Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “MANDIBULAR CONDYLE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,369 records · Page 76Linked to original sources
PubMed1990

A serial study on the development of the temporomandibular joint in the fetal mouse--in particular on the fibrous component in the condylar cartilage.

The development of the temporomandibular joint of 400 fetal mice at stages ranging from the 13th to the 20th day after insemination was investigated under the light, scanning (SEM) and transmission electron (TEM) microscopes. The differentiation and development of a cartilaginous tissue were observed at the supero-posterior end of the mandible at the 13 days after insemination. This tissue grew backward, upward and lateralward continuously and maintained a constant articulation with the squamosal part of the temporal bone. Seventeen days after insemination, cell layers in the condylar process and articular disc were arranged regularly. An supero- and inferno-directional cellular differentiation initiated from the subfibrous (SF) layer toward the articular spaces and cartilaginous layer was observed. The perichondrial ossification had taken place with the invasion of capillaries and the differentiation of osteoblasts in the SF layer, and was followed with a hypertrophic degeneration and endochondral ossification in the condylar process. Such a bi-directional growth of collagen and elastic fibers starting from the SF layer was also observed. Observation under SEM and TEM on the autoclaved condylar process revealed a complicated network consisted of main elastic fibers running in the sagittal direction. These fibers as well as the proteoglycan which contributes to the resilient property of the condylar cartilage and the ability to endure tensile or compressive stress from surrounding tissues during the growth and development of the mandibular condyle. The developing cartilaginous tissue was stimulated with the pressure from the masticatory muscles to initiate an active differentiation of the fibrous layer, which was invaded by the blood capillary system closely related with the subsequent endochondral ossification. These results elucidate that the development of the temporomandibular joint has closely kept relations with the functional influences from surrounding tissues, which also play an important role in regulating postnatal growth of the mandible.

Animals↗
PubMed1991

Flattened condylar projection in children: reflection of seasonal growth?

'Deformed or flattened' X-ray projections of the mandibular condyle are incidentally reported in the literature. However, when studied longitudinally in a growing child, this characteristic appears to come and go in an unpredictable order. In addition, there is experimental evidence that in the rat elongated 'flattened' condyles can be cultured and that the rat condylar growth exhibits seasonal fluctuations. Therefore, the hypothesis was formulated that a part of the flattened condylar projections may reflect a temporarily active growth vector. The result of this study suggests that condylar flattened projections in children exhibit a seasonal variation and may possibly be interpreted as the reflection of a temporarily active growth vector.

Adolescent↗
PubMed2002

Regeneration of defects in the articular cartilage in rabbit temporomandibular joints by bone morphogenetic protein-2.

The purpose of this study was to investigate the therapeutic use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in internally deranged temporomandibular joints (TMJ). Defects (2 mm in diameter) were created in the surface of the condylar head. Lyophilized rhBMP-2 with collagen as the carrier was implanted in the defects in different doses: rhBMP-2 15 microg (n = 5); rhBMP-2 3 microg (n = 5); rhBMP-2 0.6 microg (n = 5). In the two control groups, the defects were either filled with collagen alone (n = 5) or left untreated (n = 5). Three weeks postoperatively the sites of defects were examined under light microscopy. In the 15 micromg and the 3 microg groups, new cartilage had filled the defects; endochondral ossification was also found deep within the defect. In the 0.6 microg group, fibrous tissue was proliferating in most areas of the defect, although cartilage was also found in some parts. In the two control groups, there was either soft tissue repair only or no evidence of tissue repair. These findings suggest that BMP-2 could stimulate the repair of defects in the articular cartilage of the mandibular condyle head during the 3 weeks postoperatively. To observe the progress of endochondral ossification in more detail, it may be necessary to extend the experiment for a longer period of time. However, this study supports the contention that BMP-2 may be useful in the regeneration of cartilage in TMJ disease.

Animals↗
PubMed1981

A method for quantitatively determining temporomandibular joint bony relationships.

The spatial relationship of the mandibular condyle to the temporal component of the TMJ is determined quantitatively from lateral tomograms using a new method of measuring specific areas of the joint space. Condyle position along the posteroanterior axis of the joint is expressed as a ratio of the posterior joint space area divided by the anterior joint space area (the P/A ratio). A description of the method, as used in a clinical evaluation of 50 asymptomatic tMJs, and a statistical evaluation of the method's reproducibility and accuracy are given. The method was found to have both high reproducibility and high accuracy.

Adult↗
PubMed1993

[Histological studies on growth and function of condylar process in rat mandible].

The purpose of this study was to investigate the growth direction and the function of the mandibular condyle with the observations of the bone structure. Seven week-old rats were used as materials and the condylar processes were studied by macroscopic, light microscopic and electron microscopic observations. The results were as follows: 1. Many types of bone of different degree of calcification and differentiation were observed in the condylar processes. The calcified cartilage and immature bone, which were highly calcified, function as the core of bone trabeculae and compact bone. Each core was surrounded by other types of bone, and then, it seemed that some of these types of bone gave the characteristics of stiffness and flexibility to the bone trabeculae and compact bone. 2. The bone trabeculae indicated the rational arrangements in the condylar process, and as a result, the pressure from the mandibular fossa was transmitted to the compact bone efficiently in the masticatory movement. 3. The condylar processes in these week-old rats were growing only backward. 4. It seemed that the function as the articular head was enhanced mainly after seven week-old though the condylar process grew while it was functioning until this stage.

Animals↗
PubMed1989

Effects of leukemogenic retroviruses on condylar cartilage in vitro: an ultrastructural study.

Mandibular condyles of late embryonic NMRI mice were used in an in vitro organ culture system to study the effect of bone tumor-derived murine leukemia viruses OS-5 MuLV and OA MuLV known to induce osteopetrosis and osteomas. Skeletal precursor cells present in the condylar tissue normally undergo rapid differentiation in vitro which results in new bone formation. The infection of condyles with either OS-5 MuLV or OA MuLV markedly interfered with the normal developmental pattern of the organ leading to the formation of an atypical, heavily mineralized tissue. Many spindlelike cells and pleomorphic cells were encountered, whereas fibroblastlike cells were found to penetrate an underlying collagen substratum. These observations indicate that bone tumor-inducing leukemogenic retroviruses directly affect cartilage and/or bone precursor cells resulting in pathologic developments in the skeleton.

Animals↗
PubMed2002

The curve of Spee and craniofacial morphology: a multiple regression analysis.

The aim of this study was to investigate the relationship between the curve of Spee and skeletal facial morphology. Dental casts and lateral cephalograms were obtained from 59 orthodontic patients. The amount of concavity of the curve of Spee was calculated by a second-order quadratic interpolation of buccal cusp tips obtained from lateral digital photographs of the teeth. The cephalometric analysis aimed to evaluate the sagittal and vertical craniofacial dimensions as well as the position of the mandibular condyle with respect to the occlusal plane. These variables, included in a multiple regression model, could explain 34% of the total variance of the curve of Spee. The amount of the curvature was significantly related to (a) the horizontal position of the condyle with respect to the dentition, (b) the sagittal position of the mandible with respect to the anterior cranial base, and (c) the ratio between the posterior and anterior facial height. No significant relationship was found between the curve of Spec and any of the other cephalometric variables. The curve of Spee was not influenced by age and gender of the subjects investigated.

Adolescent↗
PubMed1993

The temporomandibular joint in rheumatoid arthritis: correlations between clinical and tomographic features.

Clinical and radiological involvement of the temporomandibular joint (TMJ) in rheumatoid arthritis (RA) varies greatly in the literature. Clinical and tomographic (sagittal plane) examination of the TMJ was performed in 26 patients with RA and 26 control subjects. Sixty-one per cent of the RA group had physical signs in the TMJ, compared with 42% in the control group (NS). Sixty-nine per cent of the RA group had erosive or cystic lesions of the TMJ compared with 31% of control subjects (P < 0.01). The clinical dysfunction score did not correlate with the tomographic TMJ score in patients with RA. It was found that a wide range of tomographic abnormalities occurs in patients with RA and in patients without the disease, and that there are no tomographic abnormalities specific for RA; however, the incidence of erosions and cysts of the mandibular condyle are significantly higher in patients with RA (P < 0.01), and should suggest the diagnosis. It was also found that there is no correlation between the clinical and tomographic findings of the TMJ in RA, and that the intensity of destructive lesions of the TMJ on tomography in RA is well correlated to the severity of the disease (evaluated with clinical and laboratory features).

Arthritis, Rheumatoid↗
PubMed1985

Cartilage surface charge. A possible determinant in aging and osteoarthritic processes.

Polycationic labels such as cationized ferritin and colloidal iron were used to evaluate the surface negative charges over the mandibular condyles of ICR mice. The effects of neuraminidase, hyaluronidase, pronase, and collagenase on the binding of cationized ferritin and colloidal iron particles to the condylar articular surface were also studied. The results of this study clearly indicate that the surface area of the cartilaginous condyle is negatively charged and that its composition consists mainly of a collagenous material embedded within a proteinaceous matrix. With age, a substantial decrease in the density of negative charges took place along the surface area and, in particular, in the context of sialic acid residues. It is, therefore, possible that the reduction in cartilage surface charge might be associated with the onset of osteoarthritic changes commonly seen in aging humans and experimental animals.

Aging↗
PubMed1994

MRI assessment of the normal temporomandibular joint with the use of projective geometry.

A new analysis, the Projective Invariant Analysis, was developed for the evaluation of magnetic resonance images of the temporomandibular joint. This method was used because it takes into account factors such as linear and angular measurements that simple Euclidean geometric methods fail to address. Forty "normal" joints (20 subjects) and 65 "abnormal" joints were analyzed. Joints were defined as normal if they had a Class I skeletal pattern and a Class I occlusion. In addition, a history was obtained and a clinical examination was performed on each of these subjects to rule out any temporomandibular joint dysfunction, masticatory muscle myalgia, or cervicalgia. The images of the 40 normal joints were compared with 65 previously taken images of 53 patients with conditions that had been diagnosed as anteriorly displaced disks with reduction. These two groups were compared with the use of the analysis method described by Drace and Enzmann that uses angular measurements. The groups were also analyzed with the use of a new method in which the structural relationships of the articular eminence, gleniod fossa, mandibular condyle, and articular disk were related to each other using projective geometry. For the projective invariant analysis, a 95% confidence ellipse was constructed on the basis of the normal data. All but one of the 40 normal points fell within this ellipse, and only three of the 65 abnormal points were inside the ellipse. Both analyses showed a significant difference between the normal and abnormal groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

The position of the dentition in the mandible and its possible relation to orthodontic abnormalities.

A method used to study human evolution has compared different positions of the lower dentition in relation to the position of the mandibular condyle in the sagittal plane. The method is modified here and, with data from the Burlington Growth Study, used to describe a normal range of positions for the human lower dentition in relation to the condyle from the ages of 4 to 20 years. Measurements of a randomly selected group of orthodontically treated patients showed that in about one half of them the lower dentition was outside the normal range before treatment. The effect of treatment was to move the dentition randomly toward or away from a normal position. It is concluded that the new cephalometric measurement described here could help in the diagnosis and treatment of orthodontic patients.

Adolescent↗
PubMed1994

The influence of altered occlusion on the condylar cartilage of the mandible and on the growth of the entire skull.

The effect of the loss of the suspensory zones of the upper jaw on the cartilage of the mandibular condyles and on the growth of both the viscerocranium and the neurocranium was examined after tooth crowns had been reduced in Wistar rats. We measured the thickness of the individual layers of the condylar cartilage and its total thickness. Alterations in the developmental processes involving the condylar cartilage expressed themselves as accelerated maturation, particularly in the centrally compressed areas of the cartilage. Alterations in occlusion influenced the development of the viscerocranium, whereas no influence on the growth of the neurocranium was detected.

Aging↗
PubMed2006

Temporomandibular joint osteochondritis dissecans: case report.

BACKGROUND: Osteochondritis dissecans is a process in which segment(s) of cartilage separate from an articular surface. It is most often reported in the larger joints of the body, including the knee, elbow, hip, wrist, and ankle. Involvement of the temporomandibular joint (TMJ) is exceedingly rare. OBJECTIVES: To describe a probable case of osteochondritis dissecans and discuss the differential diagnosis for this condition. STUDY DESIGN: In addition to clinical examination the patient was imaged using panoramic radiography, computed tomography and magnetic resonance imaging. RESULTS: Panoramic radiography showed separation of 2 rounded fragments superior to the right mandibular condyle. These were more precisely located using 3-dimensional computerized tomographic reconstructions. Magnetic resonance imaging demonstrated the right condyle as having low signal intensity area on T1-weighted images and a heterogeneous signal on T2-weighted images, with low signal dominance. No abnormality was apparent in the left TMJ. CONCLUSIONS: The patient was treated nonsurgically with a splint, occlusal adjustment, physiotherapy, and nonsteroidal antiinflammatory medications. Maximum mouth opening has increased from 24 mm to 39 mm 6 months following initiation of treatment, and pain has subsided.

Adult↗
PubMed1988

Permanent Proplast temporomandibular joint implants: MR imaging of destructive complications.

We studied the radiologic and pathologic changes in 30 patients (34 joints) in which there were locally destructive bone and soft-tissue complications associated with previously inserted permanent temporomandibular joint (TMJ) Proplast-Teflon implants. The cases were selected as representative examples of patients with failed Proplast interpositional arthroplasty, in whom images of the TMJ were obtained with conventional radiography, tomography, and MR, and in whom both surgical and histologic findings were available. Clinical indications for imaging included joint pain, restricted joint motion, crepitus, preauricular swelling, regional lymphadenopathy, malocclusion either acquired or changed since implant surgery, and facial deformity. Surgery was then performed for the purposes of implant retrieval and joint debridement because of destructive soft-tissue and osseous changes observed from the imaging analysis in conjunction with significant clinical signs and symptoms. The pathologic changes, observed 4-54 months after implant surgery, included a destructive foreign-body-type granuloma and avascular necrosis of the mandibular condyle and condylar neck. Our findings suggest that MR is useful in the detection and evaluation of destructive complications that may accompany failed Proplast-Teflon implants in the TMJ. MR is superior to conventional radiography and tomography in detecting soft-tissue lesions and avascular necrosis of bone. Tomography more accurately delineates soft-tissue calcifications and cortical margins of osseous structures.

Adult↗
PubMed2005

Mechanical strain leads to condylar growth in adult rats.

Mechanical strain produced by forward mandibular positioning was found to enhance mandibular condylar growth in experimental animals and in patients. This study was designed to identify the changes in number and rate of the proliferating mesenchymal cells in mandibular condyles of adult rats and to correlate these changes to the expression of SOX9 and type II collagen under mechanical strain. Seventy-eight 120-day-old female Sprague-Dawley rats were randomly allotted to six groups, nine animals in each experimental group according to different time points. Cell kinetic studies for expression of PCNA were used to identify number and rate of proliferating mesenchymal cells. Immunostaining of SOX9 and in situ hybridization of Col2a1 gene were carried out. Results showed a significant increase in number of replicating mesenchymal cells and proliferation rate. The expression of SOX9 was enhanced and Col2a1 gene transcript was then activated. The proliferative layer became thicker on experimental day 21. The thickness of chondroblast layer and chondrocyte layer showed significant increase from experimental day 14 to day 30. In conclusion, mechanical strain produced by mandibular advancement in adult rats promotes the proliferation of mesenchymal cells. Under control of transcription factor SOX9, these mesenchymal cells are then committed to enter the chondrogenic route leading to condylar growth.

Animals↗
PubMed2003

Palaeopathological and variant conditions of the Homo heidelbergensis type specimen (Mauer, Germany).

Although early Homo specimens are now known from a number of African, Asian and European Middle Pleistocene sites, the taxon Homo heidelbergensis was initially introduced for the Mauer jaw recovered in 1907. Fossil hominids from the earlier Middle Pleistocene of Europe are very rare and the Mauer mandible is generally accepted as one of the most ancient, with an age of approximately 700 kyr. A new preparation of the mandible was conducted in 1996 and gave rise to the detailed palaeopathological examination which is presented here. Based on comparative analyses, the extreme breadth of the mandibular ramus and its flat intercondylar incision, in conjunction with the flattening and broadening of the coronoid process tip, results either from an idiosyncratic pattern of the course and insertion of the temporalis muscle on the coronoid process or from the temporalis possessing an accessory head. The incidence of periodontal pocketing, together with a vertical reduction of the alveolar margin to approximately 3.00 mm, and a slight protuberance formed in vicinity of the right M(2)can safely be interpreted as pathognomonic indications of periodontal disease. The short distance between the enamel-dentine junction of the teeth and the horizontal alveolar margins could either be an inherited variant or may result from incipient osteoporosis. In addition, an arthrotic condition with slight osteophytic peripheral exostoses and an arthrolit (i.e. an articular calculus or "joint mouse") on the left condylus articularisand a depression in the medial part of the left mandibular condyle extending into the inferior part of the ramus are present. These features are indicative of a trauma-induced osteochondrosis dissecans. The diagnosis therefore suggests that the observed depression results from a well-healed fracture. This traumatic event illustrates the demanding living conditions endured by humans during the European Middle Pleistocene. The variations and pathological conditions observed in Mauer do not question the mandible's role as type specimen for the taxon Homo heidelbergensis.

Alveolar Process↗
PubMed1992

Effect of marrow perforation on the sheep temporomandibular joint.

The effect of surgically perforating the mandibular condyle to allow synovial fluid to contact the marrow was examined in 5 sheep temporomandibular joints. The surgical defect showed replacement of the marrow with fibro-osseous tissue and subcortical cysts. A vertical, central osteophyte emerged from the perforation, causing attenuation or perforation of the disc and temporal surface proliferation. These changes were radiographically and histologically similar to advanced osteoarthritis. This supports the concept that intraarticular micro or macrofracture may result in osteoarthritis.

Animals↗
PubMed1994

Osteosarcomagenic doses of radium (224Ra) and infectious endogenous retroviruses enhance proliferation and osteogenic differentiation of skeletal tissue differentiating in vitro.

Cartilage tissue from embryonic mice which undergoes osteogenic differentiation during in vitro cultivation was used to study the effect of osteosarcomagenic doses of alpha-irradiation and bone-tumor-inducing retroviruses on proliferation and phenotypic differentiation of skeletal cells in a defined tissue culture model. Irradiated mandibular condyles showed dose-dependent enhancement of cell proliferation at day 7 of the culture and increased osteogenic differentiation at day 14. Maximal effects were found with 7.4 Bq/ml of 224Ra-labeled medium. Doses of 740 and 7400 Bq/ml of 224Ra-labeled medium induced increasing cell death. Retrovirus infection enhanced osteogenic differentiation and extended the viability of irradiated cells. After transplantation none of the treated tissues developed tumors in syngeneic mice.

Animals↗