Idiopathic condylar resorption: The current understanding in diagnosis and treatment

Changes in occlusal relationships observed using an intraoral scanner in patients with an acquired open bite: A case report

PATIENTS

This case report describes a procedure for assessing changes in occlusal relationships in patients with acquired open bites due to temporomandibular joint disease using an intraoral scanner (IOS). A digital impression was made using the IOS at the initial visit. Subsequent impressions were made every 6 months using the IOS and magnetic resonance imaging (MRI) or computed tomography (CT). Standard triangulated language (STL) image files of two digital impressions at different points in time were superimposed, including the occlusal relationship with reference to the maxillary dentition. Finally, three-dimensional (3D) changes in the occlusal relationship over time were evaluated.

DISCUSSION

In Case 1, the superimposed STL image indicated almost no evident deviation of the mandible. Therefore, an orthodontic treatment was initiated. In contrast, in cases 2 and 3, where changes in the occlusal relationship continued, secondary treatment was postponed and patients continued to be monitored periodically. In case 3, even though left condyle resorption was progressive, the degree of open bite on the right side improved after 6 months. However, the open bite continued to progress for another 6 months despite the stability of the condyle.

CONCLUSIONS

Changes in the condylar shape observed using imaging may not always reflect changes in the occlusal relationship. In addition to changes in the condyles and eminences of the temporomandibular joint (TMJ), changes in the occlusal relationships of patients with acquired open bite should be evaluated using an intraoral scanner.

Evaluation of body composition and bone mineral density in patients with and without idiopathic condylar resorption of temporomandibular disorders by dual energy X-ray absorptiometry

Background/purpose

The impact of temporomandibular joint (TMJ) osseous destruction on bone mineral density (BMD) remains unclear due to controversial findings. Besides, no previous study has explored the relationship between idiopathic condylar resorption (ICR) and body composition. This study aimed to investigate the relationship between ICR and BMD or body composition.

Materials and methods

Between July 2018 and August 2022, patients evaluated by an experienced dentist and diagnosed with temporomandibular disorders (TMDs) were referred to our center. They were recruited while they received the magnetic resonance image (MRI) examination, BMD and body composition completely. Patients were further categorized into TMDs with or without ICR groups according to MRI findings. One-way analysis of variance was used to compare the variables of BMD and body composition in the two groups.

Results

In total, 67 patients were included in the analysis, with 42 categorized as TMDs with ICR and 25 as TMDs without ICR. Patients with ICR had a significantly higher lean mass percentage and lower fat mass percentage; lower android/gynoid fat ratio, and visceral adipose tissue area than those without ICR (P < 0.05). Besides, patients above age 30 with ICR had lower Z scores (P = 0.017) compared with subjects without ICR.

Conclusion

TMDs patients with ICR show a relationship with body composition and affect the lean and fat mass distribution, especially android/gynoid fat ratio. The pathophysiological mechanism remains unclear. Further researches to investigate teeth binding, malocclusion and dietary habits are important to understand the association of ICR, BMD and body composition.

Three-dimensional analysis of the morphological changes of the craniofacial jaw and condyle in patients with idiopathic condylar resorption

In this study we aim to describe the three-dimensional analysis of condylar deformation of the temporomandibular joint (TMJ) and morphological changes of the craniofacial jaw in patients with idiopathic condylar resorption (ICR). We also compare those with a control group that is healthy and matched for age and gender. Cone-beam computed tomography (CBCT) and cephalometric radiograph (X-ray) were conducted and analysis of craniofacial measurement, condylar width, length, height, and condylar axial angle changes were done three-dimensionally using ProPlan CMF™ 3.0 software (Materialise). The craniofacial jaw measurements of the ICR patients were significantly different than the control group and the significant changes in the mandible can be seen in ICR patients according to the results of this study. The results of smaller condylar width and height in the ICR group reflect the smaller size of the condyle compared with an unaffected condyle. Also, both right and left sagittal condylar angles (p = 0.001 and p = 0.003), respectively, and axial condylar angles (p = 0.01 and p = 0.02), respectively, displayed significant differences between the two groups. In conclusion, the vertical development of the condyle decreased along with reduced measurements in the width and height of the condyle in ICR patients, and differences in the morphology of the craniofacial jaw and condylar angles were observed between study groups.

A Comparison of the Condyle and Articular Eminence in Asian Juvenile Idiopathic Osteoarthritis Patients with Unilateral and Bilateral TMJ Involvement: A Retrospective Case-Control Study

This study compared the condylar volume, length, and articular eminence (AE) characteristics of normal individuals to those with unilateral and bilateral juvenile idiopathic osteoarthritis (JOA). The 116 patients were divided into four groups: Control (n = 16), affected condyle of unilateral JOA (Aff-Uni) (n = 36), non-affected condyle of JOA (NonAff-uni) (n = 36), and bilateral JOA (Bilateral) (n = 28). The differences in condyle volume and length and AE were analyzed using ANOVA and Bonferroni post-hoc tests. The results showed that Bilateral had a significantly different condylar volume, especially in the condylar head (p < 0.01), specifically the middle, anterior, and medial parts (p < 0.05). Condylar length also differed among the groups, with differences observed between the control group and the other three groups, as well as between the bilateral group and the other three groups (p < 0.01). AE total volume differed between the control group and Aff-Uni. In the detailed comparison, Aff-Uni and NonAff-Uni were smaller than the control group in the posterior, lateral, and medial sections (p < 0.05). In conclusion, depending on the involvement of unilateral or bilateral JOA, there were differences in condylar volume and AE when compared to the normal control group. Therefore, a prognosis should be evaluated by distinguishing between patients with unilateral and bilateral JOA.

[Study of dental arch width in patients with idiopathic condylar resorption]

Objective:To investigate the relationship between idiopathic condylar resorption （ICR） and arch width disorder. Methods:Thirty-two patients with ICR and twenty patients without condylar resorption were enrolled according to the same inclusion criteria. They were divided into experimental group and control group. The experimental group was divided into unilateral ICR group and bilateral ICR group according to the affected side of condylar resorption, and then experimental group was divided into subgroups ICR Ⅰ, ICRⅡand ICR Ⅲ according to the degree of condylar resorption. Patients with no condylar resorption were used as a control group. The width of anterior, middle and posterior segments of dental arch on cone beam computed tomography（CBCT） was measured and the two groups of measured values were statistically analyzed. Results:Compared with the control group, the width of maxillary anterior, middle and posterior segments in ICR group was significantly reduced, and the difference was statistically significant（P<0.01）. But the width of mandibular segment was not significantly different from that in control group（P>0.05）. There was no significant difference in the width of anterior, middle and posterior dental arch between subgroups（P>0.05）. Conclusion:Almost all patients with ICR have malocclusion of maxillary and mandibular arch width, but there is no significant correlation between the malocclusion width and the severity of condylar resorption.

Characteristics of patients with temporomandibular joint idiopathic condylar resorption

OBJECTIVE

To investigate characteristics of temporomandibular joint (TMJ) idiopathic condylar resorption (ICR) and analyze the related factors.

METHODS

A total of 755 consecutive patients (150 with ICR and 605 with anterior disc displacement [ADD]) from July 2015 to December 2018 were recruited. A comprehensive questionnaire characterizing the multidimensional impact of the TMJ was designed. Clinical examination and radiological evaluation were also performed. The odds ratio for each variable in the ICR group versus the ADD group was computed using logistic regression analysis.

RESULTS

Multivariate logistic regression analysis showed significant correlations between mouth opening restriction, disease course, mandibular retrusion, mandibular retrusion progression, skeletal Class II profile, and overjet in ICR patients.

CONCLUSION

These results suggest that a longer ADD disease course might have a strong relationship with ICR.

Signs and Symptoms of Temporomandibular Dysfunction and Radiographic Condylar Morphology in Patients with Idiopathic Condylar Resorption

Background: Little is known about the clinical characteristics of idiopathic condylar resorption (ICR). The aim of this study was to examine the signs and symptoms of temporomandibular dysfunction (TMD) and evaluate the morphological characteristics of the condyles in patients with ICR. Methods: Sixty patients with ICR (41 in the bilateral ICR group and 19 in the unilateral ICR group) and forty-one healthy controls were examined. Signs and symptoms of TMD were described, and three-dimensional models of the condyles were measured and analyzed. Results: In total, 81.7% of ICR patients had self-reported symptoms and 78.3% of ICR patients had objective-found signs. The anteroposterior diameter, transverse diameter, height, maximal sectional area, volume of the condyles, axial angle, and the distance from the posterior point of the condyle to the Saggittal standard line were significantly smaller in the ICR condyles compared with the controls (p < 0.05). The condylar neck angle was significantly larger in the ICR condyles compared with the controls (p < 0.05). Conclusions: Most patients with ICR had signs and symptoms of TMD. The prevalence of clicking and opening−closing deviation was significantly different between the bilateral and the unilateral ICR groups. In patients with ICR, the size of the condyles decreased significantly; the condyles also rotated inward, moved forward, and inclined posteriorly.

The use of SPECT/CT to assess resorptive activity in mandibular condyles

The aim of this study was to clarify the clinical significance of bone metabolism in the mandibular condyles in determining condylar resorptive changes. Twelve condyles of patients with idiopathic condylar resorption and degenerative joint disease were analysed using ^99mTc HMDP SPECT/CT at baseline and subsequent computed tomography during the follow-up period. Twenty-two healthy condyles were enrolled as controls. After generating three-dimensional SPECT/CT images, two independent observers scored the degree of condylar uptake and measured the morphological changes in the condylar height and condylar volume. In the group with positive condylar uptake, the follow-up computed tomography showed significant decreases in condylar height (-1.69 ± 0.93 mm) and condylar volume (-12.51 ± 10.30%) when compared to healthy controls (condylar height, 0.09 ± 0.54 mm; condylar volume, -0.29 ± 4.22%) (P < 0.001). Moreover, the degree of uptake correlated with the changes in condylar height (observer 1, P = 0.012; observer 2, P = 0.039) and condylar volume (observer 1, P = 0.005; observer 2, P = 0.037). These results suggest that condylar bone metabolism is closely related to the resorptive activity. Thus, SPECT/CT would be useful in the prognostic evaluation or determination of treatment strategies for idiopathic condylar resorption and degenerative joint disease.

Chairside risk assessment for first-onset temporomandibular disorders: Result from the Orofacial Pain: Prospective Evaluation and Risk Assessment data set

BACKGROUND

Temporomandibular disorders (TMD) risk assessment is difficult in general dentistry owing to the complexity of multifactorial risk contributions and the lack of standardized education. The authors explored a health history-based chairside risk assessment.

METHODS

Secondary data analysis was performed on the Orofacial Pain: Prospective Evaluation and Risk Assessment data set. Potential demographic, systemic, and local risk contributors were conceptualized into 10 risk categories. Multivariate Cox proportional hazards modeling with backward selection was applied. Variables with P values < .05 were kept in each successive model.

RESULTS

The analysis included data from 2,737 participants. The final model indicated that people with any psychological conditions, pain disorders, sleep disorders, or orofacial symptoms were at elevated risks of developing first-onset TMD. Results of post hoc analysis showed the coexistence of conditions from multiple body systems conferred greater risk of developing TMD.

CONCLUSIONS

Coexisting conditions and symptoms from multiple body systems substantially increase the risk of developing TMD pain. Therefore, multisystem risk assessment and interprofessional collaborations are important for the prevention of TMD.

PRACTICAL IMPLICATIONS

Dentists should include psychological conditions, pain disorders, sleep disorders, and orofacial symptoms when assessing patients' risk of developing TMD pain.

Are There Mandibular Morphological Differences in the Various Facial Asymmetry Etiologies? A Tomographic Three-Dimensional Reconstruction Study

PURPOSE

Facial asymmetries (FAs) have been classified according to the mandibular morphological differences to obtain better diagnostic and treatment decisions. The purpose of the present study was to establish diagnostic differentiation among FAs using computed tomography (CT) and 3-dimensional (3D) reconstruction.

MATERIALS AND METHODS

We performed a cross-sectional study of patients with a diagnosis of FA, who had been evaluated by CT and 3D reconstruction in the same clinical center from 2015 to 2018. The following mandibular anatomic characteristics were compared between the 2 sides (deviated side vs contralateral side) and type of FA: condylar length, mandibular ramus length and width, mandibular body length, and symphysis deviation.

RESULTS

The 53 patients included 23 men and 30 women (age range, 16 to 25 years). Six categories of FA were identified: hemimandibular elongation (n = 25), hemimandibular hyperplasia (n = 2), hybrid hyperplasia (n = 3), asymmetric mandibular prognathism (n = 14), asymmetry of the glenoid fossa (n = 2), and functional laterognathism (n = 7). The condylar length and mandibular ramus width were greater in the displaced side than in the contralateral side, with differences of -2.0 ± 2.8 mm (P < .001) and -0.5 ± 1.7 mm (P = .009), respectively. The mandibular body length was greater on the contralateral side (mean difference, 2.1 ± 3.5 mm; P < .001). The symphysis deviation was 5.0 ± 3.4 mm, and those with a hybrid form presented with a greater deviation, with values greater than 10 mm, followed by those with hemimandibular elongation.

CONCLUSIONS

The evaluation of the CT images and 3D reconstructions in patients with FA provided detailed information of the mandibular structure that is useful to compare the differences between sides and to classify the entities associated with FA.

Estrogen-Mediated MicroRNA-101-3p Expression Represses Hyaluronan Synthase 2 in Synovial Fibroblasts From Idiopathic Condylar Resorption Patients

PURPOSE

Idiopathic condylar resorption (ICR) is an aggressive form of osteoarthritis that is frequently observed in adolescent female patients. We hypothesized that an estrogen-mediated pathway may contribute to ICR development.

MATERIALS AND METHODS

An enzyme-linked immunosorbent assay was used to detect the levels of estradiol (E2) and hyaluronan in synovial fluid. Immunohistochemistry, real-time polymerase chain reaction, and Western blotting were used to detect the expression of microRNAs (miRNAs) and related genes after transfection of miRNA-101-3p mimics, inhibitor, or short interfering RNA into synovial fibroblasts. Dual-luciferase activity was determined to identify the direct effect of miRNA-101-3p on hyaluronan synthase 2 (HAS2). Linear regression analysis, the nonparametric Mann-Whitney U test, the Student t test, and 1-way analysis of variance were carried out to analyze the results of each group.

RESULTS

The relationship between hyaluronan and E2 was negatively correlated in synovial fluid (Pearson r = -0.3179, P = .0230). Among the screened miRNAs, miRNA-101-3p was the most overexpressed in ICR. E2 mostly upregulated the expression of miRNA-101-3p at a dose of 10 nmol/L 12 hours after transfection in synovial fibroblasts of patients with ICR. However, E2 induction of miRNA-101-3p expression was significantly repressed by estrogen receptor α interference (P = 0.0286). The dual-luciferase assay showed that miRNA-101-3p regulated the expression of HAS2 by directly targeting its 3' untranslated region.

CONCLUSIONS

We speculate that E2 regulates HAS2 expression by targeting miRNA-101-3p in synovial fibroblasts of patients with ICR. Thus, the E2-miRNA-101-3p-HAS2 pathway might play an important role in the pathogenesis of ICR.

Temporomandibular joint arthritis in juvenile idiopathic arthritis, now what?

BACKGROUND

Arthritis involving the temporomandibular joint (TMJ) complicates 40 - 96% of cases of juvenile idiopathic arthritis (JIA), potentially leading to devastating changes to form and function. Optimal evaluation and management of this joint remains a matter of ongoing discussion.

METHODS

We performed a PubMed search for all articles with keywords "temporomandibular" and "arthritis", covering the dates 2002 through February 28, 2018. A separate PubMed search was performed for all articles with keywords "temporomandibular joint", "arthritis", and "treatment" covering the same dates.

FINDINGS

The TMJ is a particularly challenging joint to assess, both clinically and with imaging studies. Clinical assessment of the TMJ is hampered by the low sensitivity of joint pain as well as the absence of physical exam findings early in the disease process. As with all joints, plain radiography and computed tomography only detect arthritic sequelae. Additionally, there is mixed data on the sensitivity of ultrasound, leaving magnetic resonance imaging (MRI) as the optimal diagnostic modality. However, several recent studies have shown that non-arthritic children can have subtle findings on MRI consistent with TMJ arthritis, such as joint effusion and contrast enhancement. Consequently, there has been an intense effort to identify features that can be used to differentiate mild TMJ arthritis from normal TMJs, such as the ratio of the enhancement within the TMJ itself compared to the enhancement in surrounding musculature. With respect to treatment of TMJ arthritis, there is minimal prospective data on medical therapy of this complicated joint. Retrospective studies have suggested that the response to medical therapy of the TMJ may lag behind that of other joints, prompting use of intraarticular (IA) therapy. Although most studies have shown short-term effectiveness of corticosteroids, the long-term safety of this therapy on local growth as well as on the development of IA heterotopic bone have prompted recommendations to limit use of IA corticosteroids. Severe TMJ disease from JIA can also be managed non-operatively with splints in a growing child, as well as with surgery.

CONCLUSION

In this review, we summarize literature on the diagnosis and management of TMJ arthritis in JIA and suggest a diagnostic and therapeutic algorithm for children with refractory TMJ arthritis.