The prevalence of clinical symptoms of TMD in an American population was about 6 – 12% [9]. However, there is a peak occurrence between 20 and 40 years of age [10]. One part of TMD is the articular disorders (internal derangement) which is a noninflammatory arthropathy and equates changes in the disc-condyle relationship

[11] and [12]. A recent study among 6-8 year old children showed that 35% of these children had at least one clinical sign of TMD. [13] The TMJ also plays a role in posture and body biostatics [14]. T1 mapping of cartilage after http://www.selleckchem.com/erk.html delayed gadolinium diethylenetriaminepentaacetate acid ion (Gd-DTPA)2- enhancement, called delayed Gadolinium-Enhanced Magnetic Resonance Imaging of Cartilage (dGEMRIC), has emerged as a promising biochemical Magnetic Resonance Imaging (MRI) technique for the quantitative evaluation of articular cartilage [15]. The dGEMRIC has been validated as

a clinically useful tool for the relative glycosaminoglycan content of repair issue after various types of chondrocyte transplantation [16]. Furthermore, in combination with T2 mapping a dGEMRIC provided complementary information on a biochemical properties of a cartilage repair tissue [17]. The dGEMRIC index, i.e., the T1 relaxation time following (Gd-DTPA)2- administration (T1(Gd)), is an indirect measure of the glycosaminoglycan (GAG) concentration of cartilage tissue [18], [19] and [20]. At field-strengths of 3 T, the biochemical MRI measurement of smaller joint cartilage, such as the ankle joint or lumbar facets, becomes possible in find more satisfactory image resolution and clinically reasonable measurement time [21], [22] and [23]. Recently, these biochemical techniques were adapted to fibrocartilaginous tissues, such as the menisci [24] and [25], where, similar to the fibrocartilage structure of the TMJ disc, GAGs are less abundant compared to hyaline cartilage [2] and [26]. Recent results showed that T2 mapping

technique enables ultrastructural analysis of the composition of the TMJ disc and is feasible in vivo [24]. Developed heptaminol for hyaline cartilage, dGEMRIC imaging is an important step towards noninvasive compositional cartilage imaging, because it can show the biochemical ultrastructure of healthy and diseased cartilage. Different studies have demonstrated the ability of dGEMRIC to detect changes in cartilage degeneration before morphological changes occur, in early-stage osteoarthritis (OA) [27] and [28]. The dGEMRIC method can also be used for the monitoring of the maturation of repair tissue after different cartilage repair surgeries [25] and [29] and for longitudinal cohort evaluation of cartilage regeneration [30]. To our best knowledge, no dGEMRIC feasibility studies have been done yet on the disc of the TMJ.