Magnetic resonance imaging of the temporomandibular joint in patients with skeletal open bite and subjects with no dentofacial abnormalities.

We aimed to record the prevalence of disc displacement and bony changes in the temporomandibular joints (TMJs) of patients with skeletal open bite. We studied 25 patients (50 joints) with skeletal open bite, 25 volunteers with no dentofacial abnormalities (50 joints), and 44 patients with closed lock and no dentofacial abnormalities (60 joints) using magnetic resonance imaging (MRI) of the TMJ. We found anterior disc displacement without reduction in 6 of the volunteers and in 24 of the patients with skeletal open bite (p=0.01). Among the 24 affected joints, 16 showed signs of bony change (67%) as did 24 of those with closed lock (40%). The fact that we found a significant difference in the incidence of anterior disc displacement without reduction and bony change between patients with skeletal open bite and control groups without deformities of the jaw indicates that these changes may be caused by skeletal open bite.