A Study on the Size of TMD Patient's Condyle Head

OBJECTIVE: In many TMD cases, deformed and reduced condyle heads were frequently observed. This study was prepared to compare the dimensions between normal and symptomatic condyles, using MR images. MATERIALS: One hundred and twenty one patients with clinical signs and MRI-confirmed diagnosis of disc displacement were selected for this study. Thirty eight TMJs from nineteen asymptomatic volunteers who had no clinical symptoms and no disc displacement on sagittal and coronal view of MRI, were served as normal. METHODS: Symptomatic condyles were classified according to the severity of the anterior disc displacement. The amount of anterior disc displacement was evaluated at sagittal section, and they were classified into 4 groups as normal(N), little(G0), mild(G1), moderate(G2) and severe displacement(G3). The dimentions of condyle were measured at the 200% magnified view, by digitizing program. All dimensions were compared among each groups on the central section of sagittal and coronal views, and the statistical analysis was performed. RESULTS: The mean value of anteroposterior length of normal condyle was 0.79+/-0.13cm at sagittal section and mediolateral length was 2.12+/-0.22cm on coronal section. The mean value of anteroposterior length of symptomatic condyle was 0.67+/-0.16cm at sagittal section and mediolateral length was 1.97+/-0.28cm on coronal section. CONCLUSIONS: The size of symptomatic condyle was smaller than normal TMJ. The size of condyle was decreased as the amount of the disc displacement was increased. The dimensional change was found on the anterior articular surface of condyle at the mild or moderate disc displacement. And at the case of severe disc displacement, dimensional change was found on the superior articular surface.

A Study On The Morphology Of Mandibular Condyle

OBJECTIVE: This study was prepared to figure out a certain dimension and morphology of the condyle at the central, medial and lateral aspects on MR images of asymptomatic volunteers, which could be comparable with those of the TMD patient's condyle. MATERIALS: Sixty TMJs from 30 asymptomatic volunteers(15 male, 15 female) who had no clinical symptoms and no disc displacement on sagital and coronal view of MRI were served as normal. METHOD: MR images were taken from the asymptomatic volunteers and the dimension of the anteroposterior length, mediolateral width, height, convexities were measured through the images on the sagittal and coronal sections of mandibular condyle. Then, these data were collected and analyzed. RESULT: The mean value of anteroposterior length was 8.00+/-1.21mm at central section and mediolateral length was 21.40+/-2.32mm on coronal view. The anterior condylar length at medial side was the shortest and the convexity of anterior slop at the lateral side was roved to be the flattest among 3 sections. There were little dimensional and morphological differences at sagittal sections, but the ediolateral width of condyle at coronal section was significantly different between male and female. CONCLUSION: In sagittal sections, the anterior condyle length was shortest at medial side and the convexity of anterior slop was flattest at lateral side, and there were little dimensional and morphologic differences between male and female. In coronal section, male's condyle was more wider and flatter than female's.

Change of Joint Space according to Sideways Disc Displacement of TMJ

OBJECTIVE: Disc displacement may affect the joint space narrowing between condyle head and glenoid fossa. This study was designed to evaluate the correlation between the joint space change and the directions of disc displacement. STUDY DESIGN: Two hundreds temporomandibular joints MR images of TMD patients (170 joints) and asymptomatic volunteers (30 joints) were evaluated for this purpose. Anterior disc displacement was divided into 3 stages (normal, little to mild, and moderate to severe displacement) based on sagittal images. And sideways displacement was classified as 3 categories (center, medial and lateral displacement) based on coronal images, then joint spaces were measured at medial, central and lateral parts of condyle head on coronal MR images, respectively. The joint spaces of 7 groups divided according to the severity and the direction of disc displacement were compared. RESULTS: The reduction of the joint space was affected by sideways disc displacement at the opposite side of the condyle head, except the cases accompanied with severe anteriorly and laterally displaced disc. CONCLUSION: The sideways disc displacement affected on the opposite side temporomandibular joint space width.