Significance of condylar positions in patients with temporomandibular disorders

Distraction osteogenesis promotes temporomandibular joint self-remodeling in the treatment of mandibular deviation caused by condylar ankylosis

Craniofacial deformity and malocclusion are primary concerns following temporomandibular joint ankylosis (TMJa) in growing patients, and they pose even greater challenges in adult patients. The treatment objectives always involve restoring proper jawbone structure, achieving stable occlusion, and attaining satisfactory joint mobility. This report presents a 4-year follow-up of an adult patient with TMJa-induced mandibular deviation, who underwent a combined treatment approach involving distraction osteogenesis (DO) and orthodontic-orthognathic surgery. Orthodontic treatment resulted in favorable occlusion and improved facial esthetics. A new condyle with a reconstructed glenoid fossa in a forward position was established after mandibular DO and the damaged TMJ experienced self-remodeling owing to functional improvement. Thus, this case demonstrates the efficacy of DO in promoting adaptive TMJ self-remodeling with long-term stability when treating mandibular deviation caused by condylar ankylosis in adult patients.

Functional Assessment of the Stomatognathic System, after the Treatment of Edentulous Patients, with Different Methods of Establishing the Centric Relation

The study compares subjective experiences of patients, wearing complete dentures. Two different methods of determining a centric relation were performed: the traditional method using wax occlusal rims and the Gerber method, based on gothic arch tracings. The success rate of establishing a centric relation in both methods was evaluated (rentgenodiagnostics). The influence of the method used to obtain the centric relation on patients' stomatognathic system (condyle centralization, pain) was also evaluated. Better results were achieved in gothic arch tracing method. Before every prosthetic treatment of edentulous patients, a functional analysis of the TMJ is necessary. The lack of centric relation, in a long term adaptation patients, does not lead to TMD symptoms. This trial is registered with NCT03343015.

Analysis of the condyle/fossa relationship before and after prosthetic rehabilitation with maxillary complete denture and mandibular removable partial denture

STATEMENT OF PROBLEM

The influence of the loss of posterior teeth on the condylar position and on temporomandibular disorders (TMDs) remains a controversial issue.

PURPOSE

This study investigated whether prosthetic rehabilitation promoted modification of the condylar position in subjects without symptoms of TMDs.

MATERIAL AND METHODS

The temporomandibular joints (TMJs) of 12 women (age 37 to 74), all with existing maxillary complete dentures but no removable partial denture (RPD) restoring the Kennedy class I partially edentulous mandibular arch and no clinical signs of TMDs according to the criteria established by Helkimo, were viewed in maximal intercuspal position with corrected lateral tomography before and after prosthetic rehabilitation with a new maxillary complete denture and a mandibular RPD. Before prosthetic rehabilitation, a mandibular stabilizing base was fabricated to prevent the existing maxillary complete denture from dislodging during tomographic examination. Two methods were used to evaluate tomograms: (1) linear measurements of the subjective narrowest anterior and posterior intra-articular joint spaces made from the tomograms by use of a digital caliper and (2) linear measurements of the anterior and posterior intra-articular joint spaces on the basis of drawings and tracings. Repeated-measures analysis of variance followed by orthogonal contrasts were used to evaluate differences between measurements carried out on the same subject under the different test conditions of the study (before prosthetic rehabilitation, before prosthetic rehabilitation with a mandibular stabilizing base in position, and after prosthetic rehabilitation) (P<.05).

RESULTS

Before prosthetic rehabilitation, a predominance of posterior condylar positions was observed. Before prosthetic rehabilitation with a mandibular stabilizing base in position, a significant decrease was observed in posterior condylar positions (P=.03). This decrease was more marked after prosthetic rehabilitation (P=.02). The subjective evaluation and comparison on the basis of drawings and tracings used to analyze the tomograms produced similar results (P=.70).

CONCLUSION

Within the limitations of this study, significant changes in the condylar position occurred after prosthetic rehabilitation in subjects without symptoms of TMDs.

Condyle position as a predictor of temporomandibular joint internal derangement

STATEMENT OF PROBLEM

The significance of the position of the mandibular condyle in the glenoid fossa remains a controversial subject.

PURPOSE

This study evaluated the relationship between condyle position and disk displacement.

MATERIAL AND METHODS

Fifty-two asymptomatic volunteers and 130 symptomatic patients underwent linear tomography and bilateral temporomandibular joint magnetic resonance scans.

RESULTS

There was a higher prevalence of distal condyles in symptomatic patients with disk displacement compared with asymptomatic volunteers (P <.05). Distally positioned condyles identified joints with disk displacement with reduction, disk displacement without reduction, or a symptomatic normal joint with a sensitivity of 0.64, 0.56, and 0.33, respectively. Distally positioned condyles identified joints with disk displacement with reduction, disk displacement without reduction, or a symptomatic normal joint with a specificity of 0.56, 0.65, and 0.55, respectively.

CONCLUSION

There were more distal condyles in symptomatic subjects with disk displacement, but the reliability of a distal condyle to predict the presence or absence of disk displacement was low.

Radiographic diagnosis of temporomandibular disorders

Although many of the disorders involving the temporomandibular joint and associated structures can be diagnosed clinically on the basis of the history and physical findings, there are others that require the use of various imaging techniques to make an accurate diagnosis or to determine the extent of involvement. To take maximum advantage of the benefits of these procedures, however, it is not only important for the clinician to be able to select the correct methods, but also to understand their limitations as well as their capabilities. In this article the various techniques used for imaging the hard and soft tissues of the temporomandibular joint are reviewed and recommendations are made regarding their appropriate applications.

Reliability and validity of diagnostic modalities for temporomandibular disorders

Temporomandibular disorders (TMD) encompass a group of musculoskeletal conditions that involve the temporomandibular joint (TMJ) or joints, the masticatory musculature, or both. These conditions are typically characterized by pain in the pre-auricular area that is usually aggravated by chewing or other jaw function and is often accompanied, either singly or in combination, by limitation of jaw movement, joint sounds, palpable muscle tenderness, or joint soreness. As with most other musculoskeletal conditions, the diagnostic "gold standard" for TMD is based upon an evaluation of the patient's history and clinical examination, supplemented, when appropriate, by TM joint imaging. It is against this "gold standard" that the reliability and validity of diagnostic modalities must be compared. With regard to electronic devices, several reviews of the scientific literature have concluded that the diagnostic reliability, validity, sensitivity, and specificity of such devices in the diagnosis of TMD have not been established. In addition, although clinical examination of the dentition may provide useful diagnostic information for some conditions, specific occlusal relationships have poor sensitivity and specificity when related to the presence or absence of TMD. TMJ imaging, when indicated, is useful in the detection of pathology within the joint, provided that validated criteria are applied to an analysis of the image. However, the assessment of condylar position as a diagnostic criterion for TMD has very poor reliability and validity.

Reliability and validity of imaging diagnosis of temporomandibular joint disorder

The purpose of this article is to review reliability and validity of imaging diagnosis of temporomandibular joint disorders. Plain-film and tomography are basic imaging techniques for assessment of the temporomandibular joint. These can be used for evaluation of osseous disease and as a baseline for follow-up. In patients with symptoms from the joint, plain-film and tomography are rarely definitive, and evaluation of the soft tissues is frequently necessary. Arthrography, computed tomography, and magnetic resonance imaging have all been used for evaluation of the soft-tissue components of the joints. Accuracy studies of these techniques have demonstrated the highest diagnostic accuracy for magnetic resonance imaging. Arthrography is relatively insensitive for detection of medial and lateral displacements. Magnetic resonance imaging accurately depicts both hard and soft tissues, and this technique is emerging as the prime diagnostic imaging technique in patients presenting with clinical signs and symptoms of a disorder of the temporomandibular joint. The most frequent findings when patients with clinical symptoms of temporomandibular joint disorders are "imaged" are different forms of disc displacement and degenerative joint disease. Studies have demonstrated a high prevalence of different forms of disc displacement in patients, although these abnormalities are also seen in some asymptomatic volunteers. Future research should further refine imaging techniques to come closer to an understanding of the association between morphologic alterations and patient symptoms.

Condylar position in superior maxillary repositioning and its effect on the temporomandibular joint

Twenty-nine patients (58 joints) were tomographically evaluated for condylar position and assessed for temporomandibular joint function following superior maxillary repositioning with mandibular autorotation. Seventy-six percent of the condyles showed postoperative posterior repositioning, whereas tomographic measurement of the joint spaces revealed significantly posterior condylar position (P less than .01) relative to the preoperative position. Pre- and postoperative comparative values of condylar displacement from absolute concentricity based on the Pullinger index also showed posterior condylar repositioning postoperatively (P less than .001). However, there was no correlation between condylar position and the presence of temporomandibular joint symptoms in both the asymptomatic and symptomatic groups.

Condylar position as a predictor of temporomandibular joint internal derangement

Scout tomograms and arthrograms of 243 patients were separated and numbered. The location of the condyle within the fossa in the closed-mouth position was assessed by means of three evaluation techniques. Later, the arthrograms were interpreted and matched with the corresponding tomograms to evaluate the relationship between posterior displacement of the condyle and anterior displacement of the articular disk. The position of the disk within the fossa was found to be extremely variable whether disk position was normal or abnormal.

Computed tomography of condylar and articular disk positions within the temporomandibular joint

The computed tomograms of temporomandibular joints in 25 patients (41 joints) were retrospectively evaluated for condylar position and joint space with General Electric computer software. Computed tomography scans of the temporomandibular joint were made in the axial plane with the teeth in centric occlusion, and measurements were made from vertically reformatted images. Interarticular joint spaces were measured anterosuperiorly, superiorly, posterosuperiorly, and posteriorly from the condylar surfaces. This was repeated in five equidistant (3.1 mm) serial sagittal planes across the condyle, beginning and ending, on average, 2.5 mm from the lateral and medial condylar poles. Articular disk positions (anterolateral, anterior, anteromedial, medial, and normal) were correlated with condylar position. Significant differences between disk positions and joint spaces were found most frequently in the anterosuperior and the superior joint interval. When the disk was positioned normally, the anterosuperior joint space was consistent (1.5 to 2.0 mm) across the joint (standard deviation, 0.3 to 0.8 mm). The superior, the posterosuperior, and the posterior joint spaces in the normal joint were greater than the anterosuperior joint space. When the disk was anterior to the condyle, the anterosuperior joint interval was widened. When the disk was medial, the superior joint space was significantly wider than normal across the breadth of the condyle. In those joints in which the disk was anteromedial, there was an absence (0.2 mm) of joint space, and this occurred in all areas of the condyle except in its medial one fourth. In the internally deranged joint, joint space narrowing may be focal in nature.