Surgical Management of Idiopathic Condylar Resorption

Exploring the effect of disc displacement on the risk and severity of condylar erosion in adult temporomandibular disorder patients: A CBCT and MRI study

OBJECTIVE

The objective of the study was to investigate the relationship between types of disc displacement (DD) diagnosed by magnetic resonance imaging (MRI), and the risk (presence or absence) and severity of condylar erosion (CE) graded using cone-beam computed tomography (CBCT) in adult Temporomandibular disorders (TMD) patients.

METHODS

A total of 353 TMD patients (283 females, 70 males) underwent MRI scans to categorise DD as normal (NA), anterior displacement with reduction (ADDR), or anterior displacement without reduction (ADDNR). CE severity was graded on a scale of 0-3 (absence, mild, moderate or severe) using CBCT. To establish the plausibility and cut-off points for CE diagnosis, the severity of CE was then further divided into three classifications: Grade 0 versus 1 + 2 + 3; Grades 0 + 1 versus 2 + 3; Grades 0 + 1 + 2 versus 3. Logistic regression analysis was performed, adjusting for age, gender and joint correlation.

RESULTS

ADDNR significantly increased the risk of CE compared with NA (OR = 10.04, 95% CI: [6.41, 15.73]) and showed a significant increase in CE severity across all classifications (ORs = 10.04-18.95). The effects of ADDNR were significant in both genders (p < .001) and had a greater impact in females. ADDR was predominantly associated with mild CE.

CONCLUSIONS

ADDNR significantly increased the risk and severity of CE independent of gender when compared to NA, whereas ADDR was mainly associated with mild CE. Slight cortical discontinuity may represent a subclinical diagnosis requiring further investigation.

Hanna's Modified Sagittal Split Osteotomy (HSSO): An Alternative to Inverted L Osteotomy-Merging Function and Aesthetics for Enhanced Stability, Attractiveness, and Nerve Protection

Background: The current high standards in orthognathic surgery demand surgical solutions that are both ⁠ functionally ⁠ effective and aesthetically pleasing. Our approach offers one for enhanced stability, attractiveness, and nerve protection ⁠ with improved accessibility ⁠ in the majority of orthognathic scenarios ⁠ compared to an inverted L osteotomy. Methods: A case series is presented to illustrate the application and outcomes of HSSO, an optimised approach that combines the advantages of a transoral inverted L osteotomy with specific enhancements and increased versatility, ⁠ with accessibility and exposure similar to a BSSO. Results: HSSO as a completely transoral technique, demonstrate the ability to perform significant counterclockwise rotations of the mandible, eliminating the need for trocars or skin incisions. We experinced high postoperative stability when HSSO was performed in conjunction with a three-piece LeFort 1 osteotomy on a dynamic opposing arch. In comparison to an inverted L approach, we postulated that HSSO offers advantages in stability, due to the increased segmental overlap of the proximal and distal segments of the mandible. This approach is designed to enhance the safety of the inferior alveolar nerve compared to traditional sagittal split methods. Furthermore, HSSO represents an alternative to total joint replacement in select cases of idiopathic condylar resorption and is effective for correcting mandibular asymmetries while maintaining jawline aesthetics. This is achieved through the manipulation of the mandibular angle, ramus height, and inferior border without creating a step deformity in the soft tissue. Conclusions: The outcomes of HSSO highlight its capacity to deliver predictable, functional, and aesthetically pleasing results, offering a viable alternative to more traditional orthognathic techniques.

3D analysis of condylar and mandibular remodeling one year after intra-oral ramus vertical lengthening osteotomy

OBJECTIVES

Among the existing techniques for the correction of mandibular posterior vertical insufficiency (PVI), the intra-oral ramus vertical lengthening osteotomy (IORVLO) can be proposed as it allows simultaneous correction of mandibular height and retrusion. This study assessed the 3D morpho-anatomical changes of the ramus-condyle unit and occlusal stability after IORVLO.

MATERIALS AND METHODS

This retrospective analysis compared immediate and 1-year post-operative 3D CBCT reconstructions. The analysis focused on the condylar height (primary endpoint) and on the changes in condylar (condylar diameter, condylar axis angle) and mandibular (ramus height, Frankfort-mandibular plane angle, gonion position, intergonial distance, angular remodeling) parameters. Additionally, this analysis investigated the maxillary markers and occlusal stability.

RESULTS

On the 38 condyles studied in 21 included patients (mean age 23.7 ± 3.9 years), a condylar height (CH) loss of 0.66 mm (p < 0,03) was observed, with no correlation with the degree of ramus lengthening (mean 13.3 ± 0.76 mm). Only one patient presented an occlusal relapse of Class II, but a 3.4 mm (28%) condylar diameter loss and a 33% condylar volume reduction with loss of 1 mm and 3.4 mm in CH and condyle diameter, respectively. A mean 3.56 mm (p < 0.001) decrease in ramus height was noted, mainly due to bone resorption in the mandibular angles.

CONCLUSION

This study confirms the overall stability obtained with IORVLO for the correction of PVI.

CLINICAL RELEVANCE

This study aims to precise indication of IORVLO, and to validate the clinical and anatomical stability of results.

Hybrid treatment of varied orthodontic appliances for a patient with skeletal class II and temporomandibular joint disorders: A case report and review of literature

BACKGROUND

The relation between orthodontic treatment and temporomandibular disorders (TMDs) is under debate; the management of TMD during orthodontic treatment has always been a challenge. If TMD symptoms occur during orthodontic treatment, an immediate pause of orthodontic adjustments is recommended; the treatment can resume when the symptoms are managed and stabilized.

CASE SUMMARY

This case report presents a patient (26-year-old, female) with angle class I, skeletal class II and TMDs. The treatment was a hybrid of clear aligners, fixed appliances and temporary anchorage devices (TADs). After 3 mo resting and treatment on her TMD, the patient's TMD symptom alleviated, but her anterior occlusion displayed deep overbite. Therefore, the fixed appliances with TAD were used to correct the anterior deep-bite and level maxillary and mandibular deep curves. After the levelling, the patient showed dual bite with centric relation and maximum intercuspation discrepancy on her occlusion. After careful examination of temporomandibular joints (TMJ) position, the stable bite splint and Invisible Mandibular Advancement appliance were used to reconstruct her occlusion. Eventually, the improved facial appearance and relatively stable occlusion were achieved. The 1-year follow-up records showed there was no obvious change in TMJ morphology, and her occlusion was stable.

CONCLUSION

TMD screening and monitoring is of great clinical importance in the TMD susceptible patients. Hybrid treatment with clear aligners and fixed appliances and TADs is an effective treatment modality for the complex cases.

An Overview of Clinical Conditions and a Systematic Review of Personalized TMJ Replacement

The temporomandibular joint (TMJ) is a complex structure in the cranio-maxillomandibular region. The pathological changes of the joint cause deficiencies at different levels, making its replacement necessary in some cases. The aim of this article is to analyze the current indications, treatment and criteria, and follow-up using a systematic review and case series. A systematic review was carried out, identifying the indications for the use of a customized TMJ prosthesis and evaluating criteria and validation in the international literature. After review and exclusion, 8 articles were included with a minimum follow-up of 12 months. The age of the subjects was between 18 and 47 years old. In 226 patients, 310 TMJ prostheses were installed, 168 bilaterally and 142 unilaterally. In most of the articles, a good condition in the follow-up was observed, with a reduction in pain and better conditions of mandibular movement and function. TMJ prosthesis and replacement is a protocolized, defined, stable, and predictable procedure. Indications and criteria must be evaluated by specialists and patients related to the pathology involved in TMJ deformity or degeneration. Randomized research with an accurate diagnosis and follow-up is necessary to obtain the best indication for this treatment.

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.

Modified Intraoral C-Osteotomy

ABSTRACT

Repeated sagittal split osteotomy might impose an increased risk for damage of the inferior alveolar nerve. Another contemporary orthognathic issue is surgical management of malocclusion following condylar resorption. Here we describe a modified C-osteotomy technique as a proposed solution for these difficulties in orthognathic surgery. The modified C-osteotomy might induce less stress on the condyles reducing the risk for relapse subsequent to condylar resorption, as well as reduce the risk of inferior alveolar nerve damage.

The efficacy of mesenchymal stem cells in regenerating structures associated with the temporomandibular joint: A systematic review

OBJECTIVES

The objective of this systematic review is to evaluate the role of mesenchymal stem cells in the regenerative treatment of temporomandibular joint resorption.

DESIGN

Search strategies were performed in the following databases: PubMed/MEDLINE, EMBASE, Cochrane Collaboration Library, and Web of Science. Two independent reviewers selected the included articles using a two-phase process based on the eligibility criteria. The reviewers independently collected the required information from the included articles. The methodological quality of the selected studies was assessed individually.

RESULT

In accordance with the inclusion and exclusion criteria, 703 studies were found and 8 articles were included. Thus, six studies using animal models and two human studies were included in this systematic review.

CONCLUSION

Based on the data of our systematic review, the use of mesenchymal stem cells is a promising method for the repair and regeneration of temporomandibular joint components.

Low skeletal bone mineral density as a potential aetiological factor towards idiopathic condylar resorption

The aim of this study was to investigate the contributing factor of impaired skeletal quality in the pathogenesis of idiopathic condylar resorption (ICR). One hundred and twenty-six patients with MRI-confirmed ICR and 596 patients with disc displacement (DD) without a diminished condyle, of both sexes, were included. Dental examinations and retrospective surveys regarding temporomandibular joint symptoms and progression of maxillofacial deformities were conducted. Skeletal bone mineral density (BMD) was measured by dual energy X-ray absorptiometry (DXA) and converted to T-scores and Z-scores. Results showed that ICR patients had a smaller overbite (1.56±3.3 vs 3.05±2.0mm), larger overjet (4.9±2.4 vs 3.5±1.9mm), larger range of mouth opening (36.5±6.7 vs 33.6±7.1mm), and higher rates of anterior open bite and mandibular retrusion compared to DD patients (all P<0.001). ICR was associated with an increased probability of low skeletal BMD at chronological age in females (P=0.020) but not in males (P=0.095). This study indicates that reduced BMD may predispose females to an exacerbated condylar resorption process in addition to increased joint loading initiated from DD.

Biomechanical analysis of costochondral graft fracture in temporomandibular joint replacement

This study is the first attempt to explore the reason of costochondral graft fracture after lengthy mandible advancement and bilateral coronoidectomy by combining finite element analysis and mechanical test. Eleven groups of models were established to simulate costochondral graft reconstruction in different degrees of mandible advancement, ranging from 0 to 20 mm, in 2 mm increment. Force and stress distribution in the rib-cartilage area were analyzed by finite element analysis. Mechanical test was used to evaluate the resistance of the rib-cartilage complex. Results showed a sharp increase in horizontal force between 8 and 10 mm mandible advancement, from 26.7 to 196.7 N in the left side, and continue increased after 10 mm, which was beyond bone-cartilage junction resistance according to mechanical test. Therefore, we concluded that bilateral reconstruction with coronoidectomy for lengthy mandible advancement (≥ 10 mm) may lead to prominent increase in shear force and result in a costal-cartilage junction fracture, in this situation, alloplastic prosthesis could be a better choice. We also suggested that coronoidectomy should be carefully considered unless necessary.

Patient-specific Implant for Temporomandibular Joint Replacement in Juvenile Arthritis and Facial Asymmetry

The aim of this report is to present a patient with juvenile arthritis, condylar resorption, and residual facial asymmetry treated with orthognathic surgery and unilateral joint replacement with a full three-dimensional computer-aided design and computer-aided manufacture (CAD-CAM) temporomandibular joint (TMJ) prosthesis, including an increase in the left ramus and mandibular angle to achieve facial symmetry. The patient, a 30-year-old male, came to our department for orthosurgical treatment. The patient had been receiving treatment for juvenile arthritis for 15 years; at facial level, he had a chin deviation of 12 mm from the facial midline, maxillary retrusion, and Angle Class III. The computed tomography revealed a reduced height of the left condyle and a significant difference in the morphology of the mandibular ramus and angle. Using CAD-CAM technology and additive manufacturing, a TMJ prosthesis was produced, through the use of the mirror image, orthognathic surgery was realized using the right side as “esthetic side” with suitable shape and angulation. The prosthesis was created, and this was taken to the surgery. The surgery was performed without problems, a mouth opening of 35 mm and absence of pain were noted after 12 months of follow-up. The surgery remained stable, and facial symmetry was restored. In conclusion, it is viable to develop a TMJ prosthesis by CAD-CAM that includes esthetic modifications to the face; prospective and clinical studies must be conducted to confirm protocols. Level of Evidence: V.

Protocol for fully digital and customized management of concomitant temporomandibular joint replacement and orthognathic surgery

End-stage temporomandibular joint (TMJ) disease is caused by a multitude of pathological processes that impair TMJ anatomy and function. In many cases, end-stage TMJ disease and dentofacial skeletal deformities coexist. The optimal treatment for such conditions is total alloplastic joint replacement and orthognathic surgery. Such procedures have historically been conducted in two separate stages. Furthermore, while technological improvements resulting from the widespread adoption of virtual reality initially led to significant improvements in the field of orthognathic planning, the adoption of virtual design techniques to optimize TMJ reconstruction was a later achievement. Therefore, planning for TMJ replacement and orthognathic surgery did not develop in parallel, leading to various combinations of planning for orthognathic surgery and TMJ replacement with the aim of performing both procedures simultaneously in one stage. Nowadays, improvements in virtual planning and three-dimensional printing have allowed these procedures to be conducted in the same surgical step based on fully digital planning and entirely customized surgery. This paper introduces a fully digital protocol for the treatment of end-stage TMJ disease and associated acquired dentofacial deformities, in which all surgical steps are customized and the whole surgery is performed in succession using automated procedures, thanks to the combined use of virtual surgical planning, surgical guides, custom-designed TMJ prostheses, and patient-fitted osteosynthesis devices.

MRI Changes in the Temporomandibular Joint after Mandibular Advancement

PURPOSE

Esthetic dental and skeletal component correction can affect the temporomandibular joint (TMJ). Arthrogenic TMJ dysfunction can be present in the joint at the outset or it can develop during the treatment or later. The aim of the present study was to examine the changes found on magnetic resonance imaging (MRI) studies of the TMJ in patients with skeletal Class II malocclusion who had undergone combined orthodontic and bilateral sagittal split ramus osteotomy (BSSRO) advancement. Our objective was to measure the changes in the disc position, condylar translation, secondary bony changes, and joint effusion on MRI before and after treatment.

MATERIALS AND METHODS

An analytical, single-surgeon, single-institution, retrospective radiological (MRI) study was designed. We included patients who had undergone combined orthodontic and BSSRO advancement from 2011 to 2018. All 36 patients were examined using a 1.5-Tesla MRI unit (Siemens Symphony, Erlangen, Germany) with a 6 × 8-cm diameter surface coil, which allowed for simultaneous imaging of both TMJs.

RESULTS

Analysis using the Wilcoxon signed rank test revealed statistically significant differences in the pre- and post-treatment groups in the changes in the position of the disc from anterior disc displacement with reduction (ADDWR) to the normal position (P = .008), condylar translation from excessive to normal (P = .046), and an increase in secondary bony changes (P = .005).

CONCLUSIONS

Combined orthodontic and orthognathic movement in the treatment of skeletal Class II malocclusion can increase secondary bony changes, improve the disc position in ADDWR cases, and control excessive translation of the TMJ. No improvement was noted in the position of the disc in those with anterior disc displacement without reduction, hypomobility and joint effusion.