SEARCH · PubMed Health

Results for “Condylar position”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources

PubMed1978

Laminagraphic study of mandibular condyle position when recording centric relation.

Laminagraphs were made of each temporomandibular joint of 20 subjects (1) with the mandible forcefully retruded to centric relation and (2) with the mandible positioned by a closing force while an anterior guidance prosthesis was being used. The radiographs were compared by measurements of condylar position; results indicated the condyles to be significantly more superior in the glenoid fossa when anterior guidance was used. The difference in anterior-posterior positioning of the condyles appeared to occur randomly. Measurements of the joint spaces with the mandible in centric relation using anterior guidance indicated that mandibular condyles were not centered in the fossae. There seemed to be a range in the size of the space that could be considered normal.

Dental Occlusion↗

PubMed1990

Positioning and mobility of the mandibular condyle after surgical correction of the asymmetric, prognathic mandible.

Following the extraoral vertical subcondylar osteotomy in the correction of the highly asymmetric and prognathic mandible, only insignificant radiographic changes were observed in the temporomandibular joint 12 months postoperatively. Slight morphologic alterations of the condylar seating were demonstrated at occlusion, but there was no significant difference in condylar position between the two sides of the surgically corrected asymmetric mandible. The condylar axis did not deviate from the preoperative situation, and condylar axis did not deviate from the preoperative situation, and condylar mobility was fully resumed 12 months postoperatively. The extraoral vertical subcondylar osteotomy procedure is applicable in the treatment of combined mandibular asymmetry and prognathism and does not create morphologic changes that differ in the two temporomandibular joints.

Adolescent↗

PubMed2006

Conscious analgesia and sedation during orthognathic surgery: preliminary results of a method of preventing condylar displacement.

A patient who is unconscious and paralysed has a condyle that is different from what it would be were he awake and the same force applied. The occlusion may relapse as a result of changes in condylar position immediately after the removal of intermaxillary fixation (IMF). Examination of the occlusion and an understanding of the changes secondary to a condylar displacement can identify it reliably during the operation. A study group (n=78) and a control group (n=74) were chosen randomly from patients listed for bimaxillary orthognathic surgery. No local anaesthetic was infiltrated so as not to disturb proprioception. In the study group, the IMF was removed immediately after the fixation and the occlusions were checked with light digital pressure on the chin. The patients were then woken rapidly (maintaining the intubation) in a state of conscious analgesia and sedation and invited to open and close their mouths and to move the mandible laterally. If clinical examination of the passive and active movements of the mandible were suitable, the anaesthetics were topped up and the operation completed. "Conscious" analgesia and sedation is certainly a valid aid during orthognathic surgery.

Adolescent↗

PubMed2000

Effect of eccentric clenching on mandibular deviation in the vicinity of mandibular rest position.

Although the mechanical compression of the temporomandibular joint (TMJ), which could be caused by bruxism, would probably result in a slight change of the occlusal relationship, the effect of clenching in the eccentric mandibular position on the occlusal contact has not yet been clarified. This study aimed to investigate the effect of eccentric clenching on bilateral condylar position and thus to estimate any change of occlusal contact. Before and after voluntary clenching, with one third of the maximal voluntary clenching force, for 3 min at the canine edge-to-edge position, vertical deviation of the bilateral condyles was measured at the 1 mm open mandibular position. This was regulated by the three-dimensional position of the anterior reference point which stands for the incisor point. The mean vertical displacement of the highly deviated side of the condyle was 141+/-55 microm, and the calculated mean displacement of the mandibular first molar region of the highly deviated side was 65+/-27 microm. From the results of this study, it was revealed that the eccentric clenching gave rise to three-dimensional deviation of the mandible even when the mandible was in the vicinity of the rest position.

Adult↗

PubMed2002

Effective temporomandibular joint growth and chin position changes: Activator versus Herbst treatment. A cephalometric roentgenographic study.

In 138 successfully treated Class II division 1 patients (40 Activator and 98 Herbst) effective temporomandibular joint (TMJ) growth changes (a summation of condylar remodelling, glenoid fossa remodelling, and condylar position changes within the fossa), and their influence on the position of the chin and the rotation of the mandible were analysed retrospectively. Lateral head films in habitual occlusion from before and after an average treatment period of 2.6 years for the Activator patients and 0.6 years for the Herbst patients were evaluated. Two different treatment changes were assessed: (1) overall growth changes and (2) treatment effects (overall growth changes minus age-related normal growth values: Bolton Standards). The comparison between the Activator and the Herbst group revealed larger effective TMJ and chin changes during Activator therapy due to the longer observation period (2.6 years versus 0.6 years). The treatment effects showed marked group differences for both the amount and direction of effective TMJ changes. The changes were vertical and slightly anterior in the Activator group, and predominantly posterior in the Herbst group. Concerning the chin changes, the treatment effects for the Herbst group exceeded those for the Activator group in both directions, caudally and anteriorly. The Activator group showed an anterior rotation and the Herbst group a slight posterior rotation of the mandible. The present investigation revealed that the effective TMJ and chin changes were increased by both Activator and Herbst treatment. However, the Herbst appliance renders more favourable sagittally orientated treatment effects in a much shorter period of time compared with the Activator.

Activator Appliances↗

PubMed1989

[Study on grinding movements in chewing. 1. A comparison between grinding movement in chewing-like empty jaw movement and lateral excursion].

The purpose of this study is to clarify the relationship between grinding movements during chewing, and lateral excursions starting from the intercuspal position. For this purpose, I measured two different types of three-dimensional mandibular movement; lateral excursions and empty-jaw movement like chewing in 10 subjects, and compared these paths with each other in the lateral occlusal position, when the incisal point is 2.0 mm distant from the intercuspal position. The results can be summarized as follows: 1. The two positions of the incisal point were statistically coincident. 2. The position of both working and non-working side molars during chewing tended to be inferior to that during lateral excursion. 3. The moved distance of the working side condyle during chewing was significantly less than that during lateral excursion. 4. The position of the non-working side condyle during chewing tended to be medial to that during lateral excursion. 5. The difference in the condylar position was deeply related to that in the molar position. The differences mentioned above were considered to be originated from the difference in the masticatory muscle activity and the occlusal contact.

Dental Occlusion, Centric↗

PubMed1992

Occlusal adjustment as treatment for tenderness in the muscles of mastication in category 1 patients.

When a lateral pterygoid muscle is more tender to palpation than the other muscles of mastication, and a stress test is positive, an occlusal cause should be suspected. Patients with lateral pterygoid tenderness are divided into three categories according to two criteria: the position of the condyles in their glenoid fossae and the degree of dysfunction in the articulation. Only patients in category 1, those with a centered condylar position and without dysfunction, are discussed in this article. Occlusal adjustment is executed on the basis of information gathered from radiographs of the temporomandibular joint, diagnostic casts, and leaf gauge measurements of unequal bilateral occlusal contact. The amount of tooth structure requiring removal can be determined by using leaf gauges of differing thicknesses. Occlusal adjustments are performed without mandibular manipulation until the tenderness of the lateral pterygoid muscle is relieved.

Dental Occlusion↗

PubMed2001

Three-dimensional finite element analysis of the cartilaginous structures in the human temporomandibular joint.

While the movability of the human temporomandibular joint is great, the strains and stresses in the cartilaginous structures might largely depend on the position of the mandible with respect to the skull. This hypothesis was investigated by means of static three-dimensional finite element simulations involving different habitual condylar positions. Furthermore, the influence of several model parameters was examined by sensitivity analyses. The results indicated that the disc moved together with the condyle in the anterior direction without the presence of ligaments and the lateral pterygoid muscle. By adapting its shape to the changing geometry of the articular surfaces, the disc prevented small contact areas and thus local peak loading. In a jaw-closed configuration, the influence of 30 degrees variations of the loading direction was negligible. The load distribution capability of the disc appeared to be proportional to its elasticity and was enhanced by the fibrocartilage layers on the articular surfaces.

Aged↗

PubMed1990

[Intraoral condyle-related positioning of the maxilla in Le Fort 1 osteotomies].

A new technique for positioning control in Le Fort I osteotomies is presented. This intraoral procedure allows three-dimensional positioning of the condyles in the desired centric or therapeutic relation and of the maxilla at the same time. It combines the intraoperative use of the "Condylar Positioning Appliance" with the "3D Doublesplint Method".

Dental Articulators↗

PubMed1991

The role of functional occlusal relationships in temporomandibular disorders: a review.

This review highlights the consensus existing in past research on the role of functional occlusal factors in the pathophysiology of temporomandibular disorders (TMD). The functional occlusal relationships considered are balancing and working occlusal contacts, length and symmetry of retruded contact position-intercuspal position (RCP-ICP) slides, occlusal guidance patterns, parafunction, and dental attrition. Controlled studies fail to demonstrate any association between occlusal interferences and TMD signs or symptoms. Temporomandibular joint condylar autorepositioning secondary to intracapsular arthrosis is associated with larger and asymmetric RCP-ICP slides. Other TMD conditions are not associated with any slide length or asymmetries. Occlusal guidance patterns are not associated with TMD symptom provocation or, conversely, health. Parafunction appears to be universal and is not associated with TMD development or symptomatology in healthy individuals. Furthermore, parafunction is not provoked by longstanding, naturally occurring occlusal variations. Dental attrition is not associated with TMD, and any observed increased attrition in osteoarthrosis patients is likely the result of age effects and occlusal alterations secondary to condylar positional changes.

Bruxism↗

PubMed2001

Effective condylar growth and chin position changes in activator treatment: a cephalometric roentgenographic study.

Effective condylar growth (a summation of condylar remodeling, glenoid fossa remodeling, and condylar position changes within the fossa) and its influence on the position of the chin was analyzed in 40 class II, division I malocclusions treated successfully with activators. Additionally, the amount of mandibular rotation was assessed. Lateral head films in habitual occlusion from before and after an average treatment period of 2.6 years were evaluated. The Bolton Standards (32 untreated individuals with ideal occlusion) served as controls. Two different treatment effects were evaluated: overall growth change and treatment effects (overall growth changes minus age-related Bolton values). In comparison with the Bolton group, the activator patients exhibited an increase in the amount of vertical effective condylar growth (3.0 mm; P < .001), a decrease in the amount of sagittal effective condylar growth (0.6 mm; P < .05), and an increase in the amount of vertical development of the chin (1.8 mm; P < .001). No group differences could be found for sagittal development of the chin. In the Bolton group, the mandible rotated posteriorly, and in the activator group it rotated anteriorly (2.7 degrees; P < .001). The present investigation revealed that effective condylar growth can be increased and the chin position can be changed by activator treatment. Thus activator treatment induces skeletal changes, although not always in the desired (sagittal) therapeutic direction.

Activator Appliances↗

PubMed2005

Skeletal effects in class II treatment with the functional mandibular advancer (FMA)?

OBJECTIVE: The aim of this clinical study was to reveal skeletal effects during the treatment of Class II malocclusions in adolescents and young adults using a protrusive-acting fixed, rigid functional orthodontic appliance, and to quantify them in comparison with an untreated control group. We aimed to determine whether, and if so, to what extent skeletal effects diminish with increasing age, and whether inter-individual differences can be observed. METHOD: To correct their intermaxillary jaw relationship, the functional mandibular advancer (FMA) was inserted in 16 adolescents and young adults (eight males, eight females, aged from 12 years, 3 months to 18 years, 7 months) presenting with a skeletal Class II malocclusion. The course of treatment was documented cephalometrically. RESULTS: In all patients, the FMA treatment led to neutroclusion or overcorrected neutroclusion and a marked reduction in overjet. The occlusion's improvement in the sagittal dimension (overjet reduction by 4.43 +/- 2.10 mm, molar relationship improvement by 3.88 +/- 1.12 mm) was achieved by a combination of dental effects (distalization of upper teeth, mesialization of lower teeth) and skeletal effects (mandibular growth stimulation). Excepting the position and morphology of the maxillary base and the condyle's dorsal position in the fossa, all sagittal skeletal and dental changes induced by the FMA treatment were statistically significant. There was a mean increase of 1.71 +/- 1.11 mm in sagittal length of the mandible, in the sagittal-diagonal dimension of 1.42 +/- 1.51 mm and 1.53 +/- 2.15 mm, as well as a slight, significant increase in the gonial angle area. Whereas the condylar position remained stable, a forward positioning of the chin and thus significant increase in distance length was recorded from the posterior condylar margin to the anterior mandibular margin. CONCLUSIONS: Treatment with a fixed functional appliance in Class II patients effected significant changes in mandibular growth and correction of the distal intermaxillary relationship even after the pubertal growth spurt in adolescents and young adults. While the proportion of the orthopedically-induced skeletal share is subject to substantial inter-individual variability in adolescents, the overall conclusion can be drawn that skeletal effects (= stimulation of mandibular growth) in general clearly lessen with increasing patient age. In young adult patients, the correction of a distal intermaxillary jaw relationship is manifested primarily as a dento-alveolar compensation for the skeletal malocclusion.

Adolescent↗

PubMed1997

The reproducibility of centric relation: a clinical approach.

This study addresses the reproducibility of the centric relation, or CR, position. Using bimanual manipulation, several dentists were randomly assigned to one of five patients to clinically determine CR and record this position by using the same wax recording technique. These bite records, which were then analyzed by using the Denar Centri-Check marking system (Teledyne Water-Pik), were found to capture condylar positions with a maximum variation of 0.1 millimeter, as measured within the tolerances of the Denar Centri-Check.

Centric Relation↗

PubMed2007

Pivot appliances - is there a distractive effect on the temporomandibular joint?

The purpose of this study was to investigate the distractive effect of posterior occlusal pivots on the temporomandibular joint. The study comprised 23 healthy subjects. None of them had a third molar and none of them had a missing tooth or showed tooth mobility. All subjects clenched (i) on 1 mm tin foil positioned between the teeth 17/47 and 27/37; (ii) on a stiff bite registration material of 1 mm thickness that prevented protrusion because of its bold occlusal relief. During clenching on the tin foil and on the protrusion preventing bite registration material, respectively, the vertical and horizontal condylar position was measured using a 6 d.f. ultrasonic motion analyser. Clenching with maximal force on the tin foil lead to a noticeable anterior downward directed movement of the condyle. Clenching on the protrusion preventing pivot, however, caused a statistically significant upward condylar movement of about 0.3 mm. These results indicate that occlusal pivots have no distractive effect on the temporomandibular joint but can lead to unwanted joint compression, if they are designed in a way that is preventing protrusion.

Adult↗

PubMed2003

Posterior occlusal support and bite force influence on the mandibular position.

Three-dimensional mandibular displacement related to loss of posterior occlusal support was investigated. Five subjects, whose mandibular premolars and molars needed to be restored, were selected. Their experimental prostheses were removed in sequence from the most posterior to anterior. The more the absence of posterior occlusal support increased, the more condylar displacements were increased. On the other hand, maximum bite forces were decreased, by removing each prosthesis in sequence from posterior to anterior. These results suggest that condylar position would be easily displaced with low level bite force following loss of posterior occlusal support.

Adult↗

PubMed1999

Sliding plates on complete dentures as a treatment of temporomandibular disorder: a case report.

This work presents a case report of a woman, aged 62, who presented with signs and symptoms of temporomandibular disorder (TMD). The patient reported pain in the masticatory system and examination showed a reduction in the occlusal vertical dimension (OVD). She was treated with complete dentures incorporating a modification to the posterior regions developed by the authors and which were termed "sliding plates." Through analysis of photographs taken of the patient prior to the extraction of the patient's natural dentition, sliding plates were utilized to reestablish the OVD. The sliding plates also allowed for unrestricted eccentric mandibular movements, thereby accelerating the neuromuscular deprogramming and making it possible for the mandible to adopt a more physiologic position. The dentures reduced the pain and were well-accepted by the patient. Therefore, sliding plates may be of great benefit to completely edentulous patients with painful symptoms that result from alterations in the OVD and inappropriate condylar positioning.

Centric Relation↗

PubMed1992

Accuracy of quantification of mandibular condyle displacement in digitally subtracted linear tomograms.

Using a TMJ skeletal phantom, we assessed validity and reliability of digitally subtracted linear tomographic images to quantify condylar position changes. Horizontally corrected frontal and lateral tomographic images were made with the condyle in a 'centred' position and displaced by 1, 2 and 3 mm increments in two of three directions (inferior, and posterior, or lateral). Film images were sequentially subtracted and then randomized so that observers were blinded to the amount and direction of condylar movement. Averages of three measurements of the dark bands representing condylar shifts were made using a digitizing tablet. The study utilized a nested design where the series of film images was subtracted twice and each subtraction was read twice by two examiners. We repeated the study with a second series of films treated in an identical manner. Average differences from expected values were similar for frontal and lateral techniques and all directions and increments of displacement. Typical average difference for any increment was less than 0.1 mm. Standard deviations in measures were similar across techniques and increments and were typically less than 0.1 mm. Significant variation in the absolute value of differences between measured and expected values by direction of condylar displacement was attributed to greater accuracy of registration on the vertical axis for frontal images. A significant source of variation in the study design element 'film set' was attributed to errors in repositioning the phantom.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗

PubMed2002

A three-dimensional method of visualizing the temporomandibular joint based on magnetic resonance imaging in a case of juvenile chronic arthritis.

AIM: The purpose of this study was to present a new visualizing method for temporomandibular joint (TMJ) pathology in 3D at several condylar positions and to apply the method to a case of juvenile chronic arthritis (JCA) with previously diagnosed bilateral TMJ disorder and to a subject without signs and symptoms from the TMJ. SUBJECT: The 20-year-old female patient had suffered from polyarticular JCA from the age of 6 years 8 months. The present study is based on a follow-up examination after the completion of orthodontic treatment with the Herbst appliance. Both TMJs were examined using magnetic resonance imaging (MRI) at closed and open mouth positions. The mandibular condyle, the glenoid fossa and the articular disc were segmented and 3D reconstruction of these structures was carried out. RESULTS: The condyle was characterized by an increased sagittal diameter with osteophyte-like formation at the anterior aspect of the condylar head and flattening of the superior surface. The depth of the glenoid fossa was reduced and the articular eminence was remarkably flat. The articular disc was markedly diminished and posteriorly placed on the condylar head. The distance of the condylar path during mouth opening was reduced and the curvature of the condylar path was quite flat. The disc moved slightly posteriorly on the condylar head and remained in the glenoid fossa during mouth opening. CONCLUSION: The imaging modality described improves visualization of TMJ morphology and gains insight into the TMJ pathology of the JCA patient, adding to understanding of the clinical problems.

Adult↗