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PubMed1990

Conventional radiographic and computed tomographic findings in cases of fracture of the mandibular condylar process.

A total of 40 patients with 46 fractures of the mandibular condylar process were examined an average of 47 months after the injury. The conventional radiologic examination consisted of panoramic radiography and lateral transcranial view of the fracture in the mouth-open and mouth-closed positions. Sixteen patients with 21 fractures of the condylar process were examined additionally by computed tomography (CT) because of temporomandibular joint problems in the sagittal and coronal projection. Computed tomography revealed bony changes in the fractured mandibular condyle and its position in the mandibular fossa more exactly than conventional radiographic examinations. Furthermore, the results showed that disturbances in the position and function of the articular disc may be more common than was earlier anticipated, suggesting the more frequent use of CT examinations to evaluate temporomandibular joint changes after condylar process fractures.

Adolescent↗

PubMed2004

Rheumatoid arthritis of TMJ--a diagnostic dilemma?

Rheumatoid arthritis is a chronic disease affecting the musculo-skeletal connective tissue of the body with a strong predilection for the joints. The temporomandibular joint (TMJ) is commonly affected with rheumatoid arthritis in adults and children, but it is usually among the last joints to be affected. A case report is presented of a patient undergoing orthodontic treatment who developed unilateral condylar changes and whose serum was also positive for rheumatoid factor. The involvement of TMJ in several systemic disorders is a well established fact. When such disorders manifest in an atypical manner, it poses a diagnostic dilemma. This article aims to discuss various disorders causing condylar erosions.

Adult↗

PubMed1977

Phosphomonoesterases in growth cartilages of the rat.

Epiphyseal plate cartilage, epiphyseal cartilage, synchondroseal cartilage and mandibular condylar cartilage were studied morphologically and histochemically in 14 days old rats. Ordinary decalcified paraffin sections were stained with hematoxylin & eosin, van Giesons connective tissue stain, or toluidine blue, and used for morphological studies of the different cartilaginous structures. Undecalcified cryostat sections were used for demonstration of acid and alkaline phosphatase. The enzyme activity was tested for at regular intervals during incubation from 15 sec to 120 min. The morphologic study revealed that a marked similarity of construction exists between epiphyseal plate cartilage and synchrondroseal cartilage. The construction of epiphyseal and condylar cartilage differ from that of the other two structures and also differ mutually. With small variations the reaction for both alkaline and acid phosphatase was found to be identical in the zones of erosion, hypertrophy and maturation of the four structures. Intercellularly, acid phosphatase is present in all zones in the synchondroseal and the epiphyseal plate cartilage, while in the epiphyseal and condylar cartilages it is only present in the zones of erosion, hypertrophy and maturation. The identical reaction for acid phosphatase in the epiphyseal and the condylar cartilage is thought, in all likelihood, to be accidental. When kinetic conditions are taken into account, epiphyseal cartilage seems to react like epiphyseal plate and synchondroseal cartilage, while the condylar cartilage takes up an exceptional position among growth cartilages.

Acid Phosphatase↗

PubMed1983

Posterior condylar displacement: prosthetic therapy.

Condylar repositioning with a prosthesis programmed intraorally effectively uses patient feedback in determining the therapeutic position. A series of therapeutic positions may be required to allow rehabilitation of dentoalveolar, neuromuscular, and internal TMJ tissues for a final treatment position to be determined. Twelve dentulous patients with unilateral or bilateral posterior condylar displacement have been successfully treated with this approach. Time to establish the final treatment position varied from 3 to 18 months.

Equipment Design↗

PubMed2002

Local kinematic and anthropometric factors related to the maximum mouth opening in healthy individuals.

The aim of the present study was to investigate the influence of local anthropometric (mandibular length and width) and kinematic (forward and downward condylar translation and angle of rotation) variables upon the maximum mouth opening (MMO). Thirty-five healthy individuals, 17 men and 18 women, mean age 23 years with a range from 18 to 31 years, performed six to eight maximal, symmetrical and pain-free open-close movements during a 20-s recording. Mandibular movements were recorded by means of the OKAS-3D jaw movement recording system. A stepwise regression analysis showed that differences in MMO are mainly explained by differences in the angle of rotation and in mandibular length (R2adj=91.5%). Including the downward and forward component of condylar translation into the regression model increased the explained variance with only 4.7%. A second stepwise analysis showed that the angle of rotation is positively related to the forward component of the condylar translation and negatively related to its downward component (R2adj=52.7%). In conclusion, differences in MMO between healthy individuals are, to a large extent, explained by differences in the angle of rotation and in mandibular length. In its turn, differences in the angle of rotation are related to differences in condylar translation.

Adolescent↗

PubMed2002

Photoelastic analysis of bone deformation in the region of the mandibular condyle during mastication.

INTRODUCTION: The purpose of this experimental study was to demonstrate the stress patterns arising in the region of the mandibular condyle during mastication. MATERIAL AND METHOD: Stress analysis was performed using reflection photoelasticity to demonstrate deformation occurring on the surface of the mandible. The rami of three fresh dentate human mandibles were coated with a shell of photoelastic resin. Using a novel loading device, these mandibles were then subjected to external forces (muscular traction, resultant mandibular forces and intra-articular reaction force) reproducing a unilateral biting task between the first right molars. Deformations were measured from the working side. RESULTS: The trace of isostatic lines from the isoclinic fringes revealed major differences in stress distributions between the three mandibles. These differences were attributed to differences in shape between the three mandibles. Conversely, we consistently found compressive stress patterns along the posterior border of the ramus and tensile stress patterns along the anterior border of the ramus and in the zone situated below the siqmoid notch. CONCLUSION: These findings suggest that during this particular task, the mandible is subjected to sagittal forces which tend to straighten the mandibular angle. This implies that new concepts are needed for the positioning of osteosynthesis plates in the condylar region, close to the tensile strain lines, as has been recommended also for other parts of the mandible when applying semi-rigid internal fixation.

Biomechanical Phenomena↗

PubMed2000

A prospective study of Twin-block appliance therapy assessed by magnetic resonance imaging.

Forty children displaying Class II Division 1 malocclusion were involved in a prospective magnetic resonance image investigation to evaluate the effects of Twin-block functional appliances on the temporomandibular joints. None of these children had clinical signs or symptoms of temporomandibular disorders. Nineteen children were treated with a Clark Twin-block appliance for 6 months; the other 21 children received no treatment and served as controls. Comparison between control and Clark Twin-block groups suggested that reduction of the condylar axial angle represents a feature of untreated Class II growth patterns, whereas axial angle stability with Clark Twin-block therapy may suggest alteration of condylar growth direction. Condyles that were positioned at the crest of the articular eminence by the Clark Twin-block at the beginning of treatment had reseated back into the glenoid fossa after 6 months. However, 75% of the condyles were more anteriorly positioned in successfully treated Clark Twin-block cases. There was no clear evidence of remodeling of the glenoid fossa at the eminence as a result of Clark Twin-block treatment. The initial prevalence of disk displacements for the combined groups was 7.5% anterior, 5% medial, and 12.5% for lateral disk displacement. Clark Twin-block therapy had neither positive nor negative effects on disk position, and there was no convincing evidence that the disk was recaptured.

Adaptation, Physiological↗

PubMed1994

Horizontal condylar path in patients with disk displacement with reduction.

In 32 patients with disk displacement with reduction, the condylar path in the horizontal plane during opening and closing movements of the mandible were analyzed with a computerized axiograph. The horizontal condylar tracings during opening were divided into 15 types. There was no clear relationship between the types and clinical symptoms. The specific correspondence of the types were revealed between the right and left joint. In 21 of 32 patients, the condyle on one side deviated medially, while the contralateral condyle deviated laterally at maximum opening. In most of the patients showing medio-lateral condylar deviation at maximum opening, a straight condylar path was observed from the maximum opening to the position just before the closing click. In some of the patients, the type of horizontal condylar tracing during opening was related to the displacement pattern of the disk assessed by magnetic resonance imaging (MRI).

Adolescent↗

PubMed1980

The surface structure of the temporomandibular joint disk: a scanning electron microscopic study.

The surface appearance of seven temporomandibular joint disks obtained at postmortem has been studied by scanning electron microscopy. Two of the disks had lateral perforations which corresponded, in position, to macroscopic changes in the condylar and temporal joint components. The nature of the disk surfaces has been described. The central portion of the disks consisted of tightly bound collagen bundles; the bundles of the anterior and posterior parts were more loosely bound and irregularly orientated. The implications of the findings have been discussed in terms of articular function and dysfunction and of disease processes within the joint.

Aged↗

PubMed1977

Operational definitions of mandibular morphogenetic and positional rotations.

A material of 30 patients with metallic implants was used in a longitudinal study, based on lateral headplates, of the mandibular rotational pattern. The complexity of the rotational phenomenon in the mandibular rotation has necessitated the proposal of some operational definitions: morphogenetic and positional rotations of the mandible. A relationship has been established between the variation of the gonial angle and the variation of both morphogenetic and positional rotations of the mandible. A relationship has been established between the variation of the condylar growth direction and the variation of both morphogenetc and positional rotations of the mandible: this relationship is the strongest when the morphogenetic rotation of the corpus is considered.

Dental Implantation↗

PubMed1996

Assessment of temporomandibular joint disease by panoramic radiography: reliability and validity in relation to tomography.

OBJECTIVES: To assess the reliability and validity of panoramic radiography for TMJ evaluation in comparison with tomography. METHODS: One TMD specialist assessed the panoramic radiographs of 50 TMD patients and 20 non-TMD subjects on two occasions. A third evaluation was made after calibration with an oral radiologist who also assessed the radiographs twice and the patients' corresponding tomograms. Each TMJ was assessed for five features. RESULTS: Absence of TMJ disease varied between 56 and 87% for the different features and the two observers on the panoramic radiographs. Condylar flattening was the most frequent positive finding. Mean intra-observer agreement varied between 0.34 and 0.79. Mean inter-observer agreement varied between 0.22 and 0.65 and increased after calibration. Agreement was worse for the temporal component. Pathological findings were more frequent on the tomograms and varied between 6 and 19%. Mean sensitivity varied between 0.00 and 0.60 and mean specificity between 0.59 and 0.95. Mean PPV ranged from 0.25 to 0.90 and NPV from 0.02 to 0.22. CONCLUSIONS: Evaluation of bony changes on the condyles has acceptable reliability and specificity but low sensitivity, whereas the temporal component has low reliability and accuracy. Positive findings often correspond to disease while negative findings do not exclude it. If bony abnormality is suspected in the TMJ, and the panoramic radiograph is negative, tomography may be indicated.

Adult↗

PubMed1985

Computerized tomography as a guide in the diagnosis of temporomandibular joint disease.

As described, CT is a noninvasive method for providing detailed views of both the soft and hard tissues of the TMJ region. Because internal derangements of the joint involve both of these structures, CT can provide an invaluable tool in the study, diagnosis, and treatment of various disorders of this nature. It is extremely important, however, to create a close working relationship with the radiologist who will be performing these studies. Only with adequate clinical study and information communicated to the radiologist can true benefits be obtained. As CT scans are available nationwide, this technique should be available to nearly any practitioner in the country. CT can be useful in both diagnostic and therapeutic modalities. On a diagnostic basis, it can provide a tomographic study of the osseous structures of the condyle, fossa, articular eminence, and surrounding hard tissues. By varying the slices, views of the medial and lateral poles as well as the central portions of the region, can be obtained. In this way, various arthroses, tumors, cysts, fractures, true ankylosis, neoplasias, developmental abnormalities, and other bony abnormalities can be clearly found. Therapeutically, CT can evaluate the success of treatment aimed at reestablishing proper disk-condylar relationships. However, the major advantage of TMJ CT is the observation of the soft tissue of the articular disk. By the use of CT, especially enhanced by the blink mode, we can see how the disk relates to the condyle. If a series of views are taken in both the closed and open position, we can observe the disk-condylar relationship during this range of motion.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnosis, Differential↗

PubMed2005

[The distribution of collagen I, II, X and alkaline phosphatase in the development of condylar cartilage of fetal mouse mandible].

OBJECTIVE: The purpose of this study was to investigate the distribution of collagen I, II , X, alkaline phosphatase (ALP) and their roles during initiation of condylar cartilage of the fetal mouse. METHODS: Coronary sections of mandible of mouse embryo aged from 14th to 18th day were studied under light microscope after stained by immunohistochemical method with antibody of types I, II, X collagen and ALP. RESULTS: On the 14th day of mouse embryo, it was found that mesenchymal cells condensation continuous with the periosteum. Type I collagen and ALP were positive behind the terminal of the ossifying mandibular periosteum where future condylar will form. On the 15th day, positive staining for types I, II collagen was found in mesenchymal cells around hypertrophic cells and type X collagen was detected in hypertrophic cells. ALP was positive in both mesenchymal cells and hypertrophic cells. On the 16th day, type I collagen was observed from periosteal osteogenic cells and mesenchymal cells of the fibrous cell layer to the upper hypertrophic cell layer while Type II collagen was restricted from the lower polymorphic cell layer to the bottom of the hypertropic cell layer. Type X collagen was positive in the hypertrophic cell layer. ALP was positive in periosteal osteogenic cells and hypertrophic chondral cells, but not in the polymorphic cell layer. CONCLUSION: Development of condylar cartilage is different from that of limb bone. Types I, II, X collagen are expressed in the condylar chondrocyte on the early stage of endochondral ossification. The histology evidence supports the conjecture that condylar cartilage is derived from differentiated mesenchymal cells of the preperiosteum or periosteum of the mandible where ALP is positively expressed.

Alkaline Phosphatase↗

PubMed1983

Definitive prosthodontic therapy for TMJ patients. Part I: Anterior and posterior condylar displacement.

The final prosthodontic treatment procedure for anterior condylar displacement (functional centric relation) has been described. Deflective interferences in centric relation were removed and a removable partial denture constructed to the classical most retruded centric relation position of the mandible. Several patients with posterior condylar displacement (dysfunctional centric relation) have been documented. Anterior condylar repositioning was accomplished on a denture patient by merely establishing the correct vertical dimension of occlusion. Another patient required an increase in vertical dimension as well as anterior condylar repositioning.

Acrylic Resins↗

PubMed1993

Histometric study of synovial cavity dimensions of human temporomandibular joints with normal and anterior disc position.

To evaluate effects of internal derangement, the sagittal lengths of the condylar, temporal, and disc articular surfaces, as well as those of the disc attachments, were measured in histologic sections of human temporomandibular joints obtained at autopsy, mainly from adolescent, young adult, and middle-aged subjects. While the upper joint compartment appeared little affected, anterior disc position was significantly associated with comparatively long inferior disc attachments and a short condylar articular surface, indicative of possibly aberrant insertions of the attachments. Such discrepancies in size or alignment between condyle and disc complex could primarily reflect a constitutional deviation or result secondarily from remodeling.

Adolescent↗

PubMed2002

The mediolateral temporomandibular joint disc position: an in vivo quantitative study.

AIMS: Temporomandibular joint (TMJ) discs displaced simultaneously, dorsoventrally, and mediolaterally are assumed to be rotated. However, a pilot study performed with individualized oblique-axial scans on supposedly rotated discs did not show disc rotation consistently. The aim of this study was the quantitative evaluation of disc rotation on a larger sample size, assessing the mediolateral disc geometry and position by the use of a reference system determined by the condylar long axis. METHODS: Eighty-five TMJs from 50 subjects were analyzed. One series of sagittal and 1 of 14 individualized oblique-axial magnetic resonance (MR) scans were taken for each joint. The dorsoventral disc position was diagnosed by means of the sagittal scans. The mediolateral disc width and position were then measured on every oblique-axial scan. The width and midline was computed for each disc and its deviation from the perpendicular to the condylar long axis was calculated. Finally, a statistical analysis was performed to study whether the disc width and the direction of the disc midline varied between discs normally positioned and anteriorly displaced. RESULTS: The disc width varied significantly more within the anteriorly displaced discs than within the normal ones. The midline of the anteriorly displaced discs deviated more from the perpendicular to the condylar long axis than that of normally positioned discs and was mostly in a lateral direction. The disc midline also deviated more in the ventral than in the dorsal part of the disc. CONCLUSION: Most anteriorly displaced discs were laterally displaced and showed a larger width variation than normally positioned discs. This fact seems to indicate disc deformation.

Adult↗

PubMed1991

Magnetic resonance imaging and tomographic evaluation of occlusal appliance treatment for advanced internal derangement of the temporomandibular joint.

This study evaluates the positional relationship of the disc and mandibular condyle in patients with late opening clicks treated with appliance therapy. A total of 30 joints (18 patients) were studied. Twenty-seven of these 30 joints were treated with the appliance until the joints were silent to auscultation. The patients were then evaluated with axial corrected tomography and magnetic resonance imaging (MRI) in the centric occlusion position and with their bite appliance (Sved-type) in place. Comparisons were made between condyle position in centric occlusion and with the appliance in place. Magnetic resonance imaging was then used to evaluate disc positional changes. Each imaging procedure was made in the same sagittal plane. Only changes in condyle positioning could be identified. Evidence of disc repositioning with the appliance in place was seen in only three MRI examinations. The remaining 27 joints continued to exhibit disc displacement with various changes in disc morphology. It is concluded that the concept of "disc capture" is a clinical term only, and that such perceived clinical success should not lead to the assumption that an actual change in intra-articular anatomic relationships has occurred. Joint noises may decrease because joint space is increased, allowing smoother condylar translation beyond disc surface irregularities and positional abnormalities.

Cartilage, Articular↗

PubMed2005

Role of endochondral ossification of articular cartilage and functional adaptation of the subchondral plate in the development of fatigue microcracking of joints.

The mechanisms that regulate functional adaptation of the articular ends of long bones are poorly understood. However, endochondral ossification of articular cartilage and modeling/remodeling of the subchondral plate and epiphyseal trabeculae are important components of the adaptive response. We performed a histologic study of the distal end of the third metacarpal/metatarsal bone of Thoroughbreds after bones were bulk-stained in basic fuchsin and calcified sections were prepared. The Thoroughbred racehorse is a model of an extreme athlete which experiences particularly high cyclic strains in distal limb bones. The following variables were quantified: microcrack boundary density in calcified cartilage (N.Cr/B.Bd); blood vessel boundary density in calcified cartilage (N.Ve/B.Bd); calcified cartilage width (Cl.Cg.Wi); duplication of the tidemark; and bone volume fraction of the subchondral plate (B.Ar/T.Ar). Measurements were made in five joint regions (lateral condyle and condylar groove; sagittal ridge; medial condylar and condylar groove). N.Cr/B.Bd was site-specific and was increased in the condylar groove region; this is the joint region from which parasagittal articular fatigue (condylar) fractures are typically propagated. Formation of resorption spaces in the subchondral plate was co-localized with microcracking. N.Ve/B.Bd was also site-specific. In the sagittal ridge region, N.Ve/B.Bd was increased, Cl.Cg.Wi was decreased, and B.Ar/T.Ar was decreased, when compared with the other joint regions. Multiple tidemarks were seen in all joint regions. Cumulative athletic activity was associated with a significant decrease in B.Ar/T.Ar in the condylar groove regions. N.Cr/B.Bd was positively correlated with B.Ar/T.Ar (P < 0.05, r(s) = 0.29) and N.Ve/B.Bd was negatively correlated with B.Ar/T.Ar (P < 0.005, r2 = 0.14) and Cl.Cg.Wi (P < 0.05, r2 = 0.07). We conclude that endochondral ossification of articular cartilage and modeling/remodeling of the subchondral plate promote initiation and propagation of site-specific fatigue microcracking of the joint surface, respectively, in this model. Microcracking of articular calcified cartilage likely represents mechanical failure of the joint surface. Propagation of microcracks into the subchondral plate is a critical factor in the pathogenesis of articular condylar fatigue (stress) fracture. Functional adaptation of the joint likely protects hyaline cartilage from injury in the short-term but may promote joint degeneration and osteoarthritis with ongoing athleticism.

Adaptation, Physiological↗