Usefulness of cone beam computed tomography in temporomandibular joints with soft tissue pathology

Abstract

Objective: the aim of the study was to evaluate the usefulness of cone beam CT (CBCT) in temporomandibular joints (TMJs) with soft tissue pathology.

Methods: 106 TMJs of 55 patients with temporomandibular disorder (TMD) were examined by MRI and CBCT. MR images were used for the evaluation of disc displacement, disc deformity, joint effusion and obscurity of temporal posterior attachment (TPA). CBCT images were evaluated for the presence or absence of osseous abnormalities. The chi(2) test was used to analyse the association between MRI and CBCT findings.

Results: MRI of 106 TMJs revealed disc displacement, disc deformity, joint effusion and obscurity of the TPA in 68, 73, 28 and 27 joints, respectively. Of the 68 TMJs with disc displacement, anterior disc displacement without reduction (ADDWR) was seen most frequently (47/68). CBCT imaging found 65 TMJs were characterized by the presence of osseous abnormalities and were significantly associated with disc deformity and ADDWR (P < 0.05). There was no statistically significant association between the presence of joint effusion and obscurity of TPA and TMJ osseous abnormalities.

Conclusions: TMD patients with confirmed ADDWR or disc deformity on MRI are at risk of having osseous abnormalities in the TMJ and further examination with CBCT is recommended.

Figure 1

Patient with suspected condylar erosion (e). The articular disc looks normal in shape and position on closed and open sagittal proton density-weighted MR image (a and b, white arrows), there is no sign of joint effusion on T₂ weighted image sequence (c) and the temporal posterior attachment could be visualized (a and b, black arrows). The corresponding cone beam CT image revealed no osseous abnormality in the condylar head (d, arrow)

Figure 2

Patient with suspected condylar osteophyte (s).The deformed articular disc is anteriorly displaced in closed sagittal proton density-weighted MR image (a, arrow) and was not reduced in open sagittal proton density-weighted MR image (b, arrow).There is no sign of joint effusion on T₂ weighted image sequence (c) and the temporal posterior attachment could not be visualized in any image. The corresponding cone beam CT image revealed osteophyte in the condylar head (d, arrow)

Figure 3

Patient with joint effusion. The deformed articular disc is anteriorly displaced in closed sagittal proton density-weighted MR image (a, white arrow) and reduced on open sagittal proton density-weighted MR image (b, arrow). Superior joint space effusion was revealed on T₂ weighted image sequence (c, arrow) and the temporal posterior attachment could be visualized in closed sagittal proton density-weighted MR (a, black arrow). The corresponding cone beam CT image revealed no osseous abnormality in the condylar head (d)

Figure 4

Patient with suspected ankylosis (a). The deformed articular disc is anteriorly displaced in closed sagittal proton density-weighted MR image (a, white arrow) and was not reduced in open sagittal proton density-weighted MR image (b, arrow), there is no sign of joint effusion on T₂ weighted image sequence (c) and the temporal posterior attachment could be visualized in closed sagittal proton density-weighted MR (a, black arrow). The corresponding cone beam CT image revealed ankylosis in the temporomandibular joint (d, arrow)