Evaluation of lateral pterygoid muscles in painful temporomandibular joints by signal intensity on fluid-attenuated inversion recovery images

Objectives

Pathological changes of the lateral pterygoid muscle (LPM) have been investigated using various modalities, including magnetic resonance (MR) imaging and electromyography. Fluid-attenuated inversion recovery (FLAIR) is an MR sequence that we hypothesized can be used to evaluate abnormalities of the LPM. The purpose of this study was to analyze the FLAIR signal intensity of the LPM in painful temporomandibular joints (TMJs) and investigate the pathological changes of the muscle.

Methods

The study was based on 149 TMJs of 77 patients who were referred for MR imaging of the TMJ. Patients rated their degree of pain during chewing and mouth opening using a visual analog scale (VAS). Regions of interest were placed over the superior and inferior heads of the LPM and gray matter on FLAIR sagittal images. Using the signal intensity of gray matter as a reference, the signal intensity ratio (SIR) of the LPM was calculated. Spearman’s rank-correlation coefficient was used to analyze the correlation between the SIR and the VAS score (p?<?0.05).

Results

A significant correlation was present between the SIR on FLAIR images and the VAS score.

Conclusions

These results suggest that the FLAIR signal intensity of the superior and inferior heads of the LPM significantly increases as TMJ pain becomes more severe. Thus, FLAIR could be useful in assessing the relationship between the MR signals of the LPM and clinical symptoms.

     

Cone-beam computed tomography findings of temporomandibular joints with osseous abnormalities

Objective

To evaluate the cone-beam computed tomography (CBCT) findings of temporomandibular joints (TMJs) with osseous abnormalities.

Methods

CBCT images of 88 TMJs in 44 patients with arthrogenic TMJ disorder and 40 normal TMJs of 20 asymptomatic patients were selected for the study. All images were used for evaluation of the condyles (position and width), glenoid fossae (width and depth), and joint spaces (anterior, posterior, and maximum superior). The frequencies of the condylar positions were compared between the two groups using the Chi-square test. The mean values of the remaining CBCT findings were compared between the two groups using the Mann?CWhitney U test.

Results

In the 88 TMJs with osseous abnormalities, a dorsal position of the condyle was most frequently seen (62/88), whereas central and ventral positions of the condyle were seen in two and 24 joints, respectively. The TMJs with osseous abnormalities exhibited a significantly lower mean value for the condyle width and a significantly higher mean value for the anterior joint space than the TMJs without such abnormalities.

Conclusions

Small and dorsally positioned condyles are characteristic CBCT findings of TMJs with osseous abnormalities.     

Differences in signal intensities of temporomandibular joint (TMJ) effusion on fluid-attenuated inversion recovery (FLAIR) images

Objectives

Joint effusion is demonstrated by high signal intensity in the upper and lower temporomandibular joint (TMJ) spaces on T2-weighted images. The fluid-attenuated inversion recovery (FLAIR) technique can be applied to analyze joint effusion in the TMJ. FLAIR signal intensity can be more sensitively influenced by the contents of joint effusion than T2-weighted signal intensity. The purpose of this study was to analyze the signal intensity of joint effusion on FLAIR images and to investigate the changes in joint effusion contents according to the status of TMJ disorders.

Methods

A total of 48 joints (45 patients) with joint effusion were investigated by magnetic resonance (MR) imaging. Regions of interest were placed over the joint effusion and gray matter on FLAIR images. The joints were categorized as normal disk position (NL), disk displacement with reduction (DWR), disk displacement without reduction (DWOR), and osteoarthritis (OA). The signal intensity ratio of joint effusion was calculated using gray matter as the reference point. The Kruskal–Wallis test and Steel test were applied. A probability of less than 0.05 was considered statistically significant.

Results

The median signal intensity ratios of joint effusion differed significantly among the four joint categories (p?=?0.02, Kruskal–Wallis test). The median signal intensity ratio of joint effusion in the OA category was significantly higher than that in the NL category (p?=?0.04, Steel test).

Conclusions

The present findings suggest that FLAIR images can demonstrate the changes in joint effusion contents according to the status of TMJ disorders.

     

Unilateral bony ankylosis of the temporomandibular joint in a case of ankylosing spondylitis

Background

Ankylosing spondylitis (AS) is a chronic inflammatory disease with multiple articular and para-articular involvement that has a predilection for the axial skeleton. In spite of its high prevalence, ankylosis secondary to AS is a rare condition.

Case report

A 31-year-old male diagnosed with AS was referred for computed tomography (CT) of the temporomandibular joint (TMJ) due to severe mouth opening limitation. The patient had a 16-year medical history of AS and sought assistance due to TMJ pain and incapacity to open his mouth.

Results

Previous bony scintigraphy revealed involvement of the spine, sacroiliac joints, right knee, and left TMJ. Magnetic resonance imaging revealed erosion of the left condyle and posterior slope of the articular eminence, and a mass of heterogeneous signal intensity between these structures. The left condyle also presented sclerosis/edema of the bone marrow and the disk could not be identified. Sagittal and coronal CT images showed moderate alterations of the TMJ on the right side. On the left side, the images displayed markedly eroded condyle and mandibular fossa, and a bony mass resulting in ankylosis of the osseous components of the joint.

Conclusion

TMJ ankylosis in AS patients is rare and very few reports have presented imaging features of the condition through advanced diagnostic techniques.     

Diagnosis of retrodiscal tissue in painful temporomandibular joint (TMJ) by fluid-attenuated inversion recovery (FLAIR) signal intensity

The purpose of the present study is to analyze the fluid-attenuated inversion recovery (FLAIR) signal intensity of the retrodiscal tissue in a painful temporomandibular joint (TMJ), and to develop a diagnostic system based on FLAIR data.

Methodology:The study was based on 33 joints of 17 patients referred for MR imaging of the TMJ. Regions of interest were placed over retrodiscal tissue and gray matter (GM) on FLAIR images. Using signal intensities of GM as reference points, signal intensity ratios (SIR) of retrodiscal tissue were calculated. SIRs in painful TMJ were compared with those in painless TMJ. Wilcoxon’s Rank Sum Test was used to analyze the difference in SIRs between the painful and painless groups (P<0·05).

Results:The SIRs of retrodiscal tissue were significantly higher in painful joints than in painless joints.

Conclusion:FLAIR sequences provide a high signal in patients having painful TMJ, and it suggests that retrodiscal tissue in painful TMJ contains elements such as protein.     

Total antioxidant capacity and total oxidant status of synovial fluids in patients with temporomandibular joint pain and dysfunction

Objectives

The objective of this study was to investigate whether a relationship exists between total antioxidant capacity (TAC) and total oxidant status (TOS) of synovial fluids (SFs) of temporomandibular joint (TMJ) pain patients with pain and dysfunction.

Materials and methods

Forty-two patients with TMJ pain were included in this study. TAC and TOS values of SFs were measured with a novel colorimetric method. Independent t test and correlations were used to analyze the data.

Results

TAC of SFs in patients with TMJ pain and limited mouth opening (LMO; n?=?21) were significantly lower (P?=?0.03) than patients without LMO (n?=?21). TOS of SF was negatively correlated with duration of the disease. There was no correlation between TAC, TOS, and VAS scores of the patients as well as age and maximum mouth opening values.

Conclusions

Antioxidant response to oxidative changes (TAC and TOS) in SF decreased as the stage of dysfunction increased.

Clinical relevance

Local administration of antioxidant agents might be considered in management of TMJ pain and dysfunction to prevent possible increased oxidative stress.     

Das Landschwein als Modell für Ausbildung, wissenschaftliche Untersuchungen und Entwicklung neuer arthroskopischer Operationsmethoden am Kiefergelenk

Aim of the study

The aim of this study was to establish a reliable educational model for and a further refinement of arthroscopic surgery in the temporomandibular joint (TMJ).

Material and methods

As a first step, the lateral-medial (length) and anterior-posterior distances (width) of the mandibular head of nine pig cadavers (country breed) of about 30 (n=3), 60 (n=3) and 90 kg (n=3) body weight were measured and compared with findings in 12 adult human cadavers. The best points of access for the arthroscopic and lavage channels using the triangulation technique were determined. As determined by these findings, 15 arthroscopies were performed on eight pig TMJs under general anaesthetic. A control arthroscopy was performed after 2 weeks followed by another clinical follow-up at 4 weeks before the pigs were sacrificed.

Results

The TMJ of the pigs between 30 and 60 kg body weight was found to be highly comparable to the human TMJ. The best locations for puncturing the upper joint compartment of the TMJ in pigs were 5.0 cm and 6.1 cm anterior to the tragus on a line drawn along the lower margin of the zygoma. The only complication encountered was a subcutaneous infection treated successfully by antibiotics and incision.

Conclusions

In our opinion, a standard and easily reproducible model is necessary for further studies in arthroscopic TMJ-surgery. The country bred pig represents a good model for educational purposes and for studying further refinements of arthroscopic technique.      

Arthroskopische dorsale Kiefergelenkbandstraffung mit Wasserstrahlskalpell

Purpose

The aim of the study was the development and proof testing of an arthroscopic dorsal ligament plasty using a hydrojet knife in the pig TMJ before using in man.

Material and methods

The dorsal TMJ ligament of ten pigs (country breed) was irradiated with a hydrojet (diameter 120 µm, working pressure 90 bar) under arthroscopic visualization. Postoperatively the pigs were controlled for 10 weeks before sacrifice. The isolated TMJs were examined by light microscope and the results compared with untreated pig TMJs. The flows over our arthroscopic instruments were measured to exclude the possibility of damaging surrounding structures by pressure.

Results

Clinically we found no complications after arthroscopic surgery. Food intake was normal and development of body weight according to the food offered. Histology revealed tissue reorganization connected with increased collagen fibre production. Our calculations showed no pressure higher than 1000 mm water column in the TMJ under our working conditions.

Conclusions

The idea of arthroscopic dorsal ligament plasty using a hydrojet works in pig TMJs. Experience in TMJ arthroscopy is necessary. We found no danger of barotrauma under arthroscopy with the hydrojet. The results indicate dorsal ligament shortening by development of scar formations. In our opinion the method can be used for the therapy of dorsal ligament elongation and disk displacements in the TMJ of man.     

Classification of temporomandibular joint erosion,arthritis, and inflammation in patients with juvenile idiopathic arthritis

Introduction

Juvenile idiopathic arthritis is the most common disease in pediatric rheumatology. It is characterized by chronically progressive joint destruction. The temporomandibular joints (TMJs) are involved in up to 87% of patients and may take an asymptomatic course in 69% of cases. Other than contrast-enhanced magnetic resonance imaging (MRI), there are no reliable screening symptoms or non-invasive procedures available to diagnose the inflammation in its acute form. The goal of this study was to establish an imaging-based classification system for TMJ erosion via MRI and cone-beam computed tomography (CBCT) in an effort to improve indication-specific treatment approaches and to facilitate the comparison of findings.

Materials and methods

A total of 46 patients were included. Contrast-enhanced MRI and CBCT images obtained during treatment by pediatric rheumatologists and orthodontists were available from 23 patients with juvenile idiopathic arthritis. We devised a classification system combining the findings of both imaging techniques based on this patient sample in comparison with CBCT findings from an age- and gender-matched group of 23 non-arthritis patients, taking into consideration the available literature and administration of contrast medium.

Results

Our cohort of 46 patients comprised 60% female and 40% male patients with a mean age of 14 years, providing a total of 92 TMJs for evaluation. We were able to apply the findings efficiently and conveniently to this classification system with no relevant interobserver differences. Mild structural abnormalities were noted in 21% of TMJs in the control group, whereas 83% of TMJs in the arthritis group exhibited severe anomalies, including cases of extreme destruction. Age and gender did not affect the degree of destruction significantly.

Conclusion

This is the first classification system to link CBCT and MRI with the use of contrast medium. Contrast-enhanced MRI is an internationally recognized technique that permits acute inflammation to be unequivocally diagnosed. Although structural erosion of the TMJs in our arthritis group was generally severe and significant, we were surprised to observe some cases that were clinically asymptomatic.     

Role of magnetic resonance imaging in diagnosis of bisphosphonate-related osteonecrosis of the jaw

Objectives

To clarify the magnetic resonance (MR) imaging features of bisphosphonate-related osteonecrosis of the jaw (BRONJ), particularly those in the early stage, through a literature review and case analysis.

Methods

Literature on MR imaging of BRONJ was collected, and the MR imaging features were summarized. On MR images of patients with BRONJ, the signal intensity of the bone marrow was evaluated quantitatively by means of the contrast-to-noise ratio (CNR). The relationships of the imaging features with the presence of exposed bone, types and administration routes of bisphosphonates (BP), and duration of symptoms were investigated.

Results

Fifteen articles were identified. In the early stages, the region of osteonecrosis displayed decreased signal intensity on T1-weighted images and normal signal intensity on T2-weighted images. In the late stages, the signal intensity of the bone marrow on T2-weighted images was variable: the exposed diseased bone displayed decreased signal intensity, and the unexposed diseased bone displayed increased signal intensity. These changes were also seen in BRONJ cases. There was a significant difference in the CNR between the exposed and unexposed diseased bones on STIR images. There were no significant differences in the CNR among the three groups by types and administration routes of BP, both on T1-weighted and STIR images. Changes in the signal intensity of bone marrow were seen at the early duration of symptoms. In the early stage, the CNR on T1-weighted images had a significant correlation with duration of symptoms.

Conclusion

MR imaging may provide visualization of useful features in the early stage of BRONJ.     

Factors related to the incidence of anterior disc displacement without reduction and bony changes of the temporomandibular joint in patients with anterior open bite

Purpose

We aimed to investigate factors related to the prevalence of anterior disc displacement without reduction (ADDwoR) and bony changes of the condylar head (bony changes) in the temporomandibular joints (TMJs) of patients with anterior open bite.

Methods

Subjects are comprised of 36 preoperative patients (72 joints) with skeletal anterior open bite without facial asymmetry who had undergone orthognathic surgery at the Hokkaido University Hospital; magnetic resonance imaging of the TMJ and cephalometric analysis were performed before treatment. Logistic regression analysis was performed to clarify relationships among age, overbite, overjet, ANB angle, sella to nasion (SN) to mandibular plane angle (SN–MP angle), SN to ramus plane angle (GZN angle), gonial angle, and incidence of ADDwoR or bony changes in patients with anterior open bite.

Results

Fifteen patients had bilateral ADDwoR, and five patients had unilateral ADDwoR; 17 patients had bilateral bony changes, and five patients had unilateral bony changes. SN–MP angle was greater in 20 patients with ADDwoR than that in 16 patients without ADDwoR (p?p?Conclusion In terms of dentofacial morphology, SN–MP angle appears to be associated with the incidence of ADDwoR, and GZN angle appears to be associated with bony changes in the TMJ.     

Phase III,randomized, double-blind,placebo-controlled trial of topical 2 % lidocaine for the prevention and treatment of oral mucosal pain in children

Objectives

The aim of this study was to assess the efficacy in pain reduction of topical 2 % lidocaine compared to a placebo cream in children with oral mucosal lesions due to trauma or aphthous ulcers or in the prevention of clamp placement pain.

Materials and methods

The design was a double-blind, randomized, placebo-controlled, four-center trial on 64 patients. Pain intensity and relief were measured using a 100-mm visual analog scale (VAS). One-tailed Student’s t test and ANOVA were used for statistical analyses.

Results

Independent of the pain origin, application of 2 % lidocaine cream led to a mean reduction in VAS pain intensity of 19.7 mm?±?18.3, which was significantly greater than that obtained with the placebo cream (p?=?.025). Analyses showed a statistically significant efficacy of the 2 % lidocaine cream (p?<?.0001). Its efficacy was not associated to any local or systemic adverse drug reaction, as reported by the patients. As the most important population represented in our patients was children whom a rubber dam clamp was placed, we also specifically analysed this population, and we were able to demonstrate a significantly greater efficacy of the 2 % lidocaine cream on the pain caused by the rubber dam clamp placement in comparison to the placebo cream (p?<?.005).

Conclusions

A significant reduction in pain intensity occurred after application of 2 % lidocaine cream, and the effect was significantly greater than that obtained with the placebo cream. Considering the study’s limitations, this product appears safe for use in children.

Clinical relevance

For painful benign lesions of the oral mucosa (trauma or aphthous ulcers) or for preventing painful iatrogenic procedures such as rubber dam clamp placement, it is essential to treat or prevent pain onset, especially in the pediatric population for whom a painful experience could end in refusal of dental care. Application of a topical anesthetic in this specific situation is of particular interest, as is defining its efficacy and safety.     

Efficacy of Temporomandibular Joint Arthrocentesis on Mouth Opening and Pain in the Treatment of Internal Derangement of TMJ—A Clinical Study

Purpose

This study was designed to investigate the efficacy of arthrocentesis on mouth opening and pain in the treatment of temporomandibular joint (TMJ) internal derangement patients.

Materials and Methods

Fifteen males and 25 females aged between 18 and 37 years comprised the study material in the department of oral and maxillofacial surgery at Govt Dental College Srinagar (India). The patients’ complaints were limited mouth opening and TMJ pain. Arthrocentesis was performed under aseptic conditions. Clinical evaluation of the patients was done before the procedure, and 1 week and 4 months post-operatively. Intensity of TMJ pain and maximal mouth opening were recorded at each follow-up visit.

Results

There was significant improvement in mouth opening and reduction in pain scores in the post-operative period.

Conclusions

Arthrocentesis is a simple and safe procedure for patients of internal derangement with closed lock for improving mouth opening and decreasing pain.     

Biochemical analysis of the articular disc of the temporomandibular joint with magnetic resonance T2 mapping: a feasibility study

Objectives

Symptoms of temporomandibular joint (TMJ) dysfunction can seriously compromise patients' quality of life. The aim of our study was to use magnetic resonance imaging (MRI) T2 mapping of the articular disc to determine whether T2 mapping of the TMJ disc is feasible in routine clinical imaging and to assess the normal T2 relaxation time distribution within the TMJ.

Methods

Included were ten asymptomatic volunteers without pain, any mouth-opening limitations, or any clicking phenomena. MR imaging was performed on a 3-T MR scanner using a flexible, dedicated, eight-channel multielement coil. T2 mapping was performed in the oblique sagittal plane. The regions of interest (ROIs) for the T2 relaxation time maps of the disc were selected manually.

Results

The mean values for ROIs ranged between 22.4 and 28.8 ms, and the mean for all ROIs was 26.0?±?5.0 ms. Intraclass correlation (ICC) for interobserver variability was 0.698, and ICC for intraobserver variability was 0.861. There was no statistically significant difference between raters (p?=?0.091) or sides (p?=?0.810).

Conclusion

The T2 mapping technique enables ultrastructural analysis of the composition of TMJ disc. This biochemical technique is feasible in vivo, as shown in our study, when a high-field (3 T) MR and a dedicated TMJ coil are used.

Clinical relevance

T2 mapping as a biochemical technique, together with morphological MRI, may help to gain more insights into the physiology and into the pathophysiology of the articular disc in the TMJ noninvasively and in vivo.     

Evaluation of the relationships between contrast-enhanced magnetic resonance characteristics and joint pain in patients with temporomandibular disorders

Objectives

To evaluate the correlations between temporomandibular joint (TMJ) pain and both conventional and gadolinium-enhanced magnetic resonance (MR) imaging characteristics in patients with temporomandibular disorders (TMDs).

Methods

T1-weighted, T2-weighted, and fat-suppressed contrast-enhanced T1-weighted MR imaging were performed in 80 TMD patients with the main complaint of TMJ pain. A kappa statistical analysis was performed to calculate the interobserver agreement between two of three radiologists. The relationships between TMJ pain and various MR findings were analyzed by multiple comparison test, Spearman’s rank correlation test, Chi-square test, Student’s t test, and multivariate logistic regression analysis.

Results

Significant correlations were observed between anterior disk displacement without reduction, joint effusion, and TMJ pain (p < 0.01). The degree of contrast enhancement of the posterior disk attachment was correlated with the severity of TMJ pain, especially spontaneous pain (r = 0.725, p < 0.01), while no correlation was observed in the masticatory muscle pain group. The correlation tended to be higher in the latero-central portions than in the medial portion of the mandibular condyle, although no significant difference was seen.

Conclusions

It has been suggested that fat-suppressed contrast-enhanced MR imaging techniques facilitate better understanding of the sources of TMJ pain, but not masticatory muscle pain, and could reflect TMJ synovial inflammation. The severity of TMJ pain was closely correlated with the degree of contrast enhancement. The above-mentioned correlation had a tendency to be higher in the latero-central portions of the mandibular condyle.

     

髁突骨髓腔MRI信号异常与颞下颌关节疼痛的关系

目的:探讨髁突骨髓腔信号异常与关节疼痛的关系。方法:利用MRI金标准,对44例单侧关节疼痛TMD患者88侧关节进行闭口斜矢状位T1W和T2W扫描,以非疼痛侧作为自身对照;利用可视疼痛模拟标尺(VAS)进行疼痛程度的判定,观察髁突髓腔信号异常与疼痛的关系。结果:44个疼痛关节中,11个关节(25％)出现髓腔信号异常,均为水肿型;而44个非疼痛关节中,仅2个关节(4.5％)出现髓腔信号异常,分别表现为硬化型和混合型,经统计学分析,TMJ疼痛与髓腔信号异常有显著相关性(P<0.01)。44个疼痛关节中,骨髓腔信号异常及正常患者VAS平均值分别为39.5±27.5和42.6±21.9。经t检验,两组问差别无统计学意义(P=0.696)。结论:髁突髓腔信号异常与关节疼痛密切相关,而与TMJ疼痛程度无关。     

Clinical significance of T2 mapping MRI for the evaluation of masseter muscle pain in patients with temporomandibular joint disorders

Objectives

Masticatory muscle pain is one of the typical symptoms of temporomandibular joint disorders (TMD). T2 mapping (distribution of T2 values) is a notable MRI technique for evaluating water contents in tissues. We investigated the clinical significance of T2 mapping for the evaluation of masticator muscle conditions by comparing the difference in the T2 values between the painful and pain-free sides of the masseter muscle in patients with TMD.

Methods

Seventy-three patients clinically diagnosed with TMD were enrolled in this study. We divided the patients into two groups: a unilateral pain group (patients with unilateral masseter muscle pain) and a painless group (patients without muscle pain). There were 29 patients in the unilateral pain group and 44 patients in the painless group. We compared the difference in the mean T2 values between the painful and pain-free sides of the masseter muscle in the unilateral pain group and between the right and left sides in the painless group.

Results

The mean T2 values of the masseter muscle on the painful side were significantly higher than those on the pain-free side in the unilateral muscle pain group (p < 0.01). In the painless group, there was no significant difference in the mean T2 values between the right and left sides.

Conclusions

It is suggested that T2 mapping is a promising method for evaluating masseter muscle pain caused by edematous change related to TMD through monitoring of the T2 values.     

Efficacy of Temporomandibular Joint Arthrocentesis with Sodium Hyaluronate in the Management of Temporomandibular Joint Disorders: A Prospective Randomized Control Trial

Purpose

This study was designed to investigate the efficacy of the temporomandibular joint arthrocentesis with and without injection of sodium hyaluronate (SH) in the treatment of temporomandibular joint disorders.

Patients and Methods

A total of sixty two TMJs in 34 males and 28 females aged 20–65 years comprised the study material. The patients’ complaints were limited mouth opening, TMJ pain, and joint noises during function. Patients were randomly divided into 2 groups in which arthrocentesis plus intra-articular injection of sodium hyaluronate was performed in 1 group and only arthrocentesis was performed in the other group. Both groups contained patients with disc displacement with reduction and without reduction. Clinical evaluation of the patients was done before the procedure, immediately after the procedure, at 1 week and 1, 3 and 6 months postoperatively. Intensity of TMJ pain was assessed using visual analog scales. Maximal mouth opening and lateral jaw movements also were recorded at each follow-up visit.

Results

Both techniques increased maximal mouth opening, lateral movements, and function, while reducing TMJ pain and noise.

Conclusions

Although patients benefitted from both techniques, arthrocentesis with injection of SH seemed to be superior to arthrocentesis alone.

     

Value of additional axial imaging in magnetic resonance imaging of the temporomandibular joint to identify extra-articular diseases

Objectives

The conventional magnetic resonance (MR) imaging protocol for the temporomandibular joint (TMJ) is typically performed with focused oblique, sagittal, and coronal imaging of each joint and can miss extra-articular diseases and conditions that may present with similar symptoms. The purpose of this study was to investigate the value of an additional axial short tau inversion recovery (STIR) sequence to identify conditions other than ordinal TMJ disorders.

Methods

From September 2000 to April 2006, 601 patients with clinically diagnosed TMJ disorders underwent MR imaging at 0.5 T with a dedicated TMJ coil. In addition to the standard TMJ MR imaging protocol with oblique, sagittal, and coronal proton-density and T2-weighted images of each TMJ in the closed- and open-mouth positions, axial STIR images from the superior orbit to the thoracic inlet level were obtained.

Results

Of 601 patients, 580 (96.5 %) had TMJ disorders without other imaging abnormalities. Extra-articular diseases outside the TMJ were found in 21 patients (3.5 %), with all abnormalities seen only on axial STIR images. These conditions comprised 13 infectious/inflammatory processes and 8 neoplasms including 7 malignancies. Six of these patients had coexistent TMJ disorders, and 15 had no TMJ abnormality.

Conclusions

The addition of axial STIR images to the standard TMJ MR imaging protocol detected unexpected pathology in 3.5 % of patients, including malignancies (1.0 %). The addition of these images could potentially be used as an adjunct to the typical TMJ MR imaging protocol to improve detection of unexpected extra-articular disease.

     

Associations between the articular eminence inclination and condylar bone changes, condylar movements, and condyle and fossa shapes

Objectives

The purpose of the present study was to determine the inclination and height of the articular eminence with respect to the condylar bone changes, condyle shape, fossa shape and condylar movements in patients with and without temporomandibular joint (TMJ) dysfunction using cone-beam computed tomography (CBCT).

Methods

The associations between the eminence inclination and the condylar bone changes, condylar movements, condylar shape and fossa shape were evaluated in patients with TMJ disorders and control patients without TMJ disorders. The measurements of the articular eminence inclination were established on central sagittal slices of the TMJ. The central coronal slices were used to determine the condyle and fossa shapes. The types of movements of the condyles were determined on open-mouth images, and mandibular hypermobility or hypomobility was noted for each joint.

Results

There were no significant differences in the eminence inclination and height with respect to the condylar bone changes and condylar movements in the TMJ disorder group. However, there was a significant association between the eminence inclination and the fossa shape in the TMJ disorder group and significant associations between the eminence inclination and both the condyle and fossa shapes in the control group. The articular eminence inclination was steeper in the control group than in the TMJ disorder group.

Conclusions

The eminence inclination was steeper in the control patients than in the patients with TMJ disorders, and was not correlated with the condylar bone changes or condylar movements.