Relationship between increased horizontal condylar angle and resorption of the posterosuperior region of the lateral pole of the mandibular condyle in temporomandibular joint internal derangement

OBJECTIVES: The purpose of this study was to analyse the relationship between horizontal condylar angle, temporomandibular joint (TMJ) disk displacement and resorption of the lateral pole of the mandibular condyle (RLC). METHODS: The study comprised 162 TMJs (81 patients). Disk displacement was assessed and the horizontal angle of the condyle was measured on axial MR images. RLC was assessed on oblique frontal projection plain radiographs. RESULTS: The horizontal angle was increased in joints with disk displacement without reduction (one-factor ANOVA and Scheffe's f-test, P<0.05). The angle was greater in joints with RLC than in the joints without RLC (Student's t-test, P<0.05). CONCLUSIONS: Results suggest that the horizontal condylar angle is increased in joints with disk displacement without reduction. A possible relationship exists between RLC and increased horizontal condylar angle.     

Longitudinal MRI follow-up of non-reducible posterior disc displacement accompanied by bone marrow oedema in the mandibular condyle

Serial MRI was used to examine the long-term course of posterior disc displacement (PDD) after non-surgical treatment. Serial MRI was performed on a 63-year-old woman with PDD accompanied by bone marrow oedema (BME) in the mandibular condyle. The patient had joint pain of the right temporomandibular joint (TMJ) and posterior open bite immediately after manual reduction of TMJ dislocation. Initial MRI of the right TMJ showed non-reducible PDD and subchondral BME. The patient underwent non-surgical treatment, and symptoms improved. The first follow-up MRI after 5 months showed non-reducible PDD, expansion of BME and erosion of the mandibular condyle. 1 year and 8 months after the initial examination the patient was asymptomatic, and a second follow-up MRI showed resolution of both BME and erosion, despite the persistence of non-reducible PDD. The MRI findings suggest that BME in the mandibular condyle complicating PDD is a reversible change, and may contribute to joint pain. This case report complements previous observations of the longitudinal course of PDD after non-surgical treatment.     

Magnetic resonance characteristics of temporomandibular joint disc displacement in elderly patients

Objectives

The purpose of this study was to evaluate the MR characteristics of temporomandibular joint (TMJ) disc displacement in elderly patients.

Methods

Of the MR images of 1660 TMJs in 847 patients with disc displacement who underwent MRI for suspected temporomandibular disorders, 301 TMJs in 154 patients aged over 50 years were studied as an elderly group. These MR images of the elderly group were compared with those of a control group (1359 TMJs in 693 patients aged under 51 years) concerning disc displacement with or without reduction, joint effusion and osteoarthrosis.

Results

The incidence of disc displacement with osteoarthrosis was significantly different between the elderly (41.9%) and the control (19.8%) groups (p = 0.000). Logistic multivariate regression analysis demonstrated that the osteoarthrosis was a significant variable (odds ratio = 2.94, p = 0.000).

Conclusions

This study suggests that MR characteristics of TMJ disc displacement in elderly patients includes osteoarthrosis.     

Accuracy of quantification of mandibular condyle displacement in digitally subtracted linear tomograms.

Using a TMJ skeletal phantom, we assessed validity and reliability of digitally subtracted linear tomographic images to quantify condylar position changes. Horizontally corrected frontal and lateral tomographic images were made with the condyle in a 'centred' position and displaced by 1, 2 and 3 mm increments in two of three directions (inferior, and posterior, or lateral). Film images were sequentially subtracted and then randomized so that observers were blinded to the amount and direction of condylar movement. Averages of three measurements of the dark bands representing condylar shifts were made using a digitizing tablet. The study utilized a nested design where the series of film images was subtracted twice and each subtraction was read twice by two examiners. We repeated the study with a second series of films treated in an identical manner. Average differences from expected values were similar for frontal and lateral techniques and all directions and increments of displacement. Typical average difference for any increment was less than 0.1 mm. Standard deviations in measures were similar across techniques and increments and were typically less than 0.1 mm. Significant variation in the absolute value of differences between measured and expected values by direction of condylar displacement was attributed to greater accuracy of registration on the vertical axis for frontal images. A significant source of variation in the study design element 'film set' was attributed to errors in repositioning the phantom.(ABSTRACT TRUNCATED AT 250 WORDS)     

Correlation between temporomandibular joint morphology and disc displacement by MRI

Objectives:

The aim was to evaluate the morphology of the temporomandibular joint''s (TMJs) disc and condyle as well as its correlation with disc displacement, using MRI.

Methods:

190 TMJs were retrospectively analysed. The condyle morphology of each TMJ was evaluated by two observers using both axial and coronal views, as were their disc morphology and displacement, using sagittal view. Condyle morphology was classified as flat, convex, angled or rounded in the coronal sections and as anterior side flat/posterior side convex, biconvex, anterior side concave/posterior side convex, flat or biconcave in the axial view. Disc morphology was determined as biconcave, biplanar, biconvex, hemiconvex or folded. χ², Fisher exact and Bonferroni correction tests were used to evaluate the data. ANOVA followed by post hoc Tukey''s test was used to evaluate the interaction between age and disc displacement.

Results:

Anterior disc displacement with reduction; convex condyle morphology in the coronal view; anterior side concave/posterior side convex morphology in the axial view; and biconcave discs were found to be the most prevalent findings. An association was observed between disc morphology and disc displacement (p < 0.001). No correlation between condyle morphology and TMJ disc displacement was found (p = 0.291 for axial and p = 0.14 for coronal views).

Conclusions:

The results of this study suggest that TMJ disc morphology is associated with disc displacement.     

Alteration of the horizontal mandibular condyle size associated with temporomandibular joint internal derangement in adult females

OBJECTIVES: The purpose of this retrospective study was to analyse the relationship between horizontal size of the mandibular condyle and internal derangement (ID) of the temporomandibular joint (TMJ). METHODS: One hundred and thirty-nine joints in 88 women aged over 18 years were included in this study. The horizontal condylar size was measured in the antero-posterior and medio-lateral (ML) dimensions using axial magnetic resonance (MR) images. Radiological findings of ID were also assessed from MR imaging. RESULTS: The condyles in the joints with permanent disk displacement were smaller than those in joints without displacement in both dimensions (Fisher's protected least significant difference, P<0.05). There were statistically significant correlations between horizontal condylar size in the ML dimension and both disk morphology and radiological stage of ID (Spearman's correlation coefficient by rank, P<0.05). CONCLUSIONS: The results of this study suggest a possible relationship between horizontal condylar size and disk displacement. It is also suggested that the condyle becomes smaller in the ML dimension with advancement of ID.     

Bilateral bifid mandibular condyle associated with ankylosis of the temporomandibular joint in a 6-year-old child

Bifid mandibular condyle with ankylosis is an extremely rare condition and may arise as a developmental or traumatic defect. We report here a case of bilateral bifid mandibular condyle with ankylosis in a 6-year-old child. The patient had severe limitation of mouth opening and history of trauma 2 years ago.     

Aplasia of the mandibular condyle

A rare case of aplasia of the mandibular condyle is presented along with the tomographic findings. A 31-year-old Caucasian woman presented with a main complaint of facial asymmetry. No family history or any trauma was found. A CT study was performed and the sagittal CT view demonstrated a complete absence of the left condyle. This case of unknown aetiology was thoroughly examined and, based on clinical findings, we suggest that it could be of developmental origin.     

Secondary chondrosarcoma in the mandibular condyle

We report the case of a woman who had secondary chondrosarcoma in an osteochondroma in the left mandibular condyle, presenting as a large lobulated bone density mass in the left condyle process, to illustrate the clinical characteristics and imaging findings.     

Curvature analysis of the mandibular condyle

OBJECTIVE: To determine whether curvature analysis on high resolution CT images can be used as a tool for evaluation of mandibular condyle morphology. METHODS: Curvature analysis was performed on reconstructed oblique coronal CT images of 634 normal condyles from 317 patients (144 men and 173 women; age range 4-89 years) with inner or middle ear disease. The condyles were scanned with 1 mm collimation using helical CT. The CT images were analysed manually on a personal computer. RESULTS: The condyle CT images could be categorized into five curvature profile patterns: (1) bi-peak; (2) no peak; (3) tri-peak; (4) bi-peak with an intervening bottom above the base line (bi-peak with a col); and (5) bi-peak with an intervening negative phase. A separate evaluation using computer graphic condyle models indicated that these curvature patterns corresponded to flat (bi-peak), round (no peak), convex (bi-peak with a col), concave (bi-peak with a negative phase) and angled (tri-peak) contours of the condyle's superior surface. The curvature profiles were identical between bilateral condyles in 40% (126/317) of the patients. Gender-related differences in the incidence of the curvature profiles were also found, the bi-peak with a col profile being more frequently observed in women and the bi-peak with a negative phase profile being observed more frequently in men. CONCLUSION: Curvature analysis on CT images depicts condyle morphology effectively and may be an adjunctive tool for condyle morphometry.     

Recent developments in understanding temporomandibular joint disorders. Part 1: Bone marrow abnormalities of the mandibular condyle

Improvements in diagnostic imaging of the temporomandibular joint in the past 20 years have shown that disk displacement is the most frequent abnormality in patients with joint pain and dysfunction. The aetiology of the pain is poorly understood. Recent studies with magnetic resonance imaging have demonstrated a number of other changes in the TMJ. In this paper I review the possible significance of alterations in the condylar bone marrow and its relationship to osteonecrosis.     

Anterior disc displacement without reduction in the temporomandibular joint: MRI and associated clinical findings

To determine the value of MRI in temporomandibular joint (TMJ) disorders, the data of MRI-proven anterior disc dislocation without reduction (ADWOR) were correlated with clinical history and clinical data. MRI demonstrated degenerative bony changes and a reduced sagittal diameter of the condyle, a variable degree of disc deformation, and a thinned bilaminar zone in each of the joints with ADWOR, which clearly differed from patients with anterior disc dislocation with reduction (ADWR) (P = .01) and normal disc position (NDP) (P < .001). Of 59 patients and 83 TMJs that had been investigated in a 2-year period, as shown by MRI, 22 patients (27 TMJs) had ADWOR (32 %), 16 joints had NDP (19 %), and 40 patients had ADWR (49 %). In patients with ADWOR, the clinical history revealed pain in either of the joints and/or cervical or masticatory muscles in 25 (93%) joints. Clinical investigation revealed various abnormalities in 22 joints; five of those presented without any pathologic clinical finding. Mouth opening was unlimited in nine patients (47%), palpation of the muscles of mastication was painless in 13 patients (52%), and joint noises during mouth opening or closing were noted in 14 patients (56%). According to clinical histories, four patients were suspected to have become symptomatic only after dental treatment. ADWOR is difficult to diagnose with clinical methods alone. The indication for MRI evaluation of the TMJ should be extended for asymptomatic patients with a history of limitation in mouth opening and pathologic x-ray morphology of the condyle. Because symptoms may arise after dental treatment in these patients, aggravation of internal derangement may be avoided by careful handling.     

Bifid mandibular condyle with temporomandibular joint ankylosis: report of two cases and review of literature

Bifid mandibular condyle is an uncommon entity with a controversial etiology. It can be developmental or acquired and rarely may be associated with temporomandibular joint (TMJ) ankylosis. Although the patient may be asymptomatic, the radiologist should be aware of this entity and its clinical implications. We report two cases of BMC, one developmental and the other secondary to trauma. Both were diagnosed using computed tomography, which additionally revealed the associated ankylosis of TMJ in both the patients.     

Giant cell tumour of the mandibular condyle

The authors report a case of giant cell tumour of the mandibular condyle, which is a rare finding. This tumour, studied using the main three radiological modalities (plain radiography, CT and MRI), showed characteristic radiological features of giant cell tumour. Correspondence to: S. W. Della Sala     

One more look at the mandibular condyle

A great deal of attention has been given over the years to the development of highly specialized x-ray equipment that, in many instances, has reduced the complex nature of the radiographic procedure. However, it is impossible, and probably always will be, to design equipment that will automatically produce the proper radiographic position. This will remain a distinct function of the technologist, and the individual's skill will have great bearing on the quality of the radiograph. One need only review the literature to realize how innovative our profession has been in developing countless numbers of radiographic positions for demonstrating specific anatomical regions. Moreover, many useful radiographic positions can be found that, for various reasons, never gained the level of acceptance perhaps anticipated by their originators. Consequently, the practical value of these positions often escapes our attention. To illustrate this point, I have selected a radiographic position described some thiry years ago for visualization of the mandibular condyle. It is my intent to demonstrate the practical value of this projection, as well as that of some others not usually thought of, for radiography of the mandibular condyle.     

Changes in condylar mobility and radiographic alterations after treatment in patients with non-reducing disc displacement of the temporomandibular joint

OBJECTIVES: The purpose of this study was to examine changes in condylar mobility and morphological changes in the affected condyles after treatment in patients with non-reducing disc displacement of the temporomandibular joint (TMJ). METHODS: Changes in condylar mobility and morphological changes of the condyle were examined radiographically in 55 patients who were diagnosed as having non-reducing disc displacement of the unilateral TMJ and had received pumping with injection of sodium hyaluronate. In all patients, standardized lateral oblique transcranial radiographs and panoramic jaw tomograms were taken both at initial visit and at 12 months or more follow-up (mean 28.1 months after treatment; range 12-104 months). 42 joints in 21 persons with no current or previous TMJ symptoms served as a control. RESULTS: Clinical signs and symptoms improved after treatment in the patients. Condylar mobility significantly increased after treatment in patients (P<0.001), although it did not reach levels of the control group. Frequency of radiographic changes of the condyle significantly increased after treatment (P<0.005). In most of the patients, no or only mild changes were observed. Frequency of changes of the condyle in patients at follow-up was significantly greater than that in controls (P<0.001). CONCLUSIONS: In the patients, condylar mobility increased in the subsequent course after treatment. However, bony changes of the condyle appeared more frequently. Long term-follow-up after treatment on bony changes of the condyle seems to be necessary in patients with non-reducing disc displacement of the TMJ.     

Radiographic changes in the condyle of the temporomandibular joint in psoriatic arthritis

One hundred and ten patients with psoriatic arthritis (PA) and 100 matched control patients were examined by using orthopantomography to discover radiographic changes in the condyle of the temporomandibular joint (TMJ). Thirty-one per cent of the PA patients and 13 per cent of the control patients had radiographic changes in the condyle of the TMJ. The most common radiographic finding in PA patients was unilateral erosion of the condyle. Of the radiographic changes in the PA group, cortical erosions correlated negatively with age, whereas osteophytes correlated positively with the duration of PA.