[MRI observation of condylar location and morphology in the patients with temporomandibular disc displacement].

To evaluate the mandibular condylar location and morphology in the temporomandibular joint disorders. One hundred thirty-seven TMD patients (age 37.5±16.1 years, male/female=39/98) were performed with MRI scan for temporomandibular joint (TMJ) from November, 2011 to April, 2019 in Department of Radiology,Hainan Hospital of General Hospital of Chinese PLA and General Hospital of Chinese PLA. The patients were classified into 3 groups according the disc displacement: disc without displacement (DWoD) (185 TMJ), disc displacement with reduction (DDWR) (17 TMJ) and disc displacement without reduction (DDWoR) (72 TMJ). The location (anterior position, central position and posterior position) and morphology (oval shape, flat shape and beaklike shape) of the condylar head were observed on the sagittal PDWI, and the long and short axes were measured on the axial T2WI. Another groups were classified into 3 subgroups according to the disc displacement of bilateral TMJ: bilateral normal disc location (biND) (74 cases), unilateral disc displacement (uniDD) (40 cases) and bilateral disc displacement (23 cases). The inter-condyle angle was measured on the axial T2WI. There was no significant difference for the location of condylar head among DWoD, DDWR and DDwoR groups (χ(2)=7.435, 0.115). The rate for flat condylar shape was significantly higher in DWoD group [83.9%(115/137)] than that in DDWoR group [50.7%(34/67)], and the rate for beaklike condylar shape was significantly lower in DWoD group [16.1%(22/137)] than that in DDWoR group [49.3%(33/67)] (χ(2)=23.521, 0.001). The length of long axis presented significantly longer in DWoD group [(17.2±2.4) mm] than that in DDWR group [(15.4±2.0) mm] and that in DDWoR group [(14.7±2.7) mm] (0.05). The length of short axis presented significantly longer in DWoD group [(7.3±1.2) mm] than that in DDWR group [(6.5±1.3) mm] and that in DDWoR group [(6.1±1.4) mm] (0.05). The inter-condyle angle presented significantly larger in biND group (136°±13°) and uniDD group (132°±14°) than that inbiDD group (124°±17°) (0.05). The mandibular condylar morphology changes significantly presented in the patients with temporomandibular disc displacement for the temporomandibular disorders.