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Journal of Biomechanics Oct 2020Motion of the mandible and temporomandibular joint (TMJ) plays a pivotal role in the function of the dentition and associated hard and soft tissue structures, and...
Motion of the mandible and temporomandibular joint (TMJ) plays a pivotal role in the function of the dentition and associated hard and soft tissue structures, and facilitates mastication, oral communication and access to respiratory and digestive systems. Quantification of TMJ kinematics is clinically relevant in cases of prosthetic rehabilitations, TMJ disorders, osteoarthritis, trauma, tumour resection and congenital abnormalities, which are known to directly influence mandibular motion and loading. The objective of this systematic review was to critically investigate published literature on historic and contemporary measurement modalities used to quantify in vivo mandibular and TMJ kinematics in six degrees of freedom. The electronic databases of Scopus, Web of Science, Medline, Embase and Central were searched and 109 relevant articles identified. Publication quality was documented using a modified Downs and Black checklist. Axiography and ultrasonic tracking are commonly employed in the clinical setting due to their simplicity and capacity to rapidly acquire low-fidelity mandibular motion data. Magnetic and optoelectronic tracking have been used in combination with dental splints to produce higher accuracy measurements while minimising skin motion artefact, but at the expense of setup time and cost. Four-dimensional computed tomography provides direct 3D measurement of mandibular and TMJ motion while circumventing skin motion artefact entirely, but employs ionising radiation, is restricted to low sampling frequencies, and requires time-consuming image processing. Recent advances in magnetic tracking using miniature sensors adhered to the teeth in combination with intraoral scanning may facilitate rapid and high precision mandibular kinematics measurement in the clinical setting. The findings of this review will guide selection and application of mandibular and TMJ kinematic measurement for both clinical and research applications.
Topics: Biomechanical Phenomena; Mandible; Mandibular Condyle; Range of Motion, Articular; Temporomandibular Joint
PubMed: 32971491
DOI: 10.1016/j.jbiomech.2020.109994 -
Dento Maxillo Facial Radiology Jul 2020To critically synthesize the literature surrounding segmentation of the mandibular condyle using three-dimensional imaging modalities. Specifically, analyzing the...
OBJECTIVE
To critically synthesize the literature surrounding segmentation of the mandibular condyle using three-dimensional imaging modalities. Specifically, analyzing the reliability and accuracy of methods used for three-dimensional condyle segmentation.
METHODS
Three electronic databases were searched for studies reporting the reliability and accuracy of various methods used to segment mandibular condyles from three-dimensional imaging modalities. Two authors independently reviewed articles for eligibility and data extraction.
RESULTS
Nine studies fulfilled the inclusion criteria. Eight studies assessed the condylar segmentation from CBCT images and limited studies were available on non-CBCT three-dimensional imaging modalities. Threshold-based volume segmentation, manual segmentation, and semi-automatic segmentation techniques were presented. Threshold-based volume segmentation reported higher accuracy when completed by an experienced technician compared to clinicians. Adequate reliability and accuracy were observed in manual segmentation. Although adequate reliability was reported in semi-automatic segmentation, data on its accuracy were lacking.
CONCLUSION
A definitive conclusion with regards to which current technique is most reliable and accurate to efficiently segment the mandibular condyle cannot be made with the currently available evidence. This is especially true in terms of non-CBCT imaging modalities with very limited literature available.
Topics: Cone-Beam Computed Tomography; Imaging, Three-Dimensional; Mandibular Condyle; Reproducibility of Results
PubMed: 31778321
DOI: 10.1259/dmfr.20190150 -
International Journal of Oral and... Feb 2020Orthognathic surgery involving the mandible can lead to remodelling of the temporomandibular joint (TMJ). Cone beam computed tomography (CBCT) provides an easily...
Orthognathic surgery involving the mandible can lead to remodelling of the temporomandibular joint (TMJ). Cone beam computed tomography (CBCT) provides an easily accessible three-dimensional (3D) approach to study this entity. A systematic review of the literature was performed with the aim of identifying condylar remodelling analysis protocols using CBCT-derived 3D models. The search yielded 10 eligible studies. The systematic review identified three pillars of a condylar remodelling analysis protocol that were retrievable from each of the included studies: (1) registration, (2) segmentation, and (3) analysis. The studies lacked consensus on how these pillars should be transferred to their respective protocol. Through critical assessment, criteria for a universal condylar remodelling analysis are suggested: (1) performance of a regional voxel-based registration of baseline and postoperative CBCT scans using an anatomical region not prone to postoperative changes, (2) application of a (semi-)automated 3D segmentation algorithm, (3) performance of a combination of both volumetric and surface-based 3D condylar analysis, and (4) extensive validation of each step of the protocol. The homogenization of condylar remodelling analysis protocols and their incorporation into virtual planning software suites raises the potential for the inclusion of larger numbers of patients in future prospective studies in order to gain evidence-based data.
Topics: Cone-Beam Computed Tomography; Humans; Imaging, Three-Dimensional; Mandibular Condyle; Orthognathic Surgery; Orthognathic Surgical Procedures; Prospective Studies
PubMed: 31221473
DOI: 10.1016/j.ijom.2019.05.009 -
Developmental Dynamics : An Official... Feb 2019Mandibular disorders are among the most common birth defects in humans, yet the etiological factors are largely unknown. Most of the neonates affected by mandibular...
Mandibular disorders are among the most common birth defects in humans, yet the etiological factors are largely unknown. Most of the neonates affected by mandibular abnormalities have a sequence of secondary anomalies, including airway obstruction and feeding problems, that reduce the quality of life. In the event of lacking corrective surgeries, patients with mandibular congenital disorders suffer from additional lifelong problems such as sleep apnea and temporomandibular disorders, among others. The goal of this systematic review is to gather evidence on hormonal and genetic factors that are involved in signaling pathways and interactions that are potentially associated with the nonsyndromic mandibular disorders. We found that members of FGF and BMP pathways, including FGF8/10, FGFR2/3, BMP2/4/7, BMPR1A, ACVR1, and ACVR2A/B, have a prominent number of gene-gene interactions among all identified genes in this review. Gene ontology of the 154 genes showed that the functional gene sets are involved in all aspects of cellular processes and organogenesis. Some of the genes identified by the genome-wide association studies of common mandibular disorders are involved in skeletal formation and growth retardation based on animal models, suggesting a potential direct role as genetic risk factors in the common complex jaw disorders. Developmental Dynamics 248:162-172, 2019. © 2018 Wiley Periodicals, Inc.
Topics: Bone Morphogenetic Proteins; Fibroblast Growth Factors; Gene Regulatory Networks; Genome-Wide Association Study; Hormones; Humans; Mandible; Mandibular Diseases; Signal Transduction
PubMed: 30576023
DOI: 10.1002/dvdy.8 -
Medicina Oral, Patologia Oral Y Cirugia... Nov 2018Bifid mandibular condyle (BMC) constitutes an extremely rare disorder characterized by a duplication of the head of the mandibular condyle. Its prevalence ranges from...
BACKGROUND
Bifid mandibular condyle (BMC) constitutes an extremely rare disorder characterized by a duplication of the head of the mandibular condyle. Its prevalence ranges from 0.31% to 1.82% in the published literature.
OBJECTIVES
The primary objective was to describe the main etiological, clinical and radiological characteristics of patients with BMCs and the existent treatment options. The secondary objective was to simultaneously include the characteristics of two new cases of BMC.
MATERIAL AND METHODS
An electronic search in Pubmed (MEDLINE), Scopus and The Cochrane Library was carried out by two independent reviewers until April 2018. Prospective or retrospective cohort studies, case series and case reports describing clinical and/or radiological characteristics of patients with BMC were included. Registered variables were demographic, etiological factors, diagnostic exam, clinical characteristics and treatment options. The results from the articles selected were organized in a Table along with the characteristics of two new cases of BMC provided by the authors.
RESULTS
From a total of 431 articles found in the initial search, 68 articles were finally included. This systematic review included 216 patients and 270 BMC with an average age of 30.6 (SD=14.7) years and a women:men ratio of 1.4:1. Mediolateral condylar orientation was the most prevalent position (80.1%). Among cases with known etiology, 40.8% of cases had a history of traumatism, while 55.9% did not present any relevant medical background. Half of the symptomatic cases had history of trauma. The most common symptoms were hypomobility (22.7%), arthralgia (18.1%), articular noise (17.2%) and ankylosis (17.6%). Active monitoring and manufacturing an occlusal splint were the most frequent treatment options.
CONCLUSIONS
BMC may have congenital or traumatic etiology. Hypomobility and arthralgia are the most frequent symptoms and treatment options are often conservative.
Topics: Congenital Abnormalities; Female; Humans; Male; Mandibular Condyle; Middle Aged
PubMed: 30341271
DOI: 10.4317/medoral.22681 -
International Journal of Oral and... Feb 2019After orthognathic surgery for class II dentofacial deformity, remodelling of the mandibular condyle will take place. In a number of cases, this may evolve towards a...
After orthognathic surgery for class II dentofacial deformity, remodelling of the mandibular condyle will take place. In a number of cases, this may evolve towards a phenomenon of condylar resorption. Yet, studies on the occurrence of this complication after the correction of a class III deformity are scarce. A systematic review of the literature was performed with the aim of identifying reports on condylar resorption or remodelling after orthognathic surgery for class III dentofacial deformity. A search of the international databases yielded 12 eligible studies. Eight studies reported some degree of postoperative condylar remodelling, while symptoms of condylar resorption were only described in a limited group of patients. Thus, the literature may show evidence of condylar remodelling after orthognathic treatment of class III patients, and anecdotal reports of condylar resorption exist. The small sample sizes, heterogeneity in methods and outcomes, and use of two-dimensional radiographs indicate the need for updated long-term research. In the future, the use of cone beam computed tomography data for volumetric and morphological condylar analysis in combination with three-dimensional cephalometry may provide the opportunity to further elucidate this phenomenon and better characterize its aetiology.
Topics: Bone Remodeling; Bone Resorption; Humans; Malocclusion, Angle Class III; Mandibular Condyle; Orthognathic Surgical Procedures
PubMed: 30007835
DOI: 10.1016/j.ijom.2018.06.008 -
Archives of Oral Biology Oct 2018The aim of this systematic review was to provide a comprehensive synthesis of available evidence evaluating the effect of dietary loading on temporomandibular... (Meta-Analysis)
Meta-Analysis Review
The impact of dietary consistency on structural craniofacial components: Temporomandibular joint/condyle, condylar cartilage, alveolar bone and periodontal ligament. A systematic review and meta-analysis in experimental in vivo research.
OBJECTIVE
The aim of this systematic review was to provide a comprehensive synthesis of available evidence evaluating the effect of dietary loading on temporomandibular joint/condyle, condylar cartilage, alveolar bone of the mandible and the periodontal ligament in healthy mice and rats.
DESIGN
Medline via PubMed, EMBASE and Open Grey databases were searched for published and unpublished literature. Search terms included "mandiblular condyle", "alveolar bone", "temporomandibular joint", "condylar cartilage", "periodontal ligament", "rat", "mice". After data extraction, risk of bias (SYRCLE) and reporting quality (ARRIVE) were assessed. Random effects meta-analyses were performed for the outcomes of interest where applicable.
RESULTS
A total of 33 relevant articles were considered in the systematic review, while only 6 studies were included in the quantitative synthesis. Risk of Bias in all studies was judged to be unclear to high overall, while reporting quality was suboptimal. Comparing soft to hard diet animals, significantly reduced anteroposterior condylar length (4 studies, weighted mean difference: -0.40 mm; 95% CI: -0.47, -0.32; p < 0.001) and width (4 studies, weighted mean difference: -0.043 mm; 95% CI: -0.51, -0.36; p < 0.001) were found in rats. Decreased anteroposterior condylar dimensions were detected for mice as well (2 studies, weighted mean difference: -0.049; 95% CI: -0.56, -0.43; p < 0.001).
CONCLUSIONS
Overall, there was strong evidence to suggest a significant effect of soft diet on reduced condylar dimensions in rodents; however, there is need for further high quality experimental studies to inform current knowledge on condylar cartilage, alveolar bone and periodontal ligament related outcomes.
Topics: Animal Feed; Animals; Cartilage, Articular; Databases, Factual; Diet; Mandible; Mandibular Condyle; Mice; Periodontal Ligament; Rats; Temporomandibular Joint
PubMed: 29957455
DOI: 10.1016/j.archoralbio.2018.06.016 -
Medicina Oral, Patologia Oral Y Cirugia... Sep 2016Although many orthodontists have no doubts about the effectiveness of functional appliances for mandibular advancement, the impact on the temporomandibular joint (TMJ)... (Review)
Review
BACKGROUND
Although many orthodontists have no doubts about the effectiveness of functional appliances for mandibular advancement, the impact on the temporomandibular joint (TMJ) is still in dispute. The objective of this systematic review is to examine the main effects on the TMJ of using functional appliances, both in healthy patients and in patients with a pre-existing disorder.
MATERIAL AND METHODS
A systematic review of the literature was conducted in accordance with the PRISMA guidelines. Only systematic reviews, meta-analyses, randomized clinical trials (RCTs), case-control studies and cohort studies were included. A detailed language-independent electronic search was conducted in the Pubmed, Scopus, Cochrane Library and Embase databases. All studies published between 2000 and 2015 were included.
RESULTS
A total of 401 articles were identified. Of these, 159 were duplicates and were excluded. On reading the title and abstract, 213 articles were excluded because they did not answer the research question, leaving a total of 29 articles. These articles were read and assessed. Following critical reading of the full text, eight articles were excluded: seven because they were considered of low quality and one because it published redundant data. As a result, 21 articles were included.
CONCLUSIONS
After treatment with functional appliances, the condyle was found to be in a more advanced position, with remodelling of the condyle and adaptation of the morphology of the glenoid fossa. No significant adverse effects on the TMJ were observed in healthy patients and the appliances could improve joints that initially presented forward dislocation of the disk.
Topics: Humans; Mandibular Advancement; Temporomandibular Joint; Temporomandibular Joint Disorders
PubMed: 27475694
DOI: 10.4317/medoral.21180 -
European Journal of Orthodontics Jun 2017To systematically search the literature and assess the available evidence regarding the incidence and quantification of condylar resorption following bilateral sagittal... (Review)
Review
OBJECTIVE
To systematically search the literature and assess the available evidence regarding the incidence and quantification of condylar resorption following bilateral sagittal split osteotomy (BSSO) of the mandible in orthognathic patients.
SEARCH METHODS
Electronic database searches of published and unpublished literature were performed. The reference lists of eligible studies were hand searched for additional studies.
SELECTION CRITERIA
Randomized clinical trials (RCTs), prospective, and retrospective studies with patients of any age that underwent BSSO were included.
DATA COLLECTION AND ANALYSIS
Study selection, data extraction, and risk of bias assessment were performed individually and in duplicate.
RESULTS
One RCT, 3 prospective, and 10 retrospective studies were included in this review. The lack of standardized protocols and the high amount of heterogeneity precluded a valid interpretation of the actual results through pooled estimates. There was a substantial consistency among studies, however, that young, female patients with mandibular deficiency and high mandibular plane angle, submitted to surgical counterclockwise rotation of mandibular segments, were more prone to a higher risk for condylar resorption after BSSO. The level of evidence was found to be low given the high/serious risk of bias in all included studies.
CONCLUSIONS
Condylar resorption should be taken into account as a potential postsurgical complication after BSSO. However, its incidence and quantification need precautious interpretation owing to the low level of evidence and the high heterogeneity of studies. Additional high-quality prospective research assisted by 3D imaging technology is needed to allow more definitive conclusions.
REGISTRATION
Study not registered.
CONFLICT OF INTEREST
None.
Topics: Bone Resorption; Humans; Malocclusion; Mandible; Mandibular Condyle; Mandibular Osteotomy; Orthognathic Surgical Procedures; Osteotomy, Sagittal Split Ramus; Research Design; Rotation
PubMed: 27334905
DOI: 10.1093/ejo/cjw045 -
Journal of Clinical and Experimental... Jul 2015The joint space measurements of the temporomandibular joint have been used to determine the condyle position variation. Therefore, the aim of this study is to perform a... (Review)
Review
INTRODUCTION
The joint space measurements of the temporomandibular joint have been used to determine the condyle position variation. Therefore, the aim of this study is to perform a systematic review and meta-analysis on the coronal joint spaces measurements of the temporomandibular joint.
MATERIAL AND METHODS
An electronic database search was performed with the terms "condylar position"; "joint space"AND"TMJ". Inclusionary criteria included: tomographic 3D imaging of the TMJ, presentation of at least two joint space measurements on the coronal plane. Exclusionary criteria were: mandibular fractures, animal studies, surgery, presence of genetic or chronic diseases, case reports, opinion or debate articles or unpublished material. The risk of bias of each study was judged as high, moderate or low according to the "Cochrane risk of bias tool". The values used in the meta-analysis were the medial, superior and lateral joint space measurements and their differences between the right and left joint.
RESULTS
From the initial search 2706 articles were retrieved. After excluding the duplicates and all the studies that did not match the eligibility criteria 4 articles classified for final review. All the retrieved articles were judged as low level of evidence. All of the reviewed studies were included in the meta-analysis concluding that the mean coronal joint space values were: medial joint space 2.94 mm, superior 2.55 mm and lateral 2.16 mm.
CONCLUSIONS
the analysis also showed high levels of heterogeneity. Right and left comparison did not show statistically significant differences. Key words:Temporomandibular joint, systematic review, meta-analysis.
PubMed: 26330944
DOI: 10.4317/jced.52439