Temporomandibular joint internal derangement type III: relationship to magnetic resonance imaging findings internal derangement and osteoarthrosis - An intraindividual approach

The purpose of this study was to investigate whether in patients with a cli nical unilateral temporomandibular joint (TMJ)-related finding of internal derangement type (ID)-III (disk displacement without reduction) in combinat ion with TMJ-related pain. the intraindividual variable of 'unilateral TMJ ID-III pain' may be linked to subject-related magnetic resonance (MR) imagi ng findings of TMJ ID. and TMJ osteoarthrosis (OA). The study comprised 48 consecutive TMJ pain patients. who were assigned a clinical unilateral TMJ pain side-related diagnosis of ID-III. Bilateral sagittal and coronal MR im ages were obtained to establish the presence or absence of TMJ ID and/or OA . Comparison of the TMJ side-related data showed a significant relationship between the clinical finding of TMJ ID-III pain and the MR imaging diagnos es of TMJ ID (P = 0.000) and TMJ ID type (P = 0.000). There was no correlat ion between the clinical finding of TMJ ID-III pain and the MR imaging diag nosis of TMJ OA (P = 0.217), nor between the MR imaging diagnosis of TMJ OA and that of TMJ ID (P = 0.350). Regarding the diagnostic subgroups of TMJ ID. a significant relationship was found between the presence of TMJ OA and the MR imaging diagnoses of TMJ ID type(P = 0.002). Use of the Kappa stati stical test indicated a fair diagnostic agreement between the presence of T MJ ID-III pain and the MR imaging F diagnosis of disk displacement without reduction (DDNR) (K = 0.42). The results suggest that TMJ ID-III pain is re lated to TMJ-related MR imaging diagnoses of ID. Further, the data confirm the biological concept of 'DDNR and OA' as an underlying mechanism in the e tiology of TMJ-related pain and dysfunction.