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 1,477 records · Page 82Linked to original sources
PubMed2006

Comparative study of eminectomy and use of bone miniplate in the articular eminence for the treatment of recurrent temporomandibular joint dislocation.

UNLABELLED: Dislocation of the temporomandibular joint occurs when the mandibular condyle exits the glenoidal cavity and remains anteriorly locked to the articular eminence. It is repetitive (recurrent dislocation), usually associated with mandibular hypermobility and inclination of the articular eminence. AIM: This study intended to clinically and radiologically assess the technique of eminectomy and the use of a miniplate on the articular eminence for the treatment of recurrent dislocation of the temporomandibular joint of patients operated on at Oswaldo Cruz University Hospital from January to September 2003. STUDY DESIGN: Retrospective cohort. MATERIAL AND METHOD: The sample consisted of 11 patients. Eminectomy was performed on nine joints of five patients and the placement of a miniplate on the articular eminence was performed on 11 joints of six patients. Data collection was carried out through analysis of patient's medical charts and new postoperative visit. RESULTS: The results showed that there were no major postoperative complications with either technique. Maximum mouth opening was greater with eminectomy procedure and none of the patients operated on presented any recurrence of dislocation. CONCLUSION: It is concluded that both techniques were effective in the treatment of recurrent dislocation of the temporomandibular joint.

Adolescent↗
PubMed1992

[Surgical landmarks of the temporo-frontal branch of the facial nerve].

The temporal branches of the facial nerve, and in particular the rami for the frontalis muscle, have been the subject of many studies with the main objective of avoiding injury. The usual reference points, sometimes difficult to localise, anatomical variations in their branching and anastomoses are the main points of our investigation. This anatomical dissection study of 30 cadavres, with easy reference points available both superficially and in the depths allow a simple, non complicated localisation of the frontal branch and its anastomosis in a precise way on the mandibular condyle, the zygomatic arch and the temporal region. The distances described a, b, c, are useful in common surgical practice: temporo-mandibular joint surgery, facial lifting, temporal and temporo-parietal fascia flaps, and contralateral neurotomy for frontal symmetrization among others.

Dissection↗
PubMed2006

Isolated osteochondroma near the mandibular angle.

A benign tumour of osseous and cartilaginous origins, osteochondroma generally develops in osseous tissue and is frequently found near the end of long bones. It is relatively rare in the oral and maxillofacial region but is common in the mandibular condyle and coronoid process in the pediculate form. This is a report on a rare case of osteochondroma in soft tissue near the mandibular angle without pedicle to the bone.

Adult↗
PubMed2000

Kinematics of the human mandible for different head postures.

The influence of head posture on movement paths of the incisal point (IP) and of the mandibular condyles during free open-close movements was studied. Ten persons, without craniomandibular or cervical spine disorders, participated in the study. Open close mandibular movements were recorded with the head in five postures, viz., natural head posture, forward head posture, military posture, and lateroflexion to the right and to the left side, using the Oral Kinesiologic Analysis System (OKAS-3D). This study showed that in a military head posture, the opening movement path of the incisal point is shifted anteriorly relative to the path in a natural head posture. In a forward head posture, the movement path is shifted posteriorly whereas during lateroflexion, it deviates to the side the head has moved to. Moreover, the intra-articular distance in the temporomandibular joint during closing is smaller with the head in military posture and greater in forward head posture, as compared to the natural head posture. During lateroflexion, the intra-articular distance on the ipsilateral side is smaller. The influence of head posture upon the kinematics of the mandible is probably a manifestation of differences in mandibular loading in the different head postures.

Adult↗
PubMed2002

The correlation between neovascularization and bone formation in the condyle during forward mandibular positioning.

The aim of the present study was to investigate the temporal pattern of expression of VEGF (Vascular Endothelial Growth Factor) and new bone formation in the condyle during forward mandibular positioning. The importance of vascularization during endochondral ossification was investigated during natural growth of the condyle and compared to that after forward mandibular positioning. The goal was to further our understanding of the cellular responses during functional appliance therapy with a view to extending the experiment into maturity. One hundred and fifty 35 days old Sprague-Dawley rats, 100 fitted with a bite-jumping appliance and 50 untreated, were divided into 10 groups. One group was sacrificed on each of experimental days 3, 7, 14, 21, 30, 33, 37, 44, 51 and 60 respectively. Sagittal sections were cut and stained with VEGF antibodies and Periodic acid and Schiff's reagent (PAS). Each section was quantitatively analyzed with a computer assisted analyzing program and the temporal sequence of expression of VEGF and new bone formation during natural growth and after mandibular forward positioning was compared. There was significant increase in both vascularization and mandibular bone growth upon forward mandibular positioning and the highest amount of both were expressed in the posterior region of the condyle. The highest acceleration of vascularization preceded that of new bone formation. Thus, forward mandibular positioning was found to solicit a sequence of cellular events leading to increased vascularization and subsequently new bone formation resulting in enhanced condylar growth.

Analysis of Variance↗
PubMed1990

Coronoid process elongation in rhesus monkeys (Macaca mulatta) after experimentally induced mandibular hypomobility. A cephalometric and histologic study.

The present study provided an experimental model that allowed a cephalometric and histologic analysis of craniofacial growth in monkeys with induced translatory impairment of the mandibular condyle. Cauterization was performed anterior to the joint in nine experimental rhesus monkeys, while eight animals served as control subjects. The experimental procedure produced mandibular hypomobility in six animals, in three by means of temporomandibular joint ankylosis and in three by means of dense scar tissue formation anterior to the joint. In the remaining three experimental animals no restriction of mandibular mobility was created. Mandibular hypomobility was found to induce elongation of the coronoid process and was also associated with bone deposition in the gonial region. In contrast, normal remodeling of the gonial region was found in the experimental animals with normal range of movements and in the control animals.

Animals↗
PubMed1991

Light- and electron-microscopic observations on the mandibular condylar cartilages in growing rats on a low-calcium diet.

In order to obtain more insight into the physiologic mechanism of endochondral ossification, histological changes occurring in the mandibular condylar cartilage of growing rats fed on a low-calcium diet were investigated by light and electron microscopy. Twenty-three-day-old rats were fed on a normal diet or a low-calcium diet for 8 weeks. For the histological observations the mandibular condyles were dissected from each animal at 1, 2, 4, 5 and 8 weeks after the initiation of the experiment. Histological changes occurring in the mandibular condylar cartilages of the rats fed on a low-calcium diet were as follows: (1) narrow proliferative and mature cell zones and a wide hypertrophic cell zone, (2) inhibition of development of cell organelles in the mature chondrocytes, (3) decrease in dead cells in the proliferative zone, (4) decrease in glycogen accumulation in the chondrocytes and (5) inhibition of calcification in the extracellular matrix of the hypertrophic cell zone. Additionally at the end of the experimental period, the following findings were observed: (1) appearance of small light cells in the mature cell zone and the hypertrophic cell zone and (2) decrease in proteoglycan granules and appearance of large collagen fibrils in the pericellular region of the hypertrophic cell zone.

Animals↗
PubMed1991

A technique to investigate the three-dimensional kinesiology of the human temporomandibular joint.

Previous kinesiological studies of the temporomandibular joint (TMJ) were based on the motion of only one or two selected points on the mandible (such as the lower central incisor, the mandibular condyle). In the present study, a technique was developed to measure, analyze, and describe the full three-dimensional kinematic characteristics of the TMJ during any mandibular activity. The technique was based on determination of the relative position between the mandible and the temporal bone from measurement of the location of points on light-weight frames rigidly attached through splints to the maxillary and mandibular teeth. An optoelectric kinematic data acquisition system has been used to record the location of these points. The results of the study indicate the following major advantages of this technique over previously reported kinesiological methods: (1) the technique provides a full description of the motion of the mandible with respect to the temporal bone, including all the six degrees of freedom associated with this motion; (2) the description of motion in terms of joint parameters enhances interpretation of the data by clinicians; (3) the motion of any point of interest on the mandible can be easily derived from the data and; (4) the system provides only negligible interference with the natural jaw motion of the subject. It does not require head fixation, does not alter or interfere with the natural occlusion, and its light weight causes only minimal (and negligible) loading of the mandible.

Calibration↗
PubMed2002

Phenotypic switching of in vitro mandibular condylar cartilage during matrix mineralization.

In order to analyze the phenotypic conversion of chondrocytes, mandibular condyles of mice and rabbits were cultured under cell and organ culture systems, and then examined by a combination of morphological and biochemical procedures. In organ culture, mandibular condylar cartilage (MCC) obtained from newborn mice began to mineralize from the central zone and then progressively widened towards the peripheral zone. Electron microscopic observations showed that with the increasing duration of the organ culture, chondrocytes at the central zone converted into spindle-shaped osteoblastic cells accompanying the formation of the bone type of thick-banded collagen fibrils. To obtain a better understanding of the chondrocytic conversion, immunolocalizations for type I and type X collagens and osteocalcin (OC) were examined in mouse MCC cells in cell culture. Type X collagen and OC were expressed almost simultaneously at the late stage of culture, and type I collagen was detected along the calcified nodules after the production of these proteins. Northern blot analysis in cell cultures of rabbit MCC indicated that type II collagen and alkaline phosphatase (ALPase) messenger ribonucleic acids (mRNAs) were highly expressed at day 7, but subsequently decreased. In contrast, mRNA for type I collagen was expressed at a low level on day 7 and peaked on day 12. The present results suggest that, morphologically and biochemically, cellular modification in MCC cells under culture conditions occurs at a cellular morphological level and also at marker-gene-expression level.

Aging↗
PubMed1994

Lateral open bite resulting from acute temporomandibular joint effusion.

Two cases of acute open bite, one arising from trauma to the mandible without actual fracture, and one from an acute episode of rheumatoid arthritis, are presented. The resultant malocclusions were due to a sudden increase of volume in the temporomandibular joint space with subsequent displacement of the mandibular condyle, following acute effusion.

Adult↗
PubMedDate not supplied

Multiple globoid meningiomas associated with craniomandibular fibrous dysplasia: case report.

A 20-year-old male with craniomandibular deformity and almost total visual loss of the right eye due to bilateral optic atrophy underwent cerebral nonenhanced computed tomography (NECT) examinations. He had multiple sphenoidal-temporoparietal meningiomas, with adjacent hyperostoses and distant calvarial hyperdense lesions, as well as sclerotic expansion of right mandibular condyle. History, clinical and imaging findings were suggestive of associated fibrous dysplasia (FD), which explained the visual loss due to optic nerve compression through sphenoidal optic foramens. Cranial and mandibular FD and concurrent multiple globoid meningiomas in this case may suggest a mutual influence, which may explain the etiopathogenesis of FD lesions and/or bone hyperdensities adjacent or distant to meningiomas.

Adult↗
PubMed2002

Morphological variability of inferior alveolar nerve in low-grade craniofacial microsomia.

Craniofacial microsomia (CFM) involves asymmetric hypoplasia and dysmorphogenesis of the facial skeleton. Certain aspects of CFM may be treated by surgical osteotomy and distraction osteogenesis (DO). Mandibular osteotomy places the inferior alveolar nerve at risk. The aim of this study was to investigate radiological landmark relationships to the anatomy of the inferior alveolar nerve in CFM. Application of this understanding will aid intraoperative protection of the inferior alveolar nerve. Six subjects with similar presentations of hemifacial microsomia were selected. Three-dimensional reconstruction CT images was used to locate bony structures that held important relationships with the inferior alveolar nerve. Measurements (of the normal and microsomic sides) were made between fixed landmarks: mandibular notch, mandibular foramen, condyle, back of second and third molar tooth, and mental foramen. The unaffected sides acted as controls. The distance between the normal and the microsomic sides from condyle to mandibular foramen was significantly different. The sizes of condyles differed significantly between the normal and microsomic sides. Most of the remainder of the vertical distance of the ramus and most of the horizontal distance of the body were similar. In conclusion, the inferior alveolar nerve should be found in very similar locations on both normal and microsomic sides in low-grade hemifacial microsomic patients.

Adolescent↗
PubMed2005

Hyperostosis as a late sequel of parasymphyseal mandibular fractures in 2 children.

BACKGROUND: The potential problem of growth anomalies affecting a mandible following a fracture of a mandibular condyle in childhood is well established. However, there have been no previous reports of this phenomenon affecting other fracture sites in the mandible. PATIENTS: Two patients who had parasymphyseal fractures treated in childhood presented at skeletal maturity with hyperostosis at the fracture site, producing chin asymmetry in their teens. RESULTS: In both cases the hyperostosis produced significant chin asymmetry without disturbance of the occlusion. Both patients were managed with corrective genioplasty. CONCLUSION: These cases reinforce the previous recommendations regarding the need for long-term follow-up of children who sustain facial fractures of the mandible, and that the protocol should be expanded to include parasymphyseal fractures as well as fractures of the condyle.

Accidents, Traffic↗
PubMed2001

Gene and protein expression of brain-derived neurotrophic factor and TrkB in bone and cartilage.

Gene and protein expressions of brain-derived neurotrophic factor (BDNF) and TrkB, the high-affinity receptor of BDNF, were investigated in the femur and mandibular condyle of rats by in situ hybridization and immunohistochemistry. BDNF and TrkB mRNA showed overlapped expression in chondrocytes in proliferating and mature zones of the epiphyseal growth plate cartilage and mandibular condylar cartilage, and in cuboidal-shaped active osteoblasts at the site of endochondral and intramembranous ossification and in trabecular bone. Expression of BDNF protein also showed a similar localization. The present study suggests that BDNF may participate in regulating the development and remodeling of bony tissue in the developing rat.

Animals↗
PubMed2002

Msx1 is a regulator of bone formation during development and postnatal growth: in vivo investigations in a transgenic mouse model.

The present study is devoted to Msx1 distribution and function from birth to 15 months, events and periods still unexplored in vivo using Msx1 knock in transgenic mice. The study is focused on the mandible, as an exemplary model system for Msx1-dependent neural crest-derived skeletal unit. The transgenic line enabled study of morphological abnormalities in Msx1 null mutation mice and Msx1 protein expression in Msx1+/- heterozygous mice. In Msx1 null mutation, the most striking feature was an inhibition of the mandibular basal convexity, the absence of teeth and alveolar bone processes, and absence of endochondral ossification in the mandibular condyle. At birth, in Msx1+/- heterozygous animals, we identified for the first time a double Msx1 aboral-oral and disto-proximal gradient field developmental pattern located in the low border of the mandibular bone in relation with this bone segment modeling. Msx1 expression involved both osteoblast and osteoclast cells. A distinct pattern characterized bone surfaces: Periosteum osteoblast differentiation was related to Msx1 down-regulation, while in the endosteum both differentiated osteoblasts and osteoclasts expressed the homeoprotein. In postnatal stages, Msx1 expression was maintained in the alveolar bone processes and dento-alveolar cells in relation with tooth function. Our data suggest that Msx1 play a role in a site-specific manner not only in early patterning but also in skeletal growth and modeling by acting on heterogenous bone cell populations.

Animals↗
PubMed1998

[An attempt to use ultrasonic technique for confirming the diagnosis, planning and observation of long-term treatment results of painful temporo-mandibular joint dysfunction].

The author presents an attempt of using ultrasonographic technique in diagnosis, planning and observation of treatment results of temporo-mandibular joint pain dysfunctions. Temporo-mandibular joint pain dysfunctions are interchangeably also called temporo-mandibular joint functional disorders. The assessment of pain symptoms in temporo-mandibular joint dysfunctions pain symptoms is principally based on a subjective estimation by the examining practitioner. There is no univocal definition of the disease or a simple index evidencing important symptoms in decision making. Additionally X-ray technique examinations, being hitherto used, in early stages of the disorder do not allow to diagnose it, and are also burdensome to a patient. The aim of this study was to confirm visibility of anatomical elements of the temporo-mandibular joint in an ultrasound examination, assess the mobility of the articular disc before, during and after prosthetic treatment with and without the use of ultrasound technique, and to determine the period of time necessary to obtain a therapeutic effect. The study material consisted of 180 patients, 128 women and 52 men, aged 20 to 60 years, treated by applying prostheses because of temporo-mandibular joint pain dysfunction, in the Department of Prosthetic Dentistry of the Pomeranian Medical Academy. The patients were divided into 2 groups, control and study group. The control group consisted of 90 patients, 63 women and 27 men. In this group prosthetic treatment planning and observation of results was based on a subjective estimation of the practitioner. The study group here comprised 90 patients, 65 women and 25 men, aged 26 to 60 years. In this group prosthetic treatment planning and observation of treatment results were carried on with the use of ultrasound technique. Data from both groups concerning history, results of examinations carried out by ultrasound technique, and the assessment of ultrasound examination were noted on standard examination records used in the Department of Prosthetic Dentistry. For the need of this study an own ultrasound technique was elaborated which allowed for analyzing the ultrasound image in a static situation and during functioning. The ultrasound examination was accomplished with the use of Acuson 128 XP apparatus, linear probe 7.5 MHz. In both groups prosthetic treatment was carried out using different prosthetic methods such as: splints, occlusal adjustment on fixed prosthetic restorations in therapeutical occulus et height in abnormal occlusion. In the study group the therapeutical occulus height was determined under the control of ultrasound technique. Statistical analysis of the obtained results was performed with the use of chi-square test and chi-square test with Yates correction. On the basis of the accomplished study it has been determined that the ultrasound technique makes it possible to visualize morphological elements and facilitates functional observation of the temporo-mandibular joint, articular disc, mandibular condyle and lateral pterygoid muscle in a degree which allows for planning the treatment and the observation of results (Tab. 1-6). The use of ultrasound technique in determining spatial position of the mandible in temporo-mandibular joint permitted to objectively estimate examination results in the study group. A small number of publications on the use of ultrasound technique in functional examination of the temporo-mandibular joint accessible in foreign literature and general reference on the subject in Polish literature do not allow for an objective comparison of obtained study results.

Adult↗
PubMed1978

Mandibular biomechanics and temporomandibular joint function in primates.

There is disagreement as to whether the mandibular condyles are stress-bearing or stress-free during mastication. In support of alternative models, analogies have been drawn with Class III levers, links, and couple systems. Physiological data are reviewed which indicate that maximum masticatory forces are generated when maxillary and mandibular teeth are in contact, and that this phase lasts for over 100 msec during many chewing strokes. During this period, the mandible can be modeled as a beam with multiple supports. Equations of simple beam theory suggest that large condylar reaction forces are present during mastication. With unilateral molar biting in man, the total condylar reaction force may be over 75% of the bite force. Analysis of a frontal projection demonstrates that up to 80% of the total condylar reaction force is borne by the contralateral (balancing side) condyle during unilateral molar biting. A comparison of human, chimpanzee (P. troglodytes), spider monkey (A. belzebuth), and macaque (Macaca sp.) morphology indicates that the frugivorous chimpanzee and spider monkey have a relatively lower condylar reaction force than the omnivorous macaque or man during molar biting. The percentage reaction force during incisal biting is lower in man than in the other primates, and lower in the frugivorous primates than in the macaque.

Animals↗
PubMed1994

The superficial temporal and retromandibular veins as guides to expose the facial nerve branches.

The superficial temporal vein and retromandibular vein were used as a guide to expose facial nerve branches in the parotid gland, and this procedure was applied to open reduction of mandibular condyle fractures (14 patients) and to superficial parotidectomy (6 patients). The advantages of this method are as follows: It is very easy to identify the superficial temporal vein as a guide, and it produces very little surgical stress because the procedure for exposing the facial nerve branches through the course of the vein is the same as the procedure for exposing the condyle and elevating the superficial lobe of the parotid gland.

Adolescent↗