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The mammalian mandibular condyle is composed of secondary cartilage and may thus be susceptible to genes causing achondroplasia and which result in abnormal++ primary cartilage formation. This paper describes the secondary cartilage in the mandible of the stumpy achondroplastic mutation in the mouse: both primary and secondary cartilage are affected by the gene.
The effect of fluoride on the rat mandibular condyle was studied histologically and histometrically. The condyles of the rats that received 50 ppm fluoride in the drinking water for 17 weeks did not differ in structure from those of the control rats fed tap water containing 1 ppm fluoride. However, the condyles of the rats given 100 ppm fluoride in the drinking water for the same period showed a significant increase in both the thickness of the cartilage layer (P smaller than 0.02) and the density of cancellous bone (P smaller than 0.01) when compared to the controls. The thickening of the cartilage layer was due to an increase in the number of hypertrophied chondrocytes. The trabeculae of cancellous bone were thicker and consequently the bone marrow spaces were extremely reduced. The trabeculae contained more calcified cartilage in their cores.
This study was designed to evaluate the effectiveness of four radiographic techniques in demonstrating the TMJ. Mandibular condyles of a variety of sizes, as well as horizontal and vertical angulation, were selected. The location and size of the defects also varied. The mandibular condyles, in which 12 defects were created, were divided into two groups of six large and six small each. On examination of the condyles with the different defects, using each of the four radiographic techniques, the defects were localized with silver amalgam and reexamined with the radiographic techniques. The visualization of the defects was compared using the radiographs.
The authors report a case of giant cell tumour of the mandibular condyle, which is a rare finding. This tumour, studied using the main three radiological modalities (plain radiography, CT and MRI) showed characteristic radiological features of "giant cell tumour".
Practical aspects of treatment of mandibular condyle fractures are discussed. After a brief review of therapeutic measures previously applied, the different treatment modalities available for condylar fractures are discussed, indications being reviewed as a function of the clinical types of fracture. The majority of these fractures respond to effectively conducted supervised functional therapy, which appears to reduce sequelae in a significant manner.
An extremely rare location for eosinophilic granuloma of bone in the mandibular condyle has been described, illustrating the difficulties of diagnosis. Excision and reconstruction with a costochondral graft was successfully undertaken and remodelling of the graft occurred with the formation of a new condylar head. The patient is disease-free 17 months after surgery. The relevant literature is reviewed and suggestions made for management protocol.
The results of surgical treatment of fractures of the mandibular condyle are analyzed in 36 children (39 surgeries) aged 3 to 17; 33 of the operations were carried out in fractures complicated with the dislocation of the condylar head. Reposition and osteosynthesis of the fragments were carried out in 17 cases, replantation of the condyle in 10, and arthroplasty of the temporomandibular joint in 12 patients. Good late anatomico-functional and esthetic results were achieved in 84.6% of cases; this is explained by a differentiated approach to the choice of surgical strategy, an effective system of rehabilitation measures, including early exercise, orthodontic treatment, and low-frequency electromyostimulation.
Condylar growth was studied after an operation simulating functional orthodontic appliances. Twenty-five rabbits underwent a surgical operation for the induction of premature synostosis to displace the glenoid fossa posteriorly during growth. Twenty-five control rabbits underwent sham operations. At the age of 15 days, 10 experimental and 10 control animals and, at the age of 20 days, 5 experimental and 5 control animals were killed. Their mandibular condyles were organ-cultured for 3 h in the presence of radiolabelled sulphur. The condyles were used for autoradiographic purposes. Digital image analysis of autoradiograms of histological sections showed synthesis of glycosaminoglycans to have increased from the anterior to the posterior direction. This increase was more marked in experimental animals than in the condyles of control animals. Ten experimental and 10 control animals were killed at the age of 15 days, and mandibular condyles were organ-cultured for 1, 4 and 7 days. Differentiation of proliferating prechondroblasts into hypertrophied chondrocytes continued under organ culture conditions. A marked decrease in the proliferating cell layer was noticed, especially in control condyles. Hypertrophy was faster and came closer to the surface of the condyle in the anterior region of the condyle. This was most marked in the condyles of experimental animals. The results indicate that a procedure carried out on the glenoid fossa with the same effect as functional appliances increases the synthesis of extracellular matrix in the posterosuperior region of the mandibular condyle.
Reported cases of dislocation of the mandibular condyle into the middle cranial fossa have been rare, and treatment modalities have varied. The case presented represents an instance of successful closed reduction. Numerous factors should be considered when determining the technique of reduction. Primary goals in selecting the method of treatment are stabilization of the neurologic status, control of the bone fragments in the brain, reduction of the occlusion, maintenance of ramus height for facial symmetry, preservation of growth potential, and assurance of satisfactory long-term function of the mandible.
A rare case of peripheral osteoma, which developed in the right mandibular condyle of a 27-year-old man, is presented. Condylectomy with reconstruction of the condyle using a rib graft and subsequent mouth opening exercise as well as orthodontic treatment were performed. Occlusion disharmony and facial asymmetry were substantially improved, with no sign of recurrence two years after surgery. Long-term post-operative care of mouth opening exercise is highlighted. Orthodontic treatment is also indicated for better results on occlusal function and facial appearance. Therefore, a team composed of interdisciplinary specialists such as dentist, oral & maxillofacial and chest surgeons is indispensable to successful treatment.
The purpose of this report is to present our experience in the management of unilateral condylar fractures between 1995 and 1998. This prospective study was carried out at a Regional Maxillofacial Unit and Teaching Hospital in the UK, and included 54 patients, of whom 32 attended for review. In all, 42 men and 12 women (age range 17-40 years) entered the study: 28 patients had unilateral fractures of the mandibular condyle alone; the remainder also had another mandibular fracture, invariably at the parasymphysis. Thirty-five of the patients (65%) had allegedly been assaulted. This is at variance with a recent study published by the British Association of Oral and Maxillofacial Surgeons, which showed that only 24% of facial injuries were the result of inter-personal violence. Open reduction and internal fixation of the mandibular condyle seems to carry low morbidity and may be of considerable functional benefit to the patient.
BACKGROUND: Unilateral condylar hyperplasia can lead to marked and disfiguring changes in the face and occlusion. A method of determining side-to-side differences in condylar activity is an important step in managing this condition. AIMS: To determine the growth activity in normal mandibular condyles and to devise an index of side-to-side differences in condylar activity in different individuals. METHODS: Thirty eight patients, ranging from 13 to 34 years, who were undergoing skeletal scintigraphy for a variety of conditions agreed to participate in this study. No subjects had clinical or radiographic signs of mandibular hyperplasia. After injection of 25 mci Tc99 the uptake by the right and left mandibular condyles was measured and the side-to-side differences used to calculate an index. RESULTS: The maximum side-to-side differences were 6.2 per cent (Right side versus left side: 53.1 per cent and 46.9 per cent respectively) in the male patients and 5.7 per cent in the female patients (Right side versus Left side: 52.85 per cent and 47.15 per cent respectively). CONCLUSIONS: The variation in growth activity in normal right and left mandibular condyles was less than 6.2 per cent.
This prospective study was designed to record relevant characteristics of mandibular condyle fractures and to evaluate the relationship between these. Data were recorded on sex, age, cause of trauma, level of fracture, dislocation of the mandibular head, dental state and associated fractures of all patients diagnosed in our hospital during the period 1984-1996 with mandibular condyle fractures. Data were analysed in our Computer Department. The sample comprised 348 patients with 444 fractures, and a male:female ratio of 2:1. Traffic accidents were the most common cause: 103 (41%) of the unilateral and 54 (56%) of the bilateral fractures, followed by alleged assault and falls. Low fractures were the most common -n = 314 of 444 (71%). The causes that involved considerable force (traffic accidents and falls) resulted in more dislocations of the mandibular head, more bilateral fractures, a tendency to fractures higher on the condyle and significantly more intracapsular fractures. Absence of molar occlusion also gave more high and fewer low fractures, but played no part in dislocation of the mandibular head from the glenoid fossa.
PURPOSE: The aim of the present study was to present a conservative condylectomy technique (condylectomy performed below the condylar head but high in the condylar neck) and articular disc repositioning as the surgical treatment approach for management of osteochondroma of the head of the mandibular condyle. PATIENTS AND METHODS: Six patients (4 females and 2 males) with an average age of 22.3 years (range, 13 to 32 years) and with an osteochondroma of the mandibular condyle were treated with conservative condylectomy. The remaining condylar neck stump was recontoured, and the articular disc was repositioned and stabilized over the "new" condyle. Any indicated orthognathic surgical procedures were then performed to optimize occlusion, function, and aesthetics. Clinical and radiographic evaluation was performed before surgery (T1), immediately after surgery (T2), and at the longest follow-up (T3). RESULTS: Average follow-up for the patients was 51 months (range, 22 to 108 months). No recurrence of the tumor was encountered in any of the cases. Subjective and objective evaluations of postsurgical temporomandibular joint function and range of mandibular motion were normal. Associated maxillary and/or mandibular orthognathic procedures were found to be stable in the long term. CONCLUSION: Conservative condylectomy with recontouring of the residual condylar neck to function as a condyle and repositioning of the articular disc is a viable option for treatment of osteochondromas of the mandibular condyle. The use of this method of treatment permits effective removal of the tumor and eliminates the need for autogenous grafts or total joint prostheses for temporomandibular joint reconstruction.
OBJECTIVE: The purpose of this study was to determine the feasibility of total temporomandibular joint reconstruction with the use of cryogenically preserved allograft mandibular condyle, disk, and fossa in the adult goat. STUDY DESIGN: This study consisted of an experimental group of 10 adult goats that underwent total resection of their temporomandibular joints. These animals were immediately reconstructed with cryogenically preserved mandibular condyles, disks, and fossa. These allograft were harvested from 10 donor animals matched to the recipient animal with respect to age, sex, and head dimensions. These grafts were harvested and stored at -185 degrees C for several months before implantation. At 2 years after surgery, the animals were killed. They were evaluated, clinically, radiographically, and histologically. RESULTS: Fifty percent of the eight surviving animals had a normal clinically functional joint with an intact superior joint space and viable articular surfaces. CONCLUSION: The authors conclude that this temporomandibular joint reconstruction technique is feasible in the adult goat model and is deserving of further research.
The variability of the internal architecture of bone was studied in the mandibular condyle of young rats with the aid of vital staining capable of revealing bone trabeculae. The effect of season and age was observed in Spring- and Fall-born rats 28 and 56 days of age. There was no clear left-right asymmetry in the average direction of the condylar trabeculae, but their ranges of direction within the condyles exhibited such asymmetry. Both the average directions and the internal variability were different in the medial and the lateral sides of the condyles. There were also small but in most respects significant seasonal differences. These findings indicate that even the relatively small mandibular condyle of the rat is a very complex structure.
The authors present a case of a giant cell tumor of the mandibular condyle, which is a very rare condition. Clinical history and symptoms suggested a disease of the ear. There was a destruction of the cortex of the condyle an invasion of the joint cavity, and an erosion of the adjacent temporal bone.
We investigated the effects of grape seed proanthocyanidins extract (GSPE) on bone formation by examining total and cortical bone mass, density, architecture, and strength non-invasively using mandibular condyles of Ca-restricted rats. Forty Wistar male rats, each 5 weeks old, were divided into control (C), low-Ca diet (LCaD), low-Ca diet-standard diet (LcaD x SD), and low-Ca diet x Estandard diet with supplementary GSPE (LcaD x SD+GSPE) groups. In LCaD x SD group, after the bone debility was induced by low-Ca diet, a standard diet therapy was given. In LCaD x SD+GSPE group, after the bone debility was induced by low-Ca diet, a standard diet therapy with supplementary GSPE was given. Each mandibular condyle was examined using peripheral quantitative computed tomography (pQCT). There were no significant inter-group differences in body weight seen throughout the experimental period. In LcaD x SD+GSPE, cortical bone cross-sectional area and mineral content were not significantly different from C, while bone mineral content was significantly higher in LcaD x SD+GSPE than in LcaD x SD. Cortical bone density of LcaD x SD+GSPE was not significantly different from that of C, however, that value in LCaD and LcaD x SD was significantly lower than that. The cross-sectional (bending) moment of inertia values in LcaD x SD+GSPE were the highest among all groups, though they did not differ significantly from those in C. Further, the cross-sectional (bending) Stress/Strain Index (SSI) values in LcaD x SD+GSPE were statistically similar to those in C, however, not significant higher than in LcaD x SD. These results suggest that GSPE treatment would increase both bone mass and bone strength on the rat mandibular condyles.