Differences in temporomandibular joint pain and age distribution between marrow edema and osteonecrosis in the mandibular condyle

This study investigated the differences of age distribution and temporomandibular joint (TMJ) pain between marrow edema and osteonecrosis in the mandibular condyle. Subjects consisted of 35 TMJs in 35 patients with abnormal bone marrow on MR images who were selected from a consecutive series of 527 patients with TMJ disorders. Proton density and T2-weighted MR images taken in the oblique sagittal and coronal planes were used to diagnose condylar marrow abnormalities and divide them into either edema or osteonecrosis. The differences in TMJ pain and age distribution for these two abnormalities were assessed with the one-sided Wilcoxon rank sum test with 0.05 alpha level. The degree of pain was higher in joints with marrow edema than in joints with osteonecrosis (p = 0.033). The mean age was higher in joints with osteonecrosis (p < 0.001). Our results suggest that there is more severe pain in TMJs with marrow edema of the mandibular condyle than in those with osteonecrosis. Since the patients with marrow edema have lower age, it also appears that marrow edema may be a precursor condition for osteonecrosis of the TMJ.     

The relationship of bone marrow edema pattern in the mandibular condyle with joint pain in patients with temporomandibular joint disorders: longitudinal study with MR imaging

The purpose of this study was to investigate the course of bone marrow edema pattern (decreased signal intensity on T1- or proton-density-weighted images and increased signal intensity on T2-weighted fat-suppressed images) in the mandibular condyle after improvement in clinical symptoms, and to clarify its relationship with temporomandibular joint (TMJ) pain. This study was based on 14 joints of 11 patients (all female, mean age 37.5 years) with TMJ disorders showing condylar bone marrow edema pattern on initial magnetic resonance (MR) images. All joints were re-evaluated clinically and using MR images after relief of joint pain following arthrocentesis combined with non-surgical treatment. The time interval between the initial and follow-up MR images ranged from 14 to 27 months (mean 17 months). Of the 14 joints, 4 joints (28.6%) showed a normal bone marrow signal, whereas 10 joints (71.4%) showed persistent bone marrow edema pattern on follow-up MR images (P = 0.125). Therefore, the reduction in TMJ pain did not correlate with resolution of bone marrow edema pattern in most joints. The results of this study suggest that the bone marrow edema pattern in the mandibular condyle does not always contribute to the occurrence of joint pain in patients with TMJ disorders.     

Signal intensity on fluid-attenuated inversion recovery images of condylar marrow changes correspond with slight pain in patients with temporomandibular joint disorders

Objectives

Edema and necrosis of the temporomandibular joint (TMJ) have been described in terms of bone marrow signal abnormalities in magnetic resonance imaging (MRI). However, painful joints often show no such signaling abnormalities, making the diagnosis of TMJ disorders difficult in the clinical setting. An association has been suggested between TMJ bone marrow change and TMJ pain, but even when such change results in slight pain, it may be too slight to be visually apparent on MR images. We hypothesized that fluid-attenuated inversion recovery (FLAIR) can be used to detect such minimal changes. The purpose of this study was to determine whether there is an association between signal intensity on FLAIR images and pain in the TMJ.

Methods

The study included 85 TMJs in 45 patients referred to our department for MRI. The signal intensity on FLAIR images was measured. Pain was evaluated based on the visual analog scale. An unpaired t test and Pearson’s product-moment correlation coefficient were used for the statistical analysis. A p value of <0.05 was considered statistically significant.

Results

Signal intensity on the FLAIR images was significantly higher in painful than in nonpainful TMJs, although a significant correlation was not observed between the signal intensity and the pain score.

Conclusions

The results of this study suggest an association between abnormalities in the marrow of the mandibular condyle and pain. They also indicate that FLAIR imaging is a useful tool in the clinical diagnosis of painful TMJs.     

Significance of Frequency-Selective Fat Saturation T2-Weighted MR Images for the Detection of Bone Marrow Edema in the Mandibular Condyle

Abstract

The objective of this study was to evaluate the utility of frequency-selective fat saturation (FS) T2-weighted images (T2WI) for the detection of bone marrow edema in the mandibular condyle. MR evidence of bone marrow abnormalities was examined on the set of FS T2WI and conventional T1WI or of conventional T2WI and T1WI in 200 patients with temporomandibular joint (TMJ) related pain. Other parameters studied were TMJ effusion, disk displacement categories, and cortical bone abnormalities. The detection rate and area of bone marrow edema by FS T2WI and T1WI were significantly greater than those assessed by conventional T2WI and T1WI. The correlation between bone marrow abnormalities on FS T2WI and T1WI and pain was significantly stronger than with conventional T2WI and T1WI. This study confirms that FS T2WI is useful for the detection of the “edema pattern” in the mandibular condylar associated with TMJ-related pain.     

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.     

Relative odds of temporomandibular joint pain as a function of magnetic resonance imaging findings of internal derangement,osteoarthrosis, effusion,and bone marrow edema

OBJECTIVE: The purpose of this study was to evaluate whether common magnetic resonance (MR) imaging variables such as temporomandibular joint (TMJ) internal derangement, osteoarthrosis, effusion, and bone marrow edema are predictive of the presence of TMJ pain. STUDY DESIGN: The relationship between TMJ pain and TMJ internal derangement, osteoarthrosis, effusion, and bone marrow edema was analyzed in MR images of 338 TMJs in 169 patients with a clinical diagnosis of TMJ pain and dysfunction. Criteria for including a patient with TMJ pain were a report of orofacial pain referred to the TMJ, with the presence of unilateral or bilateral TMJ pain during palpation, function, or unassisted or assisted mandibular opening. The criteria for including a patient with no pain were the absence of TMJ pain during palpation, function, and unassisted or assisted mandibular opening. Application of the criteria resulted in a study group of 129 patients with unilateral TMJ pain, 18 with bilateral TMJ pain, and 22 without TMJ pain. Bilateral sagittal and coronal MR images were obtained to establish the presence or absence of TMJ internal derangement, osteoarthrosis, effusion, and bone marrow edema. Logistic regression analysis was used to compute the odds ratios for internal derangement, osteoarthrosis, effusion, and bone marrow edema for nonpainful TMJs (n = 173) versus painful TMJs (n = 165). RESULTS: For pairwise comparison, the chi(2) test was used; the resultant data showed a significant relationship between the clinical findings of TMJ pain and the MR imaging diagnoses of internal derangement (P =.000), osteoarthrosis (P =.015), effusion (P =.002), and bone marrow edema (P =.016). Of the MR imaging variables considered simultaneously in multiple logistic regression analysis, osteoarthrosis (P =.405), effusion (P =.131), and bone marrow edema (P =.231) dropped out as nonsignificant in the diagnostic TMJ pain group in comparison with the TMJ no-pain group. Significant increases in risk of TMJ pain occurred with disk displacement without reduction in combination with osteoarthrosis and bone marrow edema (3.7:1 odds ratio; P =.000) and with disk displacement without reduction in combination with osteoarthrosis and effusion (2.8:1 odds ratio; P =.000). CONCLUSIONS: The results suggest that TMJ pain is related to internal derangement, osteoarthrosis, effusion, and bone marrow edema. However, the data reemphasize that these MR imaging variables may not be regarded as the unique and dominant factors in defining TMJ pain occurrence.     

Significance of frequency-selective fat saturation T2-weighted MR images for the detection of bone marrow edema in the mandibular condyle

The objective of this study was to evaluate the utility of frequency-selective fat saturation (FS) T2-weighted images (T2WI) for the detection of bone marrow edema in the mandibular condyle. MR evidence of bone marrow abnormalities was examined on the set of FS T2WI and conventional T1WI or of conventional T2WI and T1WI in 200 patients with temporomandibular joint (TMJ) related pain. Other parameters studied were TMJ effusion, disk displacement categories, and cortical bone abnormalities. The detection rate and area of bone marrow edema by FS T2WI and T1WI were significantly greater than those assessed by conventional T2WI and T1WI. The correlation between bone marrow abnormalities on FS T2WI and T1WI and pain was significantly stronger than with conventional T2WI and T1WI. This study confirms that FS T2WI is useful for the detection of the "edema pattern" in the mandibular condylar associated with TMJ-related pain.     

MR Evidence of Characteristics in Symptomatic Osteoarthritis of the Temporomandibular Joint: Increased Signal Intensity Ratio on Proton Density-Weighted Images of Bone Marrow in the Mandibular Condyle

Abstract

The purpose of this study was to clarify the presence of pain and a correlation between pain and characteristics of signal intensity of mandibular bone marrow in temporomandibular joints (TMJ) with osteoarthritis (OA). A total of 196 joints in 98 patients with TMJ disorders were examined using magnetic resonance imaging (MRI). A pain score and signal intensity on mandibular bone marrow were analyzed in the TMJ with OA. TMJ with OA showed a higher degree of pain compared to those without (p<0.05). During opening, the joints in the higher signal intensity group showed a significantly higher degree of pain compared to the joints in the lower signal intensity group in those with OA on proton density weighted images (p<0.05). It was concluded that TMJ with osteoarthritis is related to pain and that a symptomatic osteoarthritic TMJ can accompany bone marrow changes in the condyle, showing an increased signal on proton density weighted images.     

Bone marrow edema of the mandibular condyle related to internal derangement, osteoarthrosis, and joint effusion.

PURPOSE: The purpose of this prospective study was to evaluate whether common magnetic resonance imaging (MRI) variables such as temporomandibular joint (TMJ) internal derangement, osteoarthrosis, and effusion may predict the diagnostic group of bone marrow edema of the mandibular condyle. MATERIALS AND METHODS: The relationship between bone marrow edema and TMJ disc displacement, osteoarthrosis, and effusion was analyzed in MRIs of 120 TMJs in 73 consecutive patients with TMJ pain and/or a clinical diagnosis of TMJ internal derangement type III (disc displacement without reduction). The diagnostic bone marrow edema group was comprised of 54 TMJs in 40 patients with a unilateral or bilateral MRI diagnosis of bone marrow edema. The control group consisted of 66 non-bone marrow edema TMJs in 33 patients with a bilateral MRI finding of an absence of bone marrow edema. A logistic regression analysis was used to compute the odds ratios for internal derangement, osteoarthrosis, and effusion for non-bone marrow edema TMJs (n = 66) versus TMJs with bone marrow edema (n = 54). RESULTS: Using Chi;(2) analysis for pair-wise comparison, the TMJ-related data showed a significant relationship between the MR imaging findings of TMJ bone marrow edema and those of internal derangement (P = .000), osteoarthrosis (P = .000), and effusion (P = .010). Of the MRI variables considered simultaneously in the multiple logistic regression analysis, osteoarthrosis (P = .107) and effusion (P = .102) dropped out as nonsignificant in the diagnostic bone marrow edema group when compared with the control group. The odds ratio for individuals with an internal derangement showing bone marrow edema was strong (3.6:1) and highly significant (P = .000). Significant increases in risk of bone marrow edema occurred with disc displacement without reduction and osteoarthrosis (9.2:1) (P = .000) and disc displacement without reduction and effusion (6.4:1) (P = .002). CONCLUSIONS: The results suggest that the MR imaging findings for TMJ bone marrow edema are related to those of internal derangement, osteoarthrosis, and effusion. However, the data re-emphasize the aspect that internal derangement, osteoarthrosis, and effusion may not be regarded as the unique and dominant factors in defining TMJ bone marrow edema instances.     

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.     

The relationship between bone marrow edema and bone changes in the mandibular condyle: A longitudinal study with MR imaging

PurposeDecreased signal intensity on T1- or proton-density weighted magnetic resonance imaging (MRI) and increased signal intensity on T2-weighted MRI in the bone marrow space are thought to reflect bone marrow edema (BME). The purpose of this study was to determine whether condyle BME is associated with condyle bone changes.MethodsThe subjects were 57 patients [65 temporomandibular joints (TMJs)] with TMJ disorders showing condyle BME on initial MRI. Condyle bone changes were compared between TMJs that showed a persistent BME pattern (group P, 43 TMJs in 40 patients) and those that showed normal bone marrow signals, indicating disappearance of BME (group D, 21 TMJs in 22 patients) on follow-up MRI.Results(1) In TMJs with a condyle with a normal shape on initial MRI, condyle bone changes were present in 53.9% of TMJs in group P in follow-up MRI, whereas the normally shaped condyle remained in all TMJs in group D. (2) In TMJs with condyle erosion on initial MRI, condyle erosion was also present in 35.7% of TMJs in group P in follow-up MRI, but had disappeared in all TMJs in group D. (3) In TMJs with condyle osteophytes on initial MRI, erosion was present in 22.2% of TMJs in group P, whereas osteophytes remained in all TMJs in group D.ConclusionsThe longitudinal study showed that condyle BME is associated with condyle bone changes and may cause condyle erosion.     

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。     

MR evidence of characteristics in symptomatic osteoarthritis of the temporomandibular joint: increased signal intensity ratio on proton density-weighted images of bone marrow in the mandibular condyle

The purpose of this study was to clarify the presence of pain and a correlation between pain and characteristics of signal intensity of mandibular bone marrow in temporomandibular joints (TMJ) with osteoarthritis (OA). A total of 196 joints in 98 patients with TMJ disorders were examined using magnetic resonance imaging (MRI). A pain score and signal intensity on mandibular bone marrow were analyzed in the TMJ with OA. TMJ with OA showed a higher degree of pain compared to those without (p < 0.05). During opening, the joints in the higher signal intensity group showed a significantly higher degree of pain compared to the joints in the lower signal intensity group in those with OA on proton density weighted images (p < 0.05). It was concluded that TMJ with osteoarthritis is related to pain and that a symptomatic osteoarthritic TMJ can accompany bone marrow changes in the condyle, showing an increased signal on proton density weighted images.     

Transitional joint effusion in the mandibular prognathic surgery patient: intraoral vertical ramus osteotomy versus sagittal split ramus osteotomy.

PURPOSE: The purpose of this study was to examine the cause of joint effusion (JE) appearing postoperatively in the temporomandibular joint (TMJ) of patients with mandibular prognathism on T2-weighted magnetic resonance (MR) images. PATIENTS AND METHODS: MR imaging was performed before and after surgery in 30 TMJs of 15 subjects with mandibular prognathism who underwent intraoral vertical ramus osteotomy (IVRO) and in 20 TMJs of 10 subjects with mandibular prognathism who underwent sagittal split ramus osteotomy (SSRO). The preoperative MR imaging was performed 1 month before surgery, and postoperative MR imaging was performed during maxillomandibular fixation. RESULTS: Preoperatively, none of SSRO and IVRO groups had JE. Postoperatively, 12 TMJs (40%) of the IVRO group and only 1 TMJ (5%) of the SSRO group had JE. As for the TMJs in the IVRO group, on MR imaging, the degree of downward movement of the condyle after surgery was larger in TMJs with JE (3.8 +/- 2.3 mm) than in TMJs without JE (1.8 +/- 1.6 mm). JE diminished within about 4 months after removal of the maxillomandibular fixation. CONCLUSION: JE appearing postoperatively in the TMJ of patients with mandibular prognathism might be relation to the degree of downward movement of the condyle.     

Magnetic resonance imaging of the TMJ disc in asymptomatic volunteers

Forty-two temporomandibular joints (TMJs) in 21 asymptomatic volunteers were visualized by magnetic resonance imaging (MRI). The subjects, 12 males and nine females, were between 23 and 43 years of age and had no history of TMJ pain, joint noise, limited opening, or previous treatment for TMJ disorder. A cephalometric head-holder was designed to position the TMJ in an accurate and reproducible manner and multisection parasagittal images were obtained perpendicular to the longitudinal axis of the condyle. MR images depicted anterior disc position in 32% of the asymptomatic joints (8/24 males, 5/18 females). Anterior disc position in asymptomatic subjects may be a predisposing factor to TMJ dysfunction or simply an anatomic variant whose prevalence must be considered when evaluating TMJ dysfunction.     

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.     

Magnetic resonance evidence of joint effusion of the temporomandibular joint after fractures of the mandibular condyle: a preliminary report

To investigate the clinical significance of magnetic resonance (MR) evidence of joint effusion of the temporomandibular joint after mandibular condylar fractures, magnetic resonance imaging (MRI) was performed on 18 joints in 15 patients with either unilateral or bilateral mandibular condylar fractures using a 1.5 Tesla MRI scanner (Signa, General Electric, Milwaukee, WI). MR evidence of joint effusion was evaluated and compared with the types and the positions of the fractures. MR evidence of joint effusion was observed in 11 of 18 TMJs, which was 61% of the condylar fractures. It appeared more frequently after fractures with dislocation than those without dislocation (p < 0.05). In addition, MR evidence of effusion appeared more frequently in TMJs after high condylar fractures (head to upper neck) than low condylar fractures (lower neck to subcondylar) (p < 0.05). These findings indicate that MR evidence of joint effusion may serve as a marker for the detection of severe intra-articular damage to the TMJ after mandibular condyle fractures.     

Variability of disk position in asymptomatic volunteers and patients with internal derangements of the TMJ

This study determined the variability of temporomandibular joint (TMJ) disk position in medial, central, and lateral aspects of the joint using magnetic resonance imaging (MRI). Subjects had clinical evidence of reciprocal TMJ clicking (N = 123) or restricted mandibular motion (N = 52). Eighty-nine asymptomatic volunteers provided a control group. Disk position was quantified on MRI by measuring the angle formed by a line through the middle of the condyle and perpendicular to the Frankfort plane and a line through the same midpoint of the condyle and tangential to the posterior-most aspect of the disk. The disk position in asymptomatic TMJs varied considerably with a tendency toward farther anterior placement in more lateral images. In 47 TMJs from a total of 52 TMJs (90%), restricted mobility was associated with anterior disk displacement (ADD) without reduction. The disk position demonstrated a mean displacement of 77 degrees without significant differences at the medial and lateral aspects of the condyle. One hundred TMJs from a total of 123 TMJs (81%) with reciprocal clicking demonstrated ADD with reduction. Tomograms revealed larger lateral displacements or rotational displacements in these joints, whereas medial images frequently showed similar ranges of disk positions as compared with asymptomatic TMJs. The results suggest that disk positions of up to +15 degrees on medial tomograms and +30 degrees on lateral tomograms should be regarded as normal variations. Furthermore, multisection analysis of all parasagittal images improved the separation between disk displacement and asymptomatic TMJs.     

Evaluating the correlation between the lateral pterygoid muscle attachment type and internal derangement of the temporomandibular joint with an emphasis on MR imaging findings

ObjectivesDisc displacement is accepted as one of major findings in temporomandibular disorders. Correlation between lateral pterygoid muscle (LPM) attachment type to the disc–condyle complex and TMJ dysfunction has rarely been discussed and still not clarified. The purpose of this study was to assess the prevalence LPM attachment type to the disc–condyle complex, and to investigate whether these attachment types are linked to MR imaging findings of ID and TMJ dysfunction in a Turkish population.Study designNinety-eight TMJs in 49 patients (32 males, 17 females, mean age = 36 years) with one of either: TMJ clicking, TMJ locking, restricted movement of the jaw, or pain in the TMJ region, were included. According to the clinical findings and data obtained from MRI examinations, TMJs dysfunctions were classified. LPM attachments to the condyle–disc complex were categorized into three different types. Correlation between TMJ dysfunction and LPM attachments to the condyle–disc complex was evaluated.ResultsOf 98 TMJs in 49 patients (32 males, 17 females, mean age = 36 years), 47 TMJ’s (%48) were evaluated as normal, 35 (%35.7) had a disc displacement with reduction and 16 (%16.3) TMJ had a disc displacement without reduction. Arthritis was seen in 49 TMJ’s (%50). LPM attachments to the condyle–disc complex were as follows: Type I (29.6%), Type II (40.8%), and Type III (29.6%). There was no statistically significant difference between the type of muscle attachment and the presence or absence of disc displacement (p = 0.481), disc degeneration (p = 0.752), articular surface degeneration (p = 0.117).ConclusionsThere was no statistically significant correlation between the LPM attachment types and TMJ abnormalities.     

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.