Temporomandibular joint (TMJ) disc displacement is one of the most significant subtypes of temporomandibular joint disorders, but its etiology and mechanism are poorly understood. In this study, we elucidated the mechanisms by which destruction of inflamed collagen fibrils induces alterations in the mechanical properties and positioning of the TMJ disc. By constructing a rat model of TMJ arthritis, we observed anteriorly dislocated TMJ discs with aggravated deformity in vivo from five weeks to six months after a local injection of Freund's complete adjuvant. By mimicking inflammatory conditions with interleukin-1 beta in vitro, we observed enhanced expression of collagen-synthesis markers in primary TMJ disc cells cultured in a conventional two-dimensional environment. In contrast, three-dimensional (3D)-cultivated disc cell sheets demonstrated the disordered assembly of inflamed collagen fibrils, inappropriate arrangement, and decreased Young's modulus. Mechanistically, inflammation-related activation of the nuclear factor kappa-B (NF-κB) pathway occurs during the progression of TMJ arthritis. NF-κB inhibition reduced the collagen fibril destruction in the inflamed disc cell sheets in vitro, and early NF-κB blockade alleviated collagen degeneration and dislocation of the TMJ discs in vivo. Therefore, the NF-κB pathway participates in the collagen remodeling in inflamed TMJ discs, offering a potential therapeutic target for disc displacement.
Animals ; NF-kappa B/metabolism* ; Temporomandibular Joint Disorders/pathology* ; Temporomandibular Joint Disc/metabolism* ; Rats ; Rats, Sprague-Dawley ; Disease Models, Animal ; Male ; Collagen/metabolism* ; Cells, Cultured ; Joint Dislocations/pathology* ; Interleukin-1beta ; Arthritis, Experimental

OBJECTIVES: Magnetic resonance imaging (MRI) was used to study the efficacy of modified anterior splint (MAS) combined with anterior repositioning splint (ARS) in maintaining the normal disk-condyle relationship. METHODS: We obtained clinical and imaging data of 10 patients with acute anterior disk displacement without reduction (ADDwoR) of the temporomandibular joint undergoing successful mandibular manipulation in the Affiliated Stomatological Hospital, Nanchang University from January to June 2024. The MAS and ARS were used for subsequent treatment. Maximum active mouth opening (MMO) and visual analogue score (VAS) were recorded before treatment and 2 weeks, 1 month, and 3 months after treatment. The changes in the disk-condyle relationship, disk-condyle angle, joint effusion, and double contour sign before and after treatment were analyzed through MRI. RESULTS: Three months after treatment, the MMO increased from 28.90 mm to 46.85 mm, VAS decreased from 4.68 to 0.61, and the disk-condyle angle decreased from 58.84° to 25.99°. MRI analysis found that 6 patients showed normal disk-condyle relationship, 2 patients exhibited displacement with reduction, and 2 patients exhibited ADDwoR. The disk-condyle angle was 58.84° before treatment and 25.99° after treatment. CONCLUSIONS The MAS combined with ARS could further stabilize the coordinated disk-condyle relationship and reduce the recurrence rate.
Humans ; Male ; Magnetic Resonance Imaging ; Female ; Adult ; Temporomandibular Joint Disorders/diagnostic imaging* ; Splints ; Middle Aged ; Mandible ; Temporomandibular Joint Disc ; Occlusal Splints ; Temporomandibular Joint ; Young Adult ; Joint Dislocations/therapy*

OBJECTIVES: This study aimed to evaluate the effect of disc morphology and disc-condyle angle on the treatment of anterior repositioning splint (ARS) for anterior disc displacement with reduction (ADDwR). METHODS: On the basis of the inclusion and exclusion criteria, a total of 11 patients diagnosed with ADDwR were included. The effects of changes in disc length, thickness, and morphology classifications on the clinical symptoms, disc morphology parameters, and disc-condyle angles after ARS treatment were evaluated using magnetic resonance imaging and the Helkimo index. RESULTS: After ARS treatment, the Ai and Di of all patients with ADDwR decreased, the disc length increased, and the thickness decreased. The Ai of patients with slight ADDwR and those with type 1 joint discs was reduced to 0, with the most significant decrease observed in Di. The disc length of mild ADDwR (increased to 8.65 mm±1.79 mm) and type 5 disc (increased to 10.71 mm±2.62 mm) significantly increased the most. The disc thickness of slight ADDwR decreased to 3.08 mm±0.51 mm significantly. CONCLUSIONS The therapeutic effect of ARS is correlated with the displacement degree and morphological features of the disc, providing evidence for clinical treatment decisions.
Humans ; Magnetic Resonance Imaging ; Conservative Treatment ; Temporomandibular Joint Disc/diagnostic imaging* ; Male ; Adult ; Female ; Intervertebral Disc Displacement/pathology* ; Middle Aged

OBJECTIVE: To investigate the effectiveness of modified temporomandibular joint disc reduction and suture with tragus incision assisted by arthroscopy for temporomandibular joint anterior disc displacement (ADD). METHODS: A clinical data of 30 patients (45 sides) with temporomandibular joint ADD, who met selective criteria and were admitted between September 2022 and February 2024, was retrospectively analyzed. Among them, 15 patients (23 sides) were treated with temporomandibular joint disc reduction and suture via small incision (open operation group), and 15 patients (22 sides) with modified temporomandibular joint disc reduction and suture with tragus incision assisted by arthroscopy (arthroscopy group). There was no significant difference in gender, age, disease duration, affected side, Wilkes-Bronstein stage, preoperative visual analogue scale (VAS) score, maximal interincisal opening (MIO), and temporomandibular joint dysfunction index (DI), craniomandibular index (CMI), palpation index (PI), and other baseline data between groups ( P>0.05). VAS score, MIO, and temporomandibular joint function indicators (PI, DI, CMI) of patients were recorded at 3 months after operation, and the difference (change value) of the above indicators between pre- and post-operation was calculated. At 1 week after operation, MRI was performed to evaluate the reduction of the articular disc compared to the preoperative image. The results were classified as excellent, good, and poor, with excellent and good being considered effective reduction. The condition of condyle process repair was observed by cone beam CT (CBCT) at 3 months after operation. RESULTS: All incisions healed by first intention in the two groups. All patients were followed up 3-18 months (mean, 8.2 months). Facial nerve injury occurred in 3 cases in the open operation group and 1 case in the arthroscopy group, all of which returned to normal after physiotherapy and drug treatment. At 3 months after operation, MIO and VAS scores of both groups significantly improved when compared with those before operation ( P<0.05), and temporomandibular joint function indicators (PI, DI, CMI) significantly decreased ( P<0.05). The change values of MIO and temporomandibular joint function indicators in arthroscopy group were significantly higher than those in open operation group ( P<0.05). There was no significant difference in the change value of VAS score between groups ( P>0.05). There was no recurrence during follow-up. Postoperative MRI review showed that the effective reduction rate of joint disc was 95.65% (22/23) in the open operation group and 95.45% (21/22) in the arthroscopy group, with no significant difference between groups ( P>0.05). Postoperative CBCT found that early and timely effective reduction of joint disc was conducive to condyle process repair and reconstruction. CONCLUSION Modified temporomandibular joint disc reduction and suture with tragus incision assisted by arthroscopy has a clear effect in the treatment of ADD, with less trauma, fewer postoperative complications, and good early effectiveness.
Humans ; Arthroscopy/methods* ; Retrospective Studies ; Temporomandibular Joint Disorders/surgery* ; Temporomandibular Joint Disc/surgery* ; Male ; Treatment Outcome ; Female ; Suture Techniques ; Adult ; Joint Dislocations/surgery* ; Range of Motion, Articular ; Middle Aged ; Pain Measurement ; Young Adult ; Sutures

Objective: To explore the correlation between the attachment type of lateral pterygoid muscle (LPM) and the position of temporomandibular joint (TMJ) disc in patients with temporomandibular disorders (TMD) by using wireless amplified magnetic resonance imaging detector (WAND) coupled with conventional head and neck joint coil for high resolution imaging of TMJ. Methods: Eighty-five patients with TMD diagnosed by oral and maxillofacial surgeons of Guizhou Provincial People's Hospital from October 2019 to January 2022 were collected. A total of 160 TMJ were included. There were 16 males and 69 females, aged (32.7±14.2) years. All patients were scanned with open, closed oblique sagittal and coronal WAND coupled head and neck coils with bilateral TMJ. Based on TMJ and LPM high resolution imaging, to explore the correlation between LPM attachment types and the position of TMJ disc in TMD patients, and to evaluate the potential clinical value of LPM attachment types in TMD patients. χ² test and Pearson correlation analysis were used to evaluate the correlation between LPM attachment type and TMJ disc location. Results: There were three types of LPM attachment: type Ⅰ in 51 cases [31.9% (51/160)], type Ⅱ in 77 cases [48.1% (77/160)] and type Ⅲ in 32 cases [20.0% (32/160)]. There was a significant correlation between the type of LPM attachment and the position of articular disc (χ²=28.20, P=0.002, r=0.776). There was no statistical significance between the type of LPM attachment and the reversible displacement of articular disc (χ²=0.24, P=0.887, r=0.825). Conclusions: There is a correlation between the attachment type of LPM and the position of the disc in TMD patients. WNAD coupled with conventional head and neck joint coil TMJ high resolution scan can provide reliable imaging evidence for TMD patients in evaluating the type of LPM attachment and the location of disc.
Male ; Female ; Humans ; Temporomandibular Joint Disc/pathology* ; Pterygoid Muscles/pathology* ; Joint Dislocations ; Temporomandibular Joint Disorders/diagnostic imaging* ; Magnetic Resonance Imaging/methods* ; Temporomandibular Joint/pathology*

OBJECTIVES: This study aimed to use modified articular disc anchorage in treating old irreducible temporomandibular joint (TMJ) disc displacement with perforation and rupture, as well as to explore its efficacy. METHODS: A total of 31 patients (34 sides) with 47 TMJ disc perforations who underwent surgical treatment in the Affiliated Stomatolo-gical Hospital of Nanchang University from January 2018 to December 2021 were selected. According to the location of disc perforation, it has five types: posterior disc perforation (typeⅠ), anterior disc perforation (typeⅡ), lateral disc perforation (type Ⅲ), composite disc perforation, and destruction disc perforation. The modified methods of disc anchoring were divided into two types according to the location of the perforation. TypesⅠandⅢ disc perforation were trea-ted by posterior anchoring method. For posterior ancho-ring, a screw was implanted into the posterolateral side of the condylar neck, and the disc was fixed on the screw by horizontal mattress suture. TypeⅡdisc perforation and compo-site disc perforation combined typeⅡperforation were treated by anterior and posterior double-anchoring method. For anterior anchoring, anchor screws or holes were placed at the anterior edge of the condylar neck, and horizontal mattress suture was performed at the posterior edge of the anterior perforation with an anchor wire. The articular disc was then fixed on the anchor screws or holes. For the posterior anchoring method, it was the same as the previous one. Paired t test was used to analyze the visual analog scale (VAS), maximum interincisal opening (MIO), and TMJ disorder index (CMI) of the patient before surgery and 1, 3, and 6 months after surgery. Disk-condyle position relationship by magnetic resonance imaging and postoperative quality of life in postoperative were analyzed. RESULTS: The incidence of perforation was 41.2% (14/34) in typeⅠ, 11.8% (4/34) in typeⅡ, 8.8% (3/34) in typeⅢ, 29.4% (10/34) in composite type, and 8.8% (3/34) in destruction type. The VAS, MIO, and CMI at 3, 6 months after operation significantly improved compared with those before operation (P<0.05). The effective reduction rate of disc was 96.77% (30/31). The quality of life at 6 months after surgery was 47.22±2.13, and the rate of excellent evaluation was 96.4% (27/28). CONCLUSIONS Modified articular disc anchorage achieves a good curative effect for treating temporomandibular joint disc perforation and rupture. Nevertheless, its long-term effect requires further observation.
Humans ; Temporomandibular Joint Disc/surgery* ; Quality of Life ; Joint Dislocations/surgery* ; Temporomandibular Joint Disorders/surgery* ; Magnetic Resonance Imaging/methods* ; Temporomandibular Joint/pathology* ; Mandibular Condyle

Objective: To investigate the imaging features of condylar cystic degeneration of temporomandibular joint (TMJ) by cone-beam CT (CBCT), spiral CT, MRI and radionuclide bone imaging. Methods: From January 2018 to December 2020, thirty-two patients with cyst-like lesions of condylein temporomandibular joint were examined by CBCT, spiral CT, MRI and radionuclide bone imaging at the Department of Oral and Maxillofacial Surgery in General Hospital of Chinese PLA. There were 12 males and 20 females involved, aged from 16 to 65 years with an average age of (33.9±12.5) years. The characteristics of CBCT, spiral CT, MRI and radionuclide bone imaging were analyzed. Condylar cyst like lesions were classified as type A and type B based on the presence or absence of surface bone defects. Condylar cyst like lesions were classified as type Ⅰ(yes) and type Ⅱ(no) according to the accompanying bone marrow edema-like lesions of the condyles. The incidence of condylar bone marrow edema, disc displacement and abnormal bone metabolism were analyzed. Results: A total of 64 joint images of 32 patients were included, including 34 sides with TMJ cyst-like lesion and 6 sides with multiple cyst-like lesions,the total cyst-like lesions were 42. The largest diameter of cyst-like lesion ranged from 1.0 to 12.4 mm, with an average length of (3.7± 1.8) mm. There were 24 cases of type A TMJ cyst like lesion and 10 cases of type B cyst-like lesion. The detection rate of CBCT was 95.2% (40/42) and that of spiral CT was 100% (42/42), there was no significant difference (Calibration Chi-square=0.51, P=0.474). The detection rate of nuclear magnetic resonance was 80.1% (34/42), and the detection rate of cyst-like lesions less than 2 mm was 3/11. In the cyst like lesion side, there were 9 sides with anterior disc displacement with reduction, 20 sides with anterior disc displacement without reduction. In the non-cyst like lesion side, 10 sides with anterior disc displacement with reduction and 6 sides with anterior disc displacement without reduction. There was a significant difference in the displacement of the disc between cyst-like and non-cystic lesion side (χ²=7.80, P=0.005). MRI showed that 6 cases of cystic side[17.6% (6/34)] had bone marrow edema-like lesions (all type A), 1 case of non-cyst like lesions side [3.3% (1/30)] had bone marrow edema-like lesion, there was no significant difference between cystic and non-cystic lesions (Calibration Chi-square=2.04, P=0.153). There was a significant difference between type A and B cystic lesions (Fisher exact probability method, P=0.024). Radionuclide bone imaging showed abnormal bone metabolism in 26 patients in the cyst-like lesion side and 5 patients in the non-cyst like lesion side (χ²=22.82, P<0.001). Conclusions Multi-slice Spiral CT could detect the cyst-like lesion of TMJ condyle in the early stage, which is different from the large joint. And the formation mechanism may vary from the different classifications.
Adolescent ; Adult ; Aged ; Cysts ; Female ; Humans ; Joint Dislocations ; Magnetic Resonance Imaging ; Male ; Mandibular Condyle/diagnostic imaging* ; Middle Aged ; Multimodal Imaging ; Temporomandibular Joint/diagnostic imaging* ; Temporomandibular Joint Disc ; Temporomandibular Joint Disorders/diagnostic imaging* ; Young Adult

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.
Humans ; Joint Dislocations/surgery* ; Mandible ; Mandibular Condyle ; Mandibular Fractures/surgery* ; Suture Anchors ; Temporomandibular Joint Disc/surgery*

Objective: MRI images were used to study the efficacy of anterior repositioning splint (ARS) in the treatment of different types of disc displacement with reduction (DDWR) in temporomandibular joint. Methods: From September 2020 to December 2021, 26 patients with DDWR were enrolled in the Department of Oral and Maxillofacial Surgery, the First Affiliated Hospital of Zhengzhou University. There were 5 males and 21 females with an average age of (20.8±5.8) years. ARS was used for 3-6 months. The changes of joint clicking, opening type and joint pain before and after treatment were compared. The changes of disc position, disc-condyle angle and condylar bone mass before and after treatment were compared by MRI. Paired t-test was performed on the disc-condyle angle before and after treatment, Fisher's exact test was performed on the change of disk position, and other count data were expressed as rate (%). Results: After ARS treatment, the effective rates of joint clicking,abnormal opening, joint pain and disc displacement were 97%(35/36), 14/18, 7/9 and 95%(36/38). MRI analysis found that there was a significant difference between the disc position before and after treatment (P<0.001), MRI analysis showed that the anterior disc displacement (48%, 25/52) and the anterolateral disc displacement (17%, 9/52) were the most common before treatment. In contrast, the normal superior disc (75%, 39/52) and the anterior disc displacement (17%, 9/52) were the most common after treatment, no significant changes were seen after treatment in the anteromedial disc displacement. The disc-condylar angle was (36.09±19.02) ° before ARS treatment and (3.94±10.12) ° after ARS treatment(t=9.23, P<0.001). After treatment, 46% (12/16) of the patients showed new bone formation, and the height of the condyle recovered. Conclusions: The clinical efficacy of ARS in the treatment of anterior disc displacement and anterolateral displacement of temporomandibular joint is remarkable, which can restore the disc-condylar relationship of most patients with indications.
Adolescent ; Adult ; Arthralgia ; Female ; Humans ; Joint Dislocations/therapy* ; Magnetic Resonance Imaging ; Male ; Splints ; Temporomandibular Joint ; Temporomandibular Joint Disc/diagnostic imaging* ; Young Adult

Objective: To observe the different imaging manifestations of condylar sclerosis in temporomandibular joint osteoarthrosis and explore the imaging significance of condylar sclerosis. Methods: From January 2018 to December 2020, 50 patients with temporomandibular joint condylar sclerosis were examined by cone-beam CT (CBCT) and underwent spiral CT, MRI and radionuclide bone imaging at the Department of Oral and Maxillofacial Surgery in General Hospital of Chinese PLA. There were 15 males and 35 females aged from 16 to 65 years with age of (42.7±14.5) years. The imaging manifestations of CBCT, spiral CT, MRI and radionuclide bone imaging, joint disc displacement and abnormal bone metabolism of condylar sclerosis were analyzed. And the area of condylar sclerosis was graded according to the image of CBCT. Results: A total of 50 patients were included, including 38 unilateral condylar sclerosis, 12 patients with bilateral condylar sclerosis, the total condylar sclerosis were 66. There was no significant difference between the detection rate of further spiral CT (95.5%, 63/66) and CBCT (100.0%, 66/66) (corrected χ²=1.36,P=0.244). The area of condylar sclerosis was (35.5±4.5) mm², ranged from 1 to 100 mm². In addition, spiral CT showed more clearly condylar sclerosis than CBCT. Sclerosis can occur in all parts of condyle, mainly in the upper middle region (68.2%,45/66) in coronal position and in the upper front region (71.2%,47/66) in sagittal position. Fifty-seven condylar sclerosis were detected by MRI, including 4(4/19) condylar sclerosis less than 4 mm². There was significant difference in the displacement of temporomandibular joint disc between the sclerotic side and the non sclerotic side (χ²=10.09, P=0.006). MRI display the condylar sclerosis showed low signal (56/62), followed by high signal (5/62) and medium signal (1/62). Radionuclide bone imaging showed that 4 of the 38 patients with unilateral condyle sclerosis had symmetrical bone metabolism, 34 had abnormal bone metabolism, and 21 patients had concentrated on the non-sclerotic side. Radionuclide bone imaging showed that 4 of the 38 patients with unilateral condyle sclerosis had symmetrical bone metabolism and 34 had abnormal bone metabolism. Conclusions: Spiral CT is more accurate than CBCT in terms of condyle sclerosis through different imaging analysis, and the detection rate of both is higher than MRI. Most of condylar sclerosis showed different degrees of low signal on MRI. The condylar sclerosis side is usually manifested by abnormal bone metabolism.
Male ; Female ; Humans ; Mandibular Condyle/diagnostic imaging* ; Sclerosis/diagnostic imaging* ; Temporomandibular Joint/diagnostic imaging* ; Temporomandibular Joint Disorders/etiology* ; Temporomandibular Joint Disc/diagnostic imaging* ; Cone-Beam Computed Tomography ; Temporomandibular Joint Dysfunction Syndrome ; Osteoarthritis/etiology* ; Magnetic Resonance Imaging