Diagnostic accuracy of fused CBCT images in the evaluation of temporomandibular joint condylar bone resorption.

OBJECTIVES: To evaluate the diagnostic accuracy of fused CBCT images for patients with condylar bone resorption of temporomandibular joint (TMJ) osteoarthrosis. MATERIALS AND METHODS: Forty-two TMJs from twenty-one patients were included. Bone resorption of condyles evaluated by three experts was used as the reference standard. Three oral and maxillofacial radiology residents evaluated the resorption of condyles with a five-point scale for the four sets of images (two consecutive CBCT images without fusion, fused 2D cross-sectional images, fused 3D images, and combining fused 2D cross-sectional images and fused 3D images) randomly and independently. Each set of images was evaluated at least 1 week apart, and a second evaluation was performed 4 weeks later. Intraclass correlation coefficients were calculated to assess the intra- and inter-observer agreement. The areas under the ROC curves (AUCs) were compared among the four image sets using the Z test. RESULTS: Twenty-four TMJs were determined as condylar bone resorption, and eighteen were determined as no obvious change. The average AUC values from the three observers for the three fused image sets (0.94, 0.93, 0.93) were significantly higher than the image set without fusion (p < 0.01). The intra- and inter-observer agreement on the three fused image sets (0.70-0.89, 0.91-0.92) was higher than the image set without fusion (0.37-0.63, 0.75). CONCLUSIONS: Fused CBCT images of TMJ osteoarthrosis patients can intuitively display the condylar bone resorption and significantly improve the diagnostic accuracy. CLINICAL RELEVANCE: Fused CBCT images can help clinicians intuitively observe bone changes of the condyle in TMJ osteoarthrosis patients.

[Investigation on radiographic signs of osteoarthrosis in temporomandibular joint with cone beam computed tomography in adolescents].

OBJECTIVE: To investigate the occurrence and radiographic signs of osteoarthrosis of the temporomandibular joints (TMJOA) with cone beam computed tomography (CBCT) in adolescents. METHODS: Individuals with temporomandibular disorders (aged 10-19 years) in the patients group (n=386) and pre-orthodontic patients with malocclusion (aged 10-19 years) in the control group (n=339) were included in the present study. All the patients in both groups had been examined by CBCT. The abnormalities of the condyle were evaluated. The results of radiological findings were compared between the patients group and the controls by using chi-square tests. Inter- and intra-examiner agreements were assessed using Cohen's Kappa coefficient and all statistical analysis was performed using SPSS 13.0. RESULTS: 157 patients in the patients group and 41 subjects in the control group had radiographic signs of TMJOA. The occurrence of OA was significantly higher in the patients group (40.7%, 157/386) than in the controls (12.1%, 41/339), the difference was statistically significant (P<0.05). The occurrence of TMJOA was significantly higher in females (44.6%, 123/276) than in males (30.9%, 34/110) in the patients group (P<0.05) but showed no significant difference in the controls (females: 13.7%, 32/234, and male: 8.6%, 9/105, P>0.05). In addition, the patients group showed significantly higher occurrence of ill-defined cortical bone (31.7%, 65/205) small bony defect and extensive erosion (25.4%, 52/205) than the controls (1.7%, 1/58 and 5.2%, 3/58, respectively, P<0.05), while the subjects in the control group had significantly higher occurrence of flattening and shortening of the condyle (39.7%, 23/58) and sclerosis (39.7%, 23/58) than patients with temporomandibular disorders (6.3%,13/205 and 14.6%, 30/205, respectively, P<0.05). CONCLUSION: TMJOA is not uncommon in adolescent patients with TMD and with malocclusion. Patients in the two study groups had different radiographic signs of OA. The patients with temporomandibular disorders often demonstrate erosive changes, while the pre-orthodontic patients with malocclusion often demonstrate relatively stable radiographic signs.

Quantitative assessment of condylar bone resorption using fused CBCT images: differentiating and diagnosing three distinct groups based on volume and thickness decrease.

OBJECTIVES: To investigate the accuracy of fused CBCT images in diagnosing three distinct groups of bone changes characterized by volume and thickness decrease in patients with temporomandibular joint osteoarthrosis (TMJ OA) during follow-up. METHODS: In this retrospective study, 109 patients (176 TMJs) with TMJ OA were included. Two consecutive CBCT images for the same patient were registered and fused. Then, three image sets were established: without fusion, fused 2D image, and fused 3D image. Three residents randomly and independently evaluated whether there was condylar resorption with the three image sets respectively. The samples diagnosed as condylar resorption by the expert panel were divided into three subgroups according to the volume and thickness decrease calculated after segmentation. The inter- and intraobserver agreement, receiver operating characteristic (ROC), and area under the curve (AUC) evaluated the diagnostic capability for different subgroups. RESULTS: For the volume decrease more than 50 mm3 and thickness decrease more than 1 mm groups, the AUC values for fused image sets were higher than those without fusion (p < 0.01). For the volume decrease within 50 mm3 and thickness decrease within 1 mm groups, the AUC values for fused 2D image sets were higher than the image sets without fusion (p < 0.05), but there was no significant difference between the fused 3D image sets and the image sets without fusion (p = 0.48 for volume decrease, p = 0.37 for thickness decrease). CONCLUSIONS: The fused images can improve the diagnostic accuracy and repeatability for the samples with at least 50 mm3 volume decrease or 1 mm thickness decrease compared with the image groups without fusion.

[Effect of stabilization occlusal splint on intra-articular pressure of the temporomandibular joint].

OBJECTIVE: To find out the influence of stabilization occlusal splint on intra-articular pressure of the temporomandibular joint. METHODS: A multi-channel measuring and analysis system for intra-articular pressure of the temporomandibular joint was developed in this study. Twenty-two subjects were selected to detect the intra-articular pressure of the temporomandibular joint before and after wearing stabilization splint. RESULTS: Before splint wearing, the intra-articular pressure of the temporomandibular joint at intercuspal occlusion status was 61.3+/-48.5 mm Hg (1 mm Hg = 0.133 kPa), the negative pressure at open mouth status was 33.2+/-34.2 mm Hg. After splint wearing, the pressure at intercuspal occlusion status was 39.5+/-24.5 mm Hg, the negative pressure at intercuspal at open mouth status was 36.3+/-25.3 mm Hg. The intra-articular pressure of the temporomandibular joint after wearing splint was significantly lower than the pressure before splint was used, the pressure of mouth opening status was stable before and after splint was used. CONCLUSION: Stabilization occlusal splint can reduce the intra-articular pressure of the temporomandibular joint.

[Temporomandibular joint osteoarthrosis in patients receiving orthodontic treatments: a clinical investigation].

OBJECTIVE: To investigate the clinical characteristics of temporomandibular joint osteoarthrosis (TMJOA) in patients with malocclusion before orthodontic treatment and evaluate the radiographic changes of temporomandibular joint during treatment. METHODS: Complete clinical recordings of 10,032 patients referring to the Orthodontic Department of Peking University School and Hospital of Stomatology from January 1998 to December 2003 were reviewed in present study. Patients with a history of previous orthodontic treatment, jaw surgery, facial trauma or systemic diseases which could potentially involve temporomandibular joint were excluded. The detection rate of TMJOA was calculated and its association with the possible risk factors of age, gender and malocclusion classifications was analyzed using the method of chi-square and multivariate logistic regression analysis. The clinical and radiographic characteristics were investigated and the radiographic findings before and after treatment were compared to evaluate the orthodontic effect on the articular bony structures. RESULTS: The detection rate of TMJOA in 10,032 patients before orthodontic treatment was 1.6% (159/10,032) and significantly higher in females (1.9%, 124/6,409) than in males(1.0%, 35/3,623)(chi-square = 13.925, P < 0.01).The detection rate increased positively with age (chi-square = 136.381, P < 0.01). Multivariate logistic regression analysis showed that patients with Angle II malocclusion were 1.683 times more likely to suffer from TMJOA compared with patients with Angle I malocclusion(Wald chi-square = 9.007, OR = 1.683, P < 0.01), while there was no significantly difference between the patients with Angle III and I malocclusion. Among the 85 TMJOA patients who finished their orthodontic treatments, 63 patients (74.1%, 63/85) maintained stable articular bony structure and the remaining 9(10.6%, 9/85) and 13 (15.3%, 13/85) patients showed recovering and deteriorating signs respectively according to the radiographs. CONCLUSION: The detection rate of TMJOA associated with age, gender and malocclusion classifications. Stable articular bony structure was maintained in the majority of the TMJOA patients (74.1%, 63/85) during the orthodontic treatments.

[Diagnostic evaluation of the temporomandibular joint osteoarthritis using cone beam computed tomography compared with conventional radiographic technology].

OBJECTIVE: Osteoarthritic lesions of Temporomandibular joint(TMJ) were assessed by dental cone beam computed tomography(CBCT), and compared with conventional radiographic technology. METHODS: The study was conducted retrospectively on 511 joints of 350 patients, who had undergone dental CBCT, panoramic radiography, transcranial projection and transpharygeal projection of TMJ. The results were compared and the accuracy with CBCT was assessed. The types of osseous condylar abnormalities were observed. RESULTS: (1) The occurrence of osteoarthritis in male and female were 59.04% and 69.66%, respectively, with no significant difference. (2) Compared with CBCT, panoramic radiography, transpharygeal projection examination showed no significant difference, with the accuracy being 90.64% and 94.10%, respectively; However, transcranial projection indicated a significant difference in comparison with CBCT and the accuracy was 86.97%. (3) A higher occurrence of osteoarthritic lesions of the condyle was sclerosis (39.86%). Bony proliferation or osteophyte (28.18%) and ill-defined cortical bone (18.90%) were followed. CONCLUSION: Cone beam CT, which reproduces multiple images including axial, coronal and sagittal planes of the joint, provides a complete radiographic investigation of the bony components of the TMJ. It is one of the best choices of imaging diagnosis of TMJ osteoarthritis. Panoramic radiography and transpharygeal projection examination are also good choices for showing osseous condylar abnormalities in the clinic, but transcranial projection examination is inferior.

Ankylosis of temporomandibular joint caused by psoriatic arthritis: a report of four cases with literature review.

Psoriatic arthritis (PsA) is an inflammatory joint disease associated with psoriasis. PsA is often confused with other diseases such as osteoarthritis and rheumatoid arthritis. PsA involving temporomandibular joints (TMJs) are uncommon: only 19 articles with 43 cases have been documented in the literature. TMJ ankylosis caused by PsA is rare, with only six cases having been reported. The authors present four cases of ankylosis of the TMJ secondary to PsA and review the literature. The findings of this study suggest that more attention should be paid to psoriasis patients with TMJ symptoms and proper treatment should be taken to prevent irreversible TMJ damage.

[Correlation analysis of VEGF and PTEN expression in gingival carcinoma].

PURPOSE: To study the expression of vascular endothelial growth factor (VEGF) and phosphatase and tensin homolog (PTEN) in gingival carcinoma and their correlation in order to provide reference for clinical treatment. METHODS: Sixty-six gingival cancer patients were determined by pathological examination, among which 31 were well-differentiated, 20 were moderately differentiated and 15 were poorly differentiated. 15 adjacent normal tissues were chosen as control group. The expression of VEGF and PTEN was examined by immunohistochemical method. Correlation analysis was performed with SPSS13.0 software package. RESULTS: The positive rate of PTEN in control group was significantly higher than other groups (P<0.05). The expression of VEGF in poorly differentiated group was significantly higher than other groups (P<0.05). Correlation analysis showed that the expression of VEGF was positively correlated to recurrence and lymph node metastasis (P<0.05); PTEN was negatively correlated to recurrence and lymph node metastasis (P<0.05); VEGF and PTEN in gingival carcinoma was negatively correlated (P<0.05). CONCLUSIONS: The increased expression of VEGF and decreased expression of PTEN in gingival carcinoma may play a mutual role in the development of gingival cancer.

Craniofacial morphology of Chinese patients with bilateral temporomandibular joint osteoarthrosis.

OBJECTIVE: To evaluate the morphological features of craniofacial structures in young patients affected by bilateral temporomandibular joint osteoarthrosis (TMJOA). METHODS: Forty-three males and 189 females aged 15 to 25 years who had lateral cephalograms and temporomandibular joint (TMJ) radiological examinations were included. They were classified into a TMJOA group and a control group, according to TMJ bony status. Thirty-two variables from lateral cephalogram were analysed by t test to evaluate the cranial and dentofacial differences between the two groups. RESULTS: TMJOA group showed a shorter posterior ramus height and shorter condyles, smaller SNB angle and larger ANB angle, smaller facial plane angle and larger angle of convexity, steeper mandibular plane angle and more vertical y-axis. CONCLUSION: Bilateral TMJOA is associated with dentofacial alterations characterised by a tendency toward retrognathism and shorter mandibles. However, the cause-and-effect relationship is yet to be clarified.

Cerebral activation during unilateral clenching in patients with temporomandibular joint synovitis and biting pain: an functional magnetic resonance imaging study.

BACKGROUND: Functional magnetic resonance is a non-invasive method that can examine brain activity and has been widely used in various fields including jaw movement and pain processing. Temporomandibular disorder (TMD) is one of the most frequent facial pain problems. The objective of this study was to investigate the brain activities using functional magnetic resonance imaging (fMRI) during unilateral maximal voluntary clenching tasks in the TMD synovitis patients with biting pain. METHODS: Fourteen TMD synovitis patients with unilateral biting pain and 14 controls were included in the study. Contralateral biting pain was defined as right molar clenching causing left temporomandibular joint (TMJ) pain. Ipsilateral biting pain was defined as right molar clenching causing right TMJ pain. Symptom Check List-90 (SCL-90) was administered to the patients and controls. Independent sample t-test was used to compare the SCL-90 subscales between the two groups. Unilateral clenching tasks were performed by the patients and controls. Imaging data were analyzed using SPM99. RESULTS: Patients were divided into contralateral TMD biting pain group (n = 8) and ipsilateral TMD biting pain group (n = 6). The SCL-90 subscales were significantly different between the two groups for somatization, depression, anxiety, phobic anxiety, and paranoid ideation. Group analysis of the controls demonstrated brain activations in the inferior frontal gyrus, precentral gyrus, middle frontal gyrus, superior temporal gyrus, and insular. The areas of activation were different between right and left clenching task. In TMJ synovitis patients with contralateral or ipsilateral biting pain, the group analysis showed activations in the inferior frontal gyrus, superior temporal gyrus, medium frontal gyrus, precentral gyrus, and anterior cingulate cortex. CONCLUSIONS: The inferior frontal gyrus and precentral gyrus play essential roles during the unilateral clenching task. Activation of anterior cingulate cortex in the synovitis patients with biting pain was associated with higher levels of psychological distress.

[Investigation on disc position of the temporomandibular joint in asymptomatic volunteers by magnetic resonance imaging].

OBJECTIVE: To investigate the types of disc position of the temporomandibular joint (TMJ) and their relationship with age and gender in asymptomatic volunteers by magnetic resonance imaging (MRI). METHODS: A total of 100 asymptomatic volunteers were divided into 5 groups (11-, 21-, 31-, 41-, 51 - 60 years old), 10 male and 10 female were included in each group. A total of 200 TMJs were scanned with Siemens Trio Tim 3.0T MRI system oblique-sagittally at closed- and open-mouth positions. Visual evaluation of MR images were performed on 3 neighbour slices of each TMJ (lateral, central, medial). RESULTS: There was a normal disc-condyle relationship in 59 of the 100 asymptomatic subjects. The normal disc position, anterior disc displacement and insidious anterior disc displacement (IADD) were observed in 140 (70.0%), 14(7.0%) and 46(23.0%)joints respectively, which showed no significant differences among different age groups or between genders (P > 0.05). The maximum mouth opening of the 100 asymptomatic volunteers was (46.3 +/- 5.5) mm, with no significant difference among the various types of disc position (P > 0.05). CONCLUSIONS: Disc displacement does exist in the asymptomatic volunteers, however, its occurrence is not associated with age and gender. IADD is the main type of the disc displacement in asymptomatic volunteers. There is no close relationship between the imaging manifestation of the disc displacement and clinical symptoms.

[Temporomandibular joint disc displacement: diagnosis by arthrography with dental volumetric computerized tomography].

OBJECTIVE: Temporomandibular joint sideways and rotational disc displacement was assessed by arthrography with dental volumetric computerized tomography. METHODS: The study was conducted retrospectively on 119 joints of 109 patients (87 females, 22 males, mean age 31.1 years), who had undergone arthrography with dental volumetric CT in the sagittal and coronal planes. The disc displacements were subdivided into 5 types; condylar abnormalities were subdivided into 4 types. RESULTS: Complete anterior disc displacement was the commonest (70.6%) and medial the rarest (0.8%); anterolateral and anteromedial displacements were 18.5% and 10.1% respectively. The types of disc displacements were not correlated with bone lesions. A higher prevalences of bone lesions were found in the lateral poles of condyles. CONCLUSIONS: Arthrography using dental volume CT can be taken in the sagittal and coronal planes, so the sideways and rotational disc displacements, perforations and bone lesions can be evaluated. It's superior to conventional arthrography.

[A study on relationship between the contour of articular eminence and traces of the condylar kinematic center and its application in TMD patients].

OBJECTIVE: To investigate the relationship between the contour of articular eminence and traces of the condylar kinematic center during jaw opening movement in healthy subjects, and compare trace characteristics of condylar kinematic center and MRI findings in TMD patients. METHODS: In 10 healthy subjects, jaw-opening motion was recorded. The kinematic center and terminal hinge axis point of the condyle were used as trace reference points. The contour of articular eminence was examined by MRI. Seven patients with TMD signs and/or symptoms (disk displacement) were selected for this study. The condylar trace was recorded during jaw protrusion and opening-closing. The internal derangement in temporomandibular joints was detected by MRI and defined as: (1). normal disk position, (2). disk displacement with reduction, (3). disk displacement without reduction. RESULTS: In healthy subjects, most of the opening traces of the kinematic center coincided with the contour of articular eminence (8/10 joints in left, 9/10 joints in right). For terminal hinge axis point, no trace coincided with the contour of articular eminence (0/20 joints in left and right). In TMD patients, according to MRI findings, the condylar traces of kinematic center in 3 normal disk position joints showed normal shape. However, in 6 disk displacements with reduction joints and 5 disk displacement without reduction joints, the condylar traces of kinematic center showed irregular patterns except 1 disk displacement with reduction joint. CONCLUSIONS: In comparison with the terminal hinge axis point, the opening traces of the kinematic center can be interpreted as the translatory movement of the condyle/disc along the articular eminence. The study suggests the use of kinematic center in condylar movement studies.

[Comparative study on the clinical appearances between acute and chronic anterior disc displacement without reduction].

OBJECTIVE: To compare the clinical appearances of TMD patients between acute and chronic anterior disc displacement without reduction. METHODS: Successive one hundred TMD patients with fully recorded documents diagnosed as anterior disc displacement without reduction (ADDw/oR) were included, 45 acute and 55 chronic ADDw/oR patients. Clinical appearances including signs and symptoms, maximal mouth opening, Fricton's craniomandibular index, condylar bone changes on radiograms, findings on arthrograms and MRI were compared. RESULTS: The main reason for asking treatment was joint pain in chronic, instead of limited mouth opening in acute patients. Clinical symptoms such as pain and limited mandibular movement showed improvement in chronic patients. Fricton's joint dysfunction index was higher in acute than in chronic patients, but muscle palpation index was higher in chronic than in acute patients, but Fricton's craniomandibular index was not significantly different between chronic and acute patients. The destructive bone changes of condyle on radiograms, the damage of stretched disc attachment on arthrograms and the morphological deformed disc on MRI were more frequently found in chronic than in acute patients. CONCLUSIONS: In acute patients there is a great likelihood that tissues are healthy and not morphologically changed, we suggest that early and efficacious intervention should be made to reposition the anterior displaced disc that may block the progress of pathological impairment to both the disc and the condyle of TMJ.