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*

OBJECTIVETo study the chondrocyte apoptosis in rabbit temporomandibular joint after anterior disc displacement.

METHODSExperimental anterior disc displacement was induced surgically in 20 Japanese rabbits without opening their temporomandibular joint bursas. Histopathologic and apoptotic (TUNEL) analysis was used to evaluate the changes in articular cartilage, disc and synovium.

RESULTSCondyle chondrocyte showed apoptosis most obviously at 1 or 2 weeks after surgery, and apoptotic cells concentrated in proliferative zone and hypertrophic zone. 4 or 6 weeks after surgery, the joint went into a remodelling period.

CONCLUSIONSChondrocyte apoptosis in temporomandibular joint will be activated after anterior disc displacement, which initiates the remodelling in temporomandibular joint.

Animals ; Apoptosis ; Chondrocytes ; pathology ; In Situ Nick-End Labeling ; Joint Dislocations ; physiopathology ; Rabbits ; Temporomandibular Joint ; physiopathology ; Temporomandibular Joint Disc ; physiopathology

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

OBJECTIVETo study the adaptive alterations of elastic fibers in the bilaminar zone (BZ) of rabbit temporomandibular joint (TMJ) following disc displacement.

METHODSTwenty-eight Japanese white rabbits were used in this study. The right temporomandibular joints of 20 of 28 rabbits were subjected to the surgical procedure of anterior disc displacement (ADD). Four rabbits in the surgical group were sacrificed at 2, 4, 6, 8 and 12 weeks after operation. Their temporomandibular joints were studied histochemically.

RESULTSElastic fibers were reduced in number and ran irregularly in the superior lamina of BZ from ADD rabbits. The jungly elastic fibers (EFs) could still be seen at 2 weeks after operation. At 4 weeks, the number of EFs decreased significantly; EFs lost their jungly arrangement and were shaped like rough dots, of which the arrangement and the lengths were different. Six weeks after operation, many EFs were replaced by distorted, uneven, non-oriented fine EFs, distributed unevenly and some thick or fine EFs that ran irregularly. The number of EFs decreased further and their arrangement was more deranged at 8 weeks. At 10 and 12 weeks, EFs in the superior lamina of BZ were similar to those at 8 weeks.

CONCLUSIONOur results show that EFs lost their function as well as their distribution and arrangement after disc displacement.

Adaptation, Physiological ; Animals ; Behavior, Animal ; Elastic Tissue ; pathology ; Extracellular Matrix ; pathology ; Joint Dislocations ; pathology ; Rabbits ; Temporomandibular Joint Disc ; pathology ; Temporomandibular Joint Disorders ; pathology

OBJECTIVETo study the adaptive alteration in bilaminar zone of rabbits' temporomandibular joint following disc displacement.

METHODSTwenty-six Japanese white rabbits were used in this study. Among these rabbits,6 were used as controls. The right discs of other 20 rabbits were displaced anteriorly by operation. Four of these rabbits were killedatn 1, 2, 4, 6 and 8 weeks respectively after surgery. The TMJS were studied by HE staining, Alcin bluen staining and in situ detection of type II collagen mRNA expression.

RESULTSThere appeared cartilage metaplasia after one week following disc displacement. Typical chondrocytes could be found in the bilaminar zone. The new chondrocytes expressed type II collagen.

CONCLUSIONSThe bilaminar zone of TMJ will be remodeled following disc displacement and become a disc-like tissue to function as a disc.

Animals ; Collagen Type II ; biosynthesis ; genetics ; Female ; Joint Dislocations ; metabolism ; Male ; RNA, Messenger ; biosynthesis ; Rabbits ; Temporomandibular Joint Disc ; metabolism ; pathology ; Temporomandibular Joint Disorders ; metabolism ; pathology

OBJECTIVETo investigate the relationship between condylar marrow signal abnormalities and temporomandibular joint internal derangement (TMJID).

METHODSOblique sagittal T1 weighted MR imaging at closed and open mouth and Oblique sagittal T2 weighted MR imaging at closed mouth were obtained from 88 joints of 44 patients suffering from TMD. Condylar marrow signal abnormalities were reviewed and classified into bone marrow edema pattern (hypointense T1, hyperintense T2), sclerosis pattern (hypointense T1 and hypointense T2) and combined edema and sclerosis pattern.

RESULTSOf 88 joints, 13 (14.8%) joints showed condylar marrow signal abnomalities, among which 11 belonged to edema pattern and, 1 was sclerosis pattern and the other was the combined patten. Of 13 joints with condylar marrow signal abnomalities, 11 (84.6%) had TMJID. Of 75 joints with normal marrow signal, 25 (33.3%) joints had TMJID. There was significant correlation between condylar marrow signal abnormalities and TMJID (P < 0.05).

CONCLUSIONDisc displacement is one of the factors inducing condylar marrow signal abnormalities. The pathological process from disc displacement to osteonecrosis requires further study.

Adolescent ; Adult ; Aged ; Child ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Mandibular Condyle ; pathology ; Middle Aged ; Temporomandibular Joint Disc ; pathology ; Temporomandibular Joint Disorders ; diagnosis ; pathology

The purpose of this review is to provide a reference for researchers in investigating the tissue engineering of the temporomandibular joint (TMJ) disc. Currently tissue engineering of the TMJ disc is in its infancy, and cell source is one of the key factors that define the development of the tissue engineering of TMJ disc. In this paper, 6 kinds of cells: the TMJ disc native cells, chondrocytes, dermal fibroblasts, bone marrow-derived mesenchymal stem cells, adipose-derived stem cells, and embryonic stem cells are introduced. In addition, the possibility that these cells can be used as cell sources for TMJ disc tissue engineering is described.
Animals ; Chondrocytes ; cytology ; Fibroblasts ; cytology ; Humans ; Joint Prosthesis ; Skin ; cytology ; Temporomandibular Joint Disc ; cytology ; pathology ; physiopathology ; Temporomandibular Joint Disorders ; rehabilitation ; surgery ; therapy ; Tissue Engineering ; methods ; trends

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

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

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

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

Arthrocentesis ; Humans ; Joint Dislocations ; Magnetic Resonance Imaging ; Outpatients ; Range of Motion, Articular ; Temporomandibular Joint Disc ; pathology ; surgery ; Temporomandibular Joint Disorders ; diagnosis ; surgery ; Treatment Outcome ; Visual Analog Scale

OBJECTIVETo compare the clinical appearances of TMD patients between acute and chronic anterior disc displacement without reduction.

METHODSSuccessive one hundred TMD patients with fully recorded documents diagnosed as anterior disc displacement without reduction (ADDw/oR) were included, 45 acute and 55 chronic ADDw/oR patients. Clinical appearances including signs and symptoms, maximal mouth opening, Fricton's craniomandibular index, condylar bone changes on radiograms, findings on arthrograms and MRI were compared.

RESULTSThe main reason for asking treatment was joint pain in chronic, instead of limited mouth opening in acute patients. Clinical symptoms such as pain and limited mandibular movement showed improvement in chronic patients. Fricton's joint dysfunction index was higher in acute than in chronic patients, but muscle palpation index was higher in chronic than in acute patients, but Fricton's craniomandibular index was not significantly different between chronic and acute patients. The destructive bone changes of condyle on radiograms, the damage of stretched disc attachment on arthrograms and the morphological deformed disc on MRI were more frequently found in chronic than in acute patients.

CONCLUSIONSIn acute patients there is a great likelihood that tissues are healthy and not morphologically changed, we suggest that early and efficacious intervention should be made to reposition the anterior displaced disc that may block the progress of pathological impairment to both the disc and the condyle of TMJ.

Acute Disease ; Adolescent ; Adult ; Aged ; Child ; Chronic Disease ; Female ; Humans ; Male ; Middle Aged ; Prognosis ; Temporomandibular Joint Disc ; pathology ; Temporomandibular Joint Disorders ; diagnosis ; therapy ; Young Adult

OBJECTIVETo investigate the electrosonography character of sounds emanating from anterior disc displacement with reduction of TMJ and the value of it in clinical diagnosis.

METHODSThe sounds from healthy TMJ, anterior disc displacement with or without reduction of TMJ, and osteoarthritis of TMJ were recorded and analyzed by K6-I system, then the data was used for diagnosis of anterior disc displacement with reduction in clinic.

RESULTSA special kind of waveform was found in the electrosonography of sounds from anterior disc displacement with reduction repeatedly, and seldom or not in sounds from healthy joints, anterior disc displacement without reduction or osteoarthritis of TMJ. The diagnostic sensitivity of anterior disc displacement with reduction by using electrosonography analysis was 77.2% and specificity was 93.3% when compared with the clinical diagnosis based on clinical appearance and radiography evidence.

CONCLUSIONSThe special kind of waveform may be characteristic wave of sounds from anterior disc displacement with reduction of TMJ, which is useful for assistant diagnosis of anterior disc displacement with reduction in clinic.

Adolescent ; Adult ; Aged ; Electrodiagnosis ; methods ; Female ; Humans ; Male ; Middle Aged ; Sensitivity and Specificity ; Signal Processing, Computer-Assisted ; Sound Spectrography ; Temporomandibular Joint Disc ; pathology ; Temporomandibular Joint Disorders ; diagnosis ; Young Adult