Component approach to the temporomandibular joint and coronoid process.
Ontology highlight
ABSTRACT:
SUBMITTER: Pfaff MJ
PROVIDER: S-EPMC4221151 | biostudies-other | 2014 Dec
REPOSITORIES: biostudies-other
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Project description:ObjectiveTo evaluate the changes in the jaws and the upper airways of unilateral temporomandibular joint ankylosis patients who underwent condylar reconstruction via autogenous coronoid process grafts using cone-beam computed tomography (CBCT).Study designThe 27 included patients underwent CBCT examinations at three stages: T0 (within two weeks before surgery), T1 (two weeks after surgery), and T2 (an average of 13 months after surgery). Forty items related to the maxillofacial hard tissues and the upper airway collected at the three times and the coronoid process graft volumes after surgery were compared.ResultsSome integral items related to the mandibular hard tissues exhibited statistical difference shortly after surgery. Some integral items related to maxillofacial hard tissues changing obviously long period after surgery may result from graft remodeling. Asymmetry-related item regarding local neo-condyle and some airway items were significantly different between T0 and T1. Due to variations in graft remodeling, some related local asymmetry items and airway items differed significantly between T0 and T2.ConclusionsAnteriorly and inferiorly located neo-condyles and a trend toward the pronation of the mandible were observed and the narrowness of the upper airway was improved shortly after surgery. The grafts remodeled differently and some integral and asymmetry items related to neo-condyle changed. The improvements in the upper airway were slightly reduced.
| S-EPMC5336251 | biostudies-literature
Project description:The temporomandibular joint (TMJ) is anatomically complex; with its close proximity to neurovascular structures, including the facial nerve that gives a high degree of difficulty during surgical exposure. When the first description on TMJ surgery by Orlow in 1913 was published it gave an account describing the basic retroauricular, preauricular, endoaural and submandibular approaches, on treatment of articular pathologies as used today. The proposed study of the 'Bat Wing' approach, first described in 1993 by Garcia y Sanchez J.M. as a surgical alternative, offers great advantages is that it avoids the section of the ear canal and provides a wide surgical field. The management of the proposed technique has wide application with multiple joints addressed, achieving major objectives such as avoiding facial nerve damage, as well as avoiding the section of the external auditory canal with an optimum visibility of the operative field.The Department of Maxillofacial Surgery National Medical Center XXI Century records over a period of approximately 18 months have completed twenty TMJ surgeries using the 'Bat Wing', approach.The bat wing approach is a surgical alternative that offers broad exposure of the surgical field in TMJ, it is effective and meets the goal of exposing the area to intervene safely, good visibility and access to the site to intervene. It perfectly fulfills the above described.
| S-EPMC4511896 | biostudies-other
Project description:Vertical malocclusion is a developmental condition, resulting from complex interactions among multiple etiological factors during the growth period. As a tricky dentofacial deformity clinically, long-face (LF) morphology is characterized by excessive vertical facial growth with severe disarrangement of jaws and teeth. Since the improvement of LF patients on facial profile and occlusion is often difficult and lacks long-term stability, it becomes important to unravel the etiology of LF pattern formation for early prevention and treatment. In the current studies, we identified a transgenic mouse model that exhibited a dysplastic coronoid process and LF morphology. Although the mutant mice exhibited jaw structures and occlusion comparable to controls at birth, they all acquired typical LF morphology with anterior open bite during postnatal growth, resembling clinical features of the selected skeletal class III patients. Since the coronoid process provides an insertion site for the temporalis attachment, we examined the initial development and differentiation of the temporalis and found identical results in both control and mutant mice before E17.5 when the temporal muscle makes attachment to the coronoid process. However, thereafter, we observed altered orientation and reduced size of the cross-sectional area of the temporalis in mutant mice, which persisted to the weaning stage. Biomechanical analysis and simulation modeling further support the idea that altered morphology of the coronoid process may impair the efficiency of the vertical temporalis contraction and appears to correlate with LF formation. Consistently, we present evidence that a dysplastic mandibular coronoid process was also seen in some human patients with skeletal III LF morphology. Taken together, the results presented in this study establish an association of the craniofacial bony structures with vertical patterning, which will have implications in earlier prediction for clinical precaution and intervention.
| S-EPMC7036511 | biostudies-literature
Project description:We conducted a genetic analysis of the developing temporo-mandibular joint (TMJ), a highly specialized synovial joint that permits movement and function of the mammalian jaw. First, we used laser capture microdissection to perform a genome-wide expression analysis of each of its developing components. The expression patterns of genes identified in this screen were examined in the TMJ and compared to other synovial joints including the shoulder joint and the hip joint. Striking differences were noted, indicating that the TMJ forms via a distinct molecular program. Several components of the Hedgehog (Hh) signaling pathway are among the genes identified in the screen, including Gli2, which is expressed specifically in the condyle and in the disk of the developing TMJ. We found that mice deficient in Gli2 display aberrant TMJ development such that the condyle loses its growth plate-like cellular organization and no disk is formed. In addition, we utilized a conditional strategy to remove activity of the Hh co-receptor encoded by Smo from chondrocyte progenitors. This cell autonomous loss of Hh signaling allows for disk formation, but the resulting structure fails to separate from the condyle. Thus, these experiments establish that Hh signaling acts at two distinct steps in disk morphogenesis, condyle initiation and disk-condyle separation, and provide a molecular framework for future studies of the TMJ. Experiment Overall Design: Mouse embryos fresh frozen and TMJ tissue captured by LCM. 3 samples in biological triplicate.
2009-10-23 | E-GEOD-17473 | biostudies-arrayexpress
Project description:The literature lacks a reliable holistic approach for the three-dimensional (3D) assessment of the temporomandibular joint (TMJ) including all three adaptive processes, which are believed to contribute to the position of the mandible: (1) adaptive condylar changes, (2) glenoid fossa changes, and (3) condylar positional changes within the fossa. Hence, the purpose of the present study was to propose and assess the reliability of a semi-automatic approach for a 3D assessment of the TMJ from cone-beam computed tomography (CBCT) following orthognathic surgery. The TMJs were 3D reconstructed from a pair of superimposed pre- and postoperative (two years) CBCT scans, and spatially divided into sub-regions. The changes in the TMJ were calculated and quantified by morphovolumetrical measurements. To evaluate the reliability, intra-class correlation coefficients (ICC) were calculated at a 95% confidence interval on the measurements of two observers. The approach was deemed reliable if the ICC was good (>0.60). Pre- and postoperative CBCT scans of ten subjects (nine female; one male; mean age 25.6 years) with class II malocclusion and maxillomandibular retrognathia, who underwent bimaxillary surgery, were assessed. The inter-observer reliability of the measurements on the sample of the twenty TMJs was good to excellent, ICC range (0.71-1.00). The range of the mean absolute difference of the repeated inter-observer condylar volumetric and distance measurements, glenoid fossa surface distance measurements, and change in minimum joint space distance measurements were (1.68% (1.58)-5.01% (3.85)), (0.09 mm (0.12)-0.25 mm (0.46)), (0.05 mm (0.05)-0.08 mm (0.06)) and (0.12 mm (0.09)-0.19 mm (0.18)), respectively. The proposed semi-automatic approach demonstrated good to excellent reliability for the holistic 3D assessment of the TMJ including all three adaptive processes.
| S-EPMC9959062 | biostudies-literature
Project description:The temporomandibular joint (TMJ) has many essential functions. None of its components are exempt from injury. Facial asymmetry, malocclusion, disturbances in growth, osteoarthritis, and ankylosis can manifest as complications from trauma to the TMJ. The goals of initial treatment include achievement of pretraumatic function, restoration of facial symmetry, and resolution of pain. These same objectives hold true for late repairs and reconstruction of the TMJ apparatus. Treatment is demanding, and with opposing approaches. The following article explores various treatment options for problems presenting as a result of a history of trauma to the TMJ.
| S-EPMC3052671 | biostudies-other
Project description:The goal of this paper is to review the advantages and disadvantages of the various treatment options of temporomandibular joint (TMJ) total joint replacement (TJR). TMJ articles published within the last 20 years were reviewed to collect the information on non-invasive and invasive TMD treatment methods. Recent technological advancements helped the evolution of treatment methods and offered significant value to TMD patients and surgeons. Considering the TMD levels, the therapeutic procedures can involve general health examiniations, physical therapy, medication, oral rehabilation or as an end stage clinical invention, temporomandibular joint replacement. In fact when intra-articular TMD is present, the effective treatment method appears to be TJR. However, concern for infection, material hypersensitivity, device longevity and screws loosening issues still exists. Further combined research utilizing the knowledge and expertise of, surgeons, material scientists, and bioengineers is needed for the development of improved TMD therapeutic treatment.
| S-EPMC6520419 | biostudies-literature
Project description:The aim of this article is to review temporomandibular joint symptoms as well as the effects of orthognathic surgery(OGS) on temporomandibular joint(TMJ). The causes of temporomandibular joint disease(TMD) are multifactorial, and the symptoms of TMD manifest as a limited range of motion of mandible, pain in masticatory muscles and TMJ, Joint noise (clicking, popping, or crepitus), myofascial pain, and other functional limitations. Treatment must be started based on the proper diagnosis, and almost symptoms could be subsided by reversible options. Minimally invasive options and open arthroplasty are also available following reversible treatment when indicated. TMD manifesting in a variety of symptoms, also can apply abnormal stress to mandibular condyles and affect its growth pattern of mandible. Thus, adaptive developmental changes on mandibular condyles and post-developmental degenerative changes of mandibular condyles can create alteration on facial skeleton and occlusion. The changes of facial skeleton in DFD patients following OGS have an impact on TMJ, masticatory musculature, and surrounding soft tissues, and the changes of TMJ symptoms. Maxillofacial surgeons must remind that any surgical procedures involving mandibular osteotomy can directly affect TMJ symptoms, thus pre-existing TMJ symptoms and diagnoses should be considered prior to treatment planning and OGS.
| S-EPMC4446569 | biostudies-literature
Project description:Craniofacial secondary cartilages of the mandibular condyle and temporomandibular joint (TMJ) eminence grow in response to the local mechanical environment. The intervening TMJ disc distributes normal loads over the cartilage surfaces and provides lubrication. A better understanding of the mechanical environment and its effects on growth, development, and degeneration of the TMJ may improve treatments aimed at modifying jaw growth and preventing or reversing degenerative joint disease (DJD). This review highlights data recorded in human subjects and from computer modeling that elucidate the role of mechanics in TMJ ontogeny. Presented data provide an approximation of the age-related changes in jaw-loading behaviors and TMJ contact mechanics. The cells of the mandibular condyle, eminence, and disc respond to the mechanical environment associated with behaviors and ultimately determine the TMJ components' mature morphologies and susceptibility to precocious development of DJD compared to postcranial joints. The TMJ disc may be especially prone to degenerative change due to its avascularity and steep oxygen and glucose gradients consequent to high cell density and rate of nutrient consumption, as well as low solute diffusivities. The combined effects of strain-related hypoxia and limited glucose concentrations dramatically affect synthesis of the extracellular matrix (ECM), which limit repair capabilities. Magnitude and frequency of jaw loading influence this localized in situ environment, including stem and fibrocartilage cell chemistry, as well as the rate of ECM mechanical fatigue. Key in vivo measurements to characterize the mechanical environment include the concentration of work input to articulating tissues, known as energy density, and the percentage of time that muscles are used to load the jaws out of a total recording time, known as duty factor. Combining these measurements into a mechanobehavioral score and linking these to results of computer models of strain-regulated biochemical events may elucidate the mechanisms responsible for growth, maintenance, and deterioration of TMJ tissues.
| S-EPMC6151909 | biostudies-literature
Project description:Treatments for temporomandibular joint (TMJ) disc thinning and perforation, conditions prevalent in TMJ pathologies, are palliative but not reparative. To address this, scaffold-free tissue-engineered implants were created using allogeneic, passaged costal chondrocytes. A combination of compressive and bioactive stimulation regimens produced implants with mechanical properties akin to those of the native disc. Efficacy in repairing disc thinning was examined in minipigs. Compared to empty controls, treatment with tissue-engineered implants restored disc integrity by inducing 4.4 times more complete defect closure, formed 3.4-fold stiffer repair tissue, and promoted 3.2-fold stiffer intralaminar fusion. The osteoarthritis score (indicative of degenerative changes) of the untreated group was 3.0-fold of the implant-treated group. This tissue engineering strategy paves the way for developing tissue-engineered implants as clinical treatments for TMJ disc thinning.
| S-EPMC6553461 | biostudies-literature