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Biomedical subjects

P L Westesson

Publications and source records attributed to P L Westesson.

At least 19 recordsLinked to original sources
PubMed2002

Acoustic characteristics of sounds from temporomandibular joints with and without effusion: an MRI study.

Joint effusion has been associated with temporomandibular joint (TMJ) pain but can only be diagnosed by magnetic resonance imaging (MRI). For screening of patients with suspected effusion a simple and less expensive method would be desirable. We recorded joint sounds during jaw opening and closing movement from 34 TMJs with internal derangement (ID). Seventeen joints had joint effusion seen on MRI. Spectrograms of the sounds were displayed as waterfall plots showing profiles of the consecutive Hamming windows. If the profiles were similar, as judged by initial evaluation, the displayed pattern was classified as stable. If some profiles were distinctly deviating in their pattern, this was classified as unstable. Joints with effusion showed unstable sound pattern more often than joints without effusion (P < 0.001). It was concluded that TMJ sound analyses have a potential to identify joints with effusion based on their unstable sound pattern.

Adult↗
PubMed2001

Thickening of the glenoid fossa in osteoarthritis of the temporomandibular joint. An autopsy study.

OBJECTIVE: To evaluate the thickness of the roof of the glenoid fossa of the temporomandibular joint (TMJ) in relationship to the stage of internal derangement from autopsy material. MATERIAL AND METHODS: The minimum thickness of the roof of the glenoid fossa was measured with a caliper in 61 TMJ autopsy specimens. Based on macroscopic examination the joints were categorized as normal (30 joints), disk displacement (eight joints), disk displacement with osteoarthritis (12 joints) and osteoarthritis with perforation of the disk or posterior attachment (11 joints). The relationship between thickness of roof of the glenoid fossa and status of the joint was analysed. RESULTS: The roof of the glenoid fossa was on the average 0.6 mm in normal joints, 1.1 mm in joints both with disk displacement and disk displacement with osteoarthritis and 2.6 mm in joints with osteoarthritis and perforation. The difference between the normal joints and those with perforation was significant (P<0.01). CONCLUSION: Progressive remodeling with thickening of the roof of the glenoid fossa seems to be associated with perforation of the disk or posterior attachment.

Adult↗
PubMed2001

Discectomy as an effective treatment for painful temporomandibular joint internal derangement: a 5-year clinical and radiographic follow-up.

PURPOSE: The purpose of this prospective study was to compare the preoperative and 5-year postoperative status of patients after unilateral discectomy for painful internal derangement of the temporomandibular joint. PATIENTS AND METHODS: The study was based on 64 patients. Fifty-six had disc displacement without reduction and 8 had disc displacement with reduction. The patients were examined clinically and radiographically before and 5 years after the operation according to a standardized protocol. RESULTS: Eighty-five percent of the patients (n = 52) had good results, 6% had acceptable results, and 9% had a poor outcome. Three patients (5%) were reoperated and 5 other patients (8%) needed a contralateral operation during the 5-year follow-up. The median increase in maximum mouth opening was 11 mm (range, -8 to +35 mm) and 83% of the patients had more than 40 mm maximal mouth opening postoperatively. Seventy-five percent of the patients had crepitation at 5-year follow-up compared with 27% before the operation. Postoperatively, the majority of the joints showed radiographic evidence of osteophytes, flattening, and sclerosis. The radiographic alterations did not correlate with the patients' symptoms. CONCLUSIONS: The results of this long-term follow-up after unilateral discectomy support the use of this operation in patients with painful internal derangement who show no improvement after prior nonsurgical treatment. The postoperative radiographic alterations should be interpreted as adaptive changes rather than progressive degenerative joint disease.

Adolescent↗
PubMed2001

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.

Adolescent↗
PubMed2001

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.

Adolescent↗
PubMed2001

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.

Adult↗
PubMed2000

The association of temporomandibular joint pain with abnormal bone marrow in the mandibular condyle.

PURPOSE: This study investigated the association between temporomandibular joint pain and bone marrow alterations in the mandibular condyle seen on magnetic resonance (MR) images. PATIENTS AND METHODS: The study was based on 112 temporomandibular joints in 112 patients with disc displacement without reduction. Thirty-four patients with abnormal bone marrow on MR images were compared with a control group of 78 patients with normal bone marrow. The analysis was based on proton density and T2-weighted MR images in the oblique sagittal and coronal planes. The degree of pain was correlated to the status of the bone marrow using statistical methods. RESULTS: The degree of pain in joints with abnormal bone marrow was higher than in joints with normal bone marrow signal on MR images (P = .0045). CONCLUSION: Because the stage of internal derangement was similar in both groups, more intensive pain appears to be associated with bone marrow alterations.

Adolescent↗
PubMed1999

Osteonecrosis of the temporomandibular joint: correlation of magnetic resonance imaging and histology.

PURPOSE: The aims of this study were to investigate whether osteonecrosis affects the mandibular condyle and to determine whether this condition could be diagnosed with magnetic resonance imaging (MRI). MATERIALS AND METHODS: The study was based on 50 temporomandibular joints in 44 patients in whom MRI and surgery were performed for painful internal derangements. At the time of surgery, a core biopsy specimen was obtained from the marrow of the mandibular condyles, and the histological observations were correlated to T1-(proton density) and T2-weighted MR images. RESULTS: Histological evidence of osteonecrosis was found in nine joints (18%). Bone marrow edema, which may be a precursor of osteonecrosis, was found in nine other joints. The MRI was 78% sensitive and 84% specific for the diagnosis of osteonecrosis of the mandibular condyle. However, the positive predictive value was only 54% because of a number of false-positive MRI diagnoses. CONCLUSION: Osteonecrosis can affect the mandibular condyle, and this condition can be diagnosed with MRI. A combination of edema and sclerosis of the bone marrow was the most reliable MRI sign of osteonecrosis. The cause, its clinical significance, and the need for treatment are unknown.

Adult↗
PubMed1999

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.

Adolescent↗
PubMed1999

Decreased disk-eminence ratio is associated with advanced stages of temporomandibular joint internal derangement.

OBJECTIVE: To examine the possible correlation between the stage of internal derangement and the antero-posterior length of the disk in relation to the length of the articular eminence. STUDY DESIGN: Twenty asymptomatic volunteers with normal joints and 120 patients with TMJ dysfunction underwent MR imaging. The A-P length of the disk in relation to the length of the articular eminence (D/E ratio) was measured. RESULTS: The D/E ratio was 0.95 in the asymptomatic volunteers, 0.83 in patients with disk displacement with reduction, 0.74 in those with disk displacement without reduction and 0.57 in the patients with disk displacement and osteoarthritis. The relationship between the D/E ratio and the stage of internal derangement was statistically significant (P<0.01). CONCLUSION: The D/E ratio decreases with advancing internal derangement. We suggest that it is a reliable numerical method for staging the degree of the internal derangement.

Adult↗
PubMed1999

Amplitude and frequency spectrum of temporomandibular joint sounds from subjects with and without other signs/symptoms of temporomandibular disorders.

Temporomandibular joint (TMJ) sound is one of the most commonly recognized signs in patients with temporomandibular disorders (TMD) but is also frequently seen in asymptomatic individuals. Sound recording is therefore only meaningful if the sounds from a normal healthy joint can be differentiated from those in patients. In this study, the amplitude and power spectrum of the TMJ sounds from symptomatic patients and asymptomatic individuals were recorded and compared. The result showed that TMJ sounds from symptomatic patients had a larger amplitude than sounds from asymptomatic subjects. A significant proportion of sounds had frequencies between 2000 and 3000 Hz. It was concluded that the characteristic amplitude is worthy of further study as a sign of possible diagnostic value. Secondly, the bandwidth of the sensors used at electronic TMJ sound recording should not be less than 3000 Hz.

Acoustics↗
PubMed1998

Prevalence of morphological changes in the surfaces of the temporomandibular joint disc associated with internal derangement.

PURPOSE: The purpose of this study was to determine the prevalence of morphological changes in the superior and inferior surfaces in the temporomandibular joint (TMJ) disc and relate them to disc displacement. MATERIALS AND METHODS: Thirty TMJs obtained from fresh cadavers were studied. The TMJs were dissected, and the superior and inferior surfaces of the disc were inspected and classified as intact, irregular, or perforated. These findings were corrolated to the position of the disc. RESULTS: There was a greater prevalence of morphologic changes in the inferior (57%) than in the superior surface (17%) of the disc (P < .001). This was found for joints both with normal disc position and those with disc displacement. There was no relationship between surface irregularities of the inferior surface and the position of the disc. Perforation was seen more frequently in joints with disc displacement than in those with normal disc position. CONCLUSION: Morphologic changes in the inferior surface of the TMJ disc are more prevalent than those in the superior surface, but this is not related to disc position. However, this needs to be considered when doing arthroscopy of only the superior joint compartment.

Aged↗
PubMed1998

Posterior disc displacement in the temporomandibular joint.

PURPOSE: The purpose of this study was to describe the imaging characteristics of posterior disc displacement of the temporomandibular joint (TMJ). MATERIALS AND METHODS: The study was based on 35 joints with posterior disc displacement and a control material of bilateral TMJ images of 62 healthy volunteers. The images were analyzed, and criteria for posterior disc displacement were developed. RESULTS: Posterior disc displacement was characterized by the disc or a major part of the disc being located posterior to the superior prominence of the condyle. Three subcategories of posterior disc displacement could be identified: a thin flat disc, a grossly posteriorly displaced disc, and a perforated disc with a portion of the disc displaced posteriorly. Posterior disc displacement was not seen in any of the asymptomatic volunteers. CONCLUSION: Posterior disc displacement of the TMJ is rare but has probably been overlooked in the past because of a lack of well-defined imaging characteristics.

Adolescent↗