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Bilateral atrophy of the mandibular condyles after a SRSO with advancement is reported. Although a definite cause could not be established, a biomechanical phenomenon based on increased muscle tension was the most likely causative mechanism.
The fixation of diacapitular fractures of the mandibular condyle utilising a headless cannulated bone screw (Martin HBS((R))) is described. An open approach was used with primary fixation of the fracture with a K-wire, over which the cannulated screw was inserted. The method and results are described.
Treatment of fractured mandibular condyles remains controversial. In this paper we present data collected prospectively on 42 fractured condyles treated by open reduction and internal fixation. The central issue, which is sometimes forgotten, is the informed consent of our patients. To this end we have looked at the surgical morbidity related to the retromandibular approach.
Using 3-week-old male beagle dogs, we examined the cartilage-bone replacement processes in the mandibular condyle by means of light and electron microscopy. Calcification of the cartilage matrix occurred in the central area of the longitudinal septa, but not in the transverse septa. Perivascular mononuclear cells absorbed the transverse septa which initiated the opening of the chondrocytic lacunae. These cells phagocytosed septal cartilage fragments. Shortly thereafter, a thin bone layer was deposited on the remaining longitudinal septa by invading osteoblasts. Osteoclasts in lacunae developed neither ruffled borders nor clear zones in the cartilage matrix, but once the bone layer has been deposited in the remaining cartilage, these structures formed. Our results suggest that the cartilage-bone replacement in mandibular condyle involves three sequential processes: 1) degradation and phagocytosis of cartilage fragments in the transverse septa by mononuclear cells, 2) bone deposition over the remaining longitudinal septa, and 3) degradation of both calcified cartilage and bone by osteoclasts.
BACKGROUND: The adult mandibular condyle is reported to be covered by fibrocartilage that develops from growth cartilage present earlier in life. Available data on the organization of condylar fibrocartilage are entirely descriptive or have been derived from young adult individuals. In order to examine the variability in normal appearance, condyles from a representative sample of adult humans were analyzed semiquantitatively. METHODS: With a light microscope, features of the superficial, intermediate, and deep tissue zones subjacent to small contiguous sectors of the articular surface were recorded. The distribution of each feature relative to the total surface was then calculated and respective data obtained from nine predetermined condylar regions and from males and females were compared using analysis of variance. RESULTS: The organization of the articular tissue varied significantly in the anteroposterior direction only. Unlike during growth, the superficial and deep zones in anterior and superior regions mostly contained fibrocartilage, although of markedly different appearance. Furthermore, the intermediate zone along about half of its anteroposterior extension lacked a distinctly visible layer, because the cell density was low and there was dense fibrous tissue or fibrocartilage similar to that of the superficial or deep zone, respectively. In these situations, zonation of the articular tissue was revealed only by the arrangement of collagen fibers. CONCLUSIONS: The appearance of adult condylar articular tissue, in addition to varying considerably within and between putative load-bearing and nonload-bearing regions, bears only a vague resemblance to the layered organization of the growing condyle. Current terminology that refers to that organization, therefore, is inappropriate. It is proposed to designate impartially the three articular tissue zones of the adult condyle as "superficial," "intermediate," and "deep."
Transpharyngeal examination of the mandibular condyle was compared with transcranial and transmaxillary examinations in 22 patients with mandibular pain/dysfunction. All projections were supplementary and a combination of at least two methods seemed preferable. When a single examination was used, underestimation of abnormalities was evident. In demonstrating condylar destruction, the transpharyngeal examination seemed to be superior to the more commonly used transcranial, but inferior to the transmaxillary examination.
A case of left bifid mandibular condyle (BMC) is reported in a 36-year-old female. The patient had a history of trauma in childhood. From the radiological examination, the left condyle was seen to have two anterioposteriorly situated heads. BMC is an extremely rare condition, where the condyle is duplicated or lobulated. The literature on BMC is reviewed, and possible cause of trauma and consequences of the anomaly are discussed.
A suspected case of trifid mandibular condyle that was observed on a panoramic radiograph and confirmed using computed tomography (CT) is reported. No history of previous temporomandibular joint (TMJ) trauma was reported by the subject.
This report brings the total number of bifid mandibular condyles reported so far in the English-language literature to 15 cases. In addition, one dried specimen with two distinct condylar heads is reported. This rare anomaly does not appear to have a predilection for any particular race or either gender. At the time of initial consultation, almost all patients are adults. Sixty-seven percent of the patients have no complaints related to the affected condyles, but the condition is an incidental dental panoramic radiographic finding. The left condyles seem to be affected twice as often as the right condyles. We do not yet fully know the etiology, epidemiology, and long-term functional effects of this condition. We recommend the transorbital condylar view as a good, inexpensive, and lower dosage technique, compared with the tomogram, to demonstrate this anomaly.
A case of vertical-split fracture of the right mandibular condyle and its sequelae is presented. The patient was a 16-year-old female being assessed for orthodontic treatment. Orthopantomograph and plain joint view radiographs showed a remodelled condyle which had suffered trauma 10 years previously. This type of fracture is unusual in nature but has not led to any secondary lack of growth, restriction of movement or facial asymmetry.
The vascular or cartilage canals of the mandibular condyle were studied in human fetuses, whose ages extended from the 9th to the 13th week of development. The vascular canals are firstly constituted by an invagination of mesenchimal cells which is in connection with the mesenchimal layer of the condyle envelope. During the 11th week of development a vessel penetrates in the invaginations. In the 12th and 13th weeks, the canals show a clearly defined pattern: some of them are located in the anterointernal region of the condyle, being those associated with the insertion of the lateral pterygoid muscle; two or three can be seen in the posterointernal region, whereas only one vascular canal, but th-e biggest one, is located in the posteroexternal region. This well defined disposition is related with the direction of the condylar growth during this period of the development.
We have described a rare sagittal unilateral fracture of the head of the mandibular condyle caused by a trauma around the chin area, resulting in a dislocation of the fractured middle part towards the front and downwards. The removal takes place through surgical operation carried out by the endoral method.
In several aspects the features of aging resemble those of the state of growth hormone (GH) deficiency. Alterations of bone density and increased incidence of osteoporosis are some of the characteristics of aging that are similar to the findings in GH-deficient adults. Osteoarthritis (OA), a nonfatal condition predominating in old age, is characterized by the slowly progressive destruction of articular cartilage of joints. OA lesions are observed in the temporomandibular joint of ICR mice aged 7 months and older. The aim of the present study was to compare the response of chondrocytes from mandibular condyle cartilage of young and old mice to GH and to ascertain whether chondrocytes of old animals could still be stimulated to proliferate and to synthesize matrix components under the direct effect of GH in vitro. Mandibular condyles from young (3-month-old) and old (20-month-old) female ICR mice were cultured up to 72 hours in the presence of recombinant rat GH (0.1-100 ng/ml). 3H-Thymidine and 35S-sulfate were introduced during the last 24 hours of culture. Administration of GH appeared to increase only slightly the incorporation of 3H-thymidine in cartilage from young compared with the response in cartilage from old animals which was much more significant at 24 hours and 48 hours in culture. The same pattern was seen for the effect of GH on the incorporation of 35S-sulfate. Cartilage from young animals responded only slightly to GH, whereas a significant response was observed in cartilage from old animals after 24 and 48 hours in vitro. DNA contents were significantly elevated at all time intervals in both old and young animals, yet more significantly in cultures from old animals. In contrast, the activities of both alkaline and acid phosphatases were elevated at all time intervals in cultures from young animals, whereas no induction was observed in cultures from old animals. Tissue sections from cultures of old animals treated with GH (10 ng/ml, 48 hours) revealed atypical hypertrophic cells along the articular surface and also dark staining along the cartilage-bone interface. Exposure to tetracycline (10 mg/ml, 24 hours) resulted in an induced fluorescence, indicating enhanced mineralization in this region. Results of this study indicate that mandibular condyle cartilage from OA old mice responds in vitro to the addition of GH via anabolic activities of cell proliferation, sulfated proteoglycan synthesis, and possibly enhanced mineralization.
A case of pathologic fracture of a mandibular condyle due to a primary adenocarcinoma of the rectum is presented. This is the first reported case of a secondary adenocarcinoma from the rectum to this site. Secondary metastases to the condyles are extremely rare. Only twelve have been reported in the literature. The primary tumor was from an unknown site in three cases (anaplastic adenocarcinoma); from the breast in four; and from the lung, liver, prostate, uterus, and hallux (a malignant melonama) in the remainder. Only of these tumors presented as a condylar fracture, and that was from a primary breast adenocarcinoma.
Mandibular condyles from 18- to 20-week-old human fetuses were examined in the light and electron microscope with particular attention to intratissue organization and extracellular matrix. In the human fetus the condyle has been divided into five layers: (1) the most superficial, articular layer, (2) chondroprogenitor cell layer, (3) condroblast cell layer, (4) nonmineralized hypertrophic cell layer, and (5) mineralized hypertrophic cell layer. The articular layer is rich in collagen fibers (mostly of the type I collagen), but the cells seldom divide. By contrast, in the chondroprogenitor cell layer and upper part of the chondroblastic cell layer mitosis gives rise to new cells. The matrix in the latter layer is composed of thick banded 'lucent' fibrils in a loose feltwork of granules representing cartilage proteoglycans. The daughter cells in the progenitor cell layer undergo differentiation which is apparently completed along the lower border of the mineralized hypertrophic cell layer--the ossification front. The matrix in the hypertrophic cell layer reveals distinct matrix vesicles that undergo mineralization and subsequently coalesce to form larger sheets of mineralized extracellular matrix. Mineralized cartilage serves as a backbone for new bone formation as marrow-derived osteoblasts and osteoclasts attach to remnants of mineralized cartilage, which enables the turning on of the remodeling cycles involved in new bone formation. It can be concluded that the process of endochondral ossification as has been reported in lower animals is recapitulated in the human fetus, thus the dynamics associated with condylar morphogenesis is maintained through phylogeny.
The aim was to study changes in the main masticatory muscles after mandibular condyle fracture as seen by CT, comparing the densities and sizes of the masseter, medial pterygoid and lateral pterygoid muscles on the fractured side with those on the non-fractured side. More or less permanent muscular changes are detectable several years after the accident, especially in the lateral pterygoid muscle, which is attached to the condylar head. This muscle was statistically significantly smaller (p less than 0.001) on the fractured side. Examination of the masticatory muscles immediately after the fracture and at intervals afterwards could reveal more about the pathogenesis of the changes in these muscles.
OBJECTIVE: To evaluate the feasibility and effectiveness of autogenous coronoid process grafts for reconstruction of the mandibular condyle. STUDY DESIGN: Two groups of 9 goats each were used. Each animal underwent unilateral total condyle and disk removal and was treated by grafting an autogeneous coronoid process. The animals in group A were sacrificed at 4, 12, and 24 weeks after surgical procedure, and their grafted coronoid processes were harvested for histological observation. All animals in group B received 3-dimensional CT scanning examination at different times and were sacrificed at 24 weeks after surgical procedure. The items of ramus height (RH), transverse dimension of the condyle (CT), and posteroanterior dimension of the condyle (CP) were measured for comparison with the operated and nonoperated sides. RESULTS: Despite the differences in the measurements of RH, CT, and CP between the operated and nonoperated sides, the grafted coronoid process had a similar shape and histological structures to the normal condyle at 24 weeks after surgical procedure. The head of the neocondyle was covered by a cap of fibrous tissue, which might play the role of the articular disc. CONCLUSIONS: Under the mechanical stimuli of the temporomandibular joint site, the grafted coronoid process could gradually remodel to a neocondyle with functional shape and structure in goats. This animal study suggests that autogenous coronoid process could be considered as a new donor source for reconstruction of the mandibular condyle.
In diagnosing and treating temporomandibular joint (TMJ) dysfunctions, the oral and maxillofacial surgeon can use the radiographic technique of "corrected-axis" lateral tomography of the mandibular condyles. The theory, technique, and equipment necessary for making "corrected-axis" lateral tomograms of the mandibular condyles are presented. Once familiar with this technique, the surgeon can educate the radiologist and technician if it is one with which they are unfamiliar.