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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