Evidence for minimally invasive treatment-A systematic review on surgical management of disc displacement

BACKGROUND

Surgical treatment of temporomandibular joint (TMJ) disc displacement (DD) has been established in different forms since over a century. Ther is a consensus to perform minimal invasive interventions as first-line surgical treatment since there are no evidence on best surgical practice yet.

OBJECTIVE

The aim was to perform a complex systematic review (SR) on the topic-is there evidence for surgical treatment of TMJ DD?

METHODS

The PICO was defined as DD patients (population), treated with different surgical interventions including arthrocentesis (intervention), compared with other or no treatment (control) regarding the outcome variables mandibular function, mouth opening capacity, TMJ pain, etcetera (outcome). For identification of prospective controlled trials and SRs, a search strategy was developed for application in three databases.

RESULTS

The search yielded 4931 studies of which 56 fulfilled the stipulated PICO. Studies with low or moderate risk of bias were possible to include in meta-analyses. There were evidence suggesting arthrocentesis being more effective compared to conservative management (maximum interincisal opening (MIO): p < .0001, I2 = 22%; TMJ pain: p = .0003, I2 = 84%) and arthrocentesis being slightly more effective than arthrocentesis with an adjunctive hyaluronic acid injection (MIO: p = .04, I2 = 0%; TMJ pain: p = .28, I2 = 0%). Other treatment comparisons showed nonsignificant differences. The performed meta-analyses only included 2-4 studies each, which might indicate a low grade of evidence.

CONCLUSION

Although arthrocentesis performed better than conservative management the findings should be interpreted cautiously, and non-invasive management considered as primary measure. Still, several knowledge gaps concerning surgical methods of choice remains.

Temporomandibular joint surgery: the past, present, and future

Temporomandibular joint surgery for various pathological conditions and diseases affecting the integrity, mobility, and function of the joint has a long history. However, the greatest explosion of knowledge regarding the diagnosis and management of temporomandibular joint pain, pathology, and rehabilitation has occurred in the last 50 years. This review focuses on the incremental expansion of knowledge over time that led to the development of concepts that support our current surgical decisions and techniques, with the aim of identifying gaps in knowledge that require well-designed studies to move the field forward. Using this approach will allow an enhancement of our understanding of temporomandibular joint form and function, and enable focus to be placed on the evaluation, diagnosis, and non-surgical and surgical management strategies that are the most efficacious for our patients.

A New Technique for Arthroscopic Discectomy of the Temporomandibular Joint Disc Perforation: A Technical Note

Disc perforation represents the result of the degenerative process in joint structures that may lead to pain, joint noise, restricted mouth opening, osteoarthritis, and even dentofacial anomalies. Even though discectomy has proven benefits, with promising outcomes reported, it is mainly described using an open approach. While some arthroscopic techniques have been published, they are limited to managing perforation, edge widening, and inflammation treatment and do not describe complete disc removal. We describe a novel step-by-step arthroscopic discectomy technique utilizing two operative cannulas that completely remove nonfunctional cartilaginous tissue.

Assessment of temporomandibular joint disc position and skeletal stability after bimaxillary surgery

PURPOSE

This study aimed to assess the correlation between temporomandibular joint (TMJ) disc position and skeletal stability and identify the cephalometric measurements associated with relapse after bimaxillary surgery.

METHODS

The participants were 62 women with jaw deformities (124 joints) who underwent bimaxillary surgery. The TMJ disc position was classified into four types (anterior disc displacement (ADD), anterior, fully covered, and posterior) using magnetic resonance imaging, and cephalometric analysis was performed preoperatively and 1 week and 1 year postoperatively. The differences between pre- and 1-week postoperative values (T1) and 1-week and 1-year postoperative value (T2) were calculated for all cephalometric measurements. Moreover, the relationship between skeletal stability using cephalometric measurements, skeletal class, and TMJ disc position was analyzed.

RESULTS

The participants included 28 patients in class II and 34 in class III. There was a significant difference in T2 in SNB between class II mandibular advancement cases and class III mandibular setback cases (P = 0.0001). In T2, in ramus inclination, there was a significant difference between the ADD and posterior types (P = 0.0371). Stepwise regression analysis revealed that T2 was significantly correlated with T1 for all measurements. However, the TMJ classification was not applied to all measurements.

CONCLUSION

This study suggested that TMJ disc position, including ADD, could not affect skeletal stability, including the maxilla and distal segment after bimaxillary osteotomy, and short-term relapse could be related to the movement amount or angle change by surgery for all measurements.

Specific tissue engineering for temporomandibular joint disc perforation

BACKGROUND

The temporomandibular joint (TMJ) disc is a critical fibrocartilaginous structure with limited regenerative capacity in the oral system. Perforation of the TMJ disc can lead to osteoarthritis and ankylosis of the TMJ because of the lack of disc protection. Clinical treatments for TMJ disc perforation, such as discectomy, hyaluronic acid injection, endoscopic surgery and high position arthroplasty of TMJ, are questionable with regard to long-term outcomes, and only three fourths of TMJ disc perforations are repairable by surgery, even in the short-term. Tissue engineering offers the potential for cure of repairable TMJ disc perforations and regeneration of unrepairable ones.

OBJECTIVES

This review discusses the classification of TMJ disc perforation and defines typical TMJ disc perforation. Advancements in the engineering-based repair of TMJ disc perforation by stem cell therapy, construction of a disc-like scaffold and functionalization by offering bioactive stimuli are also summarized in the review, and the barriers developing engineering technologies need to overcome to be popularized are discussed.

Arthroscopic reduction and rigid fixation of the anteriorly displaced temporomandibular joint disc without reduction using titanium screw: a case series

OBJECTIVES

To evaluate the effectiveness of arthroscopic reduction and rigid fixation (ARRF) using a suture-free titanium screw as a treatment approach to temporomandibular joint's (TMJ) anterior disc displacement without reduction (ADDwoR) and assess its impact on clinical outcomes, including improvements in symptoms related to TMJ disorders.

MATERIALS AND METHODS

A series of twenty patients presented to the Department of Orthognathic and Temporomandibular Surgery at West China Hospital of Stomatology between September 2022 and January 2023, complaining of symptoms such as pain, clicking, and limited mouth opening. Standard magnetic resonance image (MRI) imaging T1 and T2 sequences in both sagittal and coronal views study with closed and maximal open mouth positions were taken preoperatively to assess the disc's position, integrity, and shape. Also, cone-beam computed tomography (CBCT) scans images to find any degenerative changes and evaluate the condylar bone's features and volume. Additionally, the clinical examination assesses limited oral opening, mechanical pain, and the presence of any noises such as clicking and crepitus. All cases were treated under general anesthesia using the arthroscopic release, reduction, and rigid fixation of the TMJ's ADDwoR to establish a normal disc-condyle relationship and to restore the functional position.

RESULTS

Patients' symptoms, such as pain and mouth opening, improved significantly following the arthroscopic treatment. Postoperative MRI and CBCT imaging follow-up conducted at 6 months demonstrated the stable position of the reduced TMJ disc and the fixation screw. Notably, none of the patients exhibited signs of relapse during this follow-up period.

CONCLUSION

Overall, the ARRF of TMJ's ADDwoR using a suture-free titanium screw proved to be safe and provides satisfactory results, in addition to the several advantages of using suture-free titanium screws, such as biocompatibility, strong fixation, and durability. However, it is a technically demanding procedure requiring extensive, long-term training.

CLINICAL RELEVANCE

ARRF using a cost-effective fixation titanium screw to treat ADDwoR emerges as a clinically effective minimally invasive approach.

Effect of arthroscopic discopexy on condylar growth in adolescents with temporomandibular joint disc displacement without reduction: A retrospective self-controlled case series study

This study was a retrospective self-controlled study that aimed to evaluate the effect of arthroscopic discopexy on condylar height and mandibular position in adolescents with temporomandibular joint (TMJ) anterior disc displacement without reduction (ADDwoR). Patients between 10 and 20 years of age and diagnosed with bilateral TMJ ADDwoR by magnetic resonance image (MRI) were included in this study. All patients underwent a period of natural course before arthroscopic surgery and then a follow-up period postoperatively. Changes in condylar height and mandibular position were measured by MRI and X-ray radiographs. Data were analyzed by paired t-test, Pearson correlation analysis, and generalized estimating equations. This study comprised a total of 40 patients with a mean age of 14.80 years. Pearson correlation analysis showed correlations between condylar height and mandibular position changes. The condylar height change during the post-operative period was significantly higher than that during natural course period (3.57 mm, p < 0.001). The changes in mandibular position (including ANB angle, SNB angle, and Pog-Np) were significant different (all p < 0.05) between the two periods. This study found that arthroscopic discopexy can promote condylar growth and correct dentofacial deformity in adolescents with bilateral TMJ ADDwoR.

Effect of occlusal stabilisation splint with or without arthroscopic disc repositioning on condylar bone remodelling in adolescent patients

The aim of this study was to investigate the treatment effects of a stabilisation splint (SS) with and without arthroscopic disc repositioning (ADR) on condylar bone remodelling in adolescent patients with anterior disc displacement without reduction (ADDwoR). Cone beam computed tomography and magnetic resonance imaging were used to analyse condylar bone remodelling, condyle position, and disc position. Twenty-two temporomandibular joints of 14 patients who underwent ADR (age range 12-20 years; mean follow-up 12.5 ± 7.8 months) and 21 temporomandibular joints of 14 patients who did not undergo ADR (age range 13-20 years; mean follow-up 11.1 ± 5.1 months) were included. The change in bone volume (P < 0.001), rate of bone volume change (P < 0.001), and change in condyle height (P = 0.031) were significantly greater in patients with ADR than in those without ADR. The changes in posterior joint space (P = 0.013), superior joint space (P = 0.020), and ratio of condyle sagittal position (P = 0.013) were significantly greater in patients with ADR than in those without ADR. All discs in patients who underwent ADR and one disc in those who did not undergo ADR were backward repositioned. In conclusion, in adolescent patients with ADDwoR, ADR with SS therapy achieved better condyle and disc position than SS therapy alone, and also induced bone generation.

Effect of TMJ disc position on condylar bone remodeling after arthroscopic disc repositioning surgery

PURPOSE

The objective of this study was to analyze the effect of TMJ disc position on condylar bone remodeling after arthroscopic disc repositioning surgery.

METHODS

Nine patients with anterior disc displacement without reduction (ADDWoR, 15 sides) who underwent arthroscopic disc repositioning surgery were included. Three-dimensional (3D) reconstruction of the articular disc and the condyle in the closed-mouth position was performed using cone-beam computed tomography (CBCT) and magnetic resonance imaging (MRI) data. Then, the CBCT and MRI images were fused and displayed together by multimodal image registration techniques. Morphological changes in the articular disc and condyle, as well as changes in their spatial relationship, were studied by comparing preoperative and 3-month postoperative CBCT-MRI fused images.

RESULTS

The volume and superficial area of the articular disc, as well as the area of the articular disc surface in the subarticular cavity, were significantly increased compared to that before the surgical treatment（P < 0.01）. There was also a significant increase in the volume of the condyle (P < 0.001). All condyles showed bone remodeling after surgery that could be categorized as one of two types depending on the position of the articular disc, suggesting that the location of the articular disc was related to the new bone formation.

CONCLUSIONS

The morphology of the articular disc and condyle were significantly changed after arthroscopic disc repositioning surgery. The 3D changes in the position of the articular disc after surgery tended to have an effect on condylar bone remodeling and the location of new bone formation.

Studying positional changes of the disc-condyle-fossa complex in ADDWoR patients after TMJ disc repositioning surgery

OBJETIVES

To investigate the positional changes in the temporomandibular joint (TMJ) disc-condyle-fossa complex of patients with anterior disc displacement without reduction (ADDWoR) and to evaluate the effect of disc repositioning (DR) surgery.

MATERIAL AND METHODS

Fifteen patients with unilateral ADDWoR (30 joints) were included. MRI of the TMJ was performed at T0 (1 week before surgery), T1 (1 month after surgery), and T2 (9-12 months after surgery). The glenoid fossa, disc, and condyle were reconstructed and analyzed using Mimics software.

RESULTS

In the patients with unilateral ADDWoR, the disc on the ADD side showed a tendency to downward shift in the coronal direction and forward shift in the sagittal direction; the condyle of ADD side showed a tendency to backward shift in the sagittal direction and upward shift in the coronal direction. When comparing the same ADDwoR TMJ at T0, T1, and T2, the disc was found to move upward and backward after DR surgery at T1 and T2, and the condyle was found to move upward and backward after DR surgery at T1 but returned to the original position at T2.

CONCLUSIONS

ADDWoR leads to forward and downward displacement of the disc relative to the condyle and upward displacement of the condyle relative to the tuberosity. DR surgery improved upon the structural abnormalities of the TMJ complex, for which stability was maintained as determined in the 9 to 12 month postoperative follow-up.

CLINIC RELEVANCE

DR surgery effectively and constantly improves the positional abnormalities of the TMJ complex.

[MRI evaluation of condylar bone regeneration after temporomandibular joint disc reduction and suture and analysis of factors affecting bone regeneration]

Objective: To evaluate the MRI manifestations of condylar bone regeneration after disc reduction and suture for anterior disc displacement without reduction (ADDWoR) patients and to analyze the relevant factors affecting bone regeneration. Methods: A total of 61 patients of 75 joints with ADDWoR who attended the Department of Maxillofacial Surgery of the Affiliated Hospital of Stomatology of Nanjing Medical University from April 2020 to December 2021 were enrolled in the study. The characteristics of MRI condylar bone regeneration were analyzed before and after surgery (follow-up for 6 months or more), and logistic regression analysis was performed on the influencing factors of bone regeneration. Results: The new bone formation of the condyle was found in 28 patients, with age of (20.2±4.9) years. However, there were 33 patients that had no condylar bone regeneration, with age of (41.9±17.5) years. A total of 35 joints in this study were found new bone formation. There were 16 joints (45.7%) had new bone formation on the posterior slope of the condyle, 10 joints (28.6%) around the condyle, 6 joints (17.1%) on the anterior slope of the condyle, and only 3 joints (8.6%) on the top of the condyle. Multivariate logistic regression analysis showed that age, preoperative disc length and degree of condylar bone resorption correlated with postoperative condylar bone regeneration(P<0.05). Patients younger than 30 years with non-shortened preoperative disc length and less condylar bone resorption have a higher probability of new bone formation. Conclusions: The condyle has bone regeneration capacity after correcting the abnormal relationship between disc and condyle, and young age, non-shortened preoperative disc length and less condylar bone resorption are conducive to postoperative condylar bone regeneration.

[A study on the arthroscopic temporomandibular joint disc reduction on the outcome of orthodontic patients with anterior disc displacement without reduction]

Objective: To investigate the arthroscopic temporomandibular joint disc reduction on the outcome of orthodontic patients with anterior disc displacement without reduction. Methods: From January 2012 to December 2021, forty treated orthodontic patients with anterior disc displacement without reduction (unilateral/bilateral) and no obvious articular cartilage absorption were selected from Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine. The patients were (17.5±3.8) years old (12-25 years old), including 8 males and 32 females. Twenty patients who had completed arthroscopic temporomandibular joint disc reduction were included in the control group, and twenty patients with untreated temporomandibular joint disc were included in the experimental group. Model measurement (including overjet, etc.), cephalometric analysis (including ANB angle, which was formed by subspinale, nasion and supramental, etc.) and temporomandibular joint magnetic resonance imaging (including measurement of the condyle height of the displacement sides) were used to compare the difference of two groups. Objective grading system was used to evaluate the efficacy of orthodontic treatment. Results: The overjet of the experimental group and the control group after orthodontic treatment was (2.19±0.76) and (1.92±0.94) mm, respectively. Both two groups achieved ideal overjet with no statistical difference (t=1.02, P=0.314). The ANB angle difference before and after treatment in the control group (-1.97°±2.87°) was greater than that in the experimental group (0.09°±1.82°), and the difference was statistically significant (t=2.72, P=0.010). The variation of condyle height before and after treatment was (0.30±1.11) mm in the experimental group and (0.82±1.25) mm in the control group, with no statistical significance (t=1.80, P=0.076). The post-treatment objective grading system scores of the experimental group and the control group were 21.00 (16.00, 24.00) and 21.00 (17.00, 25.00), respectively, which had no statistical difference (U=0.24, P=0.808). Conclusions: In orthodontic patients with anterior disc displacement without reduction and no obvious articular cartilage absorption, whether displaced discs are repositioned after arthroscopic surgery has no significant effect on the orthodontic treatment outcome.

Clinical outcomes of the discopexy using suture anchors for repositioning disc displacement in temporomandibular joints: Systematic review and meta-analysis

The present study evaluated the literature regarding the clinical outcomes after discopexy using suture bone anchors for repositioning disc displacement. A systematic review was conducted according to the PRISMA statement and applied for the PROSPERO platform. The database searches were performed in the PubMed, Scopus, Web of Science, EMBASE, The Cochrane Library, and LILACS for full articles published from no restrictions of the initial period time to April 2022. Selection criteria included clinical studies in humans comparing maximal inter-incisal opening (MIO), pain by visual analogue scale (VAS), and protrusive and lateral excursions before and after discopexy. The screening process was performed by two independent reviewers, and if they did not agree with each other, a third reviewer was consulted before proceeding. The meta-analysis was carried out by Comprehensive Meta-Analysis software. Eleven studies met the inclusion criteria. A total of 327 patients were diagnosed with disc displacement, and 142 patients were refractory to conservative and minimally surgical therapies. Preauricular and endaural approaches were performed to place suture bone anchors on the posterior area of the condyle. A significant difference was found in MIO, which ranged from 15.5 mm pre-opeatively to 41.6 mm post-operatively (p = 0.001). Pain scores using the VAS ranged from 7.42 to 0.28 indicating improvement post-operatively (p = 0.001). Mandibular excursions were underestimated. The available results have shown that discopexy using suture anchors seemed to decrease pain and improve mouth opening. Clinical studies are required in a larger sample and lower variability of follow-up time to predict actual benefits.

Investigation of Morphologic Changes in Temporomandibular Joint With Anterior Disk Displacement Based on 3-Dimensional Reconstructive Imaging

The objective of this study was to measure the association between the disk position and condylar alteration in patients diagnosed with anterior disk displacement (ADD) of temporomandibular joint (TMJ). A retrospective cross-sectional study was designed, dividing into 4 groups: normal articular disk position (NADP) of unilateral ADD patients (n=10), ADD with reduction (ADDwR, n=16), ADD without reduction (ADDwoR, n=24), and healthy volunteers (HV, n=30) based on magnetic resonance imaging and cone-beam computed tomography. After morphologic parameters were calculated from 3-dimensional reconstructive images, differences in parameters with respect to ADD status were tested with analysis of variance and Fisher least significant difference multiple comparisons were performed. Condylar volume of ADDwR, ADDwoR, NADP, and HVs were 1768.29±404.19, 1467.13±438.20, 1814.48±753.60, and 1914.66±476.48 mm, respectively, showing a significant downward trend from healthy disk to a displaced one ( P <0.05). Same trend also found in condylar superficial area, with the condylar superficial area of the ADDwR, ADDwoR, NADP, and HVs were 842.56±138.78 mm, 748.52±157.42 mm, 842.87±263.00 mm, and 892.73±164.19 mm, respectively. From NADP to ADDwR to ADDwoR, superior joint space (SJS) was declined, [SJS (NADP) (2.10±0.91 mm) > SJS (ADDwR) (1.85±0.61 mm) > SJS (ADDwoR) (1.50±0.50 mm), P =0.034]; medial joint space was significantly associated with the different disk displacement types ( P(HV-ADDwR) =0.001; P(HV-ADDwoR) =0.021; P(NADP-ADDwR) =0.022; P(ADDwR-ADDwoR) =0.001). Our findings suggest that condylar volume and superficial area, and superior and medial joint space, albeit with a small sample size, are significantly associated with different disk displacement types, detection of which might therefore be worth exploring for assessing ADD.

Decellularized-disc based allograft and xenograft prosthesis for the long-term precise reconstruction of temporomandibular joint disc

Currently, no effective disc reconstruction treatment strategy is clinically available for temporomandibular joint (TMJ) disc-related diseases. To address this, we developed a prosthesis construct with laser-drilled decellularized natural disc reinforced by polycaprolactone, which mimics the natural morphology, and structural, biomechanical and biological property of the TMJ disc. The construct demonstrated good biocompatibility, safety and immunological tolerance both in vitro, and in a rat subcutaneous model. During 6 months implantation in an allogeneic rabbit TMJ disc reconstruction model, the disc prosthesis maintained its integrity, collagen fiber-orientation, mechanical property, joint structural stability and prevented articular cartilage and bone from damage. Furthermore, the "upgraded" disc prosthesis obtained from decellularized porcine disc was implanted into a goat TMJ disc reconstruction model. The xenograft prosthesis, with strength and viscoelasticity similar to a natural TMJ disc, was able to restore the structure and function of TMJ up to 20 weeks. These results demonstrate the translational feasibility of an allogeneic or xenogeneic decellularized disc prosthesis for treatment of advanced TMJ disc-related diseases. STATEMENT OF SIGNIFICANCE: This study makes a significant contribution to TMJ disc disease treatment both in theory and in clinics, because: (1) it provided an innovative approach to prepare an artificial TMJ disc with decent mechanical properties and long-term condyle-protecting effect; (2) it specified an advanced decellularized method for fibrocartilage decellularization and xenograft application; (3) it developed a facile and reproducible TMJ disc reconstruction model not only for middle size animal but also for large animal study; (4) the comprehensive and unreported biomechanical tests on the natural TMJ discs would act as a valuable reference for further research in the field of artificial TMJ disc materials or TMJ disc tissue engineering; (5) it suggested a potential treatment for patients with severe TMJ diseases that were commonly met but difficult to treat in clinics.

Arthroscopic osteoplasty of the medial and anteromedial wall of temporomandibular joint: surgical technique and anatomical considerations

The anterior displacement of the articular disc is the most frequent cause of pathological alterations in the TMJ. Although it is an extremely common pathology, there is no certainty about the aetiopathogenesis of this disease. The main aim of the present report is to describe new anatomical findings that could help clarifying the aetiopathogenesis of this disease and determine a typology of treatment based on the cause of the disease. All the operative records of patients who underwent arthroscopic osteoplasty of the medial TMJ wall in our centre from January 2021 to September 2021 were reviewed and analysed to identify specific anatomical features observed in every procedure. Fifty-two joints were included for analysis in this study. Twenty-two joints were classified as Wilkes stages II-III and 30 as Wilkes stages IV-V. The most common complication observed in our sample was the dysaesthesias found in the temporal and preauricular regions. Other complications observed were frontal branch paresis (n = 2), intraoperative bleeding (n = 1), and postoperative malocclusion (n = 1). The compression of the superior head of pterygoid lateral muscle (SPLM) on the medial bony wall and the consequent muscle atrophy could be key for the aetiology of the anterior TMJ disc displacement. Therapeutic actions on the osseous and muscular component in this anatomical area could improve the outcomes of patients affected by TMJ internal derangement. A meticulous dissection of the fascia of the superior fascicle of the lateral pterygoid muscle allows a remodelling of the bone surfaces with minimal complications.

Impact of Small Incision Reduction and Suture Linked with Functional Appliance of Sufferers with Irrecoverable TMJ Anterior Disc Displacement

Methods

90 patients with irreducible ADD of TMJ treated from August 2020 to August 2021 were acquired in our hospital. They were randomly divided into control group and trial group randomly. There were 45 patients in each group. The sufferers in the control group were treated with oral drug therapy and small incision reduction and suture, while those in the trial group were treated with small incision reduction and suture linked with functional appliance. The pain score, dysfunction, joint function recovery, facial improvement, and clinical impacts of the two groups were contrasted.

Results

Compared with that in the control group at 1 week, 4 weeks, and 6 months after therapy, the pain score in the trial group was markedly higher. After therapy, in the two groups, maximum vertical opening (MVO), left lateral excursion (LLE), and right lateral excursion (RLE) levels were markedly higher than those in the control group. The MRI score of the trial group was markedly higher than that of the control group at 1 week, 4 weeks, and 6 months after therapy, and the total effective rate of the trial group was markedly higher than that of the control group.

Conclusion

The use of small incision reduction and suture linked with functional appliance in the therapy of sufferers with irreducible ADD of TMJ is beneficial to relieve pain, promote the recovery of body function, and contribute to the recovery of joint function.

Inductive Remodeling of Extracellular Matrix Scaffolds in the Temporomandibular Joint of Pigs

The temporomandibular joint (TMJ) disc is a fibrocartilaginous tissue located between the condyle of the mandible and glenoid fossa and articular eminence of the temporal bone. Damage or derangement of the TMJ disc can require surgical removal (discectomy) to restore function. Removal of the TMJ disc, however, leaves the joint space vulnerable to condylar remodeling and degradation, potentially leading to long-term complications. No consistently effective clinical option exists for repair or replacement of the disc following discectomy. This study investigates the use of an acellular scaffold composed of extracellular matrix (ECM) derived from small intestinal submucosa (SIS) as a regenerative template for the TMJ disc in a porcine model. Acellular SIS ECM scaffolds were implanted following discectomy and allowed to remodel for 2, 4, 12, and 24 weeks postimplantation. Remodeling of the implanted device was assessed by longitudinal magnetic resonance imaging (MRI) over the course of 6 months, as well as gross morphologic, histologic, biochemical, and biomechanical analysis (tension and compression) of explanted tissues (disc and condyle) at the time of sacrifice. When the scaffold remained in the joint space, longitudinal MRI demonstrated that the scaffolds promoted new tissue formation within the joint space throughout the study period. The scaffolds were rapidly populated with host-derived cells and remodeled with formation of new, dense, aligned fibrocartilage resembling native tissue as early as 1 month postimplantation. De-novo formation of peripheral muscular and tendinous attachments resembling those in native tissue was also observed. The remodeled scaffolds approached native disc biochemical composition and compressive modulus, and possessed 50% of the tensile modulus within 3 months postimplantation. No degradation of the condylar surface was observed. These results suggest that this acellular bioscaffold fills a medical need for which there is currently no effective treatment and may represent a clinically relevant "off-the-shelf" implant for reconstruction of the TMJ disc.

Mini suture anchor: An effective device for reduction and fixation of displaced temporomandibular joint disc with intracapsular condylar fracture

PURPOSE

The main aim is to provide clinical reference for the application of mini suture anchor in the reduction and fixation of displaced temporomandibular joint (TMJ) disc with intracapsular condylar fracture.

METHODS

From October 2018 to October 2019, 21 patients (31 sides) with intracapsular condylar fractures and articular disc displacement from West China Hospital of Stomatology, Sichuan University were included. The selection criteria were: (1) mandibular condylar fractures accompanied by displacement of the TMJ disc, confirmed by clinical examination, CT scan and other auxiliary examinations; (2) indication for surgical treatment; (3) no surgical contraindications; (4) no previous history of surgery in the operative area; (5) no facial nerve injury before the surgery; (6) informed consent to participate in the research program and (7) complete data. Patients without surgical treatment were excluded. The employed patients were followed up at 1, 3, 6 and 12 months after operation. Outcomes were assessed by success rate of operation, TMJ function and radiological examination results at 3 months after operation. Data were expressed as number and percent and analyzed using SPSS 19.0.

RESULTS

All the surgical procedures were completed successfully and all the articular discs were firmly attached to the condyles. The articular disc sufficiently covered the condylar head after the fixation. The fixation remained stable when the mandible was moved in each direction by the surgeons. No complications occurred. The functions of the TMJ were well-recovered postoperatively in most cases. CT scan revealed that the screws were completely embedded in the bone without loosening or displacement.

CONCLUSION

Mini suture anchor can provide satisfactory stabilization for the reduced articular disc and also promote the recovery of TMJ functions.

Knee orthopedics as a template for the temporomandibular joint

Although the knee joint and temporomandibular joint (TMJ) experience similar incidence of cartilage ailments, the knee orthopedics field has greater funding and more effective end-stage treatment options. Translational research has resulted in the development of tissue-engineered products for knee cartilage repair, but the same is not true for TMJ cartilages. Here, we examine the anatomy and pathology of the joints, compare current treatments and products for cartilage afflictions, and explore ways to accelerate the TMJ field. We examine disparities, such as a 6-fold higher article count and 2,000-fold higher total joint replacement frequency in the knee compared to the TMJ, despite similarities in osteoarthritis incidence. Using knee orthopedics as a template, basic and translational research will drive the development and implementation of clinical products for the TMJ. With more funding opportunities, training programs, and federal guidance, millions of people afflicted with TMJ disorders could benefit from novel, life-changing therapeutics.

Research progress on tissue engineering in repairing tempomandibular joint

Temporomandibular joint osteoarthritis (TMJOA) is mainly manifested as perforation of temporomandibular joint disc (TMJD) and destruction of condylar osteochondral complex (COCC). In recent years, tissue engineering technology has become one of the effective strategies in repairing this damage. With the development of scaffold material technology, composite scaffolds have become an important means to optimize the performance of scaffolds with the combined advantages of natural materials and synthetic materials. The gelling method with the minimally invasive concept can greatly solve the problems of surgical trauma and material anastomosis, which is beneficial to the clinical transformation of temporomandibular joint tissue engineering. Extracellular matrix scaffolds technology can solve the problem of scaffold source and maximize the simulation of the extracellular environment, which provides an important means for the transformation of temporo joint tissue engineering to animal level. Due to the limitation of the source and amplification of costal chondrocytes, the use of mesenchymal stem cells from different sources has been widely used for temporomandibular joint tissue engineering. The fibrochondral stem cells isolated from surface layer of articular cartilage may provide one more suitable cell source. Transforming growth factor β superfamily, due to its osteochondrogenesis activity has been widely used in tissue engineering, and platelet-rich derivative as a convenient preparation of compound biological factor, gradually get used in temporomandibular joint tissue engineering. With the deepening of research on extracellular microenvironment and mechanical stimulation, mesenchymal stem cells, exosomes and stress stimulation are increasingly being used to regulate the extracellular microenvironment. In the future, the combination of complex bioactive factors and certain stress stimulation may become a trend in the temporomandibular joint tissue engineering research. In this article, the progress on tissue engineering in repairing COCC and TMJD, especially in scaffold materials, seed cells and bioactive factors, are reviewed, so as to provide information for future research design and clinical intervention.

Is Arthroscopic Disk Repositioning Equally Efficacious to Open Disk Repositioning? A Systematic Review

PURPOSE

Temporomandibular joint disc repositioning surgery is 1 of the treatment modalities used for treating anterior disc displacement of the temporomandibular joint. The procedure can be arthroscopic disc repositioning or open disc repositioning. This systematic review measured and compared the efficacy of arthroscopic and open disc repositioning procedures.

MATERIALS AND METHODS

The authors conducted a systematic review without meta-analysis by performing a literature search electronically and manually covering arthroscopic and open disc repositioning studies published up to July 2020 in Pubmed, Embase, and Cochrane databases. Surgical outcomes such as changes in maximal incisal opening (MIO) and pain scores, temporomandibular joint noises, diet consistency, malocclusion, and postoperative complications were extracted and analyzed.

RESULTS

A total of 28 studies were included in the review and split into those assessing open disc repositioning (n = 13) and those assessing arthroscopic disc repositioning (n = 15). The average age of the study patients in the included studies was 31.5 ± 6.8 years, and women represented 83.3% of the study population. Both arthroscopic and open disc repositioning showed to be efficacious in reducing pain and increasing MIO. Due to heterogeneity in study designs and data reporting between the studies, no quantitative analysis was performed, and the groups were not directly compared.

CONCLUSIONS

Both arthroscopic and open disc repositioning led to significant improvements in clinical outcomes based on pain scores and MIO. This study highlights the need for comparative studies of the 2 techniques with well-documented case selection including standardized diagnosis based on Wilkes stages and rigorous outcomes assessment including patient reported outcomes.

Does Repositioning of Temporomandibular Joint Disc With Bone Anchors Provide Better Clinical Outcomes Than Conventional Disc Plication Procedures for Anterior Disc Displacements Without Reduction in Patients Refractory to Nonsurgical Treatments?

PURPOSE

Although open temporomandibular joint arthroplasty with discopexy is a common treatment for patients with anterior disc displacements without reduction (ADDWo) unresponsive to medical management, there are no studies comparing disc repositioning with bone anchors and conventional discopexy procedure. The purpose of the study was to compare the efficacy between disc repositioning with bone anchors and the conventional discopexy procedure for ADDWo of temporomandibular joint refractory to medical management.

PATIENTS AND METHODS

A randomized controlled trial was conducted in patients with ADDWo. The primary objective was to compare the improvement in mouth opening (primary outcome variable) between the 2 treatment (primary predictor variable) groups-disc repositioning with bone anchors versus conventional disc plication. Secondary outcome variables were pain measured by visual analog scale, lateral excursions, and position of the disc evaluated by magnetic resonance imaging (MRI). Other variables of interest were age, gender, and duration of symptoms. The parameters were evaluated at preoperative, postoperative day 1, and 1-, 6-, and 12-month postoperative period. Categorical variables were compared with χ² test and continuous variables with analysis of variance and adjusted for multiple comparisons with Bonferroni test.

RESULTS

The study sample comprised 14 patients (7 in each group) with MRI-proven ADDWo. Statistically significant differences were found in the improvement of mouth opening between the 2 groups, showing better improvement with bone anchors (14.42 ± 5.96 vs 7.57 ± 7.25 mm; P < .05). The reduction in visual analog scale also showed statistically significant difference with better pain reduction achieved with bone anchor (4.57 ± 1.61 vs 3.28 ± 0.75; P < .05). There was no statistically significant difference in lateral excursions and postoperative position of the disc evaluated by MRI between the groups at the 12-month follow-up period.

CONCLUSIONS

Disc repositioning with bone anchors provides better clinical outcomes in terms of maximal mouth opening and pain scores compared with conventional disc plication.

Key points in surgical management of mandibular condylar fractures

Mandibular condylar fractures are among the most common facial fractures and some of the most difficult to manage. Opinions about the management of mandibular condylar fractures differ among surgeons. With the implementation of new technology, an increased understanding of fracture management, and better functional and morphological outcomes reported in the literature, open reduction and internal fixation is becoming many surgeons' preferred choice for the treatment of condylar fractures. Because surgical treatment of such fractures is complex, certain factors must be considered to achieve satisfactory outcomes. In this article, we summarise six key points in the management of mandibular condylar fractures: virtual evaluation of condylar fracture, a suitable surgical approach, good reduction, stable internal fixation, repair of the articular disc, and restoration of the mandibular arch width. We believe that these points will help to improve the prognosis of mandibular condyle fractures.

Fibro/chondrogenic differentiation of dental stem cells into chitosan/alginate scaffolds towards temporomandibular joint disc regeneration

Tissue engineering (TE) may provide effective alternative treatment for challenging temporomandibular joint (TMJ) pathologies associated with disc malpositioning or degeneration and leading to severe masticatory dysfunction. Aim of this study was to evaluate the potential of chitosan/alginate (Ch/Alg) scaffolds to promote fibro/chondrogenic differentiation of dental pulp stem cells (DPSCs) and production of fibrocartilage tissue, serving as a replacement of the natural TMJ disc. Ch/Alg scaffolds were fabricated by crosslinking with CaCl2 combined or not with glutaraldehyde, resulting in two scaffold types that were physicochemically characterized, seeded with DPSCs or human nucleus pulposus cells (hNPCs) used as control and evaluated for cell attachment, viability, and proliferation. The DPSCs/scaffold constructs were incubated for up to 8 weeks and assessed for extracellular matrix production by means of histology, immunofluorescence, and thermomechanical analysis. Both Ch/Alg scaffold types with a mass ratio of 1:1 presented a gel-like structure with interconnected pores. Scaffolds supported cell adhesion and long-term viability/proliferation of DPSCs and hNPCs. DPSCs cultured into Ch/Alg scaffolds demonstrated a significant increase of gene expression of fibrocartilaginous markers (COLI, COL X, SOX9, COM, ACAN) after up to 3 weeks in culture. Dynamic thermomechanical analysis revealed that scaffolds loaded with DPSCs significantly increased storage modulus and elastic response compared to cell-free scaffolds, obtaining values similar to those of native TMJ disc. Histological data and immunochemical staining for aggrecan after 4 to 8 weeks indicated that the scaffolds support abundant fibrocartilaginous tissue formation, thus providing a promising strategy for TMJ disc TE-based replacement.

Predictors of arthrocentesis outcome on joint effusion in patients with disk displacement without reduction

OBJECTIVES

The aim of this study was to investigate the preoperative variables in patients with articular disk displacement without reduction that may influence the results of arthrocentesis on joint effusion (JE).

STUDY DESIGN

The records of 203 patients with clinical signs and symptoms of unilateral painful disk displacement without reduction and JE, confirmed by magnetic resonance imaging (MRI), and treated with arthrocentesis were selected. The following preoperative data were recorded: sex; age; joint side; pain duration; pain intensity, measurement with the visual analogue scale; and maximum interincisal distance (MID). All patients underwent a second MRI examination 3 to 4 months postoperatively to assess JE. The sample was then divided into 2 groups: group 1 (n = 160) comprised patients with no signs of JE; and group 2 (n = 43) comprised patients still showing signs of JE. Univariate and multivariate analyses were used to compare the groups.

RESULTS

Among the studied variables, pain duration (P = .0175), pain intensity (P < .0001), and MID (P = .0085) were shown to affect arthrocentesis outcomes. The longer the pain duration (odds ratio [OR] = 0.930), the more intense was the pain (OR = 0.346), and the smaller the MID (OR = 0.562), the less were the chances of arthrocentesis completely eliminating JE.

CONCLUSIONS

Pain duration, pain intensity, and MID can be used as predictors for the effect of arthrocentesis on JE outcomes and considered during treatment planning.

Impact of Temporomandibular Joint Discectomy on Condyle Morphology: An Animal Study

PURPOSE

Temporomandibular disorders lead to parafunctional activity that may alter bone remodeling of mandibular components. This animal study aimed to assess the impact of temporomandibular joint discectomy on condylar bone microarchitecture.

MATERIALS AND METHODS

A total of 30 one-month-old Wistar rats were assessed and divided into 3 equal groups (2 test groups and 1 control group) of 10. The first test group underwent disc removal, the second test group underwent disc and condylar cartilage removal, and the 10 remaining rats were analyzed as sham-operated controls, following a split-mouth design. The rats were killed humanely 2 months after surgery, and the respective mandibles were scanned with micro-computed tomography for quantitative morphometric analysis.

RESULTS

There were significant differences among the 3 groups analyzed (disc removal, disc and condylar cartilage removal, and sham-operated control) for bone volume fraction (ratio of bone volume to total volume, P = .044), structure model index (P < .001), fractal dimension (P = .024), and porosity (P = .023). In addition, operated and contralateral nonoperated sides significantly differed for all variables in at least 1 of the test groups (P < .05) but not in the control group (P > .05).

CONCLUSIONS

Within the limitations of this study, our results suggest that discectomy may lead to alterations of the mandibular condylar morphology.

Abducens palsy after temporomandibular joint arthroscopy: a rare complication

BACKGROUND

Arthroscopy of the temporomandibular joint (TMJ) is a minimally invasive and safe procedure; nevertheless, some accidents and complications have been described in the literature.

CASE REPORT

The purpose of this article is to describe a case report of a patient that progressed to paralysis of the abducens nerve after a TMJ arthroscopy procedure.

[Clinical symptoms and temporomandibular joint disc deformity study of Wilkes III stage patients treated with arthrocentesis]

OBJECTIVE

This study aims to evaluate the effectiveness of arthrocentesis on Wilkes III stage patients. Clinical examinations and magnetic resonance imaging (MRI) findings before treatment and six months after treatment were compared and analyzed.

METHODS

A total of 137 outpatients diagnosed with temporomandibular joint internal derangement (TMJID) associated with Wilkes III stage through clinical examination and MRI findings from January 2013 to December 2013 were randomly included. All the patients were successfully treated with arthrocentesis. Moreover, all the patients accepted clinical and MRI examination before arthrocentesis treatment and six months after. Clinical examination included visual analogue scale and opening degree, whereas MRI examination included articular disc morphology and effusion in the upper compartments. Statistical analysis was performed using SPSS 20.0.

RESULTS

Results showed that the average score of visual analogue scale six months after treatment was significantly lower than that before treatment (P < 0.05). The success rate was 78.1% (107/137). The rate of disc deformity after arthrocentesis treatment was higher than that before the treatment. By contrast, the positive rate of effusion after arthrocentesis was significantly lower than that before the treatment (P < 0.05). Bilaminar zone adaptive changes (disk-like) were found in seven cases (5.1%, 7/137) after treatment.

CONCLUSION

Arthrocentesis could effectively relieve pain of the TMJID patients. Furthermore, MRI results indicated that arthrocentesis could significantly decrease articular effusion. Arthrocentesis was effective for the treatment of Wilkes III stage in the short term. Adaptive changes in bilaminar zone occurred in a few patients. However, serious disc deformity with the passage of time is a trend that has been observed.

[Clinical symptoms and temporomandibular joint disc deformity study of Wilkes III stage patients treated with arthrocentesis]

OBJECTIVE

This study aims to evaluate the effectiveness of arthrocentesis on Wilkes III stage patients. Clinical examinations and magnetic resonance imaging (MRI) findings before treatment and six months after treatment were compared and analyzed.

METHODS

A total of 137 outpatients diagnosed with temporomandibular joint internal derangement (TMJID) associated with Wilkes III stage through clinical examination and MRI findings from January 2013 to December 2013 were randomly included. All the patients were successfully treated with arthrocentesis. Moreover, all the patients accepted clinical and MRI examination before arthrocentesis treatment and six months after. Clinical examination included visual analogue scale and opening degree, whereas MRI examination included articular disc morphology and effusion in the upper compartments. Statistical analysis was performed using SPSS 20.0.

RESULTS

Results showed that the average score of visual analogue scale six months after treatment was significantly lower than that before treatment (P < 0.05). The success rate was 78.1% (107/137). The rate of disc deformity after arthrocentesis treatment was higher than that before the treatment. By contrast, the positive rate of effusion after arthrocentesis was significantly lower than that before the treatment (P < 0.05). Bilaminar zone adaptive changes (disk-like) were found in seven cases (5.1%, 7/137) after treatment.

CONCLUSION

Arthrocentesis could effectively relieve pain of the TMJID patients. Furthermore, MRI results indicated that arthrocentesis could significantly decrease articular effusion. Arthrocentesis was effective for the treatment of Wilkes III stage in the short term. Adaptive changes in bilaminar zone occurred in a few patients. However, serious disc deformity with the passage of time is a trend that has been observed.

Delayed progression of condylar cartilage degeneration, by reduction of the discoidin domain receptor 2, in the temporomandibular joints of osteoarthritic mouse models

OBJECTIVE

To determine whether reduction of the discoidin domain receptor 2 (Ddr2) delays the progression of condylar cartilage degeneration in the temporomandibular joint (TMJ) of mouse models with osteoarthritis (OA).

METHODS

Double-heterozygous (Col11a1- and Ddr2-haploinsufficiency, Col11a1(+/−);Ddr2(+/−)) mice were generated. TMJs of Ddr2(+/−) mice were subjected to partial discectomy. Condylar cartilage from the TMJ of Col11a1(+/−);Ddr2(+/−) mice, surgically treated (discectomy) Ddr2(+/−) mice, and their corresponding controls was characterized by means of histology and evaluated using a scoring system specific to mouse joints.

RESULTS

The progression of condylar cartilage degeneration was significantly delayed in the TMJ of Col11a1(+/−);Ddr2(+/−) mice compared with those of the Col11a1(+/−) mice. The progression of condylar cartilage degeneration in the TMJ of Ddr2(+/−) mice following discectomy was also significantly delayed when compared with their wild-type littermates.

CONCLUSION

Reduced expression of Ddr2 delays the progression of condylar cartilage degeneration, induced either by type XI collagen haploinsufficiency or by a partial discectomy, in TMJ.

Recurrent dislocation of the temporomandibular joint: a literature review and two case reports treated with eminectomy

AIMS

Dislocation of the temporomandibular joint (TMJ) is a troublesome condition that occurs in a chronic or acute form. It is a distressing and highly embarrassing situation that may occur as a result of daily activities such as yawning, laughing, or during events that require keeping the mouth open for a long time. This review aims to present and discuss different conservative and surgical techniques to treat patients with a dislocated mandible, and to present two cases of surgical treatment.

METHODOLOGY

A search of the literature was completed (Medline, PubMed) using the keywords TMJ dislocation, TMJ luxation, mandibular dislocation and surgical and non-surgical methods of treatment for this condition.

RESULTS

Eminectomy (Myrhaug's surgery) has been used with satisfactory results. Most of reports present large series of patients with more than one year of follow-up and no recurrence of complications. Is less invasive and take a short operation time; need no bone transplantation or placing any kind of foreign body into the joint.

CONCLUSION

Eminectomy results in long-term resolution of recurrent TMJ dislocations, when compared with others surgical techniques.

Temporomandibular disorders: a review of etiology, clinical management, and tissue engineering strategies

Temporomandibular disorders (TMD) are a class of degenerative musculoskeletal conditions associated with morphologic and functional deformities that affect up to 25% of the population, but their etiology and progression are poorly understood and, as a result, treatment options are limited. In up to 70% of cases, TMD are accompanied by malpositioning of the temporomandibular joint (TMJ) disc, termed "internal derangement." Although the onset is not well characterized, correlations between internal derangement and osteoarthritic change have been identified. Because of the complex and unique nature of each TMD case, diagnosis requires patient-specific analysis accompanied by various diagnostic modalities. Likewise, treatment requires customized plans to address the specific characteristics of each patient's disease. In the mechanically demanding and biochemically active environment of the TMJ, therapeutic approaches that can restore joint functionality while responding to changes in the joint have become a necessity. One such approach, tissue engineering, which may be capable of integration and adaptation in the TMJ, carries significant potential for the development of repair and replacement tissues. The following review presents a synopsis of etiology, current treatment methods, and the future of tissue engineering for repairing and/or replacing diseased joint components, specifically the mandibular condyle and TMJ disc. An analysis of native tissue characterization to assist clinicians in identifying tissue engineering objectives and validation metrics for restoring healthy and functional structures of the TMJ is followed by a discussion of current trends in tissue engineering.

The efficacy of a specific stabilization splint

BACKGROUND

The use of a Tanner type stabilization splint, fabricated on a leaf gauge articulation for the treatment of patients with disc displacement without reduction, is lacking in the literature.

OBJECTIVES

The purpose of the study is to collect non-controlled, therapy-related observations; in other words, to demonstrate the efficacy of this appliance for the treatment of patients with disc displacement without reduction.

METHODS

The study enrolled 55 patients, 5 men, and 50 women, with the clinical diagnosis disc displacement without reduction, 42 with and 13 without limited mouth opening. All patients received a splint in the musculoskeletally stable centric relation (CR) position. Mouth opening, clinical performance, and the timeframe of splint treatment were assessed.

RESULTS

For 37 patients with a disc displacement without reduction with limited opening, the largest increase in mouth opening (9.5 +/- 5.6 mm) occurred in the first week (7.9 +/- 2.5 days). No occlusal adjustment of the splint was needed during the treatment sequence. For three patients, treatment took up to 3 months (8.1%), for 13 patients, between 3 and 6 months (35.1%), and for 17 patients, within a year (45.9%), making a total of 89.1% successfully treated patients. Out of 50 patients, 29 had a total resolution of signs and symptoms, whereas 21 patients still suffered from solitary temporomandibular disorder (TMD) signs.

CONCLUSION

A Tanner type stabilization splint, fabricated in the musculoskeletally stable CR position, appears to be an effective and efficient means for the treatment of patients with disc displacement without reduction. Its efficacy makes it eligible to be tested in a randomized controlled trial.

CLINICAL IMPLICATIONS

The efficacy of this specific splint, fabricated in the musculoskeletally stable CR position, makes it a promising tool to treat TMD patients with disc displacement without reduction.

Features and management of intracranial mandibular condyle dislocation after trauma

BACKGROUND

Dislocation of the mandibular condyle into the middle cranial fossa is rare in clinics. It often occurs when the mouth is open wide during the injury. It causes restriction of mandibular motion, lower facial asymmetry, pain in the temporomandibular joint (TMJ), etc.

OBJECTIVE

To introduce the features of intracranial mandibular condyle dislocation and discuss the management to this kind of trauma.

MAJOR FINDINGS

In this paper, the authors present two cases, describing the diagnosis, surgical management, and 1-year follow-up evaluation. The results of the authors' treatment to intracranial mandibular condyle dislocation were satisfactory and stable, and no surgical complications were detected.

CONCLUSION

Advanced imaging studies are mandatory for exact diagnosis and successful treatment of intracranial mandibular condyle dislocation, and individualized management is recommended.

Lingual orthodontics as an aesthetic resource in the preparation of orthodontic/surgical treatment

The lingual technique was introduced in the late '70s and, just like orthodontics, it has developed significantly in the past few years. Adult and young adult have been attracted to such alternative aesthetic treatment. Despite their need of orthodontic treatment, they want to have an aesthetic alternative, as "invisible" as possible--something that can be achieved with the lingual technique. Nevertheless, many treatment or re-treatment cases also demand correction through orthognathic surgery, a process which is nowadays much simpler and considered an effective auxiliary method for the malocclusion correction. Having posed that, this study aims to show correction of malocclusion and discrepancy between dental arches through lingual orthodontic technique associated to orthognathic surgery. This study shows that it is possible to provide the patient who suffers frJom malocclusion with proper correction, achieving the desired aesthetics by using lingual braces and pe?forming lingual orthognathic surgery.

Unilateral bony ankylosis of the temporomandibular joint in a case of ankylosing spondylitis

BACKGROUND

Ankylosing spondylitis (AS) is a chronic inflammatory disease with multiple articular and para-articular involvement that has a predilection for the axial skeleton. In spite of its high prevalence, ankylosis secondary to AS is a rare condition.

CASE REPORT

A 31-year-old male diagnosed with AS was referred for computed tomography (CT) of the temporomandibular joint (TMJ) due to severe mouth opening limitation. The patient had a 16-year medical history of AS and sought assistance due to TMJ pain and incapacity to open his mouth.

RESULTS

Previous bony scintigraphy revealed involvement of the spine, sacroiliac joints, right knee, and left TMJ. Magnetic resonance imaging revealed erosion of the left condyle and posterior slope of the articular eminence, and a mass of heterogeneous signal intensity between these structures. The left condyle also presented sclerosis/edema of the bone marrow and the disk could not be identified. Sagittal and coronal CT images showed moderate alterations of the TMJ on the right side. On the left side, the images displayed markedly eroded condyle and mandibular fossa, and a bony mass resulting in ankylosis of the osseous components of the joint.

CONCLUSION

TMJ ankylosis in AS patients is rare and very few reports have presented imaging features of the condition through advanced diagnostic techniques.

Langzeitkontrolle von 37 Patienten mit Diskusretrofixation im Zeitraum von 1986–1995

Between January 1986 and December 1995 64 patients with anterior disc displacement were operated on, the technique being disc retrofixation. Follow-up of 37 patients was possible. Successful treatment was determined using the following criteria: one single operation, the clinical examination and the patient's opinion. The operative treatment was considered as unsuccessful if the patient had to undergo more than one operation or if, postoperatively, the clinical symptoms remained unchanged or even increased. 6 out of 37 patients were operated on twice or three times, another four patients postoperatively complained of unchanged or increased clinical symptoms. Using these criteria, disc retrofixation was ineffective in 30%. Using the correct anatomic position as an additional criterion of effective treatment, unsuccessful retrofixation would be even more than 30%. As a consequence we no longer recommend this technique.

Open versus closed reduction: diacapitular fractures of the mandibular condyle

PURPOSE

The purpose of the study was to review the literature regarding the evolution of current thoughts on management of diacapitular fractures (DFs) of the mandibular condyle.

METHODS

An electronic search in PubMed was undertaken in March 2012. The titles and abstracts from these results were read to identify studies within the selection criteria. Eligibility criteria included studies reporting clinical series of DFs, including both animal and human studies, without date or language restrictions.

RESULTS

The search strategy initially yielded 108 references. Twenty-eight studies were identified without repetition within the selection criteria. Additional hand-searching of the reference lists of selected studies yielded three additional papers.

CONCLUSIONS

The current indications for open reduction and internal fixation (ORIF) of DFs described in the literature are: (a) fractures affecting the lateral condyle with reduction of mandibular height; (b) fractures in which the proximal fragment dislocates laterally out of the glenoid fossa, which cannot be reduced by closed or open treatment of another part of the mandibular fracture. The indications for conservative treatment are: (a) fractures that do not shorten the condylar height (a fracture with displacement of the medial parts of the condyle); (b) undisplaced fractures; (c) comminution of the condylar head, when the bony fragments are too small for stable fixation; and (d) fractures in children. As the temporomandibular joint disk plays an important role as a barrier preventing ankylosis, it is important to reposition the disk (if displaced/dislocated) during the surgical treatment of DFs. The lateral pterygoid muscle should never be stripped from the medially displaced fragment because its desinsertion disrupts circulation to the medial bony fragment, and also because this muscle helps to restore the muscle function after surgery. ORIF of selected DFs improves prognosis by anatomical bone and soft tissue recovery when combined with physical therapy. If conducted properly, surgical treatment of DFs is a safe and predictable procedure and yields good results.

Computer-assisted virtual technology in intracapsular condylar fracture with two resorbable long-screws

Our aim was to fix intracapsular condylar fractures (ICF) with two resorbable long screws using preoperative computer-assisted virtual technology. From February 2008 to July 2011, 19 patients with ICF were treated with two resorbable long screws. Preoperatively we took panoramic radiographs and spiral computed tomography (CT). Depending on their digital imaging and communications in medicine (DICOM) data, the dislocated condylar segments were restored using the SimPlant Pro™ software, version 11.04. The mean (SD) widths of the condylar head and neck from lateral to medial were 19.01 (1.28)mm and 13.84 (1.13)mm, respectively. In all patients, the mandibles and the ICF seen intraoperatively corresponded with the preoperative three-dimensional and virtual reposition. All patients were followed up for 6-46 months (mean 21). Occlusion and mouth opening had been restored completely in all but one patient, and absolute anatomical reduction was also achieved in most cases. Computer-assisted virtual technology plays an important part in the diagnosis of ICF, as well as in its preoperative design. Fixation with only two resorbable long screws is an effective and reliable method for fixing ICF.

Macroscopic and histologic analysis of abdominal dermis-fat grafts retrieved from human temporomandibular joints

PURPOSE

The purpose of the present study was to examine the fate of the abdominal dermis-fat grafts that were implanted into human temporomandibular joints (TMJ) at the macroscopic and histologic levels.

PATIENTS AND METHODS

The clinical records of 123 patients who underwent TMJ discectomy with dermis-fat grafting during a 10-year period (2000 to 2009) were reviewed, and 8 patients were identified who had had the dermis-fat graft surgically removed from their TMJ at a subsequent operation. The retrieved grafts were assessed at the macroscopic and histologic levels for size, consistency, and cellular composition. The dermis-fat grafts were retrieved after a period of 8 to 46 months (mean, 22.3) after initial implantation into the TMJ.

RESULTS

The graft material was a rubbery consistency and filled the entire joint space between the condylar head and glenoid fossa/articular eminence. The average size of the retrieved grafts was 16 mm × 14 mm × 7 mm, with a mean volumetric dimension of 1.57 ± 0.38 cm(3). The interpositional tissue retrieved from all joints demonstrated clear histologic evidence of mature adipose tissue interspersed with dermal elements such as sweat glands and hair follicles that were atrophied. The ratio of fat/nonfat tissue was significantly (P < .01) less (mean, 31.3% ± 5.7%) than in the original (mean, 90.2% ± 6.3%) graft. No evidence was found of dermoid cysts or necrotic fat in any of the specimens examined.

CONCLUSION

The results of the present study showed that abdominal dermis-fat grafts transplanted to the TMJ do thrive and adapt well to the confines of the joint cavity, allowing functional movement of the joint. However, in the present study, the dermis-fat graft failed to protect the condyle against additional deterioration in 6.5% of patients who went on to have total joint replacements.

[Reconstruction of the TMJ and ramus in otomandibular dysplasia, by grafting of TMJ and homologous bone branch]

INTRODUCTION

Otomandibular dysplasia is a syndrome of deformities that can affect all latero-facial structures, although the main clinical manifestations include maxillary and mandibular hypoplasia and possibly the absence of the temporo-mandibular joint.

OBSERVATION

A 18-year-old man with otomandibular dysplasia was treated by grafting in a homologous joint and bone branch.

DISCUSSION

There is no consensus on the best age to treat the syndrome and on treatment for mandibular hypoplasia and to reconstruct the temporo-mandibular joint. An alternative to the suggested treatments consists in reconstructing the joint and the branch affected by hypoplasia by grafting in a homologous joint and bone branch.

[Application of lateral lag screw with sagittal condylar fracture and management of articular disk]

OBJECTIVE

To evaluate the application of lateral lag screw and reduction of articular disk in management of intracapsular sagittle fractures of the condylar process.

METHODS

The study group consisted of 16 cases (19 joints), including 10 males (12 joints) and 6 females (7 joints). Condylar sagittal fracture and displaced articular disk were detected in all patients. The condylar segments were repositioned and fixed by using lateral lag screw and the displaced articular disk were repositioned at the same time. The mean postoperative follow-up was 16 months (range 6-28 months). During the follow up, facial nerve function was monitored and radiologic re-examinations were performed to evaluate reposition of condylar process fractures and articular disk, while the mouth opening and occlusion were registered.

RESULTS

The reduction of the displaced condylar fragments and articular disks in all patients were excellent on 3D CT and MRI. No severe complications were observed (including permanent facial nerve palsies, malocclusion, ankylosis). Three months after surgery, all patients showed their better mobility with condylar and disk, and mouth opening reached 43 mm on maximum, 32 mm on minimum, with a mean of 37 mm.

CONCLUSION

The results by application of lateral lag screw and reduction of articular disk are helpful in anatomical and functional recovery of temporomandibular joint for patients with displaced sagittal condylar process fractures.

Histologic and histomorphometric analysis of posterior region of the human temporomandibular disc

OBJECTIVE

The aim of this study was to analyze histologic and histomorphometric features of the articular disc in groups with and without disc displacement.

STUDY DESIGN

A sample of 39 temporomandibular joints TMJs (31 case specimens, 8 control specimens) from 28 patients (mean age 31.2 years) were recruited for this study. The patients were considered to be affected and treated surgically with disc repositioning when presenting painful clinical signs of disc displacement after unsuccessful nonsurgical treatment for at least 6 months. Of the control patients, 4 presented condyle fracture which required opening to be reduced for treatment, and 4 displayed active condyle hyperplasia. The posterior region of the disc was removed and sent for histologic and histomorphometric analysis. Histologic (hematoxylin-eosin) and histomorphometric (picro-Sirius red) analyses were performed. Statistically significant differences between the analyzed groups were accessed through the chi-squared test (P <or= .05). The Mann-Whitney U test was used to observe the differences between mean values when variables did not present normal distribution [Kolmogorov-Smirnov(a) test].

RESULTS

There were no significant differences between the groups in relation to the parameters studied by histologic and histomorphometric analysis (using or not using polarization).

CONCLUSIONS

To the limits of this study, there were no significant histologic and histomorphometric differences in the articular disc between groups with and without TMJ dysfunction.

Arthroscopy vs. open-joint surgery for the management of internal derangement of the temporomandibular joint: a retrospective study comparing female subjects from two centers

AIM

The aim of this retrospective study was to assess the treatment outcome of arthroscopy and open-joint surgery in the management of internal derangement of the temporomandibular joint (TMJ).

BACKGROUND

Apart from pain being the major complaint in patients with temporomandibular joint disorders (TMDs), a variety of function-related symptoms are reported including joint noises, locking, limited movement, and alterations in occlusion. Surgical management procedures of internal derangement of the TMJ vary widely at present. The criteria for the assessment of successful outcome of the treatment are also variable.

METHODS AND MATERIALS

The retrospective study was carried out at two centers in Paris and Beirut. Sixty-two female patients with an age range of 35.1 years (28 had arthroscopy and 34 had open surgery) were included in the study. The patients were followed-up for 12 months. A standardized questionnaire and visual analogue scale (VAS) was developed and used for the assessment of pain and mandibular range of motion. A chi-square test was used to observe the significance of difference among both groups.

CONCLUSION

Within the limitations of this study, it was concluded arthroscopic surgery appeared to be safe with pain reduction and increased mandibular range of motion for 80% of the patients. Further research is needed on a larger prospective sample to assess the comparison of both techniques in terms of enhanced quality of life among the study population.

CLINICAL SIGNIFICANCE

Arthroscopic surgery appears to be a safe, minimally invasive, and effective method for treating internal derangements of the TMJ.

Walker repair of the temporomandibular joint: a retrospective evaluation of 117 patients

PURPOSE

This study evaluated the outcome of a high condylar shave with meniscal repositioning (Walker repair) in patients with internal derangement of the temporomandibular joint (TMJ). Changes in incisal opening, pain level, chewing ability, and preoperative TMJ symptoms (tinnitus, vertigo, and crepitus) were evaluated.

PATIENTS AND METHODS

A retrospective evaluation of 202 patients undergoing the Walker repair was completed using a questionnaire. A total of 117 patients responded to the questionnaire. Preoperative and postoperative examination findings, subjective questionnaire results, and panorex radiographs were analyzed.

RESULTS

The Walker repair resulted in a statistically significant (P < .001) decrease in pain by an average of 5.6 points on a scale of 0 to 10. The procedure also improved incisal opening by an average of 5.8 mm (P < .001). Improvements of 69% in tinnitus, 72% in vertigo, and 66% in crepitus were documented. Patients evaluated their motion, diet, comfort, and overall improvement; each area was rated as good or excellent by more than 90% of patients. The overall success rate for the Walker repair was 86%.

CONCLUSIONS

The Walker repair is an effective surgical treatment for internal derangement that significantly decreases pain level and increases incisal opening. No statistically significant difference in the success rate between unilateral and bilateral procedures was noted.