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PubMed2000

Anatomy of the epicondyles of the distal femur: MRI analysis of normal knees.

Knowledge of precise anatomic landmarks and relationships of the distal femur can be helpful in knee surgery, especially primary and revision total knee arthroplasty. We analyzed 104 consecutive routine knee magnetic resonance imaging studies to define useful landmarks and relationships. The epicondyles are described, and the relationship of the epicondyles to the joint line is defined in multiple planes. Some significant gender differences were noted. The distance from the epicondyles to the joint line correlates with the transepicondylar width of the distal femur. This information can be helpful in determining appropriate joint line position intraoperatively. The posterior condylar angle averaged 3.11 degrees for all patients, and a tendency for the posterior condylar angle to increase with age was noted, but further study of this tendency is needed.

Adolescent↗
PubMed1998

The validity of clinical examination for diagnosing anterior disk displacement without reduction.

OBJECTIVE: The objective of this study was to evaluate the diagnostic accuracy of patient history and clinical signs as confirmed by magnetic resonance imaging examination for diagnosing anterior disk displacement without reduction. STUDY DESIGN: A series of 273 consecutive patients with temporomandibular disorders were clinically examined according to well-defined criteria. Patients were first asked if they had a history of clicking. The following clinical characteristics of anterior disk displacement without reduction were then assessed: (1) maximal mouth opening less than 40 mm; (2) deflection of the mandible to the affected side at the maximal mouth opening position; (3) limitation of condylar translation on palpation during maximal mouth opening; (4) preauricular pain during mandibular movements; and (5) crepitation. Bilateral magnetic resonance images were obtained for all patients, and the magnetic resonance imaging interpretation was compared with the clinical examination findings to assess the diagnostic accuracy of the clinical findings. RESULTS: The sensitivity was considerably low in contrast with the relatively high specificity for all six clinical parameters tested. The overall accuracies of the clinical parameters ranged from 71% to 81%. CONCLUSION: Our results suggest that the predictability of historical or clinical findings to differentiate anterior disk displacement without reduction from other diagnoses is not high.

Adolescent↗
PubMed2001

Localization of mandibular changes in patients with class II division 1 malocclusions treated with twin-block appliances: finite element scaling analysis.

Thirty mandibular landmarks were digitized from cephalographs of 46 children (prepubertal, approximately 10 years old) and 53 adolescents (pubertal, approximately 13 years old) to determine mandibular morphological changes in patients with Class II Division 1 malocclusions treated with Twin-block appliances. Procrustes superimposition computed average geometries and an analysis of variance were performed on the cephalographs. Prepubertal pretreatment and approximately 13-month-posttreatment profiles and pubertal pretreatment and approximately 22-month-posttreatment profiles were statistically different (P <.002). In male prepubertal configurations, a color-coded finite element scaling analysis revealed a conspicuous area of positive allometry ( approximately 12%) in the condylar neck and negative allometry ( approximately 17%) at the apex of the coronoid process. For the female prepubertal configuration, local increases in size were discernible in the condylar neck ( approximately 3%) and in the apex of the coronoid process ( approximately 4%). Comparing male pubertal configurations, finite element scaling analysis revealed marked positive allometry ( approximately 27%) in the condylar neck and negative allometry ( approximately 16%) at the apex of the coronoid process. For the female pubertal configurations, local increases in size were noticeable at the condylar neck ( approximately 15%), with negative allometry ( approximately 9%) in the coronoid process. For shape change, all configurations were highly isotropic over the entire mandibular nodal mesh. Therefore, in growing patients treated for Class II Division 1 malocclusions with Twin-block appliances, condylar growth, coronoid process remodeling, and osteogenesis in corpus and dentoalveolar regions may reflect the correction of the underlying skeletal dysmorphology.

Adolescent↗
PubMed2002

Long-term results of different condylotomy designs for the management of temporomandibular joint disorders.

OBJECTIVE: The purpose of this study was to compare the long-term results of the condylotomy techniques. STUDY DESIGN: Twenty-two patients (mean age, 20.8 years; occlusion: Class I in Angle's classification of malocclusion) were studied. All showed Wilkes stage II or early stage III. The Visual Analogue Scale (VAS), maximum mouth opening (MMO), and the positional change of the condylar segment were recorded preoperatively and postoperatively. The difference in each criterion according to the operative techniques was evaluated by means of a 1-way analysis of variance, and the difference between the preoperative value and the value in the long-term follow-up was evaluated by means of a paired t test. RESULTS: Six patients underwent an extraoral vertical ramus osteotomy (EVRO), 6 patients underwent a sagittal split ramus osteotomy (SSRO), and 10 patients underwent an intraoral vertico-sagittal split ramus osteotomy (IVSRO). The preoperative value of the maximum mouth opening (MMO) was 33.0 +/- 8.3 mm, 46.1 +/- 7.0 mm, or 40.0 +/- 7.4 mm for patients undergoing EVRO, IVSRO, or SSRO, respectively. In the long-term follow-up period, the MMO was 49.3 +/- 14.6 mm, 47.3 +/- 3.2 mm, or 48.7 +/- 5.1 mm for patients undergoing EVRO, IVSRO, or SSRO, respectively. There were no differences in the amount of the MMO among the operative techniques (P >.05). The preoperative VAS in the operated-on joints was 3.9 +/- 2.4, 5.0 +/- 1.6, or 4.7 +/- 1.4 for patients undergoing EVRO, IVSRO, or SSRO, respectively. In the long-term follow-up period, it was 1.4 +/- 2.2, 2.5 plus minus 2.0, or 3.7 +/- 1.7 for patients undergoing EVRO, IVSRO, or SSRO, respectively. There were no differences in the VAS among the operative techniques (P >.05). When each measurement preoperation was compared with the long-term follow-up, the difference was statistically significant (P =.018 in the MMO, P =.004 in the VAS). CONCLUSION: The curative effect of a condylotomy on the internal derangement of the temporomandibular joint was acceptable in the long-term follow-up, but the osteotomy procedure used may be only a minor contributing factor to the long-term results.

Adult↗
PubMed2005

The adaptive remodeling of condylar cartilage---a transition from chondrogenesis to osteogenesis.

Mandibular condylar cartilage is categorized as articular cartilage but markedly distinguishes itself in many biological aspects, such as its embryonic origin, ontogenetic development, post-natal growth mode, and histological structures. The most marked uniqueness of condylar cartilage lies in its capability of adaptive remodeling in response to external stimuli during or after natural growth. The adaptation of condylar cartilage to mandibular forward positioning constitutes the fundamental rationale for orthodontic functional therapy, which partially contributes to the correction of jaw discrepancies by achieving mandibular growth modification. The adaptive remodeling of condylar cartilage proceeds with the biomolecular pathway initiating from chondrogenesis and finalizing with osteogenesis. During condylar adaptation, chondrogenesis is activated when the external stimuli, e.g., condylar repositioning, generate the differentiation of mesenchymal cells in the articular layer of cartilage into chondrocytes, which proliferate and then progressively mature into hypertrophic cells. The expression of regulatory growth factors, which govern and control phenotypic conversions of chondrocytes during chondrogenesis, increases during adaptive remodeling to enhance the transition from chondrogenesis into osteogenesis, a process in which hypertrophic chondrocytes and matrices degrade and are replaced by bone. The transition is also sustained by increased neovascularization, which brings in osteoblasts that finally result in new bone formation beneath the degraded cartilage.

Adaptation, Physiological↗
PubMedDate not supplied

Cine MRI of the TMJ: need for initial closed mouth images without the Burnett device.

OBJECTIVE: To evaluate the Burnett device when studying functional and morphologic aspects of internal derangements of the temporomandibular joint (TMJ) with cine MRI. MATERIALS AND METHODS: A patient with clicks in the TMJ cycle was studied with dynamic cine MRI both prior to the placement of the Burnett device and with the Burnett device in position. RESULTS: Review of MRI revealed clear anterior displacement of the disk in relation to the condylar head in true closed mouth position without the Burnett device in place. CONCLUSION: Closed mouth off-sagittal imaging of the disk in the closed mouth position should be included prior to appliance placement to detect anterior displacements with very early recapture.

Adult↗
PubMed2006

Relationship between TNF-alpha and TUNEL-positive chondrocytes in antigen-induced arthritis of the rabbit temporomandibular joint.

BACKGROUND: Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin nick end-labeling (TUNEL) staining is a widely accepted method for the detection of DNA fragmentation in nuclei of apoptotic cells. Tumor necrosis factor (TNF)-alpha is closely associated with changes in condylar cartilage and modulates apoptosis in various tissues including cartilage. The aim of this study was to investigate the relationship between apoptotic chondrocytes and TNF-alpha in a rabbit model of arthritis. METHOD: Unilateral temporomandibular joint (TMJ) arthritis was induced in 20 adult New Zealand White rabbits. From 1 day to 6 weeks after the induction of arthritis, immunohistochemical analysis for TNF-alpha and TUNEL was performed. RESULTS: In condylar cartilage, TNF-alpha-positive cells and TUNEL-positive cells were localized together. TNF-alpha-positive chondrocytes seemed to precede TUNEL-positive cells. CONCLUSIONS: The results of the present study suggest that TNF-alpha may be involved in apoptosis and/or apoptotic necrosis of chondrocytes as TMJ arthritis progresses from the acute to chronic stage.

Animals↗
PubMed1992

Surgical versus conservative treatment of unilateral condylar process fractures: clinical and radiographic evaluation of 80 patients.

Treatment results of 26 surgically and 54 conservatively treated unilateral condylar process fractures were investigated by standardized clinical examination and by evaluation of computer-simulated graphic presentations of posteroanterior (PA) radiographs of the mandible. The radiographic evaluation compared the relation of actual reduction of the condylar process fractures with ideally reduced fractures produced on the computer. Using clinical parameters (maximal mouth opening, deviation, protrusion), no statistical differences between surgically and conservatively treated fractures were found. However, the radiographic examinations showed a statistically better position of the surgically reduced condylar process fractures.

Adolescent↗
PubMed1989

[Long-term outcome of functional treatment for high double-sided condylar fractures].

The conservative procedures widely used to treat fractures of the condylar neck seem to provide positive short-term benefits, but on long-term observation the results sometimes are not consistent with the early prognosis. We observed a patient (adult female) from the time of the accident for a period of 7 years. The patient suffered from a high double-sided fracture of the condylar neck combined with a multiple fracture in the frontal region of the mandible. The treatment plan was: 1. primary osteosynthesis of the fracture in the frontal-region, 2. intermaxillary fixation for 14 days, 3. functional post-operative treatment using monoblock. Up to the first month it looked like a normal recovery. However, after three months the expected recovery became questionable. After 7 years it was obvious that the recovery had reached its peak between 3 months and 1 year after the operation. The patient experienced chronic pain and progressive loss of function. Such results are unsatisfactory and new operative procedures using osteosynthesis have to be developed.

Activator Appliances↗
PubMed2003

Kinematics of three variations of the Freeman-Samuelson total knee prosthesis.

The effect of changes in the articulating surfaces on the kinematics of the Freeman-Samuelson total knee replacement was evaluated. Twenty-two patients (22 knees) (median age, 69 years) were randomized to a standard design with a fixed polyethylene bearing, a design with a mobile bearing, or a new design with a spherical medial femoral condyle with a fixed bearing. The patients were studied with radiostereometry and film-exchangers at 0 degrees nonweightbearing and during active weightbearing extension from 45 degrees to 15 degrees. The center of the tibial tray with a mobile-bearing prosthesis occupied a more anterior position than observed in the designs with a fixed bearing. The medial femoral condyle center had a more posterior position in the standard design than in the design with a spherical medial condyle. From a distally displaced position at 45 degrees, the medial condylar center displaced a mean of 1.8 mm proximally during extension in the standard design and had a constant position in the meniscal design. In the spherical design the medial condyle was displaced proximally at 45 degrees and displaced a mean of 1.6 mm distally during extension. The reduced anteroposterior and proximodistal translations in the meniscal design are compatible with improved congruency between the components. The design with a spherical medial condyle stabilized anteroposterior motions, but showed more pronounced proximodistal displacement medially than did the other two designs.

Aged↗
PubMed1999

Elite system: recording of condylar movements using a modified computerized technique.

BACKGROUND: The aim was to develop a method to measure condylar movements using a computerized system. The Elite system is a computerized device for the graphic recording of mandibular movements by processing images of marks recorded with two video cameras. The Elite system has traditionally been used to measure mandibular movements; it was modified to record condylar movements as well. METHODS: The position of the markers was altered to enable 3-D recording not only of mandibular movements but also of condylar movements. New software was developed. Ten subjects (young adults; good complete dentition; no temporo-mandibular disorders; no orthodontic treatment) underwent recording with traditional and then with modified Elite system. The subjects were asked to perform the following movements: maximum opening and closing; protrusive and retrusive movements; border movements on the frontal plane. The sequence of movements was repeated three times on three different days. Data processing was effected using the Spline-smoothing method. RESULTS: The modified Elite system technique records condylar movements with extreme reliability, reproducibility and the resulting graphics are comparable. CONCLUSIONS: This method provides the chance to obtain more information about condylar movements in healthy subjects with good dentition, but also in patients with joint dysfunction.

Adult↗
PubMedDate not supplied

[Position variations of models on articulators based on terminal hinge axis and anatomical condylar points].

In this research the determination of the T.H.A. was taken aided by the TT kinematic arch, guided technique, with chin compression and by the alternative technique, the anatomic average. After confirming that the cited methods determine discrepant points among themselves, the research was carried on, studying the influence of those points upon the model's positions in the articulator. The main conclusions were: the emergence points of the T.H.A. are located in the anterio-inferior quadrant; the alterations that occur in the model's position are in most cases of rotatory type; occur alterations in model's position either in horizontal plan or frontal plan.

Dental Articulators↗
PubMed2002

[Effect of interocclusal records on the condylar path of the articulator].

Although there are studies on materials used for interocclusal records, there are no scientific data how the condylar path is influenced by the positional interocclusal records. The purpose of this in vitro study was to determine the effects of different interocclusal mediums on condylar inclination of the articulator. The materials selected for this experiment were: two addition type silicone pastes, two silicone putty materials and two waxes. The samples of protrusive records were performed on a Quick-Master semiadjustable articulator (FAG Dentaire). The same pre-established eminentia angles were used during the experiment for each type of materials. To improve the control of the condylar angles a protractor was mounted to the upper member of the articulator at right angels to each condylar fossa housing. A stylus moving simultaneously with the condylar fossa marked the eminentia angle on the protractor. 108 interocclusal records were performed and in 24 hours they were returned to the articulator. Then the articulator was adjusted and the settings of the eminentia angle were recorded. Numerical deviations between the pre-established and the adjusted settings in degrees were subjected to statistical analysis. The results indicated that these deviations for addition type silicones were significantly smaller than that of the other materials. The two waxes proved to be the least accurate materials. It is concluded that the condylar inclination is influenced by the properties of the registration materials, which may increase the shortcomings of the protrusive bite records.

Biocompatible Materials↗
PubMed2006

A 5-year follow-up of temporomandibular disorder treatment emphasizing condylar asymmetry.

The purpose of this study was to investigate the long-term effect of temporomandibular disorder (TMD) treatment giving priority to oral stability, i.e. creating stability for the mandible in the individual retruded position of the mandible (RPM), focusing condylar asymmetry. Twenty-nine (29) patients treated for TMD participated in the study. A standardized TMD examination was executed originally and an identical examination was performed at the follow-up in a private TMD practice. In general, the patients showed a significant increase of their maximum active mouth opening capacity (p < 0.01) and a significant decrease of dynamic and static pain at the performed tests (p < 0.001). Patients initially suffering facial pain showed a significant reduction of their pain with treatment (p < 0.01). The patients with condylar asymmetry >10%, and who underwent treatment aiming at permanent oral stability, showed the greatest improvement.

Facial Pain↗
PubMed1999

Conservative treatment of unilateral condylar fractures in children: a long-term clinical and radiologic follow-up of 55 patients.

The purpose of this prospectively designed study was the long-term clinical and radiological evaluation of conservatively treated unilateral condylar fractures in children. Fifty-five children aged between 2 1/2 and 9 3/4 years, presenting with a singular unilateral fracture of the mandibular condyle, were treated in a nonsurgical-functional way using an intraoral myofunctional appliance. In the follow-up period, patients were investigated by standardized clinical examination and by evaluation of panoramic radiographs taken immediately post-traumatically, after 6, 12, 24, 48 and 72 weeks, and then yearly through the period of growth. With a satisfactory clinical course in all patients, there was no instance of functional disturbance or mandibular asymmetry after the respective follow-up periods. The radiographs showed a fairly good shape of the condyle (no or only slight condylar deformity) in the 47 patients of the 2-6 year age group. In the eight patients of the 7-10 year age group presenting with a class II or III condylar fracture, healing was characterized by incomplete condylar regeneration, resulting in a moderate condylar deformity in two cases, a definite reduction in condylar neck height in two cases, and a hypertrophic condylar deformity in four cases. The positive results of this study confirm the concept of a nonsurgical-functional approach in children presenting with various types of unilateral fractures of the mandibular condyle. Condylar remodeling was the mode of fracture healing in instances of displaced and dislocated condylar fractures.

Child↗
PubMed1991

Condylar movements in clicking joints before and after arthrography.

The aim of this study was to investigate whether anaesthesia and contrast medium injection alter the biomechanics of the TMJ, thus influencing the arthrographic diagnosis in patients with anterior disc displacement with reduction. Opening and closing movements were recorded in nine patients by means of an opto-electronic motion recorder (Jaws 3D) before anaesthesia, after anaesthesia and after arthrography. The system computed the trajectories of a condylar point in the sagittal, frontal and horizontal plane. Data were analysed for changes in the position of the clicks, for the amount of condylar translation and for changes of the trajectories between recording conditions. The results indicated that arthrography had a significant effect on the position of the opening clicks in all nine patients. After injection, the clicks occurred on average 1.6 mm later than before injection. This was probably due to the excursive movements required for defusion of the contrast medium in the joint. The other parameters examined were not affected by the joint anaesthesia and the arthrographic procedure. The interventions influenced the shape and the incline of the sagittal condylar movement in three of the nine patients. In conclusion, arthrography altered the joint biomechanics, but not sufficiently to invalidate the arthrographic diagnosis.

Adult↗
PubMed2000

Functional subdivision of the human masseter and temporalis muscles as shown by the condylar movement response to electrical muscle stimulation.

In previous studies from our laboratory, a functional subdivision of the human temporalis and masseter muscles was demonstrated by means of opto-electronic recordings of the lower incisal point movement responses to electrical muscle stimulation. In the present study, it was examined whether this subdivision was also reflected in different movement responses of the mandibular condyle. To that end, the condylar movement responses to unilateral stimulation of four masseter muscle parts and three temporalis muscle parts were studied in four different jaw positions. The kinematic centre was used for condylar reference point. For both the amplitude and the direction of the movement responses, the effects of stimulation location and jaw position were studied using multivariate ANOVA and contrast analyses. It was found that for both outcome variables, the functional subdivision of the masseter and temporalis muscles was also reflected in some, but not all, of the movement responses of the mandibular condyles. The deep masseter muscle part and the (anterior) temporalis muscle part responded similarly to electrical stimulation.

Adult↗