Assessment of reference areas for superimposition of serial 3D models of patients with advanced periodontitis for volumetric soft tissue evaluation

Purpose. To evaluate the soft tissue stability around single implants inserted to replace maxillary lateral incisors, using an innovative 3D method.Methods. We have used reverse-engineering software for the superimposition of 3D surface models of the dentogingival structures, obtained from intraoral scans of the same patients taken at the delivery of the final crown (S1) and 2 years later (S2). The assessment of soft tissues changes was performed via calculation of the Euclidean surface distances between the 3D models, after the superimposition of S2 on S1; colour maps were used for quantification of changes.Results. Twenty patients (8 males, 12 females) were selected, 10 with a failing/nonrestorable lateral incisor (testgroup: immediate placement in postextraction socket) and 10 with a missing lateral incisor (controlgroup: conventional placement in healed ridge). Each patient received one immediately loaded implant (Anyridge®, Megagen, Gyeongbuk, South Korea). The superimposition of the 3D surface models taken at different times (S2 over S1) revealed a mean (±SD) reduction of 0.057 mm (±0.025) and 0.037 mm (±0.020) fortestandcontrolpatients, respectively. This difference was not statistically significant (p= 0.069).Conclusions. The superimposition of the 3D surface models revealed an excellent peri-implant soft tissue stability in both groups of patients, with minimal changes registered along time.

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Rhinoplasty Pre-Surgery Models by Using Low-Dose Computed Tomography, Magnetic Resonance Imaging, and 3D Printing

Dose-Response ◽

10.1177/15593258211060950 ◽

2021 ◽

Vol 19 (4) ◽

pp. 155932582110609

Author(s):

Dario Baldi ◽

Luca Basso ◽

Gisella Nele ◽

Giovanni Federico ◽

Giuseppe Walter Antonucci ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Soft Tissue ◽

Surgical Planning ◽

Low Dose ◽

3D Models ◽

Surgical Reconstruction ◽

Acquisition Time ◽

Resonance Imaging ◽

Expert Radiologist

Rhinoplasty and surgical reconstruction of cartilaginous structures still remain a great challenge today. This study aims to identify an imaging strategy in order to merge the information from CT scans and magnetic resonance imaging (MRI) acquisitions and build a 3D printed model true to the patient’s anatomy, for better surgical planning. Using MRI, information can be obtained about the cartilage structures of which the nose is composed. Ten rhinoplasty candidate patients underwent both a low-dose protocol CT scan and a specific MRI for characterization of nasal structures. Bone and soft tissue segmentations were performed in CT, while cartilage segmentations were extrapolated from MRI and validated by both an expert radiologist and surgeon. Subsequently, a 3D model was produced in materials and colors reproducing the density of the three main structures (bone, soft tissue, and cartilage), useful for pre-surgical evaluation. This study has highlighted that the optimization of a CT and MR dedicated protocol has allowed to reduce the CT radiation dose up to 60% compared to standard acquisitions with the same machine, and MR acquisition time of about 20%. Patient-tailored 3D models and pre-surgical planning have reduced the mean operative time by 20 minutes.

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Comparison between 2D and 3D Simulation of Contact of Two Deformable Axisymmetric Bodies

International Journal of Nonlinear Sciences and Numerical Simulation ◽

10.1515/ijnsns-2018-0157 ◽

2020 ◽

Vol 21 (2) ◽

pp. 123-133

Author(s):

Marat Dosaev ◽

Vitaly Samsonov ◽

Vladislav Bekmemetev

Keyword(s):

Soft Tissue ◽

Soft Tissues ◽

Tactile Sensor ◽

3D Models ◽

The Finite Element Method ◽

Current Version ◽

Local Stiffness ◽

2D And 3D ◽

Axisymmetric Bodies ◽

Range Of Values

AbstractA portable pneumatic video-tactile sensor for determining the local stiffness of soft tissue and the methodology for its application are considered. The expected range of local elastic modulus that can be estimated by the sensor is 100 kPa–1 MPa. The current version of the device is designed to determine the characteristics of tissues that are close in mechanical properties to the skin with subcutis and muscles. A numerical simulation of the contact between the sensor head and the soft tissue was performed using the finite-element method. Both 2D and 3D models were developed. Results of experiments with device prototype are used for approval of adequacy of mathematical modelling in case of large deformations. Simulation results can be used to create soft tissue databases, which will be required to determine the local stiffness of soft tissues by the sensor. 2D model proved to be more efficient for the chosen range of values of local stiffness of soft tissues.

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Parametrizing the genioplasty: a biomechanical virtual study on soft tissue behavior

International Journal of Computer Assisted Radiology and Surgery ◽

10.1007/s11548-021-02489-9 ◽

2021 ◽

Author(s):

F. Ruggiero ◽

G. Badiali ◽

M. Bevini ◽

C. Marchetti ◽

J. Ong ◽

...

Keyword(s):

Soft Tissue ◽

Vertical Displacement ◽

3D Models ◽

Tissue Response ◽

The Face ◽

Osteotomy Plane ◽

Bony Segment ◽

Soft Tissue Changes ◽

Soft Tissue Response ◽

Experimental Findings

Abstract Purpose Sliding genioplasty is used to surgically correct a retruded or misaligned chin: in this procedure, an osteotomy is performed and the bony segment is repositioned. In this study we investigate the effect of surgical parameters (bony segment movement, osteotomy design) on postop soft tissue changes in a patient cohort. Methods Seven patients were retrospectively recruited. Cone beam computed tomography data were obtained and soft tissue and bone shape reconstructions were performed. 3D models were created and surgical cuts were replicated according to postop scans. Each model was imported in ANSYS 2019R1 (Ansys Inc, USA) for simulation: the effect of variation in osteotomy plane as well as extent of bony segment movement were assessed by means of design of experiment: surgical parameters were varied in a surgically acceptable range and the soft tissue predictions were evaluated as displacement output of five craniometric landmarks. Results Simulation results show the overall changes of the lower third of the face are sensitive to changes in horizontal and vertical displacement of the bony segment as well as segment rotation. No significant changes in the soft tissue response were to attribute to the osteotomy design. Conclusions Our results are consistent with experimental findings reported in the literature: when planning genioplasty in orthognathic surgery, particular focus on the segment movement (horizontal translation, vertical translation and rotation), rather than on the design of the osteotomy itself, should be considered.

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Localization of Gallium-67 in Peritoneal Cells by Electron Microscopic Autoradiography

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100072460 ◽

1973 ◽

Vol 31 ◽

pp. 404-405

Author(s):

D. C. Swartzendruber ◽

Norma L. Idoyaga-Vargas

Keyword(s):

Clinical Trials ◽

Soft Tissue ◽

Tumor Tissue ◽

Soft Tissue Tumors ◽

Clinical Usefulness ◽

Electron Microscopic ◽

Normal Cells ◽

Electron Microscopic Autoradiography ◽

Peritoneal Cells ◽

Gallium 67

The radionuclide gallium-67 (67Ga) localizes preferentially but not specifically in many human and experimental soft-tissue tumors. Because of this localization, 67Ga is used in clinical trials to detect humar. cancers by external scintiscanning methods. However, the fact that 67Ga does not localize specifically in tumors requires for its eventual clinical usefulness a fuller understanding of the mechanisms that control its deposition in both malignant and normal cells. We have previously reported that 67Ga localizes in lysosomal-like bodies, notably, although not exclusively, in macrophages of the spocytaneous AKR thymoma. Further studies on the uptake of 67Ga by macrophages are needed to determine whether there are factors related to malignancy that might alter the localization of 67Ga in these cells and thus provide clues to discovering the mechanism of 67Ga localization in tumor tissue.

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Morphological Examination of a Herpes-type Virus Indigenous for Tree Shrews

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100067790 ◽

1970 ◽

Vol 28 ◽

pp. 160-161

Author(s):

J. P. Brunschwig ◽

R. M. McCombs ◽

R. Mirkovic ◽

M. Benyesh-Melnick

Keyword(s):

Electron Microscopy ◽

Soft Tissue ◽

Chick Embryo ◽

Soft Tissue Sarcoma ◽

Cell Cultures ◽

Tree Shrew ◽

Type Virus ◽

Morphological Examination ◽

Tree Shrews ◽

Embryo Cells

A new virus, established as a member of the herpesvirus group by electron microscopy, was isolated from spontaneously degenerating cell cultures derived from the kidneys and lungs of two normal tree shrews. The virus was found to replicate best in cells derived from the homologous species. The cells used were a tree shrew cell line, T-23, which was derived from a spontaneous soft tissue sarcoma. The virus did not multiply or did so poorly for a limited number of passages in human, monkey, rodent, rabbit or chick embryo cells. In the T-23 cells, the virus behaved as members of the subgroup B of herpesvirus, in that the virus remained primarily cell associated.

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