susceptive to the development of osteoarthritis (OA). More detailed knowledge of its development is essential to improve our insight into TMJ-OA. It is imperative to have a standardized reliable three-dimensional (3D) imaging method that allows for detailed assessment of both bone and cartilage in healthy and diseased joints. We aimed to determine the applicability of a contrast-enhanced microCT (µCT) technique for ex vivo research of mouse and human TMJs.

METHODS

Equilibrium partitioning of an ionic contrast agent via µCT (EPIC-µCT) was previously applied for cartilage assessment in the knee joint. The method was ex vivo, applied to the mouse TMJ and adapted for the human TMJ.

RESULTS

EPIC-µCT (30-min immersion time) was applied to mouse mandibular condyles, and 3D imaging revealed an average cartilage thickness of 110 ± 16 µm. These measurements via EPIC-µCT were similar to the histomorphometric measures (113 ± 19 µm). For human healthy OA-affected TMJ samples, the protocol was adjusted to an immersion time of 1 h. 3D imaging revealed a significant thicker cartilage layer in joints with early signs of OA compared with healthy joints (414.2 ± 122.6 and 239.7 ± 50.5 µm, respectively). A subsequent significant thinner layer was found in human joints with late signs of OA (197.4 ± 159.7 µm).

CONCLUSIONS

The EPIC-µCT technique is effective for the ex vivo assessment of 3D cartilage morphology in the mouse as well as human TMJ and allows bone-cartilage interaction research in TMJ-OA.

Nonsyndromic facial asymmetry with unilateral condylar aplasia

Introduction. The temporomandibular joint (TMJ) is the most complex elegantly designed joint in the human body. Abnormal development and growth of TMJ may lead to condyle aplasia present in several syndromes expressions, but it is extremely rare when not connected to any underlying pathological disorder or in conjunction with any syndrome. Objective. A rare case of aplasia of the mandibular condyle is presented, along with 3D computed tomography (3D CT) findings. Conclusion. Based on clinical and radiological findings we suggest the abnormal development of the TMJ as the origin. The 3D CT has provided high-quality images, which made diagnosis and a prompt treatment plan possible.

[MR imaging of the temporomandibular joints]

Disorders of the TMJ are best evaluated with MR. Anatomy and morphology of the meniscus are key features of the imaging evaluation conducted using coronal and sagittal views with open and closed mouth. There is no direct correlation between symptoms and MR imaging findings. Anterior or lateral meniscal displacement, permanent or reversible, are described. Arthroscopy or arthrography may help in diagnosis of meniscal adhesion or perforation. HRCT is an adjunct to study degenerative bone changes.