Does condylar height decrease more in temporomandibular joint nonreducing disc displacement than reducing disc displacement?: A magnetic resonance imaging retrospective study

Efficacy of Arthroscopic Diskopexy on Condylar Growth in Temporomandibular Joint Anterior Disk Displacement: A Randomized Clinical Trial

BACKGROUND

Adolescents with temporomandibular joint (TMJ) anterior disk displacement (ADD) frequently develop dentofacial deformities. It is unknown whether adjunctive arthroscopic diskopexy compared with orthodontic treatment alone increases condylar growth and then improves dentofacial deformity. This study aimed to determine whether arthroscopic diskopexy before functional appliance (joint-occlusal treatment) or single functional appliance (occlusal treatment) increases condylar growth and improves dentofacial deformity among adolescents with TMJ ADD.

METHODS

A multicenter, randomized, parallel, controlled trial was conducted in 3 centers in China. Adolescents diagnosed with TMJ ADD and dentofacial deformity were enrolled. Eligible participants were randomly assigned to a joint-occlusal group or occlusal group at a ratio of 2:1. Magnetic resonance imaging scans and cephalometric radiographs were evaluated at baseline, at 8 months, and at 14 months. The primary outcome was changes in condylar height from 14 months to baseline. Secondary outcomes were changes in skeletal position.

RESULTS

A total of 240 patients (14.65 ± 1.88 years of age) were randomized (joint-occlusal group, 160; occlusal group, 80). The overall difference in condylar height between groups was 3.65 mm (95% CI, 3.10 to 4.19 mm; P < 0.001). The between-group differences in condylar height on the left and right sides were 3.60 mm (95% CI, 2.92 to 4.28 mm; P < 0.001) and 3.69 mm (95% CI, 3.06 to 4.32 mm; P < 0.001), respectively. Significant between-group differences were noted in skeletal position (all P < 0.001).

CONCLUSION

Joint-occlusal treatment can promote condylar growth and improve dentofacial deformity in adolescents after 14 months when compared with single occlusal treatment.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, I.

A Three-branch Jointed Feature and Topology Decoder guided by game-theoretic interactions for temporomandibular joint segmentation

Segmentation of the temporomandibular joint (TMJ) disc and condyle from magnetic resonance imaging (MRI) is a crucial task in TMJ internal derangement research. The automatic segmentation of the disc structure presents challenges due to its intricate and variable shapes, low contrast, and unclear boundaries. Existing TMJ segmentation methods often overlook spatial and channel information in features and neglect overall topological considerations, with few studies exploring the interaction between segmentation and topology preservation. To address these challenges, we propose a Three-Branch Jointed Feature and Topology Decoder (TFTD) for the segmentation of TMJ disc and condyle in MRI. This structure effectively preserves the topological information of the disc structure and enhances features. We introduce a cross-dimensional spatial and channel attention mechanism (SCIA) to enhance features. This mechanism captures spatial, channel, and cross-dimensional information of the decoded features, leading to improved segmentation performance. Moreover, we explore the interaction between topology preservation and segmentation from the perspective of game theory. Based on this interaction, we design the Joint Loss Function (JLF) to fully leverage the features of segmentation, topology preservation, and joint interaction branches. Results on the TMJ MRI dataset demonstrate the superior performance of our TFTD compared to existing methods.

Assessing the Efficacy of Anterior Repositioning Splints in the Management of Temporomandibular Disc Displacement: A Systematic Review and Meta-Analysis

Disc displacement (DD) occurs when the cushioning disc of the temporomandibular joint (TMJ), situated between the jawbone and the skull, is out of position. The condition can be of two kinds: disc displacement with reduction (ddwr) and disc displacement without reduction (ddwor). The present systematic review was undertaken to assess the efficacy of anterior repositioning splints (ARS) for ddwr and ddwor. Three online databases were searched for relevant studies using MeSH keywords and Boolean operators. Initial searches of the databases extracted 552 records. Twelve studies equally representing ARS with ddwr and ddwor were selected. No clear difference could be assessed regarding ARS usage in both conditions. The outcome assessed was the improvement in TMJ symptoms. The results suggested that both ddwr and ddwor were effective in improving temporomandibular joint (TMJ) symptoms in patients who received ARS therapy. Efficacy levels ranged from 71-83% and 50-95% for ARS in ddwr and ddwor, respectively; odds ratio (OR) values ranging from 0.30 and 0.36 were obtained for ARS in both therapies, respectively, indicating similar performance levels. Both ddwr and ddwor respond well to the use of ARS; however, more clinical trials are needed to ascertain and validate the role of ARS as a treatment modality in this regard.

Effects on Facial Growth Following Masseter Muscle Resection in Growing Rats-A Systematic Review

An individual's facial appearance is heavily influenced by facial symmetry. In the asymmetric mandible, periosteal apposition and endochondral ossification in one of the condyles may stimulate asymmetric growth of the body. Our aim was to review the impact on the growth following masseter resection. Relevant studies up to October 2022 were retrieved from PubMed, Scopus, and Web of Science. The PICOS method was utilized to determine eligibility, and the SYRCLE risk of bias tool was utilized to provide an estimate of potential bias. A predetermined algorithm was used to search the databases. The results of our systematic review of seven studies indicate that the masseter muscle strongly impacts craniofacial growth and development. Resection of the masseter muscle significantly reduces the sagittal and vertical development of the jaw in rats. In addition, the masseter muscle excision influences the mandibular morphology, including the condylar area, angle, and development direction of the jaw.

Proteome Analysis of Temporomandibular Joint with Disc Displacement

Disc displacement without reduction is a common disorder of the temporomandibular joint, causing clinical symptoms and sometimes condylar degeneration. In some cases, bone regeneration is detected following disc-repositioning procedures. Until now, however, systems-wide knowledge of the protein levels for condylar outcome with disc position is still lacking. Here, we performed comprehensive expression profiling of synovial fluid from 109 patients with disc displacement without reduction using high-resolution data-independent acquisition mass spectrometry and characterized differences in 1,714 proteins. Based on magnetic resonance imaging, samples were divided into groups with versus without condylar absorption and subgroups with versus without new bone. For the proteomic analysis, 32 proteins in groups presented with statistical significance (>2-fold, P < 0.05). Pathways such as response to inorganic substances, blood coagulation, and estrogen signaling were significantly expressed in the group with bone absorption as compared with pathways such as regulation of body fluid levels, vesicle-mediated transport, and focal adhesion, which were enriched in the group without bone absorption. In subgroup analysis, 45 proteins of significant importance (>2-fold, P < 0.05) were associated with pathways including would healing, glycolysis and gluconeogenesis, and amino acid metabolism. Combined with clinical examination, molecules such as acetyl-CoA carboxylase beta (ACACB) and transforming growth factor beta 1 (TGFB1) were related to features such as visual analog scale and maximum interincisal opening (P < 0.05). In addition, 7 proteins were examined by Western blotting, including progesterone immunomodulatory binding factor 1 (PIBF1), histidine-rich glycoprotein (HRG), and protein kinase C and casein kinase substrate in neurons 2 (PACSIN2). In conclusion, this study provides the first proteome analysis of condylar absorption at disc displacement without reduction and postoperative new bone formation after disc reposition. Integrated with clinical data, this analysis provides an important insight into the proteomics of condylar modification at disc position.

Automatic detection of anteriorly displaced temporomandibular joint discs on magnetic resonance images using a deep learning algorithm

OBJECTIVES

This study aimed to develop models that can automatically detect anterior disc displacement (ADD) of the temporomandibular joint (TMJ) on MRIs before orthodontic treatment to reduce the risk of developing serious complications after treatment.

METHODS

We used 9009 sagittal MRI of the TMJ as input and constructed three sets of deep learning models to detect ADD automatically. Deep learning models were developed using a convolutional neural network (CNN) based on the ResNet architecture and the "Imagenet" database. Five-fold cross-validation, oversampling, and data augmentation techniques were applied to reduce the risk of overfitting the model. The accuracy and area under the curve (AUC) of the three models were compared.

RESULTS

The performance of the maximum open mouth position model was excellent with accuracy and AUC of 0.970 (±0.007) and 0.990 (±0.005), respectively. For closed mouth position models, the accuracy and AUC of diagnostic Criteria 1 were 0.863 (±0.008) and 0.922 (±0.009), respectively significantly higher than that of diagnostic Criteria 2 with 0.839 (±0.013) (p = 0.009) and AUC of 0.885 (±0.018) (p = 0.003). The classification activation heat map also improved our understanding of the models and visually displayed the areas that play a key role in the model recognition process.

CONCLUSION

Our CNN model resulted in high accuracy and AUC in detecting ADD and can therefore potentially be used by clinicians to assess ADD before orthodontic treatment, and hence improve treatment outcomes.

Morphometric Analysis of the Glenoid Fossa in the Skull Base

The aim of this study was to investigate the possible relationship between disc displacement and the presence of reduction by comparing condyle anteroposterior (AP) diameter, condyle height, mandibular fossa AP diameter, and mandibular fossa depth.

An Overview of Anterior Repositioning Splint Therapy for Disc Displacement-related Temporomandibular Disorders

Anterior repositioning splint (ARS) therapy is considered one of the most effective therapies for treating disc displacement-related temporomandibular disorders (TMDs), which account for a large proportion of TMD cases. Owing to the wide application of this therapy, the exact mechanism of remission has increasingly drawn attention. Given that practitioners have different views on ARS therapy, its indications are broadened, and operating methods diverged. This review attempts to provide an overview of ARS therapy and helps practitioners establish indications and suitable operating methods. Representative views in the past 10 years were summarised, and conclusions were drawn as follows: The mechanism of ARS therapy is mainly attributed to internal derangement correction, improvement of stress distribution and recently reported joint remodeling. It has an evident effect in the short term, and the most prevalent operating methods are protruding the mandible to the edge-to-edge position and wearing the ARS for 24 hours daily for 3-6 months. However, long-term stability is not optimal, and thus indications should be selected carefully. Notably, most of the clinical studies in this field are case analyses with low-quality evidence. Well-designed RCTs are required to further validate relevant theories.

The Effect of Condylar Regeneration After Different Disc Repositioning Surgeries in Adolescents with Skeletal Class II Malocclusion

PURPOSE

To evaluate the effect of different temporomandibular joint (TMJ) disc repositioning surgeries for the treatment of anterior disc displacement (ADD) in juvenile patients with skeletal Class II malocclusion.

PATIENTS AND METHODS

Patients (< 20 years, cervical vertebral maturation stage, IV-V) who had bilateral TMJ ADD with skeletal Class II malocclusion were treated by disc repositioning surgery (mini-screw anchor, [MsA]; or opening suturing, [OSu]). Magnetic resonance imaging (MRI) and lateral cephalometric films before and more than 12 months after surgery were collected from all patients. Changes of SNA, SNB, ANB, incisor overjet, pogonion position (pg'-G'), and condylar height were measured before and after surgery in different disc reposition surgeries and compared by statistical analysis.

RESULTS

Eighty-four patients with an average age of 16.44 years and follow-up time of 14.60 months (12 to 33 months) were included in the study. Among them, 16 patients had a mean follow-up of 14.8 months without treatment before disc repositioning. Their condylar height was significantly decreased (P = .004) by MRI measurement. Six patients who had cephalometric films showed significantly decreased SNB (P = .042) and increased overjet (P = .037). After disc repositioning by either OSu (54 cases) or MsA (30 cases), condylar height, SNB were significantly increased and overjet, Pg'-G', ANB were decreased in both groups (P < 0.001). There was more new bone height in OSu than MsA (P = .004), but no significant differences in SNB, ANB, overjet and Pg'-G' between the 2 groups (P > .05). The new bone height was significantly correlated with the surgical method (P = .029), age (P = .015), SNB (P = .008), overjet (P = .048) and pg'-G' (P = .001).

CONCLUSIONS

Both types of disc repositioning method can effectively promote condylar regeneration and improve skeletal Class II malocclusion in adolescents with ADD. Disc repositioning by OSu obtained more new bone height than MsA.

The effect of TMJ disk repositioning by suturing through open incision on adolescent mandibular asymmetry with and without a functional orthodontic appliance

OBJECTIVE

The objective of this study was to evaluate the effect of combined temporomandibular joint (TMJ) disk repositioning by suturing through open incision and orthodontic functional appliance (OFA) treatment for adolescents with mandibular asymmetry.

STUDY DESIGN

Adolescent patients (12-20 years old) with mandibular asymmetry combined with unilateral TMJ disk displacement without reduction were treated with disk repositioning by suturing through open incision with and without postoperative OFA. Magnetic resonance imaging and posteroanterior cephalometric radiographs (PA) were used to measure and compare the changes in condylar height, joint space, and menton deviation pre- and postoperatively.

RESULTS

Twenty-six patients were included in the study. Joint space was significantly increased postoperatively and new bone mostly formed at the superior or posterior superior part of the condyle after 6 to 18 months in all surgically treated joints. Fourteen patients with OFA had a significant increase in condylar height and menton deviation compared to 12 patients without OFA (2.29 ± 0.91 mm vs 1.22 ± 0.69 mm, P = .003; 4.56 ± 1.48 mm vs 2.01 ± 0.74 mm, P = .000).

CONCLUSIONS

Combined treatment with TMJ disk repositioning by suturing through open incision and OFA can promote condylar growth and correct mandibular deviation in adolescent patients. Postoperative OFA can maintain the increased joint space created by disk repositioning and promote new bone formation at the superior and posterior parts of the condyle.

Is Temporomandibular Joint Disc Displacement without Reduction a Plausible Cause of Condylar Hypoplasia? A Case Report

Background:

The causes of mandibular condylar hypoplasia can be congenital or acquired in nature. Cited local causes of acquired hypoplasia include trauma, infection and irradiation. We report a case of hypoplastic condyle that was attributed to temporomandibular joint (TMJ) disc displacement without reduction (DDwoR).

Clinical Presentation:

A 16-year-old male presented with restricted mouth opening and right TMJ pain for 6 months. He was subsequently diagnosed with DDwoR. Conservative treatment comprising self-care and moist-heat therapy was administered and he was followed for 27 months without any further interventions. During this period, transitions from “normal” morphology to condylar flattening / erosion, and eventually a re-modeled smaller “normal” right TMJ were observed.

Conclusion:

The present case provided initial support that DDwoR could be a plausible cause of condylar hypoplasia in adolescents / young adults.

Temporomandibular joint disc displacement with reduction: a review of mechanisms and clinical presentation

Disc displacement with reduction (DDWR) is one of the most common intra-articular disorders of the temporomandibular joint (TMJ). Factors related to the etiology, progression and treatment of such condition is still a subject of discussion. This literature review aimed to address etiology, development, related factors, diagnosis, natural course, and treatment of DDWR. A non-systematic search was conducted within PubMed, Scopus, SciELO, Medline, LILACS and Science Direct using the Medical Subjective Headings (MeSH) terms “temporomandibular disorders”, “temporomandibular joint”, “disc displacement” and “disc displacement with reduction”. No time restriction was applied. Literature reviews, systematic reviews, meta-analysis and clinical trials were included. DDWR is usually asymptomatic and requires no treatment, since the TMJ structures adapt very well and painlessly to different disc positions. Yet, long-term studies have shown the favorable progression of this condition, with no pain and/or jaw locking occurring in most of the patients.

Experimental study on mandibular length and facial symmetry of low estrogen level and anterior disc displacement of temporomandibular joint

This study was aimed at elucidating the changes of mandible symmetry in a rabbit model with low estrogen levels induced by ovariectomy (OVX) combined with temporomandibular joint (TMJ) anterior disc displacement without reduction (ADDWoR). 32 growing rabbits were randomly allocated into 4 groups; OVX group, ADDWoR group, OVX+ ADDWoR group and control group. In OVX and OVX+ ADDWoR groups, bilateral OVX was performed and then the serum level of 17β-estradiol was evaluated every week. In ADDWoR group and OVX+ ADDWoR group, the right TMJ was surgically opened and the disc was displaced anteriorly and the left TMJ was also surgically opened and closed without any manipulation of the disc. All rabbits had CT scan before and at the end of the study and the mandible measurements were performed on the 3D-reconstructed model. The mandible in ADDWoR group was consistently shorter on the right side resulting in a midline shift to the ipsilateral side. While in OVX+ ADDWoR group, the mandibular length of the right side was more shorter than in ADDWoR group, moreover, mandibular deviation was therefore more severe. In OVX group, there was no difference regarding the length of mandible compared to the control group. There was no difference regarding the mandibular length between left and right sides in the control group.

Non-invasive joint decompression: An important factor in the regeneration of the bone marrow and disc recapture in temporomandibular arthropathies

BACKGROUND

This article aims to demonstrate the importance of the TMJ (Temporomandibular Joint) decompression in the treatment of degenerative processes and disc displacements, reporting two clinical cases treated with orthopedic and decompressive correction of TMJ.

MATERIAL AND METHODS

The studies reported in this article show patients with muscle and joint pain who were evaluated pre and post-treatment through MRI (Magnetic Resonance Irradiation) to follow-up bone marrow regeneration and TMJ disc placement. Transcutaneous electrical stimulation (TENS), measurement equipment and IO (Intraoral Orthotic) were used to evaluate and treat the patients. A critical review of literature has also been conducted to confront clinical outcomes.

RESULTS

Marrow bone regeneration and disc placement were observed in both patients.

CONCLUSIONS

The use of measurement equipment associated with TENS to find the correct rest position of the Jaw an the use of IO to decompress the TMJ was an effective way to promote bone marrow regeneration and disc placement, consequently improving function and quality of life.

The Efficiency of Anterior Repositioning Splints in the Management of Pain Related to Temporomandibular Joint Disc Displacement with Reduction

Background and Objective

Intra-articular temporomandibular disorders are often related to pain in the area of the temporomandibular joint, ear, and temple. The aim of the study was to investigate the efficiency of anterior repositioning splints in decreasing pain related to temporomandibular joint disc displacement with reduction.

Methods

The research material consisted of 112 patients, aged 24 to 45 years, of both genders, who reported for treatment at the Consulting Room of Temporomandibular Joint Dysfunctions at the Jagiellonian University in Cracow between 2014 and 2016 due to pain in the area of the temporomandibular joint(s) and noise(s) of temporomandibular joint(s) present during jaw movements with comorbid contracture of masticatory muscles. Subjects were examined according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) protocol and, after diagnosis of painful disc displacement with reduction and masticatory muscle contracture, they were assigned randomly to either the study or control groups (56 patients in each). In the study group, we used an anterior repositioning splint on the full lower arch for about 20 hours usage over a 4-month period. In the control group, a noninvasive therapy was applied using a biostimulation laser over 12 sessions performed every second day on the area of both temporomandibular joints with mouth open and while performing muscle self-exercises with a dominant protrusive position of the mandible. Pain intensity was evaluated using the Verbal Numerical Rating Scale (VNRS) immediately before the treatment and then after 4 and 16 weeks. The obtained data were analyzed using the Mann–Whitney U test (p ≤ 0.005).

Results

The VNRS values reported during the final examination for the study group were significantly lower than for the control group (p=0.0004).

Conclusions

The anterior repositioning splint is an efficient tool in decreasing pain related to disc displacement with reduction. This trial is registered with Clinicaltrials.gov NCT03057262.