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Replacement of the temporomandibular joint (RTJ) has undergone decades of technological improvements and is now an important treatment for end-stage temporomandibular joint (TMJ) disease. The main complications of RTJ include aseptic loosening, heterotopic ossification, postsurgical infection, hypersensitivity reaction, prosthesis loosening or malposition, nerve injury and severe bleeding. Improvement in clinical technique is now the key to resolving complications. In the future, improvements in prosthetic materials may be an important development for newer iterations. With the development and popularity of TMJ surgical techniques, prosthesis-related complications will increasingly come into clinical view. This article provides a systematic review of the complications of RTJ prosthesis replacement and the measures to deal with them, and looks forward to the direction of the development of this field from the perspective of reducing complications, so as to provide a reference for clinical work.

Objective: To conduct a retrospective study on the treatment outcomes of patients who underwent artificial temporomandibular joint (TMJ) replacement surgery and to evaluate the effectiveness of artificial TMJ treatment. Methods: This study selected 62 patients who received standard Biomet artificial TMJ treatment at Department of Orthognathic and TMJ Surgery, West China Hospital of Stomatology, Sichuan University from May 2010 to September 2023 as the study subjects. Among them, there were 15 male patients and 47 female patients. The average age was 33.5 years old(ranging from 18 to 67 years). This study statistically analyzed postoperative indicators, including maximum mouth opening, forward jaw movement, lateral movement, postoperative pain scores, and patient satisfaction. Results: This study included a total of 62 patients with 99 TMJ joints. No infections occurred postoperatively. The average follow-up period was 33.7 months (ranging from 7 to 170 months). At 6 months postoperatively, the mean mouth opening was (36.1±6.2) mm, lateral movement was (2.1±0.9) mm, and forward jaw movement was (1.0±0.9) mm. The pain visual analog scale score at 6 months postoperatively was (2.8±0.6), and patient satisfaction with the surgery was (8.8±1.1). Spiral CT scans conducted after surgery showed no joint dislocation or migration, and the artificial joint remained stable during the follow-up period. Conclusions: Artificial TMJ replacement is a valuable method for effectively restoring TMJ structure and essential functions related to mouth opening and chewing. It is worthy of promotion as a reconstructive approach for the temporomandibular joint.

Temporomandibular joint (TMJ) surgery in China, as an important part of oral and maxillofacial surgery, has made significant progress in the past 20 years. It is mainly reflected in the reduction of TMJ dislocated joint disc, prosthetic total TMJ reconstruction, and the treatment of adult condylar fracture. There are major controversies about the surgical methods and indications for the reduction of the dislocated/displacement joint disc of the temporomandibular disorders.

The temporomandibular joint (TMJ) is the critical functional unit in the human stomatognathic system. Damage of the TMJ causes orofacial dysfunction and secondary jaw deformities, leading to seriously decreased quality of life in patients. The TMJ prosthetic replacement is an important treatment method for severe joint destruction because of its remarkable advantages compared with other methods. In recent years, this technique has gradually attracted wide attention in China, but it has not been popularized on a large scale in our country because of several limitations. Thus, in this study, the clinical experience of patients with TMJ prosthetic replacement in clinical units was summarized, and the treatment principles, treatment processes, and technical advantages were systematically discussed, aiming to promote the popularization and application of TMJ prosthetic replacement in China.

Background: Challenges in temporomandibular joint (TMJ) arthroscopy training include the cost of operating room time, surgical risks, and the accessibility of cadavers and high-fidelity simulators. A low-fidelity simulator (LFS) was developed for initial TMJ arthroscopy training., Purpose: The aim of this study was to evaluate improvement in TMJ arthroscopic skills after training with an LFS using the Arthroscopic Surgical Skill Evaluation Tool (ASSET) global rating scale., Study Design, Setting, Sample: A prospective randomized controlled study was conducted. Subjects included Oral and Maxillofacial Surgery residents in postgraduate year 1-5 at Thomas Jefferson University. Chief residents actively performing TMJ arthroscopy were excluded., Predictor Variable: The predictor variable was participation in LFS training. Subjects were randomly assigned to the LFS training or no LFS training group., Main Outcome Variables: The primary outcome variable was simulated surgical skill measured by total ASSET score (maximum score of 35). The secondary outcome variables were simulated surgical skill measured by each ASSET domain score and time to completion., Covariates: The covariates included sex, age, handedness, postgraduate year, endoscopic experience, open TMJ surgery experience, and experience with musical instruments and sports., Analyses: Data analyses included paired T-tests to determine changes in outcome variables after TMJ arthroscopy training between experimental groups, and ANOVA and χ 2 tests to identify associations between covariates. Inter-rater reliability of the blinded examiners was evaluated using Cronbach's alpha correlation. A P-value < .05 was considered significant., Results: The sample was composed of 10 residents: 5 (100%) males in the no LFS group, 3 (60%) males, and 2 (40%) females in the LFS group (P = .4). There was no significant difference between the groups in pre-TMJ arthroscopy training ASSET scores (P = .3). After training, the total ASSET score improved by 3.40 ± 6.87 in the no LFS group and by 6.27 ± 2.68 in the LFS group (P = .03)., Conclusions and Relevance: Study results showed that low-fidelity simulation can improve fundamental arthroscopic skills. Future research should be conducted on a larger scale to further validate this model and show the transfer of skill improvements to cadaver and live patient settings., (Copyright © 2024 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Mandibular angle osteotomy with outer cortex grinding is an effective cosmetic procedure for correcting square faces. However, morphological changes in the mandible may also cause temporomandibular joint (TMJ) disorders. This retrospective study aimed to investigate the morphological stabilization of the TMJ and changes in masseter muscle thickness after mandibular angle osteotomy to evaluate the safety of the procedure. Data from patients who underwent mandibular angle osteotomy with outer cortex grinding between January 2016 and January 2019 were retrospectively reviewed. Preoperative and long-term follow-up (~1 y) computed tomography data were collected from these patients, and morphological changes in the TMJ and masseter muscle were analyzed. The results from the computed tomography data showed that the condylar length and condylar height were significantly reduced 1 year after the operation ( P < 0.05). In addition, the morphology of the TMJ was stable, and the distance between the mandibular condyle and the glenoid fossa did not change significantly. No significant difference was observed in masseter muscle thickness before and after the operation. After mandibular angle osteotomy with outer cortex grinding, the length and height of the mandibular condyle were functionally restored without any disorders of the TMJ. Moreover, the masseter muscle exhibited stable function. In conclusion, the procedure is safe for occlusal function and suitable for popularization., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 by Mutaz B. Habal, MD.)

To search for the best available scientific evidence in relation to the reported overall and selective complication rates for arthroscopic surgery in patients presenting with internal derangement (ID) of the temporomandibular joint (TMJ). A comprehensive electronic search was conducted without data or language restrictions up to August 2023. Inclusion criteria were the following: study in humans, randomized or quasi-randomized controlled trials (RCTs), controlled clinical trials (CCTs), cohort studies and series of clinical cases. The proposed PICOS question was: "In clinical trials and retrospective clinical series of patients treated by arthroscopy, which were the overall and selective complication rates?" Exclusion criteria were animal studies, review papers, technical reports, and in vitro studies. The Cochrane Collaboration Tool was used to assess the risk of bias of the included studies in terms of their quality. The Strength of Recommendation Taxonomy (SORT) classification was used to determine the level of evidence of the selected studies. A total of 498 studies were identified. Of these, 16 studies fulfilled the inclusion criteria and were selected for qualitative assessment. Temporary 5th nerve deficit, ranging from 0.15% to 2.38%, was reported to occur in most larger series, comprising 7394 operated joints. Temporary 7th nerve paresis was reported to occur in 0.21%-0.7% in the largest series, comprising 6866 operated joints. Partial hearing loss was reported in 6 studies, ranging from 0.21% to 2.2% in 5845 operated joints. Edema of surrounding soft tissues, including parapharyngeal, soft palate and/or preauricular edema was reported in 8 studies, with complication rates ranging from 2% to 17.9% in 2274 operated joints. Laceration of the EAC was reported in 8 studies involving 2665 operated joints, with complication rates ranging from 0.3% to 6%. A total of 872 complicated events among 11,304 operated joints were reported, accounting for an overall complication rate of 7.71%. Complications from arthroscopic procedures have been inconsistently reported, but there are a small number of retrospective studies with well-reported complications rates. As overall complication rate accounts for less than 8% of the cases, arthroscopy seems to be a highly safe procedure for the treatment of internal derangement (ID) of the TMJ. Due to the absence of studies with high evidence, information for patients about complications should be based on clinical series of cases., Competing Interests: Declaration of competing interest There are no disclosures that might pose a potential, perceived or real conflict of interest., (Copyright © 2024 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Purpose: The study aims to analyse the effects of condylar rotation on the biomechanical environment of the TMJ after bilateral sagittal split ramus osteotomy (BSSRO) through the finite element method (FEM)., Methods: Thirteen patients with mandibular prognathism and twenty-three normal subjects were recruited. The three-dimensional (3D) models were reconstructed. 13 representative morphological parameters were measured for comparison. A patient was selected to perform virtual BSSRO surgery by rotating the condyles in MIMICS. The preoperative and postoperative 3D models of the patient were subsequently imported into ABAQUS for finite element analysis. The preoperative and postoperative stresses and joint spaces in the TMJs were investigated., Results: The maxillofacial morphologies of the patients with mandibular protrusion was significantly different from those of the asymptomatic subjects (P<.05). Stresses in the postoperative group were lower than those in the preoperative group. The rotation of the condyle could cause the variations in stress levels and joint spaces within the TMJs. Inward and upward rotation of the condyle was associated with higher stress in the TMJ, whereas the lowest stress was observed when the condyle remained stationary following surgical intervention., Significance: Lateral, medial and superior joint spaces were more related to the stresses in the TMJs. The condyle should be kept in place as much as possible to avoid disrupting the balance of the TMJ in patients with mandibular protrusion., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

The authors aim to present an updated protocol for mandibular reconstruction in nongrowing patients with Pruzansky/Kaban type IIb/III congenital craniofacial microsomia with customized temporomandibular joint (TMJ) prosthesis to reduce facial nerve (FN) damage and improve surgical accuracy. This is illustrated (using 3 cases) and is based on preoperative mapping of the FN using MRI for better virtual surgical planning of custom-made TMJ prosthesis. Intraoperative FN mapping and monitoring, as well as verification of the final result with intraoperative cone-beam computed tomography (CBCT) and 3D-reconstructed images is also achieved. All 3 patients presented mild transient postoperative facial palsy due to surgical soft tissue stretching which resolved within 2 months of surgery. All patients presented proper occlusion and mouth opening without pain, with an average incisal opening of 38.8 mm (range 35.5-42 mm) at two months of follow-up. Moreover, superposition of intraoperative and preoperative 3D reconstruction images ensured surgical accuracy and avoided the need for a potential reintervention. In conclusion, the proposed surgical protocol for mandibular reconstruction with customized alloplastic TMJ prosthesis in nongrowing patients with type IIb/III Pruzansky-Kaban congenital mandibular hypoplasia may reduce FN morbidity, improve surgical accuracy and final outcomes., (Copyright © 2024. Published by Elsevier Ltd.)

Background: Current clinical approaches to regenerate temporomandibular joint (TMJ) articulating cartilage defects only treat the symptoms (i.e. pain and dysfunction) and do not seek to restore joint integrity for long-term relief. Therefore, we investigated a novel self-assembling tissue-engineered cartilage to overcome this significant clinical issue for TMJ regenerative purposes., Objectives: Examine the maturation of dynamic self-regenerating cartilage (dSRC) using auricular chondrocytes and evaluate a novel combinatorial approach with fractional laser treatment and dSRC implantation for TMJ cartilage repair., Materials and Methods: A suspension of 10 7 freshly harvested rabbit ear chondrocytes was cultured under a continuous reciprocating motion to form the dSRC. After 2, 4 and 8 weeks of culture, dSRC samples were stained with H&E, Safranin-O and Toluidine Blue. Immunohistochemistry (IHC) was performed for collagens type I and II. Channels (300-500 μm diameter and 1.2-1.5 mm depth) were created in six freshly harvested condyles using a fractional Erbium laser. Two groups were tested: dSRC in a laser-ablated lesion (experimental) and an empty laser-ablated channel (control). TMJ condyles were cultured for up to 8 weeks and analysed as described above., Results: H&E staining showed a high cell density in dSRC compared to native cartilage. All dSRC groups demonstrated intense Safranin-O staining, indicating high glycosaminoglycan (GAG) production and intense Toluidine Blue staining showed high proteoglycan content. IHC confirmed that dSRC consisted predominantly of collagen type II. The experimental group showed improved cartilage repair at both time points compared to the empty channels., Conclusion: dSRC viability and successful matrix formation were demonstrated in vitro. The combination of fractional laser ablation and dSRC implantation enhanced cartilage repair., (© 2024 John Wiley & Sons Ltd.)

Purpose: Temporomandibular joint (TMJ) surgery is being increasingly performed globally with considerable success leading to improved quality of life for patients affected with disabling temporomandibular disorders. One of the most unusual phenomena noted during maxillofacial surgery due to stimulation of the trigeminal nerves is the Trigeminocardiac reflex (TCR), which causes sudden bradycardia and hypotension causing alarm and distress to the surgical and anesthetic team. The purpose of this systematic review is to identify the frequency and discuss the pathophysiology of the TCR especially during TMJ surgery., Methods: The authors performed a systematic review by searching PubMed, Embase, Ovid, and Cochrane databases between 1946 and 2023 to identify studies that reported on the development of TCR during TMJ surgery. Non-English publications and those with inadequate details were excluded., Results: Thirty-six papers reporting on the development of the TCR during oral and maxillofacial procedures were noted. Six papers reported specifically on TCR during TMJ surgery. A total of 25 subjects developed TCR during TMJ surgery. The mean age of the subjects was 31 (standard deviation 17.16) years. Twenty-three subjects (92%) developed bradycardia while 2 subjects (8%) developed asystole. All subjects recovered. The most common stimulant noted in these papers leading to TCR was manipulation and distraction of the TMJ., Conclusion: Although TCR is uncommon, it can occur during TMJ surgery, and it behooves the surgeon and anesthesia team to be aware of the potential for TCR to ensure adequate and timely treatment., (Crown Copyright © 2024. Published by Elsevier Inc. All rights reserved.)

Temporomandibular disorders include a wide spectrum of extra-articular and intra-articular conditions affecting the temporomandibular joint (TMJ). In salvage cases involving intra-articular end-stage disease, alloplastic temporomandibular joint replacement (TMJR) is a management option which can be utilised to rehabilitate a disabled joint's function and form. Whilst post-TMJR infection is rare, it is one of the most serious complications. The principles governing TMJR surgery antibiotic prophylaxis have been based on those established in orthopaedic surgery literature. Antibiotic resistance due to antibiotic over-use is a significant concern, therefore antibiotic stewardship has been developed to deal with this world-wide public health concern. The TMJ's anatomical proximity to the external auditory canal and oral cavity creates the potential for bacterial contamination. The aim of this study was to explore the views of 39 sub-specialist TMJ surgeons across nine nations usual approach to antibiotic prophylaxis and their management of TMJR infection. To accomplish this, an international survey was developed and conducted using Google Forms. The results demonstrated that 97.4% of the respondents employ prophylactic antibiotics at TMJR surgery, 83.8% on discharge. Variability in antibiotic choice with additional antimicrobial perioperative practices were also reported. Opinions on the management of a TMJR infection also varied. This survey establishes there is an agreement on the use of antibiotic prophylaxis, However the variability in choice, timing, course, duration of antibiotic use as well as the management of a postoperative TMJR infection demonstrates the need for further study leading to development of standardised antibiotic prophylaxis and infection management protocols for TMJR surgery., (Copyright © 2024 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Introduction: The use of alloplastic total temporomandibular joint reconstruction (TMJR) in growing patients is controversial, mainly due to immature elements of the craniomaxillofacial skeleton. The aim of this systematic review was to evaluate the use of alloplastic TMJR in growing patients, focusing on the patient's clinical presentation, surgical and medical history and efficacy of alloplastic TMJR implantation., Materials and Methods: The literature search strategy was based on the Population, Intervention, Comparator, Outcomes and Study type (PICOS) framework. We searched Pubmed, Google Scholar, Dimension, Web of Science, X-mol, Semantic Scholar and Embase to January 2023, without any restriction on the type of publication reporting alloplastic TMJR in growing patients (age ≤ 18 years for boys and age ≤ 15 years for girls)., Results: A total of 15 studies (case reports: 09, case series: 02, cohort studies: 04) met the inclusion criteria, documenting 73 patients of growing age from 07 countries. Thirty-eight (~ 52%) cases were female. The mean ± SD (range) age and follow-up of patients in all studies was 13.1 ± 3.2 (0-17) years and 34.3 ± 21.5 (7-96) months, respectively. A total of 22 (30%) patients were implanted with bilateral alloplastic TMJR. Over half of the studies (n = 10) were published in the last 3 years. All patients underwent multiple surgeries prior to implantation of alloplastic TMJR. In extreme cases, patients underwent a total of 17 surgeries. Different types of studies reporting inconsistent variables restricted our ability to perform quality assessment measures for evidence building., Conclusions: Clinical experience with alloplastic TMJR in growing patients is limited to cases showing poor prognosis with other types of reconstruction. Nevertheless, studies show promising results for the use of alloplastic TMJR in growing patients, highlighting the need for well-controlled prospective studies with long-term follow-up., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The aim of this study was to evaluate condylar and glenoid fossa remodeling after bimaxillary orthognathic surgery guided by patient-specific mandibular implants. In total, 18 patients suffering from dentofacial dysmorphism underwent a virtually planned bimaxillary mandibular PSI-guided orthognathic procedure. One month prior to surgery, patients underwent a CBCT scan and optical scans of the dental arches; these datasets were re-acquired 1 month and at least 9 months postsurgery. Three-dimensional models of the condyles, glenoid fossae, and interarticular surface space (IASS) were obtained and compared to evaluate the roto-translational positional discrepancy and surface variation of each condyle and glenoid fossa, and the IASS variation. The condylar position varied by an average of 4.31° and 2.18 mm, mainly due to surgically unavoidable ramus position correction. Condylar resorption remodeling was minimal (average ≤ 0.1 mm), and affected skeletal class III patients the most. Later condylar remodeling was positively correlated with patient age. No significant glenoid fossa remodeling was observed. No postoperative orofacial pain was recorded at clinical follow-up. The procedure was accurate in minimizing the shift in relationship between the bony components of the TMJ and their remodeling, and was effective in avoiding postoperative onset of orofacial pain. An increase in sample size, however, would be useful to confirm our findings., (Copyright © 2024. Published by Elsevier Ltd.)

Objective: To evaluate the kinematics and stability of the temporomandibular joint (TMJ) of cats and dogs with and without a TMJ replacement (TMJR) prosthesis under simulated bite forces and mouth opening., Animals: Sixteen cadaver skulls from domestic cats (n = 8) and medium- to large-breed dogs (n = 8)., Methods: Intact TMJs were tested. Following condylectomy and coronoidectomy, the skulls were fitted with a TMJR prosthesis unilaterally and retested. Prosthesis was similarly implanted in the contralateral TMJ in 4 cats and 4 dogs before retesting. Left and right bite motions were evaluated before bite contact to peak bite force (200 N in dogs, 63 N in cats). Mouth opening motion was recorded. Mandibular displacement under load was evaluated in 3 orthogonal planes. Maximal displacement was compared between TMJR groups and native TMJ. Prosthesis-bone motion of the temporal and mandibular components was evaluated during simulated bites and mouth opening., Results: TMJR resulted in joint motion not demonstrably different from the native TMJ, with the ability to fully open and close the mouth and with minimal laterotrusion. The TMJR prosthesis demonstrated similar stability after unilateral and bilateral replacement during bite force and with an open mouth. Mean implant-bone motion during bite simulations for the temporal and mandibular TMJR components was ≤ 60 µm in cats and ≤ 30 µm in dogs., Clinical Relevance: A novel TMJR can be implanted and allows normal jaw motion. Joint stability is maintained after TMJR implantation in the TMJ of dogs and cats TMJ that is devoid of muscular support.

Objectives: The study aimed to introduce and evaluate a new customized temporomandibular joint-mandible combined prosthesis with 3D printing fabrication., Materials and Methods: This was a prospective study including patients with temporomandibular joint-mandible combined lesions. A 3D-printed customized temporomandibular joint-mandible combined prosthesis was implanted to repair the joint and jaw defect. Clinical follow-up and radiographic examinations were taken to assess the clinical efficacy. The assessment indices were compared by the Wilcoxon signed rank test., Results: Eight patients were treated with the combined prosthesis and included in this study. All prostheses were accurately positioned and fixed without wound infection, prosthesis exposure, displacement, loosening, or fracture. All cases had no mass recurrence at the last follow-up point. Pain, diet, mandibular function, lateral mandibular movement to the diseased side, and maximal interincisal opening showed significant improvements at every follow-up point and went to a stable condition at 6 months after the operation. But the lateral movement to the non-operated side was still limited following surgery., Conclusion: The 3D-printed combined prosthesis may be an alternative to other well-established reconstructions for temporomandibular joint and mandible defects., (© 2023 Wiley Periodicals LLC.)

Background: Reconstruction of the temporomandibular joint (TMJ) is a significant challenge in maxillofacial surgery. A vascularized medial femoral condyle (MFC) osteocartilaginous flap is a good choice for TMJ reconstruction. In this study, we evaluated the radiographic and histological changes of MFC after TMJ reconstruction., Methods: A ramus-condyle unit (RCU) defect was created unilaterally in five adult male Bama miniature pigs. The ipsilateral vascularized MFC osteocartilaginous flap was used to reconstruct the TMJ, and the non-operative sides served as controls. Multislice spiral computed tomography (CT) was performed preoperatively, immediately postoperatively, and at two weeks, three months, and six months postoperatively. Three animals were euthanized at 6 months postoperatively. Their reconstructed condyles, natural condyles and the MFCs on the opposite side were collected and subjected to µCT and histological evaluation., Results: In the miniature pigs, the vascularized MFC osteocartilaginous flap was fused to the mandible, thus restoring the structure and function of the RCU. The postoperative radiographic changes and histological results showed that the reconstructed condyle was remodeled toward the natural condyle, forming a similar structure, which was significantly different from the MFC., Conclusions: In miniature pigs, the RCU can be successfully reconstructed by vascularized osteocartilaginous MFC flap. The reconstructed condyle had almost the same appearance and histological characteristics as the natural condyle., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Temporomandibular disorders (TMDs) affect a high percentage of children and adults worldwide. Surgery may be indicated in severe or recalcitrant cases. Several recent advancements in TMD and temporomandibular joint (TMJ) surgery have elevated understanding and the ability to treat affected patients. We discuss recent advances in TMD epidemiology, juvenile idiopathic arthritis (JIA) of the TMJ, and surgical techniques and technologies. Technical advancements have been identified in TMJ arthroscopy, the treatment of TMJ subluxation and dislocation, and extended prosthetic total TMJ reconstruction (eTMJR). Overall, this review provides valuable insights into significant recent advancements in TMJ disorders and their surgical management.

Background: The aim of this paper was to report our experience and to review the literature of arthrocentesis focusing on protocols and results., Methods: Arthrocentesis with supplemental hyaluronic acid was performed in patients with TMDs between January 2017 and December 2020 at the Division of Maxillofacial Surgery. The maximum interincisal opening (MIO) and pain score were recorded preoperatively (T0), 2 months postoperatively (T1), and 6 months postoperatively (T2). A literature search was performed to analyze the same parameters in patients with TMDs. Patient demographic, characteristics and treatment protocols used were also recorded., Results: This retrospective analysis enrolled 45 patients. Twenty-two patients (20 females, 2 males) with mean age of 37.13 years with internal derangement were included in study group A. Study group B included 23 patients with degenerative joint disease (19 females and 4 males) with mean age of 55.73 years. The outcomes trend of MIO and pain during the follow-up period showed a gradual improvement. Fifty articles meeting the proposed scientific criteria were selected for the literature revision. A range of clinical and procedural variables were analyzed by grouping the studies into two broad categories based on the diagnosis of TMD., Conclusions: Based on our experience and on the basis of the most accredited scientific studies in the literature, intra-articular injections of HA are beneficial for the improvement of the pain and/or functional symptoms of TMDs.

Background: Patients with congenital aural atresia (CAA) can present with concomitant temporomandibular joint (TMJ) retroposition, implying that even with a high Jahrsdoerfer score, canaloplasty and tympanoplasty cannot be performed. Therefore, this study aimed to summarize the clinical manifestations and share our diagnostic and treatment experience of this rare entity, which has not been described previously., Methods: Thirty patients (30 ears) with CAA and TMJ retroposition without maxillofacial dysplasia were included. Diagnosis was based on patient history, physical examination, pure-tone average test results, and temporal bone high-resolution computed tomography (HRCT) findings. Their Jahrsdoerfer scores and interventions were also recorded., Results: Twenty-four and six patients among the 30 patients (males, n = 15) had CAA and TMJ retroposition on the right and left sides, respectively. Seventeen ears had a normal auricle; most had an enlarged cavum conchae and a large tragus. Twelve ears had an accessory auricle, and two had a preauricular fistula. All external auditory canals had complete atresia, including four with a shallow concavity and four with a small orifice in the cavum conchae. Temporal bone HRCT revealed poor or undeveloped tympanic temporal bone in the diseased ears, atresia in the external auditory canals, and partial/complete occupation of the mandibular condyle with or without soft tissue. The average Jahrsdoerfer score was 8.17. Thirteen patients opted for different surgeries, three wore a bone-conduction hearing aid, and fourteen chose no intervention., Conclusions: CAA with TMJ retroposition was often unilateral, typically on the right side. Most patients had normal auricles, with an enlarged cavum conchae and a large tragus ("mirror ear"). Even with a high Jahrsdoerfer score, traditional hearing reconstruction surgery could not be performed. Patients can undergo Vibrant Soundbridge or Bonebridge implantation or wear bone-conduction hearing aids to improve hearing levels, or refuse intervention because of mild hearing loss. The TMJ location can be used as a Jahrsdoerfer Grading System supplement for preoperative evaluation., (© 2023. The Author(s).)

The main aim of this work was to evaluate the effect of intra-articular, sub-synovial steroid injections (IASSSI) with different doses during temporomandibular joint (TMJ) arthroscopy. Using a single-blind, randomized clinical trial, the investigators enrolled a sample of subjects who underwent TMJ arthroscopy with vs. without IASSSI for treating TMJ disorder (TMD). The predictor variable was the treatment group classified as no treatment (A - without IASSSI) or active treatments (IASSSI (B) with 2 mg or (C) 4-mg dexamethasone). Study medications were randomly assigned. Only subjects were blinded to treatment assignment. The main outcome variables included the following: 1) pain assessed up to postoperative day 30 with the McGill Pain Questionnaire and visual analog scale (VAS); 2) maximum mouth opening (MMO); and 3) analgesic and anti-inflammatory drug consumption. Other variables were demographic (age, sex) or pathologic (disease manifestations and classifications). Descriptive and bivariate statistics were computed. Statistical significance was set at p ≤ 0.5, one-tailed test of hypothesis. The sample comprised 36 patients (n = 12 per study group). In the active group with 4 mg corticosteroids, pain reduction measured by VAS (odds ratio [OR] = 0.18; p = 0.013) and McGill scale scores (OR = 0.15; p = 0.048) was significantly higher than in the control group. The McGill scale scores significantly decreased in both IASSSI groups, compared to the control group, at the final follow-up (all p < 0.012), and IASSSI was significantly associated with reduced analgesic consumption at postoperative days 7 and 14 (p = 0.003). However, there was no significant difference regarding MMO among the three groups. Within the limitations of the study, it seems that intra-articular, sub-synovial steroid injections (IASSSI) with 4 mg dexamethasone should be preferred whenever appropriate when pain relief is the priority of the procedure. Brazilian Registry of Clinical Trials (ReBec)- 28yb2g., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

The aim of this study was to evaluate the efficacy of the retromandibular approach (RMA) to produce three-dimensional (3-D) reduction of the unilateral subcondylar fracture and Temporomandibular Joint (TMJ) functional implication., Methods:  A prospective cohort study was designed. Twenty-nine patients with unilateral subcondylar fracture underwent consecutively Open Reduction, and Internal Fixation. The cohorts were divided into two groups; RMA group (n = 16, 55.17%) and submandibular approach SMA group (n = 13, 44.82%). The primary outcome was the anatomical 3-D reduction of the condyle. The secondary outcome was to compare the condyle position and inclination finding with TMJ outcomes. Helkimo Index score was used to evaluate the TMJ outcome at six months postoperatively., Result:  There was a significant difference between the mediolateral condylar inclination, condylar medial and vertical positions when RMA compared with SMA groups (P < 0.05). The medial joint space was correlated with the medial condylar position in both groups (P < 0.05). The Helkimo Ai and Di was associated with mediolateral condylar inclination in SMG; however, Helkimo Ai was found to be correlated with the RMA group., Conclusion:  The current study demonstrates that the RMA could re-establish the anatomical position of the unilateral subcondylar fracture in patients undergoing ORIF. The clinical outcome of the TMJ with RMA was better than SMA., (© 2022. The Author(s).)

Medical device embodiment involves the following elements: materials, design, and manufacturing. Failure of any one of these elements can result in failure of the device, despite the others being satisfactory. The abundance of clinical and basic science literature published since 1986, demonstrates the safety and efficacy of alloplastic temporomandibular joint replacement (TMJR). Currently, there are 19 countries producing 41 TMJR devices. More than 75% are custom designed, and 27% are additively manufactured. In light of the increasing number of TMJR devices being designed and manufactured around the world, this paper will discuss TMJR embodiment so that clinicians understand their present status as well as the prospects for the future of new and/or improved TMJR devices, to ensure that these devices continue to be safe and effective long-term surgical options for the management of end-stage TMJ pathologies., (Copyright © 2022 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Dental occlusion ties (Minne Ties®) are a new example of the concept of an oral zip tie used to establish maxillomandibular fixation (MMF). Each tie uses a blunt introducer that is easily passed between embrasures and fed through a self-locking, unidirectional clasp. Five to six ties are used to establish MMF. They are fast, easy to use, and relatively safe because there are no sharps or wires associated with their use. The authors report their experience using this MMF method for temporomandibular joint replacement surgery, where over the last 2 years, over 65 collective cases have been completed using this method., (Published by Elsevier Inc.)

Surgical management of temporomandibular joint (TMJ) ankylosis involves various techniques from which interpositional arthroplasty (IPA) involves using several materials. The objectives of this study were to assess and compare post arthroplasty maximum mouth opening (MMO), symptoms like pain and discomfort in jaw opening and movements, failures such as reankylosis, neurosensory disturbances, and the effect of confounding variables such as age, gender, physiotherapy, etc. The search (conducted in September, 2021) included studies published in English on otherwise healthy individuals (11 months to 88 years) having undergone arthroplasty with a minimum of six months' follow up. We used search engines such as Cochrane database, PubMed, Embase, Scopus, EBSCO host, Pro quest, J gate, Google Scholar, and manual search to include books and grey literature. Randomised clinical (RCT) and non-randomised clinical trials, observational studies, case series and reports meeting the inclusion criteria were selected. Two reviewers (HD and NP) independently extracted the data. Risk of bias was assessed using the Cochrane tool, Rangel checklist, and Joanna Briggs Institute. Data were analysed using RevMan (Version 5.4). Fifty studies with 1524 participants (442 bilateral and 891 unilateral joints) were included; six RCTs, 31 retrospective, 10 prospective, and three case series and reports. Amongst all interpositional materials, the highest increase in mouth opening was seen with dermis fat graft with a mean difference (Pooled MD) being 35.29mm (95% CI [32.36 to 38.22]). Comparison of temporalis myofascial with gap arthroplasty (GA) showed significant increase in MMO (Pooled MD in mm 1.30 95% CI [0.14 to 2.45]). Recurrence was significantly reduced when (IPA) was used, compared with GA (Risk difference 0.08mm 95% CI [-0.15 to -0.02]) and for Temporalis Myofascial Flap (TMF) when compared with GA (Risk difference -0.07mm 95% CI [-0.15 to 0]). Higher odds for developing neurosensory disturbances were seen with Al-Kayat Bramley incision (Pooled OR 0.11 95% CI [0.04 to 0.34]) compared to pre-auricular incision (Pooled OR 0.03 95% CI [0.01 to 0.09]). IPA was superior to GA with respect to maximum mouth opening (MMO) (Pooled MD in mm 1.21 95% CI [0.41 to 2.07]). Dermis fat graft offers the highest MMO. The overall quality of evidence for RCTs is poor while that of observational studies is moderate as per the relevant assessment of quality of evidence. More research with appropriate study designs is needed. Similar to the findings from the previous reviews, outcomes with IPA were superior when compared to GA in terms of mouth opening and less recurrence., (Copyright © 2022 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Competing Interests: Conflict of interest The author had no conflicts of interest in the writing of this article. He provides lectures on behalf of SORG (KLS Martin), Biomet, and Stryker.

Competing Interests: Disclosure The authors have nothing to disclose. All the figures are original works.

Introduction: Numerous factors have been indicated as possible causes of alterations in the articular disc of the temporomandibular joint (TMJ). The main aim of the present study was to demonstrate the effectiveness of arthroscopic osteoplasty of the medial TMJ wall associated with myotomy of the superior head of the lateral pterygoid muscle for treating TMJ internal derangement., Material and Methods: A retrospective and comparative study was performed analyzing patients diagnosed with TMJ internal derangement and underwent TMJ arthroscopic surgery in our Hospital. These patients presented signs and symptoms of TMJ internal derangement along with pathological magnetic resonance imaging images, and underwent either arthroscopic osteoplasty of the medial TMJ and myotomy of lateral pterygoid muscle (group 1) or arthroscopic eminoplasty (group 2) in our center., Results: The sample consisted of 109 patients (21 male, 88 females) who agreed to voluntarily participate in our study. The results revealed that the patients who had undergone arthroscopic osteoplasty of the medial TMJ and myotomy of lateral pterygoid muscle showed better outcomes in terms of pain reduction when compared with patients who had undergone arthroscopic eminoplasty. No statistically significant differences were found between the 2 groups in terms of postoperative mouth opening., Conclusions: Arthroscopic osteoplasty of the medial and anterior medial wall of TMJ associated with arthroscopic myotomy of the SLEM represent an effective treatment option for TMJ internal derangement even in advanced stages (Wilkes IV and V)., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 by Mutaz B. Habal, MD.)

Purpose: Discectomy is one of the preferred temporomandibular joint (TMJ) surgical procedures for the treatment of internal derangements when conservative and minimally invasive treatments have failed. The purpose of the current study is to investigate whether a TMJ discectomy operation influences auditory function and clinical variables., Methods: This prospective study was composed of patients who underwent a TMJ discectomy operation between 2016 and 2020. Auditory function was evaluated with pure tone audiometry, tympanometry, and acoustic reflex tests at preoperatively (T 0 ), postoperative first week (T 1 ), first month (T 2 ), and third month (T 3 ). Clinical parameters including maximum mouth opening (MMO) and TMJ pain were also evaluated at T 0 , T 1 , T 2 , T 3 , and sixth month (T 4 )., Results: The study consisted of 17 patients (5 males, 12 females) with a mean age of 42.65. A significant reduction in visual analogue scale (VAS) pain scores and MMO values compared to baseline values was achieved in all follow up periods (P T0-T1 = .001; P T0-T2/T3/T4 < .001). In pure tone audiometry, a significant increase in T 1 -T 0 comparisons at 1000 Hz, 2000 Hz, 6000 Hz, 8000 Hz frequencies, and pure tone average (P = .008; P = .005; P = .012; P = .002; P = .001) was observed. In T 3 -T 0 comparisons, a statistically significant decrease was observed in pure tone thresholds at 125 Hz and 8000 Hz frequencies (P = .008; P = .01). There was no statistically significant difference in middle ear pressure and compliance values at T 1 , T 2 , and T 3 compared to T 0 (P > .05). Type C tympanogram was seen in 3 patients at T 1 and in 1 patient at T 2 . Acoustic reflex tests were positive in all patients., Conclusions: Although mild changes occurred in auditory tests in the early postoperative period, TMJ discectomy procedure has no permanent effect on auditory function., (Copyright © 2021 The American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: To explore the effect of bilateral coronoidectomy on stress distribution after reconstruction of temporomandibular joint (TMJ) by costochondral graft., Methods: Ten groups of models were established to simulate costochondral graft reconstruction with simultaneously different distances (0, 2, 4, 6, 8 mm) of mandibular advancement, with or without coronoidectomy. Force and stress distribution in the rib-cartilage area were analyzed by finite element analysis., Results: In the process of bilateral joint reconstruction with simultaneously mandible advancement ranging from 0 mm to 8 mm, when the coronoid processes were retained, the forward deformation of the cartilage occurred and the shear force decreased in turn, from 113.2 N to 26.7 N on the left side and from 133.7 N to 1.9 N on the right side. When the coronoid processes were removed, the cartilage deformed backward and the shear force increased successively, from 94.6 N to 188.5 N on the left and 70.1 N to 157.7 N on the right. The stress in the neck was obviously concentrated when mandible advanced 8 mm., Conclusions: Coronoidectomy has an important impact on stress distribution in the TMJ area, and keeping the coronoid process is beneficial to maintain the mechanical balance. Bilateral CCG reconstruction with coronoidectomy for lengthy mandible advancement (≥ 8 mm) may lead to prominent increase in shear force beyond CCG resistance, resulting in a costal-cartilage junction fracture.

Background: Dislocation of the mandibular condyle (MC) is not a common condition, but when a traumatic case involves erosion of the middle fossa floor, it becomes a much more complicated and even rarer pathology., Objective: To describe the management of traumatic dislocation of the MCs with erosion of the middle fossa floor. We provide a step-by-step surgical video demonstrating reestablishment of the condylar position and occlusion., Methods: A 65-yr-old woman with rheumatoid arthritis presented after a ground-level fall. She was admitted to the intensive care unit with simultaneous complex medical conditions, intubated, and medically treated for over a month. She was seen in outpatient follow-up 2 mo later and noted to have an anterior open bite and bilateral temporomandibular joint pain. Computed tomography of the face showed bilateral dislocation of the MCs with erosion of the middle fossa floor., Results: Open surgical treatment with bilateral eminectomies was performed to obtain adequate reduction, involving a multidisciplinary team including neurosurgery, oral-maxillofacial surgery, and otolaryngological surgery. She did well postoperatively., Conclusion: Multiple factors predispose a patient to MC dislocation, but we believe the catalyst in this case was significant manipulation of the jaw during endotracheal intubation. A chronic postoperative open bite can lead to much more difficult treatment, given bony erosion and fibrotic tissue formation. This case highlights the challenges of diagnosis and treatment of a bilateral traumatic dislocation and provides a surgical video reference description of repair and resolution., (Copyright © Congress of Neurological Surgeons 2021. All rights reserved.)

Purpose: First bite syndrome (FBS) can develop after head and neck surgical procedures. The aim of this study is to identify patients diagnosed with FSB after temporomandibular joint (TMJ) surgery, including their pain characteristics and risk factors for FBS., Methods: Using a retrospective study design, a cohort of 24 patients with confirmed diagnosis of FBS were identified from the oral and maxillofacial surgery and orofacial pain (OFP) practices at Massachusetts General Hospital and Research Patient Data Registry (RPDR) between 1975 and 2019. The inclusion criteria were facial pain that was triggered by taste stimulus only and followed by a refractory period until the next gustatory stimulus., Results: Of the 24 patients identified, 19 had undergone TMJ surgery, 3 patients had idiopathic FBS, 1 had a parapharyngeal space tumor and 1 developed FBS after facial burns. In the surgical patients, the median duration of onset was 2.75 months post-surgery. Most patients reported pain in the parotid region. Pain was only triggered by a taste stimulus and subsided with subsequent bites of food. 2 patients underwent spontaneous resolution of their symptoms and 1 reported complete resolution with onabotulinum toxin A (BTX) injections. Anxiety and depression were the most common comorbid conditions., Conclusion: FBS is an underrecognized pain complication in TMJ surgery patients. A precise history and accurate description of the pain is necessary for correct diagnosis which is important for improved treatment outcomes., (Copyright © 2021 The American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

In order to optimize patient selection for temporomandibular joint (TMJ) arthroscopic discopexy to achieve favorable outcomes, prognostic indicators impacting the results are important to analyze. This longitudinal retrospective study aimed to analyze various prognostic factors impacting surgical outcomes following arthroscopic discopexy for management of TMJ closed lock using success criteria based on pain, maximal interincisal opening, diet, and quality of life. Furthermore, a quantitative MRI assessment was performed pre- and post-operatively. Multivariate analysis was used to evaluate various prognostic variables including gender, age, side, duration of illness, Wilkes staging, parafunctional habits, splint therapy and orthodontic treatment. A total of 147 patients (201 joints) were included. The outcome was categorized as excellent (n = 154/76.61%), good (n = 34/16.91%), or poor (n = 13/6.46%) with a success rate of 93.54%. Patients aged > 30 years old (p = 0.048), longer duration of illness (12-24 months: p = 0.034) and (> 24 months: p = 0.022), and patients with Wilkes stage IV (p = 0.002) were all significantly more likely to be in the poor outcome group. Finally, orthodontic treatment showed a significant association with excellent outcomes (p = 0.015). Age, duration of illness, Wilkes staging, and orthodontic treatment are considered significant prognostic factors that can predict the outcomes following the arthroscopic discopexy for management of TMJ closed lock., (© 2022. The Author(s).)

Objective: The aim of this study was to record mandibular kinematics in patients after total TMJ endoprosthesis using a magnetic sensory system., Material and Methods: The movement of the mandibular was examined in 10 patients who underwent TMJ reconstruction using total endoprostheses. The condylar range of motion, the angle of the transversal condylar inclination (TCI), the speed of joint movement (max S) and the stability distance between the position at the beginning of movement and at the end (Start/end) of TMJ prostheses and native joints were measured 1 week before surgery (T0) and 12 months after (T1)., Results: The study showed an increase in the linear distance of the native joint when opening ( p =0.004), protrusion ( p =0.004), balancing side ( p =0.001) and max S of the native joint and endoprosthesis when opening ( p =0.009), working side ( p =0.008) and balancing side ( p =0.001). A decrease in indicators was observed in the Start/end of the native joint when opening ( p =0.035), protrusion ( p =0.02), working side ( p =0.004), as well as the endoprosthesis relative to the pathological joint when opening ( p =0.028), protrusion ( p =0.001) and balancing side ( p =0.003)., Conclusion: In the present study, in all cases, a slight but clearly defined translational shift on the side of the intervention was detected on the control condylograms, which can be referred to as «pseudotranslation».

The mandibular condyle is an integral structure in the temporomandibular joint (TMJ) serving not only as the hinge point for mandibular opening, but also facilitating mandibular growth and contributing to facial aesthetics. Significant compromise of the TMJ can be debilitating functionally, psychologically, and aesthetically. Reconstruction of the mandibular condyle is rarely straightforward. Multiple considerations must be accounted for when preparing for condylar reconstruction such as ensuring eradication of all chronically diseased or infected bone, proving clear oncologic margins following tumor resection, or achieving stability of the surrounding architecture in the setting of a traumatic injury. Today, there is not one single gold-standard reconstructive method or material; ongoing investigation and innovation continue to improve and transform condylar reconstruction. Herein, we review methods of condylar reconstruction focusing on autologous and alloplastic materials, surgical techniques, and recent technological advances., Competing Interests: None declared., (Thieme. All rights reserved.)

Background: Accurate placement of TMJ implant components may be facilitated by virtual surgical planning (VSP) technologies. The aim of this study was to assess the accuracy of a typical VSP protocol and describe the pattern of surgical error associated with total alloplastic TMJ replacement., Methods: A retrospective analysis was undertaken on 40 adult patients who were implanted with a fully customised, 3D printed TMJ prosthesis due to end-stage TMJ disease. Planned TMJ implant position based on preoperative CBCT images was compared with final position on postoperative OPGs using a previously validated linear rescaling method. Translational discrepancy was described in the anterior-posterior direction and superior-inferior direction. Rotational discrepancy was described as anterior or posterior., Results: Lin's concordance between preoperative and postoperative position was 0.97, with no significant differences (p > 0.05). The Bland-Altman analysis showed a 95% limit of agreement between planned and final position of - 5.9 to 5.4 mm. Overall, final implant position was more anterior (0.4 mm), superior (0.4 mm) and posteriorly rotated (2.4°) compared with planned position., Conclusion: The use of VSP in TMJ replacement surgery results in accurate implant placement with good agreement between planned and final implant position. Discrepancies in planned and final implant position tended to result in the mandibular component of the implant being translated anterior superiorly and rotated posteriorly, with potential implications for the biomechanical performance of the implant and overall device longevity. These results should be used to assist TMJ surgeons pre- and intraoperatively to facilitating accurate implant positioning and optimal surgical rehabilitation., (© 2020. Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: The aim of this study is to clarify the postsurgical stability of temporomandibular joints in skeletal class III patients treated with 2-jaw orthognathic surgery which was performed utilizing computer-aided three-dimensional simulation and navigation in orthognathic surgery (CASNOS) protocol., Materials and Methods: 23 consecutive nongrowing skeletal class III patients with mandibular prognathism associated with maxillary retrognathism treated with 2-jaw orthognathic surgery between 2018 and 2019 were enrolled in this study. The surgery was planned according to the standardized protocol of CASNOS (computer-aided three-dimensional simulation and navigation in orthognathic surgery). Computed tomography (CT) scans were performed in all patients 3 weeks presurgically and 6 months postsurgically. ITKSNAP and 3D Slicer software were used to reconstruct three-dimensional facial skeletal images, to carry out image segmentation, and to superimpose and quantify the TMJ position changes before and after surgery. Amount of displacement of the most medial and lateral points of the condyles and the change of intercondylar angles were measured to evaluate the postsurgical stability of TMJ., Results: A total amount of 23 skeletal class III patients (female : male = 12 : 11) with age ranged from 20.3 to 33.5 years (mean: 24.39 ± 4.8 years old) underwent Le Fort I maxillary advancement and BSSO setback of the mandible. The surgical outcome revealed the satisfactory correction of their skeletal deformities. The mean displacement of the right most lateral condylar point (RL-RL') was 1.04 ± 0.42 mm and the mean displacement of the left most lateral condylar point (LL-LL') was 1.19 ± 0.41 mm. The mean displacement of the right most medial condylar point (RM-RM') was 1.03 ± 0.39 mm and the left most medial condylar point (LM-LM') was 0.96 ± 0.39 mm. The mean intercondylar angle was 161.61 ± 5.08° presurgically and 159.28 ± 4.92° postsurgically., Conclusion: The postsurgical position of TM joint condyles in our study only presented a mild change with all the landmark displacement within a range of 1.2 mm. This indicates the bimaxillary orthognathic surgery via 3D CASNOS protocol can achieve a desired and stable result of TMJ position in treating skeletal class III adult patients with retrognathic maxilla and prognathic mandible., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2021 Ling-Chun Wang et al.)

Temporomandibular joint (TMJ) replacement with an implant is only used when all other conservative treatments fail. Despite the promising short-term results, the long-term implications of TMJ replacement in masticatory function are not fully understood. Previous human and animal studies have shown that perturbations to the normal masticatory function can lead to morphological and functional changes in the craniomaxillofacial system. A clearer understanding of the biomechanical implications of TMJ replacement in masticatory function may help identify design shortcomings that hinder their long-term success. In this study, patient-specific finite element models of the intact and implanted mandible were developed and simulated under four different biting tasks. In addition, the impact of re-attaching of the lateral pterygoid was also evaluated. The biomechanics of both models was compared regarding both mandibular displacements and principal strain patterns. The results show an excessive mediolateral and anteroposterior displacement of the TMJ implant compared to the intact joint in three biting tasks, namely incisor (INC), left moral (LML), and right molar (RML) biting. The main differences in principal strain distributions were found across the entire mandible, most notably from the symphysis to the ramus of the implanted side. Furthermore, the re-attachment of the lateral pterygoid seems to increase joint anteroposterior displacement in both INC, LML and RML biting while reducing it during LGF. Accordingly, any new TMJ implant design must consider stabilising both mediolateral and anteroposterior movement of the condyle during biting activities and promoting a more natural load transmission along the entire mandible.

Primary temporal bone squamous cell carcinoma is sporadic. According to previous studies, margin-negative resection provides the best prognosis (Nakagawa et al., 2006; Moody et al., 2000; Yin et al., 2006; Komune et al., 2021 [1-4]). When tumors extend behind the tympanic membrane, lateral temporal bone resection, which is a well-established procedure, is insufficient to achieve a tumor-free margin. For these cases, subtotal temporal bone resection (STBR) can achieve a complete en bloc resection with a tumor-free margin. Furthermore, STBR en bloc with surrounding structures, including the temporomandibular joint and parotid gland, complicates surgical techniques. We previously reported this surgical procedure in a stepwise manner using cadaveric dissection (Komune et al., 2014 [5]). The STBR en bloc with the parotid gland and temporomandibular joint is composed of three approaches according to our previous report: high cervical exposure (neck dissection), a subtemporal-infratemporal fossa approach, and a retromastoid-paracondylar approach. However, we currently lack demonstrative surgical videos. According to our previous report, this video first demonstrates STBR en bloc with the parotid gland and temporomandibular joint (Komune et al., 2014 [5]). The histopathological diagnosis of a 57-year-old woman suffering from a large tumor protruding from her auricle indicated squamous cell carcinoma; after the diagnosis she was referred to our hospital. Computed tomography revealed the full extent of the tumor, which was about 8 cm in diameter and had damaged the middle cranial base, mastoid bone, and middle ear cavity. Magnetic resonance imaging indicated invasion of the glenoid fossa and parotid gland, equivalent to a Pittsburg stage cT4 tumor. The patient underwent STBR en bloc with the parotid gland and temporomandibular joint. Lower cranial nerves (CN IX-XII) were preserved, and the patient achieved normal oral intake without additional procedures after surgery. At six months post-operation, no recurrence was noted. In this video, we first demonstrate the surgical procedure of the STBR en bloc with the parotid gland and temporomandibular joint for far-advanced temporal bone squamous cell carcinoma, and it can be one of the surgical options to achieve the complete resection without exposure of the tumor. Informed consent was obtained from the patient. The video was reproduced with the written informed consent of the patient. Primary temporal bone squamous cell carcinoma is sporadic. According to previous studies, margin-negative resection provides the best prognosis (Nakagawa et al., 2006; Moody et al., 2000; Yin et al., 2006; Komune et al., 2021 [1-4]). When tumors extend behind the tympanic membrane, lateral temporal bone resection, which is a well-established procedure, is insufficient to achieve a tumor-free margin. For these cases, subtotal temporal bone resection (STBR) can achieve a complete en bloc resection with a tumor-free margin. Furthermore, STBR en bloc with surrounding structures, including the temporomandibular joint and parotid gland, complicates surgical techniques. We previously reported this surgical procedure in a stepwise manner using cadaveric dissection (Komune et al., 2014 [5]). The STBR en bloc with the parotid gland and temporomandibular joint is composed of three approaches according to our previous report: high cervical exposure (neck dissection), a subtemporal-infratemporal fossa approach, and a retromastoid-paracondylar approach. However, we currently lack demonstrative surgical videos. According to our previous report, this video first demonstrates STBR en bloc with the parotid gland and temporomandibular joint (Komune et al., 2014 [5]). The histopathological diagnosis of a 57-year-old woman suffering from a large tumor protruding from her auricle indicated squamous cell carcinoma; after the diagnosis she was referred to our hospital. Computed tomography revealed the full extent of the tumor, which was about 8 cm in diameter and had damaged the middle cranial base, mastoid bone, and middle ear cavity. Magnetic resonance imaging indicated invasion of the glenoid fossa and parotid gland, equivalent to a Pittsburg stage cT4 tumor. The patient underwent STBR en bloc with the parotid gland and temporomandibular joint. Lower cranial nerves (CN IX-XII) were preserved, and the patient achieved normal oral intake without additional procedures after surgery. At six months post-operation, no recurrence was noted. In this video, we first demonstrate the surgical procedure of the STBR en bloc with the parotid gland and temporomandibular joint for far-advanced temporal bone squamous cell carcinoma, and it can be one of the surgical options to achieve the complete resection without exposure of the tumor. Informed consent was obtained from the patient. The video was reproduced with the written informed consent of the patient., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objectives: The digital technologies, in recent years, have integrated with temporomandibular joint reconstruction surgeries (TRS). Therefore, a systematic study was conducted to assess the impact of digital technologies in TRS. Besides, a brief comparison between the CAD/CAM and 3D printing (3DP) technologies is presented., Materials & Methods: We searched in PubMed, ProQuest and Science direct using PRISMA guidelines. Population = Patients undergoing TRS, Intervention=CAD/CAM or 3DP, Comparison= conventional TRS (cTRS) vs technology integrated TRS (tiTRS), Outcome= Advantages/disadvantages of technology and Subjective/objective symptoms, Study design= Type of study. The quality of observational study was assessed using ROBINS-1 Assessment tool., Results: Out of 632 articles, 30 articles for CAD/CAM and 3DP were included in the study. A majority of TRS were done for ankylosis (new or re-entry), earlier failed surgery, osteoarthritis and neoplastic cases. The articles were divided into two groups. Group I: CAD/CAM(n = 16), Group II: 3DP (n = 14)., Discussion: tiTRS had definite advantages over cTRS with lesser surgery time, defined osteotomies, précised implant fitting and better final result outcome however, evidence for tiTRS in long-term follow-up is inconclusive. The cost, time, infrastructure and ethical/regulatory issues are the downsides of assisted surgeries. It was observed that 3DP technology is versatile and its adaptation in the fabrication of customized implants has outpaced CAD/CAM technology. However, literature data is feeble qualitatively and quantitatively., Conclusion: The TRS has leveraged the flexibility and precision of assisted surgeries. In future, tiTRS could successfully replace cTRS, provided that shortcomings should be dealt so that the technology can benefit the masses., Competing Interests: Declaration of Competing Interest None., (Copyright © 2021 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.)

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., Competing Interests: K.A.A. and J.C.H. are scientific consultants at Cartilage Inc. D.W. is an orthopedic surgery consultant at Cartilage Inc. M.E.K.W. serves as a director of the Osteoscience Foundation. M.E.K.W. is a consultant to Stermodontics., (© 2021 The Authors.)