The aim of this study was to determine the frequency and relationship between disk position and degenerative bone changes in the temporomandibular joints (TMJ), in subjects with internal derangement (ID). MRI and CT scans of 180 subjects with temporomandibular disorders (TMD) were studied. Different image parameters or characteristics were observed, such as disk position, joint effusion, condyle movement, degenerative bone changes (flattened, cortical erosions and irregularities), osteophytes, subchondral cysts and idiopathic condyle resorption. The present study concluded that there is a significant association between disk displacement without reduction and degenerative bone changes in patients with TMD. The study also found a high probability of degenerative bone changes when disk displacement without reduction is present. No association was found between TMD and condyle range of motion, joint effusion and/or degenerative bone changes. The following were the most frequent morphological changes observed: flattening of the anterior surface of the condyle; followed by erosions and irregularities of the joint surfaces; flattening of the articular surface of the temporal eminence, subchondral cysts, osteophytes; and idiopathic condyle resorption, in decreasing order.

This study determines the frequency and relationship between disk position and degenerative bone changes in temporomandibular joints in children and adolescent patients with internal derangement. Study design: TMJ, MRI of 88 patients were analyzed (average age: 14.7 years-old, range age: 10-18 years-old), female n=65 (73.9%) and male n=23 (26.1%). Images obtained were used to determine the frequency of disk position, joint effusion (JE) and degenerative bone changes (OA). Images were assessed by a calibrated radiologist (Kappa=0.82). Results: No significant association was found between disk displacement with reduction and degenerative bone changes (Chi2=9.894; OR= 0.375; p=0.0017), nor disk without displacement (Chi2=9.448; OR= 0.223; p=0.0021). A significant association was found between disk displacement without reduction and degenerative bone changes (Chi2=30.951; OR=6.304; p=0.0001). Conclusions: There is a significant association between disk displacement without reduction and degenerative bone changes (p=0.0001) in children and adolescent patients with TMD.

A 28-year-old woman presented with a history of clicking and mandibular clenching. She was studied clinically and with axial and coronal CT. The patient was going through a tense emotional period and reported tightening of her teeth (clenching); she was under psychological and neurological treatment for depression including pharmacological therapy. She presented slight pain only at maximum mouth opening at the right temporomandibular joint (TMJ) and in the lateral pole on palpation; there was no coincidence between initial and maximal interocclusal contacts because of premature dental contacts. She showed occlusal group function in the right side and canine guidance in the left side with a right contact of balance, local muscular pain in the right deep masseter muscle and in the superior and middle portion of the right trapezium on palpation. On CT, a spherical area of 3 mm diameter with an average density of -647 HU (SD+/-4.7) was found in the upper and posterior area of the lower space of the right TMJ, together with a thicker lower synovial tissue. This observation was confirmed by MRI. Like other joints, the TMJ could present vacuum phenomenon images inside synovial tissue in the presence of degenerative disease. It is important for radiologists to recognize this rare entity.

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Objective: The aims of this study were to detect the fibrocartilage layer (FC) of the porcine mandible condyle in ex vivo preparations using 3D SPGR (Spoiled GRASS sequence) (T1 WATS) sequences, and, to compare 3D SPGR image results with those of conventional magnetic resonance imaging (MRI) sequences for detecting the fibrocartilage layers of the temporomandibular joint (TMJ) in patients with temporomandibular disorders (TMD). Methods: Four porcine TMJ with and without FC were radiographically and histologically assessed. Additionally, fifty-nine patients were studied using T1 WATS MRI and T2 TSE and PD TSE sequences. Four trained and calibrated observers assessed the MRI images. Results: In porcine, the T1 WATS sequence was able to detect the presence or absence of FC in the mandibular condyle, histologically confirmed. In humans, 98% of fibrocartilages were detected with T1 WATS sequence in temporal fossa, and 91% in mandible condyles. Significantly poorer detection with the T2 TSE and PD TSE sequences was observed. Mean fibrocartilage ROI signal intensity was 74.07 IU (±14.7), without statistical differences between fossa and condyle. Conclusion: T1 WATS is the most reliable and efficient sequence for detecting the TMJ fibrocartilage layer (p <0.05).