Association between condylar surface computed tomography values in the coronal plane and temporomandibular joint disc position in jaw deformity patients: a retrospective study.

This study aimed to examine the relationship between computed tomography (CT) values of the condylar surface in the coronal plane, condylar morphology and the disc positions in the temporomandibular joint (TMJs) in patients with deformities before and after orthognathic surgery.  MATERIALS AND METHODS: The maximum CT values (pixel values) on the condylar surface, condylar thickness, condylar width, condylar angle, condylar height, and joint space were measured. TMJ disc position was classified into five types (anterior type, fully covered type, posterior type, anterior disc displacement with [AW] and without reduction [AWO]), using magnetic resonance imaging (MRI), before and 1 year after surgery. Statistical analysis was performed to assess differences between groups and between the pre- and postoperative values.  RESULTS: We enrolled 142 TMJs from 71 female patients diagnosed with jaw deformities. Disc position classification did not change after surgery in all TMJ. Significant differences were observed between anterior displacement (AW and AWO) and other types (fully covered type and posterior type) in the lateral CT value and condylar angle before and 1 year after surgery (P < 0.05).  CONCLUSIONS: This study demonstrated a strong relationship between condylar surface CT values in the coronal plane and condylar angle with TMJ disc position classification.