Patients with osteoporosis on steroid medication tend to sustain subsequent fractures.

BACKGROUND AND PURPOSE: Repeat fractures after percutaneous vertebroplasty can be seen in patients with osteoporotic compression fractures. The purpose of this study was to identify characteristics of patients with new fractures after vertebroplasty. MATERIALS AND METHODS: Fifty-five consecutive patients were treated with vertebroplasty for painful osteoporotic compression fractures at our institution. The charts and radiographic studies of all patients were retrospectively reviewed. Special attention was paid to patient age and sex, imaging studies, long-term use of steroid medication, and treatment for osteoporosis. We used logistic regression analysis and the Fisher exact test for statistical evaluation. RESULTS: Thirty-five patients were treated with vertebroplasty at one time and did not develop new fractures, whereas 20 patients returned with new fractures. Sixteen of 55 patients had been on steroid medication. The incidence of subsequent vertebral compression fractures after vertebroplasty in patients on long-term steroid therapy was 69% (11/16), compared with 23% (9/39) in those with primary osteoporosis (ie, those who were not on steroid therapy). There was a statistically significant association between use of steroids and new fractures (P<.01). No statistically significant difference was noted in patient age, sex, and medication for osteoporosis. CONCLUSION: Patients who are on long-term steroid medication have an elevated risk of developing new fractures after vertebroplasty.

Vertebroplasty for osteoporotic fractures with spinal canal compromise.

BACKGROUND AND PURPOSE: Percutaneous vertebroplasty can aggravate spinal canal narrowing, especially in patients with preoperative retropulsion. The purpose of this study was to evaluate changes in spinal canal dimension during percutaneous vertebroplasty for osteoporotic fractures with retropulsion. MATERIALS AND METHODS: We reviewed all cases of osteoporotic vertebral fractures treated with vertebroplasty. Twenty-one patients (25 vertebrae) had a retropulsed fragment that compromised the dimension of the spinal canal on preoperative imaging. We measured the degree of retropulsion before and after vertebroplasty to evaluate changes in spinal canal dimension. We also evaluated pain, neurologic status, vertebral body height, and wedge angle. RESULTS: Mean retropulsion was 4.2 mm before and 4.4 mm after vertebroplasty. There was no statistically significant difference (P = .32). Mean increase in vertebral body height was 2.6 mm anteriorly, 1.7 mm centrally, and 0.3 mm posteriorly. Mean decrease in wedge angle was 4.7 degrees. There were statistically significant improvements in height and wedge angle (P < .01). None of our patients developed new symptoms during vertebroplasty or thereafter. Twenty of 21 patients (95%) showed partial or complete immediate pain relief, whereas 1 patient did not improve. CONCLUSION: Vertebroplasty can be performed safely in patients with spinal canal compromise. This procedure can reduce pain, increase vertebral body height, and decrease wedge angle without worsening of retropulsion.

Radiographic assessment of asymmetry of the mandible.

PURPOSE: To assess the relationship between mandibular asymmetry and disorders of the temporomandibular joint. METHODS: We used advanced imaging of the temporomandibular joint to distinguish different causes of mandibular asymmetry. MR imaging and arthrography were applied to the temporomandibular joints of 11 patients presenting with mandibular asymmetry. RESULTS: Condyle hyperplasia was identified as the cause of the asymmetry in 5 patients. In the other 6 patients the mandibular condyle was normal on the long side, but the short side of the face demonstrated a small condyle head, short condyle neck associated with disk displacement, internal derangement, and degenerative joint disease of the temporomandibular joint. CONCLUSIONS: These observations suggest that both condyle hyperplasia on the long side of the mandible and disk displacement and degenerative joint disease of the temporomandibular joint on the short side can cause mandibular asymmetry. It was concluded that MR imaging or arthrography can be valuable for understanding the cause of mandibular asymmetry and be effective in treatment planning.

Natural course of untreated symptomatic temporomandibular joint disc displacement without reduction.

In some patients with disc displacement without reduction, the symptoms of pain and decreased range of motion have been observed to resolve spontaneously over time without treatment. The natural history of this condition, however, is not well-understood. Thus, to study the natural course of disc displacement without reduction, we followed 40 patients without treatment for a period of 2.5 years. The diagnosis was established by history and physical examination and confirmed with magnetic resonance (MR) imaging. After 2.5 years, 43% of the patients were asymptomatic, 33% had decreased symptoms, and 25% of the patients showed no improvement or had required treatment. MR evidence of osteoarthritis and advanced stages of internal derangement at the initial evaluation was associated with a poor prognosis. The result of this prospective cohort study indicated that approximately 40% of patients with symptomatic disc displacement without reduction will be free of symptoms within 2.5 years, one-third will improve, whereas one-quarter will continue to be symptomatic. This knowledge should be valuable for the treatment planning and evaluation of prognosis of patients with non-reducing symptomatic disc displacement.

Duplication of the extracranial internal carotid artery.

We describe a case of duplication of the left internal carotid artery from a point 1 cm distal to the origin to the proximal petrous segment where the vessel reunites. Duplication and fenestration of the internal carotid artery are discussed. A review of embryologic development is presented. Identification of these entities is important, especially in patients who require surgical intervention involving the internal carotid artery.

Leiomyosarcoma of the maxillary sinus: CT and MRI findings.

This report describes the CT and MRI appearances of a leiomyosarcoma of the maxillary sinus. CT showed frank bony destruction, no calcification and a low attenuation area within the mass. MRI showed intermediate intensity on T1 weighted images, intermediate to slightly high signal intensity on T2 weighted images and moderate inhomogeneous enhancement. Precise identification of the extent of the tumour, especially of orbital invasion, is of utmost importance because local recurrence is common after the resection of leiomyosarcomas.

Temporomandibular joint and dental imaging.

CT scanning of the jaws with cross-sectional images perpendicular to the curvature of the alveolar processes can be used to facilitate surgical planning for placement of dental implants. After ruling out pathologic changes, the radiographic evaluation concentrates on the dimensions of the alveolar processes relative to adjacent structures.

MR grading of temporomandibular joint fluid: association with disk displacement categories, condyle marrow abnormalities and pain.

The purpose of this study was to investigate temporomandibular joint (TMJ) effusion on magnetic resonance (MR) images, and its association with specific categories of disk displacement, bone marrow abnormalities and pain. From a series of 523 consecutive TMJ MR imaging studies of patients referred to imaging because of pain and dysfunction, those with TMJ effusion, defined as an amount of fluid that exceeded the maximum amount seen in a control group of asymptomatic volunteers, were analysed. The selected patients were reassessed and the amount of TMJ fluid was graded bilaterally according to a set of reference films. Other parameters recorded included disk displacement categories and condyle marrow abnormalities. Pain self-records were obtained from the patients immediately before MR imaging. The association between the recorded parameters and TMJ pain was analysed with t-tests and regression analysis. Of the 523 patients, 70 (13%) had TMJ effusion, which was unilateral in 61%. Only 9% of the 70 patients had effusion bilaterally, whereas bilateral disk displacement was found in 80%. In the 76 joints with effusion, 83% showed two specific categories of disk displacement at closed mouth. Condyle marrow abnormalities were found in 31% of the 70 patients, mostly on one side, and in 24% of the 76 joints. An in-patient regression analysis of the side difference in TMJ pain showed that effusion and condyle marrow abnormalities were significant pain-increasing factors. In conclusion, patients with TMJ effusion represent a subgroup with pain and dysfunction with more severe intra-articular pathology than those with disk displacement but no other joint abnormalities.

MR evidence of temporomandibular joint fluid and condyle marrow alterations: occurrence in asymptomatic volunteers and symptomatic patients.

The purpose of this study was to estimate the frequency and amount of temporomandibular joint (TMJ) fluid, as well as the frequency and type of condyle marrow alterations in asymptomatic volunteers and compare to patients with TMJ pain and dysfunction. Proton-density and T2 weighted magnetic resonance (MR) images of the TMJs of 62 asymptomatic volunteers and 58 symptomatic patients were analysed for fluid and condyle marrow alterations as well as disk position. The amount of fluid (increased T2 signal) was characterized as none, minimal, moderate or marked and related to the disk position. The differentiation between moderate and marked fluid was based on the maximum amount of fluid seen in the volunteers; more than this amount was categorized as marked fluid. The marrow of the mandibular condyle was categorized as normal, edema (increased T2 signal) or sclerosis (decreased proton-density and T2 signal) and related to fluid and disk position. In the 62 asymptomatic volunteers, 50 (81%) had none or minimal and 12 (19%) had moderate TMJ fluid. In the 58 symptomatic patients, 40 (69%) had none or minimal and 18 (31%) had moderate or marked fluid. Both in volunteers and patients, moderate fluid could be seen in joints with normal disk position, but was significantly associated with disk displacement. In the 62 volunteers, no signal abnormalities in the condyle marrow were found. In the 58 patients, six (10%) had abnormal bone marrow. These six patients had disk displacement and two had moderate or marked fluid. Marked fluid and condyle marrow abnormalities were therefore not encountered in any of the asymptomatic volunteers but in about 10% of the patients.

Diffuse pigmented villonodular synovitis of the temporomandibular joint diagnosed by fine-needle aspiration cytology.

Diffuse pigmented villonodular synovitis is a rare tumor in the temporomandibular joint region. This article deals with a 32-yr-old male who suffered from pain and swelling in the right temporomandibular joint region associated with restricted mouth opening. Computed tomography showed a tumor lateral to the temporomandibular joint. Arthrography revealed a displaced temporomandibular joint disk. Fine-needle aspiration cytology showed characteristic cellular changes, including rounded or oval cells with abundant cytoplasm and intracytoplasmatic hemosiderin deposits and numerous multinucleated giant cells without nuclear atypia. A benign mesenchymal lesion suggestive for pigmented villonodular synovitis was diagnosed and later verified at histologic examination. Fine-needle aspiration cytology seems to be useful for this diagnosis.

Magnetic resonance imaging of the temporomandibular joint. Increased T2 signal in the retrodiskal tissue of painful joints.

The cause of pain associated with TMJ disk displacement and internal derangement is unclear. In clinical work with MR imaging we have noted increased T2 signal from the retrodiskal tissue in some patients with TMJ pain and dysfunction. The purpose of this study was to analyze a possible association between pain and the T2 signal intensity from the retrodiskal tissue on MR images. The study was based on 48 joints in 33 patients referred for MR imaging of the TMJ. The T2 signal from the retrodiskal tissue was measured on the MR scanner and was correlated to the degree of pain. The results showed a statistically significant (p < 0.05) association between pain and increased T2 weighted signal. The T2 signal intensity ranged between 251 and 478 and was highest in the painful joints and lowest in the joints without pain. We conclude that the average T2 signal from the retrodiskal tissue is higher in painful joints than in nonpainful joints. This might reflect an increased vascularity of the joint tissue.

Steepness of articular eminence and movement of the condyle and disk in asymptomatic temporomandibular joints.

OBJECTIVE: The purpose of this study was to investigate the rotational motion characteristics of the disk-condyle complex in relation to the steepness of the articular eminence of the normal temporomandibular joint. STUDY DESIGN: We studied 14 asymptomatic volunteers with normal temporomandibular joints using magnetic resonance images with gradient recoil acquisition in the steady state. The degree of condyle and disk rotation within the glenoid fossa, the inclination of the condyle path, and the steepness of the articular eminence were measured and correlated. RESULTS: The condyle and disk both rotated during forward translation within the glenoid fossa during mouth opening. The movement of the disk was smaller than the movement of the condyle, resulting in a posterior rotation of the disk relative to the condyle. The inclination of the condyle path (mean, 61.1 degrees) was significantly smaller than the steepness of the articular eminence (mean, 68.7 degrees). The steepness of the articular eminence was statistically significantly correlated with the degree of disk rotation, which indicated that the disk tended to rotate farther backward in a temporomandibular joint with steeper articular eminence. CONCLUSION: We found that on mouth opening the disk rotated backward relative to the condyle. The posterior disk rotation was more prominent in joints with a steep articular eminence than in joints with a less steep eminence. The results may be helpful for understanding the biomechanics of the temporomandibular joint, especially relative to the development of disk displacement.

Condyle position in the temporomandibular joint. Comparison between asymptomatic volunteers with normal disk position and patients with disk displacement.

Though the significance of condyle-fossa relationship in the temporomandibular joint has not yet been clarified and normal condyle position not yet defined, efforts have been made to guide the mandibular condyle into a centric position in the glenoid fossa with the aim of relieving the symptoms in patients with orofacial pain and temporomandibular joint internal derangement. The present study investigated the mandibular condyle position in 34 joints in asymptomatic volunteers with normal disk position as verified by arthrography and compared it with the mandibular condyle position in 85 joints in patients with different stages of internal derangement. The results showed that in the volunteers with normal joints including normal superior disk position, the condyles were almost randomly distributed in anterior, centric, and posterior positions in the glenoid fossa. Of the joints with anterior disk displacement approximately half of the number of joints with reducing disks and two thirds of the joints with nonreducing disks appeared to have posterior condyle position. Posterior condyle position cannot, however, be used to diagnose internal derangement because the condyle was found to be either in anterior or centric position in many joints with a displaced disk. The variety in condyle position in the healthy joints ought to be taken into consideration if treatment is chosen to normalize the mandibular condyle position by bringing it into a centric position in the glenoid fossa.

Magnetic resonance imaging of the temporomandibular joint: value of pseudodynamic images.

Magnetic resonance fast scanning technique (gradient recalled acquisition at steady state) has been reported to be useful when evaluating the dynamics of the temporomandibular joint and also to be accurate for determining the disk position. Yet in our clinical experience gradient recalled acquisition at steady state images have frequently been inferior to proton density images for diagnosis of temporomandibular joint internal derangement. The first aim of this study was to compare gradient recalled acquisition at steady state images with proton density images for diagnosis of disk position. The second aim was to identify what additional information could be gathered from gradient recalled acquisition at steady state images when compared with static proton density images. We obtained unilateral images from 20 patients with signs and symptoms of temporomandibular joint internal derangement and from 20 asymptomatic volunteers. Multiple gradient recalled acquisition at steady state images were obtained during mouth opening and closing and proton density images were obtained at the closed and open mouth positions. The results showed that the gradient recalled acquisition at steady state images were in accordance with the proton density images in 32 joints (80%) and were false negative in 8 joints (20%). Six of the joints with false-negative gradient recalled acquisition at steady state images showed sideways disk displacement, and two showed partial anterior disk displacement. Gradient recalled acquisition at steady state images, on the other hand, provided information about movement pattern and also demonstrated impingement of the joint structures on the muscles anterior to the joint at maximal mouth opening. It was concluded that gradient recalled acquisition at steady state images cannot replace proton density images for diagnosis of disk position but they can provide supplementary information for evaluation of joint function.

Comparison of tomography and midfield magnetic resonance imaging for osseous changes of the temporomandibular joint.

The purpose of this study was to compare midfield (0.3 Tesla) magnetic resonance imaging with conventional tomography for assessment of osseous changes of the temporomandibular joint. The material consisted of magnetic resonance images and tomograms of 66 temporomandibular joints. Each set of images was assessed for osseous changes without knowledge about patient symptoms or findings of the other imaging modality. The results showed that 30 joints were normal both by magnetic resonance imaging and tomography, 21 joints showed osseous changes with both techniques, and there were discrepancies between the two techniques in 15 joints. In 12 of these 15 joints magnetic resonance imaging was negative, but tomography showed osseous changes. In the other three joints tomography was normal, but magnetic resonance imaging showed osseous changes. Based on previous tomographic and midfield magnetic resonance imaging studies with correlation to cryosections and dissection and the quality of the depiction of the osseous changes in these images, it was apparent that tomography represented a more accurate representation of the osseous anatomy. The results therefore suggest that conventional tomography is superior to midfield magnetic resonance imaging for assessment of osseous changes of the temporomandibular joint.

Steepness of the articular eminence in the temporomandibular joint. Tomographic comparison between asymptomatic volunteers with normal disk position and patients with disk displacement.

OBJECTIVE: A steep articular eminence has been proposed as one etiologic factor for the development of TMJ disk displacement. The purpose of this study was to determine the steepness of the articular eminence in asymptomatic volunteers with superior disk position and to compare it with the articular eminence in patients with internal derangement. STUDY DESIGN: We investigated 34 asymptomatic volunteers and 71 patients. The steepness of the articular eminence was determined on sagittally corrected tomograms, and disk position was diagnosed by dual space arthrotomography. RESULTS: The results showed that the articular eminence was on the average steeper in the asymptomatic volunteers in the lateral (64.9 degrees), central (64.4 degrees), and medial (65.4 degrees) sections of the joint than in the patients (56.1 degrees, 60.2 degrees, 58.9 degrees, respectively). When the comparison of the steepness of the eminence was based on the presence or absence of osseous changes in the form of remodeling or osteoarthrosis, no difference was found between the asymptomatic volunteers and the patients with disk displacement but without such changes. The largest difference in the steepness of the eminence was found between the persons with osseous changes and those without. CONCLUSION: These findings contradict earlier studies that have indicated a steep articular eminence to be one etiologic factor for the development of disk displacement. The results of this study showed that the steepness of the articular eminence is decreased in the patients as a result of remodeling or degenerative changes of the bone that are a result of the internal derangement.

Disk displacement and temporomandibular joint symptoms in orthognathic surgery patients.

The purpose of this study was to document the prevalence of disk displacement and temporomandibular joint symptoms in orthognathic surgery patients. Fifty-three consecutive patients with different types of dentofacial anomalies were examined clinically and with bilateral arthrography. Disk displacement unilaterally or bilaterally was found in 57% of the patients or 46% of the joints. Displacement with reduction was seen in 38 joints, and displacement without reduction was seen in 11 joints. Fifty-three percent of the patients had pain in the temporomandibular joint or masticatory muscles, 30% of the joints demonstrated clicking, and 4% had crepitation. No association was found between disk displacement and clinical symptoms except for an association between clicking and anterior disk displacement with reduction. Neither could an association between disk displacement and the type of dentofacial anomaly be appreciated. It was concluded that disk displacement was frequent in patients with dentofacial anomalies, but no relationship to temporomandibular joint symptoms and the type of dentofacial anomaly could be clearly demonstrated.

Ortho cubic super-high resolution computed tomography: a new radiographic technique with application to the temporomandibular joint.

OBJECTIVE: The purpose of this study was to present a newly developed ortho cubic super-high resolution computerized radiographic technique (Ortho-CT) and its application to the temporomandibular joint. METHOD AND PATIENTS: A prototype was assembled on a Scanora (Soredex Findent Co) with the use of a 4-inch image intensifier instead of film. Data were collected from a single 360 degrees scan and a cylinder 32 mm in height and 38 mm in diameter. Images were reconstructed with a software program on a personal computer. Imaging data consisted of 240 (height) x 280 (diameter) cubic voxels, each with a dimension of 0.136 mm. With this small voxel size, the image resolution was high and was the same in any direction. Three patients with temporomandibular joint disease (trauma, pain and dysfunction, fibroosseous ankylosis) were evaluated with Ortho-CT, and the images were compared to routine radiographic films. CONCLUSION: Preliminary clinical experience with Ortho-CT demonstrates subjectively superior image quality compared to panoramic and conventional tomographic images. The images were similar to conventional computed tomography, but this new radiographic technique is less expensive, takes less space, and gives a lesser patient dose.

Osteoarthritis and abnormal bone marrow of the mandibular condyle.

OBJECTIVE: The purpose of this study was to analyze the relationship between abnormal bone marrow of the mandibular condyle and osteoarthritis. STUDY DESIGN: The relationship between abnormal bone marrow and osteoarthritis of the mandibular condyle was analyzed in magnetic resonance images of the temporomandibular joints of 74 patients. Thirty-seven patients had magnetic resonance evidence of abnormal bone marrow, and 37 control patients had magnetic resonance images with normal bone marrow. RESULTS: Fifteen of 37 patients with magnetic resonance evidence of abnormal bone marrow had no magnetic resonance evidence of osteoarthritis; the other 22 patients had both abnormal bone marrow and osteoarthritis. CONCLUSIONS: Abnormal bone marrow of the mandibular condyle can occur separately from osteoarthritis; nearly one half of the joints with magnetic resonance evidence of abnormal bone marrow did not have any evident osteoarthritis. Abnormal bone marrow may therefore initially represent a separate disease entity. Over time, secondary osteoarthritis probably develops in joints with initial bone marrow abnormalities.

Imaging of the temporomandibular joint: a position paper of the American Academy of Oral and Maxillofacial Radiology.

Various imaging techniques for the temporomandibular joint are discussed with respect to uses, strengths, and limitations. An imaging protocol is outlined for evaluating patients with a wide variety of temporomandibular joint related signs and symptoms.