Biomedical subjects

P L Westesson

Publications and source records attributed to P L Westesson.

At least 19 recordsLinked to original sources

PubMed1992

Temporomandibular joint: surgically created disk displacement causes arthrosis in the rabbit.

To document a causal relationship between temporomandibular joint disk displacement and arthrosis, the disk was surgically displaced in one temporomandibular joint in each of three rabbits. The rabbits were sacrificed after 4 weeks and the mandibular condyles were studied radiographically and histologically. All three joints that underwent disk displacement had radiographic and histologic evidence of arthrosis, which included erosion of the bone, irregularity and fissure formation of the articular soft tissue cover, disruption of the subchondral layer of cartilage cells, and chondrocyte proliferation. No radiographic or histologic changes occurred in the joints that were untouched. The results suggest that surgically created disk displacement can cause arthrosis in the temporomandibular joint of the rabbit.

Animals↗

PubMed1992

Temporomandibular joint disk displacement without reduction. Treatment with flat occlusal splint versus no treatment.

A flat occlusal splint has been extensively used in the treatment of patients with temporomandibular joint disk displacement without reduction, but no studies with untreated controls have assessed its effect. We randomly assigned 51 patients with temporomandibular joint pain and arthrographically verified disk displacement without reduction to be treated with a flat occlusal splint or to serve as untreated control subjects in a 12-month clinical trial. Pain symptoms disappeared in about one third of the patients in each group. Another third of the patients in the control group improved. Sixteen percent of the patients in the control group and 40% of the patients treated with a flat occlusal splint were worse at the end than at the beginning of the study. Joint pain and muscle tenderness decreased more frequently in the nontreatment controls than in the treatment group. A statistically significant benefit of a flat occlusal splint over nontreatment control subjects could not be identified in this study of patients with painful disk displacement without reduction. The use of a flat occlusal splint in this patient group should therefore be reconsidered.

Adolescent↗

PubMed1992

Temporomandibular joint diskectomy. No positive effect of temporary silicone implant in a 5-year follow-up.

The purpose of this study was to evaluate the long-term clinical and radiologic effects of a temporary silicone implant after diskectomy of the temporomandibular joint. Forty-three temporomandibular joints in 43 patients with painful disk displacement underwent a diskectomy. A sheet of medical-grade silicone was temporarily placed in 22 patients; 21 patients did not receive an implant. The patients were clinically and radiologically examined 5 years after surgery. On the basis of symptoms and jaw function, they were classified as having good (30 patients), acceptable (8 patients), and bad (5 patients) results. All the patients with bad results and five of the eight patients with acceptable results had received implants. Erosive changes of the condyle or fossa were seen radiographically at follow-up in eight patients, each of whom had received an implant. No positive clinical or radiologic effects of the implants could be identified. The use of a temporary silicone implant after diskectomy of the temporomandibular joint in patients with internal derangement should be seriously questioned.

Adult↗

PubMed1992

Accuracy of clinical diagnosis for TMJ internal derangement and arthrosis.

This study investigated the accuracy of clinical examination in determining the status of the temporomandibular joint with respect to internal derangement and arthrosis. A series of 110 patients was given standard clinical examinations followed by bilateral imaging with arthrography and/or magnetic resonance imaging. There was agreement between the clinical diagnosis and the imaging finding in 95 joints (43%). In the other 125 joints (57%), the clinical diagnosis did not agree with imaging findings. There were false-positive clinical diagnoses in 39 joints and false-negative clinical diagnoses in 31 joints. In the other 55 joints the clinical diagnosis correctly indicated that the joint was abnormal but was incorrect about the stage of abnormality. On the basis of the overall diagnostic accuracy of 43%, it was concluded that a clinical examination is not reliable for determining the status of the joint in patients with signs and symptoms of temporomandibular joint internal derangement.

Adolescent↗

PubMed1992

Temporomandibular joint: diagnosis of medial and lateral disk displacement with anteroposterior arthrography. Correlation with cryosections.

The purpose of this investigation was to determine whether it is possible to diagnose medial and lateral disk displacements by single-contrast lower-compartment arthrography with an anteroposterior projection. Contrast medium was injected into the lower joint space of 29 fresh temporomandibular joint autopsy specimens. Anteroposterior arthrograms and anteroposterior arthrotomograms were obtained. Enlargement of the medial or lateral recess of the lower joint space was considered an arthrographic indication of medial or lateral displacement of the disk. After arthrography the joints were deep frozen and cryosectioned in the coronal plane. Imaging findings were correlated to observations in the cryosections in a blind fashion. The anteroposterior arthrograms were 48% accurate in determining the position of the disk in the coronal plane. The anteroposterior arthrotomograms were 59% accurate. It was concluded that anteroposterior lower joint space arthrography as well as arthrotomography is not reliable for diagnosis of medial or lateral disk displacement.

Aged↗

PubMed1992

Prevalence of osseous changes in the temporomandibular joint of asymptomatic persons without internal derangement.

There is a controversy in the literature regarding the prevalence of osseous changes in the temporomandibular joint (TMJ) of asymptomatic persons. Using cephalometrically corrected tomograms, we assessed one TMJ of each of 34 asymptomatic persons who had no arthrographic or magnetic resonance imaging evidence of internal derangement. Minimal flattening of the condyle or articular eminence was seen in 12 joints (35%). More advanced osseous changes such as erosion, osteophytosis, or sclerosis were not seen in any joint. The findings suggest that generally no osseous changes occur in the TMJ in asymptomatic persons without internal derangement. When osseous changes occur, they are confined to minimal flattenings. Minimal flattening is probably of no clinical significance because the persons were asymptomatic, and arthrography and magnetic resonance imaging showed no evidence of abnormalities in the soft tissues.

Adolescent↗

PubMed1992

Magnetic resonance evaluation after temporomandibular joint diskectomy.

The aim of this study was to investigate the value of magnetic resonance imaging after diskectomy of the temporomandibular joint. Magnetic resonance images were obtained before and 12 months after unilateral diskectomy without disk replacement. Magnetic resonance findings at follow-up were correlated to residual pain. At the follow-up, 20 of 28 patients were free of pain in the joint that had been surgically treated, four patients had mild pain, and four patients had significant residual pain. The magnetic resonance images at follow-up showed that the joint space was filled with soft tissue after diskectomy. In patients without pain at follow-up, this soft tissue had a magnetic resonance signal that was equal or higher than that of the muscles. In the four patients with significant residual pain and in one patient with mild residual pain, the soft tissue in the joint space between the condyle and glenoid fossa had a magnetic resonance signal intensity that was lower than the muscle. On the basis of findings in a previous study, the areas of low signal intensity were interpreted as fibrous adhesions. The study suggests that areas of low signal intensity in the joint space appear to be associated with residual pain and that magnetic resonance imaging could be a valuable tool for assessment of the temporomandibular joint after diskectomy.

Cartilage, Articular↗

PubMed1992

Creation of disc displacement in human temporomandibular joint autopsy specimens.

The purpose of this study was to investigate the possibility of iatrogenically creating disc displacement in the human temporomandibular joint (TMJ). Fourteen fresh TMJ autopsy specimens with superior disc position were selected for the study. The upper and lower joint spaces were exposed via a preauricular incision and two to three superficial mediolateral incisions were made in the inferior surface of the posterior disc attachment (ie, retrodiscal tissue). After these incisions were made it was possible to manually displace the disc anteriorly. To maintain the disc in the anterior position the condyle was positioned against the posterior disc attachment in a manner corresponding to the closed mouth position. The joints were then fixed in this relationship and magnetic resonance imaging (MRI) was repeated using the same scanning plane and scanning parameters as before intervention. After imaging, the joints were cryosectioned to show the degree of disc displacement. Histologic analysis was made of the posterior disc attachment. Postoperative MR images and cryosections showed the disc to be displaced anteriorly in 12 of the 14 joints. Displacement of the disc was complete in eight joints (the entire mediolateral dimension of the joint) and partial (only in the lateral part of the joint) in four joints. The disc remained in a superior position in two joints. Cryosections and histologic analysis showed the incisions in the inferior aspect of the posterior disc attachment to be superficial. The results of this study suggest that the integrity of the inferior aspect of the posterior attachment of the disc to the condyle is essential for keeping the disc in its position superior to the condyle.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1992

Diagnosis of medial temporomandibular joint disc displacement with dual space anteroposterior arthrotomography: correlation with cryosectional morphology.

This study was undertaken to determine if it is possible to identify medial disc displacement with dual space anteroposterior (AP) arthrotomography. Contrast medium was injected into the upper and lower joint spaces of 11 fresh temporomandibular joint (TMJ) autopsy specimens and arthrotomograms were obtained with an AP projection. The arthrotomograms of five joints showed an enlargement of the medial recess of the upper joint compartment with folding of the disc inferiorly. This was interpreted as an indication of medial disc displacement. Cryosections confirmed medial displacement of the disc in these five joints and showed a slight medial displacement of a disc in one additional joint. Retrospective evaluation of the arthrotomogram of this joint showed that the disc was slightly medially displaced, but without folding. The results of this study suggest that AP dual space arthrotomography can be useful for the diagnosis of medial disc displacement in cadaver material.

Aged↗

PubMed1992

Prevalence of temporomandibular joint internal derangement in patients with craniomandibular disorders.

To determine the prevalence of temporomandibular joint internal derangement in patients with signs and symptoms of craniomandibular disorders, bilateral imaging was performed in a consecutive series of 115 patients with signs and symptoms of craniomandibular disorders. Ninety patients (78%) had different stages of unilateral or bilateral internal derangement, and 25 patients (22%) had normal temporomandibular joints bilaterally. Out of 230 joints, 60 showed disk displacement with reduction, 8 showed disk displacement without reduction, and 29 showed disk displacement without reduction associated with anthrosis. The study indicates that almost 80% of patients with signs and symptoms of craniomandibular disorders have different forms of internal derangement.

Adolescent↗

PubMed1992

Temporomandibular joint sounds: correlation to joint structure in fresh autopsy specimens.

In an attempt to better understand the cause of different types of temporomandibular joint (TMJ) sounds, we recorded joint sounds from 27 fresh autopsy specimens, displayed the time frequency distribution of the sound as a three-dimensional graph, and correlated the sound character to morphologic observations at subsequent dissection. Eleven joints elicited sounds, and 16 joints were silent. All joints with sounds had different degrees of intraarticular changes. These ranged from disk displacement with reduction to displacement without reduction and arthrosis of the articular surfaces. Reciprocal clicking occurred both in joints with disk displacement with and without reduction, as well as in joints with arthrotic changes. Crepitation only occurred in joints with arthrosis and perforation. The sample was too small to demonstrate any statistically significant association between the joint sound classified as clicking or crepitation and joint structure types of joint pathosis in this small sample. A high frequency component to the sound appeared to be associated with arthrosis of the articular surfaces. It was concluded that joint sounds indicate joint abnormality but that the absence of joint sound does not exclude intraarticular pathosis.

Aged↗

PubMed1992

Temporomandibular joint: improved MR image quality with decreased section thickness.

To determine if the quality of spin-echo magnetic resonance (MR) images of the temporomandibular joint (TMJ) could be improved by reducing section thickness, coronal and sagittal 3.0- and 1.5-mm MR images of the same joints were evaluated. Depiction of the disk, trabecular pattern, and cortex of the condyle was better on coronal 1.5-mm images than on 3.0-mm images (P less than .01), and 1.5-mm sagittal images were better for depiction of the trabecular pattern of the condyle than were 3.0-mm images (P less than .05). The ability of MR imaging with thinner sections to reveal more anatomic details should result in improved diagnostic accuracy.

Adult↗

PubMed1992

Temporomandibular joint: relationship between MR evidence of effusion and the presence of pain and disk displacement.

OBJECTIVE: The purpose of this study was to correlate MR evidence of joint effusion in the temporomandibular joint with symptoms of joint pain and the presence of disk displacement and arthrosis. SUBJECTS AND METHODS: The temporomandibular joints of 379 patients with clinical symptoms of temporomandibular joint disorders and 11 asymptomatic volunteers were imaged bilaterally. Sagittal and coronal proton density-weighted and T2-weighted images were obtained. Imaging findings of joint effusion were correlated with the presence of disk displacement and arthrosis and the symptom of pain. RESULTS: MR showed effusion in 7% of the joints with normal superior disk position, 40% of the joints with disk displacement with reduction, 50% of the joints with disk displacement without reduction, and 27% of the joints with arthrosis. Two of the control subjects had disk displacement with reduction; MR did not show joint effusion in any of the control subjects. A strong association was seen between joint effusion and joint pain. Joint effusion was seen in 46% of the joints on the more painful side and in 13% of the joints on the less painful side. CONCLUSION: The results show that temporomandibular joint effusions primarily occur in joints with disk displacement and are strongly associated with joint pain.

Humans↗

PubMed1991

Clinical signs of temporomandibular joint internal derangement in adults. An epidemiologic study.

This study investigated the frequency and distribution of clinical signs of temporomandibular joint (TMJ) internal derangement in an adult non-TMJ patient population. Four hundred three persons who participated in an epidemiologic investigation were examined for clinical signs of TMJ internal derangement by four examiners who followed a standardized form. Clinical signs of internal derangement were found in 76 persons (19%). Twenty-nine persons (7%) had reciprocal clicking and 47 (12%) had a history of clicking replaced by limitation of mouth opening with deviation to the affected side. Reciprocal clicking was associated with TMJ pain during mouth opening and with limitation of jaw movement. A history of clicking replaced by limitation of mouth opening with deviation to the affected side was associated with pain during mouth opening, limitation of opening, and palpatory tenderness of the TMJ. The study indicates that clinical signs of TMJ internal derangement are present in nearly one fifth of non-TMJ patients. Those with clinical signs of internal derangement frequently also have subjective symptoms but they have not sought treatment for these symptoms.

Adult↗

PubMed1991

Osseous and muscular changes after vertical ramus osteotomy. A magnetic resonance imaging study.

Magnetic resonance (MR) imaging was performed about 2 years after vertical ramus osteotomy of 10 patients to study changes in the mandibular condyle, cortical and cancellous bone of the proximal fragment, and muscles of mastication. MR imaging observations of the surgically treated patients were compared with findings in 10 asymptomatic untreated control subjects. The results showed that the MR appearance of bone marrow of the mandibular condyle was normal in all patients and in all control subjects. No MR evidence of avascular necrosis of the mandibular condyle was found. MR imaging artifacts from microscopic metallic particles were seen in all surgically treated regions. Thickening of the buccal and lingual cortical bone with narrowing of the bone marrow space was seen bilaterally in eight patients and unilaterally in two patients. Slight medial tipping of the mandibular condyle was seen unilaterally in two patients. Atrophic changes with decreased muscle volume and fatty replacement of muscle tissue was seen unilaterally in eight patients. None of these alterations were seen in the control subjects. MR imaging appears to be an excellent method to study morphologic changes of the muscles of mastication and osseous fragments after orthognathic surgery of the mandible. Thickening of the cortical bone and narrowing of the bone marrow space of the proximal fragment was frequently seen after vertical ramus osteotomy of the mandible and most likely represents remodeling associated with normal healing.

Adolescent↗

PubMed1991

Ultrathin arthroscope for use in the lower compartment of the temporomandibular joint.

Arthroscopy of the temporomandibular joint has been performed mainly in the upper joint space because the instruments available have been too thick to be safely inserted into the lower joint space. This article describes a newly developed ultrathin arthroscope with an outer diameter of 0.69 mm that has been specifically developed to be used in the lower space of the temporomandibular joint. This arthroscope can be inserted into the lower joint space with a standard 18-gauge needle. The article describes the arthroscope in its initial application to patient and cadaver material.

Arthroscopes↗

PubMed1991

Increased horizontal angle of the mandibular condyle in abnormal temporomandibular joints. A magnetic resonance imaging study.

The horizontal condylar angle was measured in axial magnetic resonance images of normal and abnormal temporomandibular joints (TMJs). The average condylar angle in the normal joints was 21.2 degrees. In joints with disk displacement with reduction it was 29.7 degrees; joints with disk displacement without reduction, 33.5 degrees; and in joints with degenerative joint disease, 36.5 degrees. There were statistically significant differences between all four groups. Thus the condylar angle seemed to be increasingly larger with more advanced pathologic changes related to internal derangement and degenerative disease in the joint. The reason for the larger condylar angle in the abnormal joint was unclear. Joints with a larger condylar angle might have a greater tendency for internal derangement and degenerative joint disease to develop. Another possible explanation could be that remodeling associated with internal derangement and degenerative joint disease might result in a larger condylar angle. Further studies with longitudinal observations are needed to determine whether a causal relationship exists between the changes of the joint and a large condylar angle.

Adult↗

PubMed1991

Improved magnetic resonance imaging of the temporomandibular joint by oblique scanning planes.

This study was undertaken to investigate whether the quality of magnetic resonance images of the temporomandibular joint could be improved by scanning in oblique planes oriented according to the individual angle of the mandibular condyle (oblique images) instead of in the true anatomic sagittal and coronal planes (orthogonal images). Sagittal and coronal magnetic resonance images obtained by both methods in 21 patients were compared for image quality of the disk. In more than half the patients the oblique images demonstrated the anatomy of the disk better than the orthogonal images. Oblique images are therefore recommended.

Adolescent↗