Evaluation of the effects of temporomandibular joint disk displacement and its progression on dentocraniofacial morphology in symptomatic patients using lateral cephalometric analysis.

The aim of this study was to evaluate the effects of disk displacement (DD) and its progression on dentocraniofacial morphology in symptomatic patients and compare the results with asymptomatic volunteers. Skeletal and dental Class I female patients with DD, diagnosed using magnetic resonance imaging (MRI) and lateral cephalometric analysis were included in the study. Subjects were grouped as follows: control group with bilateral normal disk position (group 1, n=12), unilateral DD with reduction (group 2, n=16), bilateral DD with reduction (group 3, n=26), unilateral DD without reduction (group 4, n=12), and bilateral DD without reduction (group 5, n=8). Thirty-two (32) cephalometric variables were measured, and statistically significant differences were found in 11. Dental and soft tissue measurements did not reveal any differences, but variables related to the mandible showed statistically significant differences. Progression of DD was associated with an increase in all angular measurements related to vertical skeletal relationships and articular angle and a decrease in the ratio of posterior face height to anterior face height indicating clockwise rotation of the mandible. Similarly, the height of ramus was decreased with the progression of DD. The results of this study demonstrated that the presence of DD in skeletal Class I female patients effects facial morphology, and its progression makes the differences more significant and remarkable. These results emphasize the importance of early diagnosis and treatment in the management of DD.