Temporomandibular Disc Research Articles

Vascularized Fibular Flap for Reconstruction of the Condyle After Mandibular Ablation

The purpose of this study was to evaluate the outcome of the vascularized fibular free flap for the reconstruction of mandibular resections involving the condylar segment. Six patients underwent mandibular resection including the condyle. Two patients were diagnosed with squamous cell carcinoma, whereas the other 4 presented fibrous dysplasia, mandibular osteoradionecrosis, mandibular ameloblastoma, and giant cell granuloma of the mandible. All of them underwent condylar reconstruction by means of transplant of the free fibular flap. In all the cases, the fibula was placed directly into the glenoid fossa. The temporomandibular disc was preserved over the pole of the fibula. Panoramic radiographs were performed postoperatively to evaluate condylar position and grade of bone resorption. Five patients developed adequate temporofibular function with absence of hypomobility and optimum interincisal opening, whereas 1 patient developed a temporofibular ankylosis with severe limitation of mandibular mobility and mouth opening. The use of the fibula flap directly fitted into the glenoid fossa constitutes a reliable method in condylar reconstruction. However, the possibility of severe complications such as ankylosis has to be considered.

Agreement between Research Diagnostic Criteria for Temporomandibular Disorders and Magnetic Resonance Diagnoses of Temporomandibular disc displacement in a patient population

The aim of this work was to evaluate the agreement between the clinical Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) examination and magnetic resonance (MR) findings of temporomandibular joint (TMJ) disc position abnormalities in a sample of clinically symptomatic patients, recruited from a population seeking TMD treatment. Two-hundred and thirty-two TMJs of 116 patients were evaluated to detect disc position abnormalities by means of a standardized clinical assessment according to RDC/TMD guidelines and MR performed blind by a radiologist. The overall kappa value for agreement between clinical examination according to RDC/TMD classification system and MR imaging for assessment of the disc–condyle relationship was fairly good (K = 0.63). The kappa values for the agreement between RDC/TMD and MR diagnosis of disc displacement with reduction (DDR), disc displacement without reduction (DDNR) and normal disk position were 0.69, 0.57, and 0.61, respectively. The observation that clinically predicted cases of DDR and DDNR show good to excellent agreement with MR findings, and the potential MR over-diagnosis of DDR and DDNR in the absence of clinical symptoms, support the usefulness of a standardized examination conducted by a trained investigator in the evaluation of patients with TMD.

Changes in temporomandibular disc position during growth in young Japanese

To detect the initial changes in temporomandibular disc position during growth with MRI examination in a prospective longitudinal study of a young Japanese population. Forty-four temporomandibular joints in 22 healthy asymptomatic volunteers, mean age 11.8 years, age range 9-16 years, were examined by MRI. They were re-examined 2-3 years later. The mean age and age range at the second examination were 14.5 years and 12-19 years, respectively. The discs were assessed at three different locations by oblique sagittal planes at the lateral, central and medial parts, and the displacement was evaluated as a partial anterior or total anterior position. Six joints already had a partial anterior position of the disc at the initial examination and no developmental change in disc position was observed during the examination period. Nine joints developed partial disc displacement during the examination period. Every partial displacement was observed at the lateral part of the disc. One joint developed a total anterior position from the lateral to the medial images. Initial changes in the disc position are likely to start from the lateral part of the joint in the early teenage years and are often asymptomatic.

Poster 242: Histologic and Histomorphometric Analysis of Posterior Region of the Human Temporomandibular Disc

Objective. The aim of this study was to analyze histologic and histomorphometric features of the articular disc in groups with and without disc displacement. Study design. A sample of 39 temporomandibular joints TMJs (31 case specimens, 8 control specimens) from 28 patients (mean age 31.2 years) were recruited for this study. The patients were considered to be affected and treated surgically with disc repositioning when presenting painful clinical signs of disc displacement after unsuccessful nonsurgical treatment for at least 6 months. Of the control patients, 4 presented condyle fracture which required opening to be reduced for treatment, and 4 displayed active condyle hyperplasia. The posterior region of the disc was removed and sent for histologic and histomorphometric analysis. Histologic (hematoxylin-eosin) and histomorphometric (picro-Sirius red) analyses were performed. Statistically significant differences between the analyzed groups were accessed through the chi-squared test (P .05). The Mann-Whitney U test was used to observe the differences between mean values when variables did not present normal distribution [Kolmogorov-Smirnov(a) test]. Results. There were no significant differences between the groups in relation to the parameters studied by histologic and histomorphometric analysis (using or not using polarization). Conclusions. To the limits of this study, there were no significant histologic and histomorphometric differences in the articular disc between groups with and without TMJ dysfunction. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008;105:e6-e11)

Rare Benign Tumors of the Mandibular Condyle: Report of 2 Cases and Literature Review

There have been few reports of tumors in the mandibular condyle, in particular pure chondromas, with 6 cases reported, and osteoid osteomas, with only 2 cases in the literature reviewed (Table 1). Chondromas are benign tumors of mature hyaline cartilage that are rarely seen in the facial bones. Osteoid osteoma is a very painful but small bone lesion with its maximum diameter rarely exceeding 2 cm and consisting of a central nidus of osteoid, atypical bone, and a discrete surrounding zone of reactive bone sclerosis. It is also rarely seen in the jaws. This article describes a case of a young woman with an osteoid osteoma located at the right mandibular condyle associated with the displacement of the right temporomandibular disc, which was treated by resection of the tumor and placement of the disc. A case of condylar enchondroma is also presented that was treated by condylectomy; the reshaped condyle was used for immediate articular reconstruction and to reestablish the height of the mandibular ramus. The clinical symptoms, anatomic features, histologic characteristics, and differential diagnosis of these lesions are discussed. Report of Cases

Unilateral Posterior Crossbite is Not Associated with TMJ Clicking in Young Adolescents

Unilateral posterior crossbite has been considered as a risk factor for temporomandibular joint clicking, with conflicting findings. The aim of this study was to investigate a possible association between unilateral posterior crossbite and temporomandibular disk displacement with reduction, by means of a survey carried out in young adolescents recruited from three schools. The sample included 1291 participants (708 males and 583 females) with a mean age of 12.3 yrs (range, 10.1-16.1 yrs), who underwent an orthodontic and functional examination performed by two independent examiners. Unilateral posterior crossbite was found in 157 participants (12.2%). Fifty-three participants (4.1%) were diagnosed as having disk displacement with reduction. Logistic regression analysis failed to reveal a significant association between unilateral posterior crossbite and disk displacement with reduction (odds ratio = 1.3; confidence limits = 0.6-2.9). Posterior unilateral crossbite does not appear to be a risk factor for temporomandibular joint clicking, at least in young adolescents.

Quantitative analysis of the elastic fibres in the human temporomandibular articular disc and its attachments

A quantitative study of the elastic fibres found in the human temporomandibular disc and its attachments was performed. Seven left discs from 57- to 82-year-old subjects, without macroscopic evidence of a TMJ disorder, were analysed and prepared in parasagittal sections. The surface amount was measured, thresholded and expressed from 0 to 1, using microscopic digitized views after Weigert's resorcin–fuchsin staining of elastic fibres. Fibre density rates ranged from 0 to 0.687. The mean density was 0.1532 ( σ = 0.1150) in the upper bilaminary zone, 0.1097 ( σ = 0.1159) in the lower bilaminary zone, 0.0474 ( σ = 0.0782) in the anterior band, 0.0180 ( σ = 0.0603) in the posterior band and null in the intermediate zone. The difference in density rate between the structures was significant, except for the posterior band and the intermediate zone. The elastic fibre density rates in central and medial locations of the upper and lower bilaminary zones were twice as big as in the lateral locations. In the anterior band, the elastic fibre density was less abundant medially than in its lateral part. These quantitative results support the current elastic fibre distribution scheme, and confirm the necessity of studying their orientation, taking into account age and temporomandibular joint health parameters.

Fracture toughness estimation for the TMJ disc

J contour integral fracture toughness of the temporomandibular (TMJ) disc was estimated from a computational model based on fracture load data derived from experimental tests. The computational model involved a stress analysis of TMJ disc specimens with cracks oriented parallel and perpendicular to the primary collagen fiber axis within the intermediate zone of the disc. The results demonstrated differences occurred between crack orientations when an orthotropic model was used. Fracture toughness was much lower for a crack oriented parallel to the collagen fiber direction than that for a crack oriented perpendicularly. Thickness, crack size, and anisotropy ratio were observed as additional variables affecting the fracture toughness of the TMJ disc. Future model enhancements may be achieved by considering the poroviscoelastic nature of the TMJ disc.

Surgical management of temporomandibular disc perforation

颞下颌关节盘穿孔是颞下颌关节紊乱病骨关节病中的一种病症,多因外伤、关节盘前移位和骨关节病导致关节盘后带与双板区交界处和双板区穿孔,以及关节盘本体穿孔或破裂.临床上常伴有关节组织的退行性改变.颞下颌关节盘穿孔的治疗有保守治疗和手术治疗,以下重点介绍颞下颌关节盘穿孔的外科治疗。

Possible link between extraction of wisdom teeth and temporomandibular disc displacement with reduction: matched case control study

We undertook a case control study that compared 220 patients diagnosed with disc displacement with reduction at the Dental Hospital of Manchester with 1100 controls drawn from participants in the 1998 Adult Dental Health Survey. We found that patients were not significantly more likely to have had extraction of third molars than controls; odds ratio: 1.28, 95% CI: 0.96-1.71. Also only 21 patients (9.5%) reported having had extraction of third molars in the 5 years before their diagnosis. We conclude that for most patients extraction of third molars is unlikely to have caused disc displacement with reduction.

Effects of Repositioning Splints for Juvenile Patients with Temporomandibular Disc Disorders

Effects of Repositioning Splints for Juvenile Patients with Temporomandibular Disc Disorders

Magnetic Resonance Imaging of the Temporomandibular Disc in Individuals With and Without Jaw Deformity

Objectives: To record the prevalence of disc displacement of the temporomandibular joint (TMJ) in patients with jaw deformity.Patients and Methods: Fifty patients with deformity and 50 volunteers without deformity were examined using magnetic resonance imaging.Results: Anterior disc displacement with reduction was noted in 20%, and anterior disc displacement without reduction in 7% of volunteers. In patients with jaw deformity, anterior disc displacement with reduction and anterior disc displacement without reduction were documented in 13% and 12%, respectively. There was no statistically significant difference in the prevalence of disc displacement between these 2 groups. On the side of deviation in mandibular asymmetry, the prevalence of anterior disc displacement with reduction or anterior disc displacement without reduction was 27.6% and 24.1 %, respectively, and there was a higher incidence of anterior disc displacement without reduction than in the TMJ of volunteers and those with symmetrical deformity.Conclusion: The fact that no significant difference was found in the incidence of anterior disc displacement with reduction and anterior disc displacement without reduction between patients with jaw deformity and volunteers without deformity indicates that disc displacement is not always caused by jaw deformity.

Fränkel appliance therapy and the temporomandibular disc: A prospective magnetic resonance imaging study

This prospective clinical study assessed the effect of the Fränkel Functional Regulator-II (FR-II) treatment on the position and shape of the articular disc of the temporomandibular joint. The sample included magnetic resonance images of 112 temporomandibular joints taken initially (T1) and after 18 ± 1 months (T2). The subjects were 56 white Brazilian children who were beginning their pubertal growth spurt. They had Class II Division 1 malocclusions and were selected from 800 children in neighborhood schools. They were randomly dichotomized into either the treated group (treated with the FR-II for 18 months) or the control group (not treated during the observation period). Our findings showed a low prevalence (3.57%) of disc displacement in the 112 temporomandibular joints. Mandibular propulsion with the FR-II had no unfavorable effect on the temporomandibular joints of the treated group; 100% of the patients kept an upper and interposed disc position (closed and open mouth, respectively) at T1 and T2. The control group had 7.1% partial anterior medial disc displacement, both at T1 and T2. Regarding disc morphology, the control group showed biconcave-shaped discs in 82.1% of the joints, statistically similar to the treated group (89.3%) at the beginning of the observation period. At T2, the articular disc morphology of the control group was unchanged, but that of the treated group was significantly more normal (P = .016), progressing from nonbiconcave at T1 (10.7%) to biconcave at T2 (100%). Our results showed that disc displacement is not a complication of functional appliance therapy; in fact, such treatment might help some children with incipient temporomandibular disorders. (Am J Orthod Dentofacial Orthop 2002;121:447-57)

Discussion

The authors' observation of the presence of elastic and oxytalan fibers running parallel to the collagen bundles in the human temporomandibular disc confirms our prior observation using similar staining methods. 1 Helmy E Larke V Bays R et al. Identification of elastic and oxytalan fibers in human cadaver TMJ. J Dent Res. 1984; 63: 228 Google Scholar Unlike the course and much more abundant elastic fibers in the bilaminar zone and collateral ligaments, the elastic fibers in normal human discs are much finer and require higher magnification to visualize under the light microscope 1 Helmy E Larke V Bays R et al. Identification of elastic and oxytalan fibers in human cadaver TMJ. J Dent Res. 1984; 63: 228 Google Scholar .

Ultrastructure of collagen fibers and distribution of extracellular matrix in the temporomandibular disk of the human fetus and adult.

We quantitatively examined the distribution of these differences in extracellular matrices (collagen types I, III, and fibronectin) and elastic fibers under confocal laser scanning microscopy and electron scanning microscopy in terms of their contribution to the mechanics of the TMJ during development and in adults. Elastic fibers were found in the anterior and posterior bands in adults aged 40 years, and a few elastic fibers in the anterior band of the disk in adults aged 80 to 90 years. The extracellular matrix contents of the TMJ disk are shown in various detected levels in the anterior, intermediate, posterior bands of TMJ disk. During development, collagen fibers are arranged in a complex fashion from 28 weeks' gestation. These ultrastructures of the embryonic TMJ are resembled to that of adults aged the 40s, however the difference in extracellular matrix distribution found in embryonic stages and adults. They might reflect the differences in function between mastication and sucking or the changes in shape and form as results of functional disorders of the TMJ.

Comparative Study of Repositioning Splint Therapy and Passive Manual Range of Motion Techniques for Anterior Displaced Temporomandibular Discs with Unstable Excursive Reduction

Summary Background The purpose of this study was to compare two treatment methods: Mobilisation with active exercises, and soft repositioning splinting, as treatment protocols for relief of symptoms secondary to anterior displaced temporo- mandibular disc (ADTMD) syndrome. Methods Thirty-six individuals between 19 and 43 years old with ADTMD participated in this study. Eighteen patients were chosen randomly to receive four weeks of treatment with a soft repositioning splint, and the other 18 received passive mobilisation and active exercises. All subjects were assessed for active range of motion for maximum mouth opening and pain levels, which were measured according to the pain-physiopathology instrument, before and after treatment. Results The manual mobilisation with exercises group demonstrated a significant decrease in total pain level (p Conclusion This study suggests that manual mobilisation and active exercises are more effective for treatment of pain and range of motion deficits associated with ADTMD, than soft repositioning splint therapy. These improvements do not necessarily mean that the disorder is cured.

A comparative study on meniscectomy and autogenous graft replacement of the rhesus monkey temporomandibular joint articular disc - Part II

This study investigated the effects of free auricular cartilage and pedicled temporalis myofascial flap replacement of the temporomandibular joint articular disc in eight rhesus monkeys (Macaca mulatta). The eight animals were divided into two groups (four animals in each group) for replacement of the disc with either auricular cartilage graft or pedicled temporalis myofascial graft. Degenerative changes (osteoarthritis) were observed in all the experimental joints. Despite degeneration of grafted cartilage tissue, histologic and clinical responses after auricular cartilage grafting were favourable. Pedicled temporalis myofascial flap resulted in re-formation of a disc-like interpositional structure in most of the studied joints with the most favourable histologic response.

Evaluation of position and configuration of the temporomandibular disk in asymptomatic adult volunteers using MR image

Evaluation of position and configuration of the temporomandibular disk in asymptomatic adult volunteers using MR image

The distribution of the auriculotemporal nerve around the temporomandibular joint

Objective. The purpose of this cadaver dissection was to study the position of the auriculotemporal nerve in relation to the mandibular condyle, capsular tissues, articular fossa, and lateral pterygoid muscle and to evaluate the anatomic possibility of nerve impingement or irritation by the surrounding structures. Study design. Eight cadaveric heads (16 sides) were dissected. The auriculotemporal nerve was identified by following its course around the middle meningeal artery. The course of the nerve trunk was dissected from the middle meningeal artery to the terminal branches within the temporomandibular disk. The horizontal distance between the auriculotemporal nerve and the medial portion of the condyle/condylar neck was measured. The vertical distance from the most superior portion of the articular condyle to the superior border of the auriculotemporal nerve was measured. Results. The auriculotemporal nerve was identified on each side, and a single trunk was evident along the medial aspect of the condylar neck. At the posterior border of the lateral pterygoid muscle, the nerve trunk was in direct contact with the condylar neck in every specimen. The average vertical distance between the superior condyle and the nerve was 7.06 mm (± 3.21 mm); the range was 0 to 13 mm. The vertical distance between the nerve and the superior condyle on one side of the specimen did not correlate with the distance on the contralateral side. Conclusion. The auriculotemporal nerve trunk has a close anatomic relationship with the condyle and the temporomandibular joint capsular region, and there is evidence of a possible mechanism for sensory disturbances in the temporomandibular joint region. In all cases, the nerve was in direct contact with the medial aspect of the capsule or condylar neck. Because there is no correlation between the positions of the nerves on the right and left sides, only one side may be affected. The nerve was also observed to course in direct apposition to the lateral pterygoid muscle. The findings support the hypothesis that the anatomic and clinical relationship of the auriculotemporal nerve to the condyle, articular fossa, and lateral pterygoid muscle may be causally related to compression or irritation of the nerve, producing numbness or pain, or both, in the temporomandibular joint region.

TMJ internal derangement and adolescent craniofacial morphology: a pilot study.

Intrinsic and extrinsic factors influence the growth of mandibular condylar cartilage. Local environmental factors, such as temporomandibular disc displacement, may alter condylar cartilage growth resulting in facial changes. The aim of this study was to determine if there was an association between identifiable altered craniofacial morphology and disc displacement. Magnetic resonance imaging (MRI) was employed to determine disc position in 25 preorthodontic adolescent patients (mean age 12.8 years, range 10 to 17 years). Magnetic resonance imaging and lateral cephalometric radiography were performed with the teeth held in centric occlusion by means of a polyvinylsiloxane bite registration. Radiographs were traced and variability between tracings within patients was insignificant for all variables (p > 0.04) except Co-Go, S-Go, and SN/Go-Me (p < 0.01). For each patient, 10 linear, 4 angular, and 3 ratio measurements were compared with an age- and sex-matched population in the Craniofacial Growth Series. Multiple regression analysis showed positive and negative associations between disc displacement and cephalometric variables. R-square value was .91 for the left TMJ and .82 for the right. Disc displacement in an adolescent population may be associated with altered craniofacial morphology.