Contributions of the Radiocarpal and Midcarpal Jointin Flexion-extension Motion of Wrist / 대한정형외과학회잡지

PURPOSE: Flexion and extension of the wrist occurs at the radiocarpal and midcarpal joints. This study examined the angular contribution of the radiocarpal and midcarpal joints to the total arc of motion. MATERIALS AND METHODS: Five healthy adults were selected and ten wrists were tested. Lateral X-rays were taken with the wrist in the neutral position, 30 degrees flexion, 60 degrees flexion, 90 degrees flexion, 30 degrees extension, 60 degrees extension, and 90 degrees extension. The radiocarpal and midcarpal angle were measured. The angular contribution of the radiocarpal and midcarpal angle was calculated at each phase of motion; neutral to 30 degrees, 30 degrees to 60 degrees, 60 degrees to 90 degrees. RESULTS: During wrist flexion, the angular contribution of the midcarpal joint was 65%, 72%, 71% at each phase of motion, respectively. During wrist extension, the angular contribution of midcarpal joint was 37%, 53%, 78% at each phase of motion, respectively. Therefore, during wrist extension, the main contributor of motion is changed from the radiocarpal joint in the early phase to the midcarpal joint in the late phase. CONCLUSION: It is suggested that the proximal carpal low is not moved passively by just the link system but the motion is guided by the peculiar shape of midcarpal articulation and ligaments complex at each phase. The link system is believed to act in the early phase of flexion and in late phase of extension.

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.

Normal Temporomandibular Joint Space

Disc displacement, deformation, perforation or osteoarthritis may induce the joint space narrowing. This study was designed to get the normal joint space width which could be used as a standard comparing with damaged joints. Twenty asymptomatic volunteers' MR images were evaluated and coronal images of thirty joints having normal disc position in sagittal and coronal views, were selected. The joint spaces were measured at center, medial and lateral side on the coronal views. In normal joints, the mean joint space was 3.57+/-0.63mm at center, 2.77+/-0.51mm at medial and 2.41+/-0.41mm at lateral side of mandibular condyle. The mean of joint space of male was wider than that of female at center, but not significantly different at medial and lateral side of the condyle.

A STUDY ON TMJ DISC POSITION BY MAPPING METHOD

According to the autopsy study for the temporomandibular joint disc position, rotation and sideway displacements as well as anterior displacement of TMJ discs are important aspect of internal derangement. There were some trials to suspect anterior and sideway disc displacements through MR images. But the sagittal and the coronal views of MRI could only show the image of cutted slices, these images were not sufficient for showing the entire correlations amomg glenoid fossa, condylar head and articular disc. In this study we combined the images of the each slice of sagittal views like drawing a map, then we could see the interrelations among these three major components of TMJ smore precisely. Applying this method to both asymtomatic volunteers and TMD patients, we classified the interrelationships between condylar head and articular disc of TMJ as twelve types. The distributions are as follows: 1. In asymptomatic volunteers cases, normal relations were 65.0%, sideways or rotational displacements without anterior displacement were 20.0%, only anterior displacements were 15.0%, and anterior displacements combined with rotational displacements were 5.0%. 2. In unaffected sides of TMD patients, normal relations were 42.1%, rotational displacements were 11.8% and anterior displacements were 47.0%. 3. In affected sides of TMD patients, normal relations were 10.6%, sideways or rotational displacements were 13.6%, anterior displacements were 75.8%. 4. In asymptomatic volunteers or unaffected sides of TMD patients, pure anterior displacement was more prominent than combined with sideways or rotational displacement, but in affected sides of TMD patients pure anterior displacement was less prominent.

A Study Of Joint Effusion On Temporomandibular Joint Mri

The purpose of this study was to correlate MR evidence of joint effusion in the temporomandibular joint with disc displacement, disc reducibility, bony change of articular surface, joint pain, muscular tenderness and headache. The temporomandibular joint of TMD patients (94 affected sites and 46 unaffected sites) and 20 asymptomatic volunteers were imaged bilaterally. Sagittal and coronal T1, proton density, and T2-weighted images were obtained. Image findings of joint effusion were correlated with the pathologic changes of articular structures and pain-related symptoms. The results ere s follows: 1. MR showed effusion in 5.0% of asymptomatic joints, 28.3% of unaffected joints and 54.3% of affected joints. Joint effusion was more prevalent in symptomatic joints than symptom-free joints. 2. Disc displacement was observed 2.8% in asymptomatic joints, 37.0% in unaffected joints and 79.8% in affected joints. Joint effusion was more prevalent in displacement was observed joint and the rate of joint effusion increased according to the severity of disc displacement. 3. Nonreduced disc displacement was observed 2.5% in asymptomatic joints, 15.2% in unaffected joints and 53.2% in affected joints. Joint effusion was more prevalent in the disc-displaced joints without reduction. 4. The bony change of articular surface was observed 6.5% in unaffected joints and 12.8% in affected joints. Joint effusion was more prevalent in articular surface-damaged joints but the rate of joint effusion was high in the affected joints with mild damaged articular surface. 5. Joint effusion was seen in 56.9% of mild painful joints and in 85.7% of moderate to severe painful joint. A strong association was seen between joint effusion and moderate to severe joint pain. 6. Joint effusion was seen in 51.2% of the joints without headache and in 56.6% if the moderate to severe painful joint. There was little difference between the presence and the absence of the muscular tenderness. 7. Joint effusion was seen in 51.7% of the joints without headache and in 58.8% of the joint with headache. There was little difference between the presence and the absence of headache, but joint effusion was seen as a high rate(72.7%) in the joints having moderate to severe headache.

A STUDY ON TMJ DISC POSITION- Evaluation of the anterior disc displacement by GC+ line-

The present study proposes a method delineating the extent of the anterior displacement of the temporomandibular articular disc through the angle formed by the deepest point in the glenoid fossa, the center of the mandibular condyle and the junction between the end of the posterior band and the retrodiscal tissue. The method was applied to the normal group and TMD group. The TMD group was further divide into 3 groups Group I(little disc displacement), Group II(anterior disc displacement with reduction) and Group III(anterior disc displacement without reduction). The results were as follows. 1. The normal group showed the location of the articular disc within -10-0degree or with a wider allowance, within -10-10degree from the reference line GC. 2. The TMD group showed the disc located within -21.0-125.8degree,with two peaks at 0-100 and 60-800, suggesting that the group may be composed of more than two different subgroups. 3. The threshold point delineating the normal and TMD states was 0degree, because 82.5% of normal group appeared below 0degree and 94.8% of TMD group appeared above 0degree. 4. Since the angular disc displacement tends to increase from Group I to Group III, the angular displacement increases as the overall severiety of the disease increases, and the chance for a reduction of the disc decreases. 5. The normal group, Group I, Group II, and Group III can be categorized into statistically different groups. The normal group and TMD group can be distinguished in reference to 0degree, while the presence-absence of the anterior disc displacement is judged in reference to 10degree, and the probability of the disc reduction can be estimated in reference to 50degree. The present study assesses the location of the articular disc from the sagittal central section offering a supplementary clinical classification. This system provides an additional information concerning the location of the disc, thereby offering an objective mean to evaluate the progress of the disease. Further studies may be needed on the clinical changes according to location of the disc, as well as the relationship between the morphological changes and the anterior or sideways displacement of the disc.

A STUDY ON MEDIOLATERAL DISC DISPLACEMENT OF TMJ

MRI and arthrograms were used to diagnose the disc displacement of temporomandibular joint, but most of these trials focused on the anterior disc displacement. The discs could be displaced laterally or medially and in some case this sideway displacement may play a role as a main problem of temporomandibular disorder. In this study, 45 patients(31 unaffected sites, 59 affected sites) and 20 asymptomatic volunteers' sagittal and coronal MRI views were reviewed, then some results were found as follows 1. In sagittal plan, anterior disc displacements were found 15% in normal sites, 45% in unaffected sites and 69% in affected sites. 2. In coronal plan, sideways disc displacements were found 15% as medial in normal, 6% as medial and 13% as lateral in unaffected, 8% as medial and 14% as lateral diaplacement in affected sites. 3. In asymptomatic sites involving unaffected sites, medial disc displacements(11.3%) but in symptomatic joints, lateral disc displacements(13.8%) were prevalent. 4. The sideways disc displacement were observed 10.1% as medial and 2.9% as lateral dispalcement without and 9.8% as medial and 16.4% lateral dispalcements with anterior disc displacement. And, the coronal views of MRI were beneficial to evaluate the sideways disc displacement. Further studies may be needed on evaluation of the relations between sideways displacements and clinical symptoms or the treatment results.

A study of the meniscus position on the arthrotomography of thepatients of the TMJ internal derangement

No abstract available.