Biomedical subjects

R H Tallents

Publications and source records attributed to R H Tallents.

At least 19 recordsLinked to original sources

PubMed1996

Anatomic disorders of the temporomandibular joint disc in asymptomatic subjects.

PURPOSE: This study determined the prevalence and specific anatomic types of disc displacement in asymptomatic versus symptomatic subjects using magnetic resonance imaging (MRI). PATIENTS AND METHODS: A detailed MRI assessment was performed on both temporomandibular joints (TMJ) in 76 volunteers and 102 successive patients. Attention was placed on the functional aspects of disc displacement with and without reduction and on the anatomic aspects of disc displacement in the anterior, lateral, medial, anterolateral, and anteromedial directions. These assessments were made by radiologists blinded to the clinical information. RESULTS: Disc displacement was found in at least one joint in 25 of 76 (33%) of asymptomatic subjects and 79 of 102 (77%) of symptomatic subjects. The anatomic types of disc displacement between groups was not statistically significant (P = .55). However, there was a significant difference between asymptomatic and symptomatic subjects, with an odds ratio of 3.91 for disc displacement with reduction and 42.71 for disc displacement without reduction (P < .001). CONCLUSION: Although there was a 33% prevalence of disc displacement in asymptomatic volunteers, there was a highly significant difference in the prevalence of internal derangement in symptomatic subjects. Bruxing was statistically linked to TMJ disc displacement and could explain the anatomic variation in abnormal disc position.

Adolescent↗

PubMed1996

Orthodontics and temporomandibular joint internal derangement.

The purpose of this investigation is to compare the prevalence of internal derangement of the temporomandibular joints (TMJ) in asymptomatic volunteers versus symptomatic subjects using magnetic resonance imaging (MRI), with a detailed comparison to clinical signs and symptoms and with attention to a prior history of orthodontic treatment. Bilateral MRI scans were obtained of the TMJs in 76 asymptomatic volunteers and 102 symptomatic patients. A comparison was made to the clinical signs and symptoms, a history of orthodontic treatment, and to the MR findings. The MRI scans were reviewed using established criteria for disk displacement and the reviewers were blinded as to the clinical information. Our results show a prevalence of disk displacement in 25 of 76 (33%) volunteers and 79 of 102 (77%) patients with a statistically significant difference (p < 0.001). No statistical link was noted between a history of prior orthodontic treatment and internal derangement of the TMJ.

Adolescent↗

PubMed1996

Classification and prevalence of temporomandibular joint disk displacement in patients and symptom-free volunteers.

The purposes of this study were to develop a classification system for disk displacement in the temporomandibular joint (TMJ) and to study the prevalence of the various types of TMJ disk displacement in patients and symptom-free volunteers. The study was based on bilateral MRIs of 243 patients and 57 symptom-free volunteers. Eight different types of disk displacements were identified in addition to the superior disk position and a tenth indeterminate category. Superior disk position was observed bilaterally in 18% of the patients and bilaterally in 70% of the symptom-free volunteers.

Adolescent↗

PubMed1995

Lateral cephalometric analysis of skeletal patterns in patients with and without internal derangement of the temporomandibular joint.

Twenty-three female volunteers with normal temporomandibular joints (TMJ) were compared with 24 female patients with documented TMJ internal derangements. Magnetic resonance imaging and lateral cephalometric radiographs were used to investigate the relationship between TMJ disk displacement and skeletal facial form. Results indicated that the patients with internal derangements have significantly smaller mandibles and maxillae. However, these sagittal measurements of jaw length were not associated with disproportionate changes in other cephalometric variables. In general, no district relationship was found between the morphologic features of the face and the internal derangements of the temporomandibular joint.

Adolescent↗

PubMed1995

Angle of the articular eminence in patients with temporomandibular joint dysfunction and asymptomatic volunteers.

OBJECTIVE: The purpose of this study was to compare structural variations of the temporomandibular joint anatomy between symptomatic patients with temporomandibular joint dysfunction and asymptomatic controls. STUDY DESIGN: There were 74 symptomatic patients with temporomandibular joint dysfunction, 29 asymptomatic volunteers with normal joints, and 6 asymptomatic volunteers with disk displacement with reduction included in this study. All subjects had bilateral high resolution magnetic resonance imaging scans performed in the sagittal (closed and opened) and coronal (closed) positions. All subjects had right and left full profile laminagraphs, one in the centric occlusal position, and one with the incisors edge to edge. RESULTS: Student-Newman-Keuls tests demonstrated no significant angular or linear differences for depth of the articular fossa, angle of the articular eminence, horizontal and vertical overlap of the incisor teeth, and linear condylar translation. CONCLUSION: This study concludes that there are no significant differences in angular and linear measurements in the articular fossa of asymptomatic volunteers and symptomatic subjects with temporomandibular joint dysfunction.

Adult↗

PubMed1994

Evaluation of the reproducibility of rest activity of the anterior temporal and masseter muscles in asymptomatic and symptomatic temporomandibular subjects.

There is a general assumption that temporomandibular disorders and the pain and tenderness of mastication muscles may be caused by hyperactivity. Five asymptomatic men, five asymptomatic women, and five women with temporomandibular disorders participated in this study. Multiple examinations were performed to provide information concerning the reproducibility of the rest electromyographic signals. No significant differences between groups were noted. This study supports the contention that the mean rest activity in women with pain and dysfunction is less than or equal to that of sex-matched controls.

Adult↗

PubMed1994

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.

Adult↗

PubMed1993

Temporomandibular joint sounds in asymptomatic volunteers.

Abnormalities within the temporomandibular joints often produce audible sounds. Electronic recording of joint sounds has been used as a method of staging internal derangement. This study had three objectives: first, to determine whether the characterization of temporomandibular sounds can provide a sensitive and accurate measure for the presence or absence of joint abnormalities in asymptomatic volunteers; second, to evaluate the reproducibility of the sounds, when present, with successive recordings; and third, to evaluate the sound characteristics to determine their predictability for the types of internal derangement. Fifty asymptomatic volunteers (100 joints) were evaluated with an electronic device for the presence of joint sounds. Of the patients, 24% (N = 50, five men and seven women) (16% of all joints) had one or two abnormal joints as diagnosed by magnetic resonance imaging. Forty-four percent of all joints had identifiable sounds; 50% of the sounds were produced when the condyle was located at the apex of the articular eminence. Sounds often occurred in the early opening phase of jaw movement in joints diagnosed as normal by magnetic resonance imaging. Finally, the characteristics of these events did not produce adequate separation to stage the internal derangement.

Analysis of Variance↗

PubMed1993

Temporomandibular joint axiography and MRI findings: a comparative study.

Axiography may be useful in the evaluation of condyle motion and the effects of internal derangements on this motion. Fifty-one patients were selected by one investigator (RHT) to provide a representative sample of asymptomatic and symptomatic subjects for the following categories: (1) normal disk position, (2) disk displacement with reduction, (3) disk displacement without reduction and (4) disk displacement without reduction associated with degenerative joint disease. Axiography was performed by a separate investigator (KGP) in a blinded fashion. The diagnosis of the presence of internal derangement was based on the tracings only. All subjects had bilateral magnetic resonance imaging scans to evaluate for the presence or absence of internal derangement. The diagnostic sensitivity was 0.64, which indicated that axiography is marginal at identifying disease when present. The negative predictive value was 0.78, which indicated that axiography is accurate in the detection of normal disk condyle relationship.

Adult↗

PubMed1993

Activity of anterior temporalis and masseter muscles during deliberate unilateral mastication.

The reproducibility of electromyographic parameters descriptive of deliberate unilateral chewing (activity, timing, curve symmetry) was investigated in normal asymptomatic volunteers. The best time for the initiation of muscle activity was also examined, with the future aim of staging TMJ internal derangements. The results suggest that activity is the most reliable variable, indicating that it may be helpful in describing muscle incoordination. When time was used in conjunction with another variable, overall reproducibility decreased.

Adult↗

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

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

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

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↗

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↗

PubMed1991

Magnetic resonance imaging of temporomandibular joint after surgical treatment of internal derangement.

Sagittal and coronal surface coil magnetic resonance imaging was performed on 21 patients who about 2 years earlier had surgery for temporomandibular joint internal derangement. Surgical procedure included disk repositioning (23 joints) and diskectomy (seven joints). At the time of reimaging, 20 joints showed recurrence of pain and 10 joints were asymptomatic. Extensive fibrous tissue was seen in the joint space and in the joint capsule in 13 of the 20 painful joints, whereas minimal fibrous tissue in the lateral capsule wall was seen in 3 of the 10 nonpainful joints. Fibrous tissue was surgically confirmed in 10 of the painful joints. Disk displacement was seen in 11 of the 23 joints that had surgical disk repositioning. Disk displacement was seen in both painful (9/17) and nonpainful joints (2/6). It was concluded that magnetic resonance imaging is an excellent method for postoperative imaging of the temporomandibular joint and that attention should be directed to the presence or absence and extension of the fibrous tissue in the joint space and in the joint capsule.

Adolescent↗

PubMed1991

The clinical predictability of internal derangements of the temporomandibular joint.

The value of clinical parameters as predictors of the arthrographic findings in patients with temporomandibular joint (TMJ) pain and dysfunction was examined in this study. We developed a series of simplified clinical prediction rules based on previous studies correlating clinical signs and symptoms with arthrographic diagnosis of the condition of the TMJ meniscus. One hundred eighty-six patients with signs and symptoms of TMJ dysfunction were clinically examined before TMJ arthrography. Arthrograms were performed on 246 joints (126 unilateral, 60 bilateral). The rules predicted 91 of the 246 joints to be normal when actually 59 were shown to be normal arthrographically. The rules slightly underpredicted those patients with positive arthrographic findings for internal derangements. Although there were some individual variations in the predictability of unilateral versus bilateral arthrograms (patients), there was very little overall difference, 58% and 60%, respectively. This study confirms previous suggestions that clinical findings alone are not consistently accurate in diagnosing the exact type of TMJ internal derangements depicted by arthrographic criteria.

Adult↗