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.     

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.     

Medical Managed Care for Temporomandibular Disorders and Orofacial Pain

Abstract

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.     

Relationship between temporomandibular joint pain and magnetic resonance imaging findings in patients with temporomandibular joint disorders

The purpose of this study was to evaluate abnormal magnetic resonance imaging (MRI) findings related to temporomandibular joint (TMJ) pain. This study included 245 joints of 152 patients with temporomandibular disorders with anterior disc displacement; of these, 129 joints had joint pain whereas 116 joints had no joint pain. MRI was used to evaluate the reduction of anterior disc displacement, joint effusion, mandible condylar morphology, bone marrow oedema of the mandibular condyle, and signal intensity of the posterior disc attachment (PDA) on fat-suppressed T2-weighted images. The odds ratio (OR) for each MRI variable for the pain group versus the no pain group was computed using logistic regression analysis. Univariate logistic regression analysis showed significant correlations between TMJ pain and all MRI findings. Multivariate logistic regression analysis showed significant correlations with joint effusion (P = 0.03, OR 2.21), bone marrow oedema (P < 0.001, OR 11.75), and signal intensity of the PDA (P < 0.001, OR 6.21). These results suggest that bone marrow oedema, high signal intensity of the PDA on fat-suppressed T2-weighted images, and joint effusion, in descending order of influence, are factors related to TMJ 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.     

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

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.     

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.     

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.     

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.     

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.     

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.     

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.     

Magnetic resonance imaging of the temporomandibular joint in the rat compared with low-powered light microscopy

Objective

High magnetic field magnetic resonance imaging (MRI) was applied to the temporomandibular joint (TMJ) in the rat. The purpose of this study was the depiction of the internal structure of the TMJ, including the articular disc, articular cartilage, and the upper and lower joint cavities. We also proposed MRI settings and slices suitable for imaging the TMJ in the rat.

Methods

Temporomandibular joints from one female and eight male Sprague Dawley rats (5–8 weeks old) and four male Wistar–Hamamatsu rats (7–8 weeks old) were used. Using scout images, the horizontal plane was defined as being parallel to the body of the basisphenoid bone underneath the base of the brain. The coronal plane was defined as a slice vertical to the horizontal plane and vertical to the longitudinal fissure of the cerebrum. The sagittal plane was defined as a slice vertical to the horizontal plane and parallel to the longitudinal fissure of the cerebrum.

Results

T₁-weighted MR images with a spatial resolution of 75 μm were obtained for 5 min. The temporal bone and mandibular condyle were depicted as lower signal intensity images and the articular disc was depicted as an intermediate signal intensity image. In accordance with Gd-DTPA-enhanced MR or T₂-weighted MR images, the articular disc, articular cartilage, and the upper and lower joint cavities could be assigned clearly.

Conclusion

These MRI findings closely agreed with those observed with haematoxylin–eosin staining under light microscopy, suggesting that MRI is a useful method for analyzing the complex structure of the TMJ in the rat.     

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。     

Comparison of the clinical outcomes of patients having sounds in the temporomandibular joint with skeletal mandibular deformities treated by vertico-sagittal ramus osteotomy or vertical ramus osteotomy

OBJECTIVE: This article describes the effects of the intraoral vertico-sagittal ramus osteotomy (IVSRO) procedure on the jaw of patients with temporomandibular joint (TMJ) disorders. STUDY DESIGN: IVSRO was performed on 15 patients (30 sides) who had mandibular protrusion or asymmetry with TMJ dysfunction. IVRO was performed on another 15 patients (30 sides). All of the 30 patients had sounds in the TMJ uni- or bilaterally. The relative positions of the condyle and disc and the range of motion of the condyles were determined by magnetic resonance imaging (MRI) before and 12 months after the operations. RESULTS: Sounds such as clicking improved in 92% (24/26) of the joints in the IVSRO group, and in 83% (20/24) of the joints in the IVRO group 12 months after the operation. The positional relationship between the condyle and disc on the MR images improved in 82% (9/11) of the joints with reduction of the anterior disc displacement; in 60% (3/5) of the joints without reduction of the anterior disc displacement in the IVSRO group; in 75% (9/12) of the joints with reduction of the anterior disc displacement; and in 40% (2/5) of the joints without reduction of the anterior disc displacement in the IVRO group. Immediately after the operation, the condyle was displaced anterio-inferiorly in all joints in both groups, but gradually returned to close to the preoperative position. There were no significant differences between the 2 groups regarding the extent of shift of the condylar head at 2 weeks and 12 months after the operation. CONCLUSION: The clinical outcomes of the IVSRO procedure are similar to those of the IVRO procedure. Therefore, IVSRO may be a suitable procedure for patients having TMJ dysfunction with skeletal mandibular deformities, particularly when an IVRO is unsuitable.     

Advantages of intraoral verticosagittal ramus osteotomy in skeletofacial deformity patients with temporomandibular joint disorders.

PURPOSE: This preliminary study was performed to clarify the usefulness of intraoral verticosagittal ramus osteotomy (IVSRO) in patients with temporomandibular joint (TMJ) disorders. PATIENTS AND METHODS: We examined 34 sides in 19 consecutive patients with dentofacial deformities with TMJ dysfunction undergoing IVSRO. Preoperatively, 15 patients had TMJ sounds bilaterally and 4 had sounds unilaterally. Five sides in 3 patients had pain in the TMJ, and 4 sides in 3 patients had masticatory muscle pain. The TMJ symptoms, including TMJ sounds, pain in the TMJ, and masticatory muscle pain in each patient, were assessed clinically before and approximately 12 months after IVSRO. Magnetic resonance imaging was also performed to determine joint status, including determination of the positions of the condyle and disc. RESULTS: The symptoms of the TMJ after 12 months of orthodontic treatment showed marked improvements, with the disappearance of the TMJ sounds in 94% of the sides examined. Pain in the TMJ improved in 4 of 5 sides, and pain of the masticatory muscle improved in 3 of 4 sides. With regard to the relative positions of the condyle and disc on magnetic resonance imaging, 6 of 8 joints and 5 of 7 joints showed improvement in anterior disc displacement with and without reduction, respectively. The direction and mean amount of movement in the distal segment were 8 mm in setback, 4 mm in advance, and 5 mm counterclockwise. CONCLUSION: IVSRO is potentially as useful for the treatment of TMJ disorders in orthognathic surgery patients as is intraoral vertical ramus osteotomy, and IVSRO can be used selectively in cases in which intraoral vertical ramus osteotomy is contraindicated.     

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.     

Arthroscopic eminoplasty for habitual dislocation of the temporomandibular joint: preliminary study.

A unique surgical technique, arthroscopic eminoplasty was undertaken in 16 joints of 11 patients with habitual dislocation of the temporomandibular joint (TMJ). There were 10 joints with subluxation and 6 joints with complete dislocation in 4 male and 7 female patients with a mean age of 33 +/- 20 years. The procedure consisted of conventional diagnostic arthroscopy, followed by shaving of approximately 3 to 5 mm in height of the articular eminence with an electric motorized shaver with bone files, depending on the bone thickness as detected by preoperative imaging. The arthroscopic eminoplasty was accomplished without any peri- or postoperative complication. During the postoperative follow-up period of 19 months on average (6-36 months), all patients were free of dislocation of the TMJ, except for one joint. The patients could open their mouth 42 +/- 6 mm without arthralgia 2 weeks after surgery, and finally 47 +/- 7 mm without any subjective symptom but small joint noises (clicking or crepitus) in 10 joints. On postoperative radiographs only minor changes of the mandibular condyle were apparent in four joints. Arthroscopic eminoplasty might become a significant procedure for habitual dislocation of the TMJ and seems to produce results comparable to open arthrotomy. Further study will be required to assess this method as an acceptable modality in the future.