• Imaging Science in Dentistry
• /
• v.31 no.1
• /
• pp.9-16
• /
• 2001

Purpose: To investigate bone and disc configuration on MR images in internal derangement related to age. Materials and methods: MR images of 150 TMJs in 107 patients were analyzed to determine the morphologic changes. Two groups were distinguished to be correlated with age. Group I consisted of TMJs that were diagnosed as having anterior disc displacement with reduction (ADDwR), and Group 2 consisted of TMJs that were diagnosed as having anterior disc displacement without reduction (ADDwoR). We assessed the configuration of the articular disc, degree of anterior disc displacement, and osseous changes of TMJs. Results: The third decade (83 of 150 joints) was most frequent in this study. In the ADDwR group biconcave discs was most frequent at all ages except fifth decade, but in the ADDwoR group deformed discs was most frequent at third and forth decades. In the ADDwR group slightly displaced discs was most frequent at all ages, but in the ADDwoR group severely displaced discs was most frequent at second decade, and the degree of disc displacement was increased with aging over 30 years of age. TM joints showed osseous changes in 17% of the ADDwR group, and in 30% of the ADDwoR group. MR findings of osseous changes of the TMJ were not found to be significantly correlated with age. Conclusion: The prevalence of deformation of disc, displacement of disc, and osseous changes of TMJ was higher in the ADDwoR group than in the ADDwR group. MR findings of disc configuration and degree of disc displacement were found to be correlated with age.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.27 no.5
• /
• pp.417-422
• /
• 2001

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 $0.79{\pm}0.13cm$ at sagittal section and mediolateral length was $2.12{\pm}0.22cm$ on coronal section. The mean value of anteroposterior length of symptomatic condyle was $0.67{\pm}0.16cm$ at sagittal section and mediolateral length was $1.97{\pm}0.28cm$ 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.

• Journal of Oral Medicine and Pain
• /
• v.49 no.2
• /
• pp.29-34
• /
• 2024

Acute malocclusion can occur in conditions related to temporomandibular joint (TMJ) disorders. This report presents two cases of acute malocclusion related to posterior disc displacement according to complete disc tearing. A 65-year-old male and an 88-yearold female presented with TMJ pain and occlusal discrepancies. Clinical examination, computed tomography, and magnetic resonance imaging revealed complete disc tearing and posterior displacement of a partial disc fragment. Dental cast analysis revealed a slight anterior and lateral deviation of the mandible toward the non-affected side; however, clinically, significant occlusal changes were not observed. This was attributed to the displacement of a small disc fragment rather than the entire disc. Including the cases presented, most instances of complete disc tearing responded well to conservative treatment such as pharmacotherapy and physical therapy, resulting in pain alleviation, and residual occlusal changes were tolerable for the patients in their daily activities. However, persistent occlusal changes or severe chewing difficulty may require surgical intervention.

• Journal of Oral Medicine and Pain
• /
• v.42 no.1
• /
• pp.16-19
• /
• 2017

Clinicians are familiar with limitation of opening mouth caused by temporomandibular disorders. Sometimes, patients also complain of difficulty in closing mouth. Difficulty in closing mouth can be caused by anterior, posterior disc displacement, and subluxation of temporomandibular joint (TMJ). In this report, we presented a patient who had a difficulty in both opening and closing mouth. The patient complained of TMJ noises and intermittent limitation of opening mouth, and inability to get teeth back into maximal intercuspal position. Magnetic resonance images revealed that the left TMJ had an anterior disc displacement with relative posterior disc displacement. We reviewed the possible causes, signs and symptoms, and treatment for difficulty in closing mouth with related literatures.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.27 no.4
• /
• pp.337-343
• /
• 2001

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.

• Imaging Science in Dentistry
• /
• v.31 no.4
• /
• pp.235-240
• /
• 2001

Purpose: To evaluate displacement and morphologic changes of the temporomandibular joint (TMJ) disc in patient with internal derangement using magnetic resonance imaging (MRI). Materials and Methods: One hundred and forty five MR images of TMJs in 73 patients were evaluated. Positional and morphologic changes of the TMJ discs were assessed. Lateral or medial disc displacement was also evaluated on coronal images. Results: Among 63 discs with anterior disc displacement, 37 discs were assessed as a biconcave disc and 21 as a deformed disc. Rotational disc displacement was observed in 35 discs. Anteromedial disc displacement was observed in 29 discs, and anterolateral direction in 6 discs. Among 35 rotational displacement, 5 biconcave discs and 21 deformed discs were observed. Conclusion : Rotational and sideways displacement of TMJ discs were found to be common and an important aspect of internal derangement. This study also suggests that sagittal and coronal images of the TMJ have complementary abilities for an assessment of joint abnormality.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.34 no.3
• /
• pp.173-179
• /
• 2012

Purpose: This study was to determine the effects of surgical induction of anterior disc displacement (ADD) on the distribution of glycosaminoglycan (GAG) and collagen fiber arrangement in the rabbit temporomandibular joint (TMJ) tissues including articular cartilage of condyle, disc, retrodiscal tissue, and articular eminence. Methods: We used van Gieson staining and Alcian blue critical electrolyte concentration (CEC) method to observe change of collagen fibers on disc and to measure GAG up to 10 weeks in TMJ tissues after surgical induction of ADD on 25 rabbits. Results: CEC measurements for GAG showed 0.3 M, 0.4 M, 0.6 M, and 0.8 M at 1 week, 2 weeks, 3, 4, and 8 weeks, 10 weeks, respectively. This result indicated that GAGs shifted to highly sulphated ones as time passed. Disruption of collagen fiber arrangement in the disk occurred at 10 days and aggravated at 3 weeks. Conclusion: Our study showed degenerative osteoarthritis changes in rabbit TMJ following surgical induction of ADD up to 10-week period.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.29 no.6
• /
• pp.392-396
• /
• 2003

Purpose : The purpose of this study was to find the predictors for successful arthrocentesis for anterior disc displacement without reduction(ADD without Reduction) of the temporomandibular joint (TMJ). Patients and Methods : Arthrocentesis and lavage was carried out in 25TMJs of 22patients whose MRI findings were all anterior disc displacement without reduction. The effectiveness of the treatment was evaluated in terms of the postoperative range of maximal mouth opening (MMO) and the degree of postoperative pain score. Predectors which was analyzed were age, duration of painful locking, MMO, the degree of pain, perioperative clicking and the amounts of irrigation fluid. Results: 18cases (72%) was included to criteria for success. There were no significant differences in age, duration of locking, MMO and the degree of pain statistically. But In 15cases(83%) of successful cases, amouts of irrigated solution recovered to normal MMO were less than 150ml. And In 8cases (44%) of successful cases, perioperative clicking was appeared. Conclusion : Amounts of irrigated solution recovered to normal MMO and the appeareance of perioperative clkicking may be predictors of the successful results of arthrocenetesis of ADD without reduction of TMJ.

• Journal of Oral Medicine and Pain
• /
• v.37 no.4
• /
• pp.205-211
• /
• 2012

A 35 year-old female presented with the complaint of sudden occurrence of bite change and concurrent opening limitation, as well as pain in the right temporomandibular joint (TMJ) during mouth opening. From her history it was revealed that she had simple clicking of right TMJ for several years before onset of these symptoms, and that the clicking sound subsided recently after development of opening limitation. On clinical examination, anterior open bite, midline shift of the mandible to right, and premature contacts on left posterior teeth were observed. Maximum mouth opening and lateral movement to left were also restricted. On magnetic resonance images, the right TMJ showed anterior disc displacement without reduction and the posterior joint space is greatly collapsed by retrusion of the condyle. It was thought that the sudden occurrence of occlusal change would be resulted from abrupt displacement of the mandible associated with development of the anterior disc displacement without reduction. The stabilization appliance traction therapy was performed initially for first 3 months along with physical and pharmacologic therapy. However, the anterior open bite and opening limitation didn't resolve and the position of mandible still remained altered. So the stabilization appliance was changed to intermaxillary traction device. Then the mandible returned progressively to normal position and the occlusion became more stable and comfortable. After 5 months of intermaxillary traction therapy, the anterior open bite was dissolved completely and the occlusion became stabilized satisfactorily along with recovery of normal mouth opening range. On post-treatment magnetic resonance image, remodeling of condylar head was observed.

• Journal of Oral Medicine and Pain
• /
• v.36 no.2
• /
• pp.107-115
• /
• 2011

We report 4 patients who developed change of occlusion which seemed to be related to anterior disc dislocation without reduction, but there was no distinct evidence of condylar destruction or collapse. They experienced sudden occurrence of occlusal change, anterior open bite in 2 patients, lateral CR-CO discrepancy in 1 patient, and anteroposterior CR-CO discrepancy in 1 patient. Also, this report is to find out if there is a relation between sudden occurrence of occlusal change and anterior disc dislocation without reduction.