Thickening of the glenoid fossa in osteoarthritis of the temporomandibular joint. An autopsy study

Morphometric evaluation of the temporomandibular joint on cone-beam computed tomography

INTRODUCTION

Evaluation of the temporomandibular joint (TMJ) pathologies with cone-beam computed tomography (CBCT) provides essential information about the bone structures of the TMJ. It is important to know the normal reference range when defining these pathologies. The aim of this study is to examine the morphometric and morphologic analyses of the bone structures of TMJ on the CBCT images in detail according to age, gender, and joint side.

MATERIAL AND METHODS

A total of 35 parameters related to the condylar process, articular tubercle, mandibular fossa, ramus of mandible, and joint space were examined on the CBCT images. These parameters were compared with the joint sides and gender, and correlated with age.

RESULTS

Thirty-five parameters were evaluated. A statistically significant difference was found between genders in 22 parameters and joint sides in 6 parameters. When the correlation of parameters with age was examined; it was found that there was a very weak positive relationship in nine parameters, a weak positive relationship in one parameter, and a very weak relationship in the negative direction in two parameters.

CONCLUSION

In this study, the condylar process, articular tubercle, mandibular fossa, ramus of mandible, and joint spaces, which are usually examined separately in the literature, were examined, and the normal reference range was determined for all these parameters. We think that these normal reference ranges will be useful for researchers interested in TMJ pathologies.

Morphology of the Temporomandibular Joints Regarding the Presence of Osteoarthritic Changes

(1) Osteoarthritis, the most common disease of the temporomandibular joints (TMJs), is diagnosed by clinical and radiographic examination. Cone beam computed tomography (CBCT) is a method of choice for the imaging of osteoarthritic changes. The objective was to compare the morphology of the TMJs in CBCT images regarding the number of the osteoarthritic changes diagnosed in the area of the condyle. (2) A total of 105 patients participated in the study; their 210 TMJs were allocated into one of three groups regarding the number of diagnosed osteoarthritic changes: 1 (none or 1 type), 2 (2 types), 3 (3 or more types). The morphology of the TMJ was examined for each TMJ in the CBCT images. Statistical analysis was performed with STATISTICA version 12.0. The statistical significance level was p = 0.05 for all the measurements included. (3) The articular surface flattening was the most common type of the osteoarthritic changes (90%). The condylar A-P dimension differed significantly among the groups (p = 0.0001). The bigger the number of osteoarthritic changes diagnosed in one joint, the smaller the condylar A-P dimension that was observed. (4) The temporomandibular joints’ osteoarthritic changes occur very often, even among asymptomatic patients. The increased number of osteoarthritic changes seems to have an impact on the condylar anteroposterior dimension.

Comparison between Glenoid Fossa Roof Thickness in TMD and non-TMD Patients, a CBCT Study

Statement of the Problem

Various pathologic conditions can affect the thickness of the roof of glenoid fossa (RGF). The relationship between the RGF thickness and temporomandibular joint disorder (TMD) is not explicitly investigated. Considering the changes in RGF thickness, as a radiographic sign for TMD diagnosis, the phenomenon may necessitate specific treatment and may influence the treatment course and results.

Purpose

This research was designed to examine the relationship between TMD and RGF thickness changes compared to non-TMD group.

Materials and Method

In this cross sectional analytic research CBCT images of 70 TMD patients (140 joints) and 70 non-TMD individuals (140 joints) as control group were evaluated for thickness of RGF and presence of discontinuity in RGF. The distance between superior and inferior cortex of glenoid fossa was measured as RGF thickness. Inability to follow the course of cortex in any given image was considered as discontinuity. T-test, Chi-square and odds ratio (OR) were used for statistical analysis. In this study, p< 0.05 was considered meaningful.

Results

The mean thickness of RGF in our non-TMD samples was 1.12 mm. RGF thickness was significantly increased in TMD patients compared non-TMD group (p= 0.00). This value was also greater in males. On the other hand, TMD patient showed a higher incidence of discontinuity in RGF, in comparison with non-TMD patients (p= 0.006).

Conclusion

The increased thickness of RGF can be considered as a sign of TMD, which may help in diagnosis of TMD. It seems that there is a direct relationship between TMD and discontinuity of RGF.

Zygomatic Air Cell Defect - Magnetic Resonance Imaging of the Temporomandibular Joint Compared with Panoramic Radiographs

SUMMARY – The aim of the study was to analyze zygomatic air cell defect (ZACD) incidence using magnetic resonance imaging (MRI) and validity of panoramic radiograph as a comparative method of ZACD diagnostics. The connection between ZACD incidence, age, left/right temporomandibular joint (TMJ) and comorbidity with diagnosis of TMJ disorder was analyzed. Panoramic radiographs and MRIs of 140 TMJs of 70 consecutive patients with previously confirmed TMJ diagnosis were compared in the study. A grading system (4-point scale from ‘0’ for absence to ‘3’ for most extended pneumatization) was used to determine low signal on MRIs as pneumatization of temporal bone. ZACD was diagnosed in 22 joints of 15 patients (incidence, 20.4%), with seven patients having bilateral appearance. In the joints of nine patients, ZACD was identified as extensive according to the grading scale. The validity of ZACD findings on panoramic radiographs compared with MRI findings yielded 0.45 sensitivity and 0.98 specificity. There was no relation (p>0.05) between comorbidity of ZACD and TMJ disorder, either by age or side of the body. More prevalent ZACD in our MRI analysis than in other researches based on panoramic radiographs could be explained by the expected superimposed osseous structures in the area of articular eminence.

Articular eminence inclination, height, and condyle morphology on cone beam computed tomography

Aim. The aim of the present study was to examine the relationship between articular eminence inclination, height, and thickness of the roof of the glenoid fossa (RGF) according to age and gender and to assess condyle morphology including incidental findings of osseous characteristics associated with osteoarthritis (OA) of the temporomandibular joint (TMJ) using cone beam computed tomography (CBCT). Materials and Methods. CBCT images of 105 patients were evaluated retrospectively. For articular eminence inclination and height, axial views on which the condylar processes were seen with their widest mediolateral extent being used as a reference view for secondary reconstruction. Condyle morphology was categorized both in the sagittal and coronal plane. Results. The mean values of eminence inclination and height of males were higher than those of females (P < 0.05). There were significant differences in the RGF thickness in relation to sagittal condyle morphology. Among the group of OA, the mean value of the RGF thickness for “OA-osteophyte” group was the highest (1.59 mm), whereas the lowest RGF values were seen in the “OA-flattening.” Conclusion. The sagittal osteoarthritic changes may have an effect on RGF thickness by mechanical stimulation and changed stress distribution. Gender has a significant effect on eminence height (Eh) and inclination.

Relationship between the thickness of the roof of glenoid fossa, condyle morphology and remaining teeth in asymptomatic European patients based on cone beam CT data sets

OBJECTIVES

The aim of this study was to examine the relationship between the roof of the glenoid fossa (RGF) thickness and condyle morphology and the influence of the number of remaining teeth and age.

METHODS

Cone beam CT data sets from 77 asymptomatic European patients were analysed retrospectively in this study. The thinnest area of RGF was identified among the sagittal and coronal slices on a computer screen; distance measurement software was used to measure the thickness. Moreover, we applied a free digital imaging and communications in medicine viewer for classification of condyle head type. It was also used to analyse any relation between RGF thickness and the number of remaining teeth. We performed a correlation analysis for RGF, age and missing teeth. Finally, we investigated combining sagittal condyle morphological characterization with coronal condyle morphology in relation to the number of joints and RGF thickness.

RESULTS

The Kruskal-Wallis test revealed no significant differences in RGF thickness among any of the coronal condyle head morphology groups (p > 0.05). There were significant differences in the thinnest part of RGF in relation to the sagittal plane for condyle morphological characterization, because we observed increased RGF thickness in joints with osteoarthritis features (p < 0.05). There is a non-significant correlation between the thinnest part of the RGF and the number of remaining teeth (p > 0.05).

CONCLUSIONS

We found that the RGF thickness is unaffected by the coronal condyle head morphology and the number of remaining teeth. Osteoarthritic changes (sagittal condyle morphology) have an effect on RGF.

MRI analysis of the relationship between bone changes in the temporomandibular joint and articular disc position in symptomatic patients

OBJECTIVES

The aim of this study was to investigate bone changes in the condyle, articular eminence and glenoid fossa in relation to the position of the articular disc.

METHODS

148 temporomandibular joints (TMJs) of 74 symptomatic patients who underwent MRI were evaluated. The position of the disc was classified as either normal (N), disc displacement with reduction (DDwR), disc displacement without reduction (DDwoR) and posterior displacement (PD). Bone changes were investigated in the condyle and temporal components of the TMJ and classified as osteophytosis, sclerosis or erosion.

RESULTS

There were no bone changes in the glenoid fossa of the temporal bone. Of the total number of TMJs studied, 94 (63.5%) were N, 34 (23%) presented DDwoR, 19 (12.8%) presented DDwR and 1 (0.7%) presented PD. The bone changes in the condyle and posterior aspect of the articular eminence were associated with the position of the disc. The bone changes in the anterior aspect of the articular eminence were not associated with the position of the disc.

CONCLUSION

In cases of DDwoR, bone changes in the condyles were more common. The combination of erosion and osteophytosis in the condyle and the bone changes of the posterior aspect of the articular eminence were associated with disc position.

Evaluation of the severity of temporomandibular joint osteoarthritic changes related to age using cone beam computed tomography

OBJECTIVES

The aim of this study is to evaluate and correlate with age the severity of temporomandibular joint (TMJ) osteoarthritic changes using cone beam CT (CBCT).

METHODS

The images of 71 patients with findings of degenerative arthritis were retrieved from the computer data base. All patients had been examined with CBCT (NewTom 9000 QR-DVT). Left and right TMJs were evaluated independently for each patient. TMJ evaluation included: (a) bony changes of the condyle (flattening, erosion, sclerosis, osteophytes, resorption); (b) joint space (normal, increased, reduced, bony contact between the condyle and the mandibular fossa); and (c) bony changes of mandibular fossa (normal, sclerosis, erosion, resorption). The radiographic findings were statistically analysed.

RESULTS

Significant differences in the mean age were found: (a) between absent and moderate erosion (P = 0.019), as well as between absent and extensive erosion (P = 0.048); (b) between absent and extensive formation of osteophyte (P = 0.003), as well as between slight and extensive formation of osteophyte (P = 0.025); (c) between normal joint space and bony contact (P = 0.0002), as well as between reduced joint space and bony contact (P = 0.001).

CONCLUSIONS

Degenerative arthritis is an age-related disease. The progression and severity of osseous changes in the condylar head and mandibular fossa are increased with age. In older age groups, patients are expected to have more frequent and severe progressive degenerative bony changes due to the development of TMJ osteoarthritis than patients in younger age groups.

Relationship between patient characteristics, mandibular head morphology and thickness of the roof of the glenoid fossa in symptomatic temporomandibular joints

OBJECTIVE

The purpose of this clinical study was to investigate the minimum thickness of the roof of the glenoid fossa (RGF) of grossly normal temporomandibular joints (TMJ) and to correlate this with patient gender, age and the morphological classification of the mandibular head.

METHODS

The study was performed on 191 TMJs from 109 patients (25 male and 84 female, age range 3-79 years, mean age 28.1 years) who visited Nihon University Dental Hospital, Japan with suspected TMJ disorders. The patients underwent cone beam computed tomography (3DX CT) to enable observation of the morphological features of the mandibular head. The minimum thickness of the RGF was measured using frontal section images acquired by CT. The morphology of the mandibular heads was classified according to the method of Yale and colleagues. Mean linear measurements were used for statistical analyses of patient gender, age and mandibular head morphology.

RESULTS

The average minimum thickness of the RGF was 0.79 mm. No significant difference in thickness was found between male and female patients. In addition, no differences were recorded as a result of variation in age or mandibular head morphology.

CONCLUSIONS

These results indicate that RGF thickness is not significantly correlated with gender, age, or mandibular head morphology, at least in this cohort of patients.

The thickness of the roof of the glenoid fossa in the temporomandibular joint: relationship to the MRI findings

OBJECTIVES

The purpose of this study was to clarify the relationship between the thickness of the roof of the glenoid fossa (RGF) and magnetic resonance imaging (MRI) findings of temporomandibular joint (TMJ) disorders (TMDs).

METHODS

Eighty-seven patients with symptoms and indications of TMD in one or both TMJs were referred for MRI. Cone-beam CT (3DX) was used to measure the thickness of the RGF at its thinnest point. Linear measurements were made three times on the monitor by three separate investigators and the mean values obtained were used for the statistical analyses.

RESULTS

The joints were categorised as normal (70 joints), anterior disc displacement with reduction (ADWR; 53 joints) or anterior disc displacement without reduction (ADWOR; 51 joints). The joint disorders were also categorised into the following subgroups: with osteoarthritis (OA) (21 joints), without OA (153 joints), with disc deformation (33 joints), without disc deformation (141 joints), with joint effusion (JE) (61 joints) and without JE (113 joints). The average minimum thickness of the RGF was 0.85 mm for normal joints, 0.90 mm with ADWR, 0.93 mm with ADWOR, 0.99 mm with OA, 0.87 mm without OA, 0.87 mm with disc deformation and 0.89 mm without disc deformation. There was no significant difference between these figures. There was a significant difference in the thickness of the RGF with (0.97 mm) and without (0.84 mm) JE.

CONCLUSIONS

These results suggest that RGF thickness is influenced by JE, but is unaffected by disc position and configuration.

Evaluation of the usefulness of the limited cone-beam CT (3DX) in the assessment of the thickness of the roof of the glenoid fossa of the temporomandibular joint

OBJECTIVES

The purpose of this study was to evaluate the usefulness of the limited cone-beam X-ray CT (3DX) (Morita Co., Japan) in measuring the thickness of the roof of the glenoid fossa (RGF) of the temporomandibular joint (TMJ).

MATERIALS AND METHODS

Twenty-one TMJs removed at autopsy from 21 cadavers were investigated macroscopically using dissection and 3DX imaging. A Digimatic Outside Micrometer and a 3DX-image tool were used to measure the minimum thickness of the RGF. Multiple measurements were made to identify the thinnest area. Once the thinnest areas had been identified, three linear measurements were made and the average value was used for statistical analysis.

RESULTS

The average macroscopic examination measurement was 1.37 mm (range 0.55-3.6 mm) and the average 3DX image measurement was 1.22 mm (range: 0.51-3.0 mm). There was no significant difference between these two groups using the Mann-Whitney U-test (P < 0.05). The Spearman's correlation coefficient by rank between these two groups was r = 0.93(P < 0.001).

CONCLUSION

These results suggest that bone thickness measurements of the RGF by 3DX imaging was effective.

Thickness of the roof of the glenoid fossa and condylar bone change: a CT study

OBJECTIVES

The aim of this study is to investigate the relationship between the thickness of the roof of the glenoid fossa in the temporomandibular joint (TMJ) and the existence and types of condylar bone change.

MATERIALS AND METHODS

Helical CT was used to measure the thickness of the roof of the glenoid fossa at its thinnest part in 37 orthodontic patients with temporomandibular disorders. Condylar bone changes were classified into four types: no bone change (24 joints); flattening (19 joints); osteophyte formation (13 joints); and erosion (18 joints).

RESULTS

The roof of the glenoid fossa was significantly thicker in joints with bone change than in joints with no bone change (Mann-Whitney U-test, P<0.05). There was also a significant difference in relation to the type of condylar bone change: the thickness of the roof of the glenoid fossa in the erosion group was significantly greater than in the no bone change (P<0.01), flattening (P<0.05) and osteophyte formation (P<0.05) groups (Kruskal-Wallis and Games-Howell tests).

CONCLUSION

Compensative bone formation in the roof of the glenoid fossa might help to withstand the increased stress in the TMJ accompanying condylar bone change, especially erosion.