OBJECTIVE: To correlate the signals and symptoms observed on clinical examination of patients with temporomandibular disorder with the results demonstrated by magnetic resonance imaging. MATERIALS AND METHODS: Thirty patients presenting with signs and symptoms of temporomandibular disorders underwent clinical evaluation and subsequent magnetic resonance imaging. The magnetic resonance imaging studies were independently evaluated by two experienced radiologists. Magnetic resonance imaging studies consisted of 12 images in coronal, T1-weighted sequences with 3 mm-thick slices with the mouth closed, sagittal, T1- and T2-weighted sequences with both open and closed mouth positions, and on progressive opening/closing movement at 5 mm intervals, in order to demonstrate the full mandibular movement. The statistical significance between the clinical findings in the evaluation of the patients and results found on the magnetic resonance imaging studies was analyzed by means the kappa test. RESULTS: Interobserver agreement was respectively 56.7% (kappa = 0.1) and 56.7 (kappa = 0) for the left and right sides. CONCLUSION: No correlation was found between the clinical and magnetic resonance imaging findings in the diagnoses of disc displacement.

Keywords: Magnetic resonance imaging, Temporomandibular joint, Disorders

OBJECTIVE: To experimentally determine the 99mTc and 111In activity recovery coefficients in SPECT imaging. MATERIALS AND METHODS: Four different 99mTc and 111In concentrations were utilized for quantifying activity in spheres of four different sizes. Images were obtained with a hybrid dual-head SPECT-CT imaging system. The ordered subset expectation maximization (OSEM) iterative method was utilized for images reconstruction. An attenuation map was utilized for attenuation correction, and the multiple energy window technique for scattering correction. RESULTS: Results for spheres < 6 ml in volume were significantly affected by the partial volume effect. For 111In quantification, results show a dependence on sphere concentrations and background levels. For 99mTc quantification, there was a tendency towards values underestimation with higher background levels. CONCLUSION: Correction factors must be utilized for compensating the partial volume effect on objects with < 6 ml in volume for both radionuclides. Background subtraction to compensate spurious count present on SPECT images has a significant influence on the quantification of activity, especially for the smaller objects.

Keywords: SPECT, 111In, 99mTc, Recovery factors

Several diseases should be considered in the differential diagnosis of disorders affecting the temporomandibular joints. Internal derangement is the main condition responsible for pain related to this joint. Clinical signs may, though, be quite non-specific, and many other conditions present with similar and not infrequently indistinguishable signs and symptoms. In the present study, the authors describe several non-dysfunctional conditions affecting the temporomandibular joints through computed tomography and magnetic resonance imaging, emphasizing the importance of these imaging methods in the diagnosis of inflammatory, neoplastic and traumatic diseases of this region. Considering that clinical presentations are frequently non-specific, radiologists play a critical role in the differential diagnosis.

Keywords: Temporomandibular joint, Computed tomography, Magnetic resonance imaging

OBJECTIVE: The present study was aimed at identifying temporomandibular joint inflammatory processes employing technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO)-labelled autonomous leukocytes. MATERIALS AND METHODS: We have utilized an experimental model of arthritis induction in ten adult male New Zealand rabbits by means of ovalbumin intra-articular injection into each left temporomandibular joint. For control purposes, saline solution was injected. After leukocytes radiolabelling with 99mTc-HMPAO and injection into rabbits, scintigraphic images were obtained. RESULTS: A higher 99mTcHMPAO-leukocytes uptake was observed in left temporomandibular joint in comparison with the contralateral joint. Wilcoxon non-parametric test was applied for statistical analysis. There was a statistically significant difference between counts of radioactivity per minute in the inflammed joint and the contralateral one (p = 0.0073). CONCLUSION: The method employing 99mTc-HMPAO-labelled autologous leukocytes allows an early and accurate detection of inflammatory processes, contributing to the adoption of a therapeutic conduct for patients before structural alterations have occurred.

Keywords: Temporomandibular joint disorder, Arthritis, 99mTc-HMPAO

OBJECTIVE: To assess radiographically the prevalence of morphological alterations of the styloid process in patients with temporomandibular joint disorders. MATERIALS AND METHODS: We have analyzed 1,500 panoramic x-ray films of temporomandibular joint from both male and female patients with no age limit, who were attended in the Service of Temporomandibular Joint Disorder of Faculty of Odontology at Universidade Federal de Juiz de Fora, MG, Brazil, in the period between 1997 and 2003. RESULTS: Eighty-three (5.53%) of the analyzed patients (74 female and 9 male), predominantly in the age range between 41 and 50 years (32.5%), presented with, at least, one of the joint sides with morphological alteration of the styloid process. As far as the type of styloid process in concerned, 113 elongated, 21 pseudoarticulated and 19 segmented were observed. Also, it was noticed that the morphological alterations of the styloid process develop in a symmetrical fashion. CONCLUSION: In individuals with temporomandibular joint disorder, styloid process alterations occur symmetrically and in a different way for each patient, independently from sex and age.

Keywords: Styloid process, Temporomandibular joint disorder, Radiography

OBJECTIVE: To use skeletal scintigraphy to detect mandibular growth through the analysis of bone metabolism in individuals with normal craniofacial growth, and to compare the findings with those seen in individuals with excessive craniofacial growth. MATERIALS AND METHODS: Forty-seven male and female patients between 18 to 28 years of age were divided in two groups - class I, control (n = 13), and class III, case (n = 34). Images were obtained two hours after intravenous injection of 99mTc-MDP (200 µCi/kg). Right and left side views of the mandible were obtained as well as a posterior view of the lumbar spine. The count rate was determined by the mean values of the count of the condyles and of the fourth lumbar vertebra, using a total of 300,000 counts. RESULTS: No asymmetrical condyle uptake was observed in both groups, and in spite of the absence of statistically significant differences, the mean condylar uptake values were higher in class III group. CONCLUSION: The increased mean uptake indicated higher condylar bone metabolism in class III individuals suggesting residual mandibular growth. Further studies are presently ongoing to increase our sample size.

Keywords: Bone scintigraphy, Mandibular condyle, Mandibular growth, Temporomandibular joint

Disc displacement of the temporomandibular joint has been defined as an abnormal relationship between the articular disc and the mandibular condyle, fossa and articular eminence. Disc displacements may occur without immediate interference in the function of the joint. Magnetic resonance imaging shows high diagnostic accuracy in the determination of articular disc position and has been indicated as the diagnostic method of choice for soft tissue abnormalities of the temporomandibular joint. The aim of this study is to review the literature including the normal features and different types of disc displacement of the temporomandibular joint as well as the imaging findings, emphasizing the role of magnetic resonance imaging.

Keywords: Temporomandibular joint, Magnetic resonance imaging, Diagnosis

Objective: To evaluate the sensitivity and specificity of high-resolution ultrasonography in the assessment of intra-capsular temporomandibular disorders. Materials and Methods: The authors have studied 38 patients (76 joints) with complaint of temporomandibular disorder. All the patients underwent ultrasonography and magnetic resonance imaging (gold standard for the evaluation) and the results were compared. Results: Among 24 joints demonstrating disc displacement at magnetic resonance imaging of patients at rest, 7 were confirmed at ultrasonography; in 13, the discs could not be visualized; and in 4, no sonographic abnormality was observed. In 48 joints, the articular discs could not be visualized at ultrasonography of patients at rest. Among them, 41 exhibited normal positioning at magnetic resonance imaging, and 7 exhibited anterior disc displacement. Morphological changes of the mandibular condyle were visualized in 13 joints at magnetic resonance imaging, and in 2 at ultrasonography. Conclusion: With the present study, the authors can conclude that ultrasonography offers high sensitivity and specificity in the diagnosis of the articular disc location with the patient at rest, either to analyze anatomical position or to analyze disc displacement. On the other hand, it does not offer significant results to analyze articular discs in patients with open mouth as well as to analyze disc/condyle morphological changes.

Keywords: Ultrasonography; Temporomandibular joint; Magnetic resonance imaging.

OBJECTIVE: To assess changes in the articular surfaces of the temporomandibular joint (TMJ) and in condylar translation, as detected by magnetic resonance imaging (MRI), determining whether such changes correlate with disc displacement. MATERIALS AND METHODS: We retrospectively analyzed the MRI scans of 2076 TMJs of 1038 patients with symptoms of temporomandibular disorder. We attempted to determine whether articular disc deformity and changes in condylar translation, as well as changes in the articular surfaces of the condyle, glenoid fossa, and articular eminence, correlated with disc displacement. RESULTS: Disc displacement with reduction was associated with changes in the shape of the articular eminence. Disc displacement without reduction was most strongly associated with disc deformity, condylar degeneration, glenoid fossa degeneration, and effusion. Neither decreases nor increases in condylar translation were associated with disc deformity, degenerative bone changes, or disc displacement. CONCLUSION: Changes in the shape of the articular eminence seem to predispose to progression of internal derangement of the TMJ.

Keywords: Magnetic resonance imaging; Temporomandibular joint; Temporomandibular joint disc; Temporomandibular joint disorders.