The study was funded by the Beijing Municipal Science &#38; Technology Commission (No.Z181100001718078), China.

The present study was approved by the ethics committee of Beijing Friendship Hospital Capital Medical University.
1. Diagnosis of the osteoporotic vertebral compression fracture (OVCF) by X-ray fluoroscopy, magnetic resonance image (MRI), bone scintigraphy, and symptoms
<ol>
	<li>Identify patients who have OVCF by older patients with back pain, tenderness in the spinous process, paraspinal muscles at back, etc.</li>
	<li>Use posterioanterior X-ray fluoroscopy to check if patient has vertebral compression fracture.</li>
	<li>Use an MRI to diagnosis whether a patient has a newly onset vertebral compression fracture, and determine the target compressed vertebrae. For patients who cannot undergo the MRI, use bone scintigraphy.</li>
	<li>Order PVP treatment for the patient who has an acute vertebral compression fracture and record the Visual Analogue Scale (VAS) score and Oawestry Disability Index (ODI)8. 
	NOTE: There are a few criteria for inclusion: 1) vertebra fractured patient whether having history of a low-energy trauma or not; 2) no history or evidence of metabolic bone disease or cancer; 3) VAS score &#8805; 7; 4) diagnosis as vertebral fracture by X-ray, MRI or bone scintigraphy.</li>
</ol>
2. Preoperative localization of target vertebra
<ol>
	<li>Before the operation, conduct prone computer tomography on the patient with three radiopaque markers placed in the midline of patient&#39;s back skin at the compressed vertebral level. While pressing the most painful part, confirm the target area by x-ray fluoroscopy and a physical examination on the patient&#39;s back.</li>
	<li>Before the prone computer tomography scan, put a gradienter on the patient&#39;s back just inferior to the fixed markers. Record the patient&#39;s body position and then remove it. Have the patient stay in the same position during surgery.</li>
	<li>Save the CT images (1 mm scanning layer thickness, 1 mm layer spacing, and either 90 slices (conventional scanning) or 400 slices (thin slice scanning) in a DICOM format. Put a cotton pad on the patient&#39;s back to ensure that the markers remain until the operation.</li>
</ol>
3. Simulating the percutaneous vertebroplasty procedure in the computer software
<ol>
	<li>Export the CT images in DICOM format into medical imaging processing software (e.g., MIMICS) and select the target slices to reconstruct the compressed vertebra.</li>
	<li>Select Threshold Segmentation to adjust the threshold range for the target vertebra from 125-3071H and create a mask. Press Duplicate Mask to make two masks: Mask A and Mask B.</li>
	<li>Click Mask Edit to erase the target vertebra in Mask A. Then click Boolean Operations to form a new Mask C by using Mask B to minus Mask A. Press Calculate 3D from Mask to reconstruct the target vertebra.</li>
	<li>Simulate PVP via a bilateral transpedicular approach in the software. First, define the Medcad cylinder in the software as the puncture needle model. Define the cylinders as the same length and radius as the puncture needle (a length of 125 mm and a radius of 1.25 mm).</li>
	<li>Simulate the entry point, the entry angle (head inclination angle and abduction angle orientation), and the puncture needle depth for a real PVP with the 3-D views of the target vertebra.</li>
	<li>Adjust the puncture needles to its ideal position by using the Move and Rotate function. Keep needle trajectories consistent with these principles: 1) the puncture needles can extrapolate through the pedicle, preferably in its superior half; 2) the ideal location of the tips is at the point within the anterior one third of the vertebral body on the lateral view.</li>
</ol>
4. Three-dimensional printing guide template
<ol>
	<li>Save all of the 3D template data and send it in the MCS format to a three-dimensional printing company.</li>
	<li>Convert MCS format data into a STL format and design the template using software. Reconstruct the base, which must cling to patient&#39;s back skin, reconstruct the trajectory canal according to all of the parameters, including skin entry points, entry angles and the depth of the two needles&#39; trajectory, print two same templates out for the operation. 
	NOTE: The guide template is made from polylactic acid, which can be sterilized and by low temperature steam disinfection.</li>
</ol>
5. Applying the three-dimensional printing guide template to assist the real PVP operation
<ol>
	<li>Make the patient lie prone on the operation table as for the CT scanning in accordance with the gradienter record. Measure the distance of the three radiopaque markers and draw the outline of the three markers to match the template with the target location.</li>
	<li>Match a skin template along with the skin outline. Insert and press two swabs through the needle&#39;s trajectories on the template to mark the insertion points on the skin. Then remove the template and draw the points as point A and B.</li>
	<li>Remove the template and disinfect the skin. Drape the area and put the tips of two puncture needles at the insertion points (point A and B). Then, use the anteroposterior view of C-arm fluoroscopy to confirm whether the puncture points determined by template are feasible.</li>
	<li>Give the patient local anesthesia by injecting a 5 mL mixture of 1% lidocaine and 1% ropavicaine at each puncture point. Fix another sterilized template on the patient&#39;s back by sterilized film.</li>
	<li>Tap the two needles into the target vertebra slightly via insertions through the guiding cylinders of the template. Verify with the C-arm fluoroscope that the trajectories are suitable for insertion. Make sure that the punctuation is within the pedicles and then tap the needles to advance further until the end of the trajectory.</li>
	<li>When the whole needles are completely inserted into the guiding cylinders, verify with the C-arm fluoroscope that the needle tips have reached their ideal location.</li>
	<li>Inject bone cement into the vertebral body through the needles. Inject 2 mL of bone cement via each trajectory for a total of 4 mL of bone cement to the vertebra.</li>
	<li>Finally, use fluoroscopy to check the distribution of the bone cement within the vertebral body by anteroposterior and lateral views. Stitch the insertions.</li>
</ol>

<ol>
	<li>Orthopaedic Society of the Chinese Medical Association. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Guidelines+for+the+diagnosis+and+treatment+of+osteoporotic+fractures.">Guidelines for the diagnosis and treatment of osteoporotic fractures.</a> Chinese Journal of Orthopaedics. 37 (1), 1-10 (2017).</li><li>Yi, H. J., Jeong, J. H., Im, S. B., Lee, J. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Percutaneous+vertebroplasty+versus+conservative+treatment+for+one+level+thoracolumbar+osteoporotic+compression+fracture:+Results+of+an+over+2-year+follow-up.">Percutaneous vertebroplasty versus conservative treatment for one level thoracolumbar osteoporotic compression fracture: Results of an over 2-year follow-up.</a> Pain Physician. 19 (5), (2016).</li><li>Balkarli, H., Demirtas, H., Kilic, M., Ozturk, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Treatment+of+osteoporotic+vertebral+compression+fractures+with+percutaneous+vertebroplasty+under+local+anesthesia:+clinical+and+radiological+results.">Treatment of osteoporotic vertebral compression fractures with percutaneous vertebroplasty under local anesthesia: clinical and radiological results.</a> International Journal of Clinical &amp; Experimental Medicine. 8 (9), 16287-16293 (2015).</li><li>Woojin, C., Varkey, J. A., Jing, C., Hwan, B. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Review+of+Current+Clinical+Applications+of+Three+Dimensional+Printing+in+Spine+Surgery.">A Review of Current Clinical Applications of Three Dimensional Printing in Spine Surgery.</a> Asian Spine Journal. 12 (1), 171-177 (2018).</li><li>Laredo, J. D., Hamze, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Complications+of+percutaneous+vertebroplasty+and+their+prevention.">Complications of percutaneous vertebroplasty and their prevention.</a> Skeletal Radiology. 33 (9), 493-505 (2004).</li><li>Saracen, A., Kotwica, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Complications+of+percutaneous+vertebroplasty:+An+analysis+of+1100+procedures+performed+in+616+patients.">Complications of percutaneous vertebroplasty: An analysis of 1100 procedures performed in 616 patients.</a> Medicine. 95 (24), e3850 (2016).</li><li>Park, H. J., Wang, C., Choi, K. H., Kim, H. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+a+life-size+three-dimensional-printed+spine+model+for+pedicle+screw+instrumentation+training.">Use of a life-size three-dimensional-printed spine model for pedicle screw instrumentation training.</a> Journal of Orthopaedic Surgery and Research. 13 (1), 86 (2018).</li><li>Gu, Y. F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Percutaneous+vertebroplasty+and+interventional+tumor+removal+for+malignant+vertebral+compression+fractures+and/or+spinal+metastatic+tumor+with+epidural+involvement:+a+prospective+pilot+study.">Percutaneous vertebroplasty and interventional tumor removal for malignant vertebral compression fractures and/or spinal metastatic tumor with epidural involvement: a prospective pilot study.</a> Journal of Pain Research. 10, 211-218 (2017).</li><li>Ruiz, S. F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+review+of+vertebroplasty+and+kyphoplasty.">Comparative review of vertebroplasty and kyphoplasty.</a> World Journal of Radiology. 6 (6), 329-343 (2014).</li><li>Cannavale, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Percutaneous+vertebroplasty+with+the+rotational+fluoroscopy+imaging+technique.">Percutaneous vertebroplasty with the rotational fluoroscopy imaging technique.</a> Skeletal Radiology. 43 (11), 1529-1536 (2014).</li><li>Ringer, A. J., Bhamidipaty, S. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Percutaneous+access+to+the+vertebral+bodies:+a+video+and+fluoroscopic+overview+of+access+techniques+for+trans-,+extra-,+and+infrapedicular+approaches.">Percutaneous access to the vertebral bodies: a video and fluoroscopic overview of access techniques for trans-, extra-, and infrapedicular approaches.</a> World Neurosurgery. 80 (3-4), 428-435 (2013).</li><li>Kaneyama, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+screw+guiding+method+with+a+screw+guide+template+system+for+posterior+C-2+fixation.">A novel screw guiding method with a screw guide template system for posterior C-2 fixation.</a> Neurosurgery Spine. 21 (2), 231-238 (2014).</li><li>Sugawara, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multistep+pedicle+screw+insertion+procedure+with+patient-specific+lamina+fit-and-lock+templates+for+the+thoracic+spine.">Multistep pedicle screw insertion procedure with patient-specific lamina fit-and-lock templates for the thoracic spine.</a> Neurosurgery Spine. 19 (2), 185-190 (2013).</li><li>Li, J., Lin, J. 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The authors have no conflict of interest regarding any drugs, materials, or devices described in this study.

Percutaneous vertebroplasty (PVP) is considered one of the best methods to treat osteoporotic vertebral compression fracture9 due to some distinct advantages: it is minimally invasive; there is less bleeding, and recovery is rapid. Traditional PVP is primarily guided by a C-arm fluoroscope that requires repeated fluoroscopy to determine safe and ideal puncture points, puncture angles and orientations, which increases the intraoperative radiation dosage and the operation time10</s...

As the most common type fracture among all kinds of osteoporotic fractures, osteoporotic vertebral compression fracture (OVCF) is a highly concerning clinical problem nowadays. As current guidelines recommend, percutaneous vertebroplasty is one of the most effective minimally invasive methods to clinically treat osteoporotic vertebral compression fractures1.
Traditionally, surgeons perform percutaneous vertebroplasty guided by a C-arm fluoroscope to treat a vertebral compression fracture to restore the compressed vertebral body and relieve early-stage pain2. Even experienced surgeons make mistakes in confirming suitable puncturing points by simply relying on their personal experience. This operation could cause some puncture-related complications (e.g., cement leakage into surrounding tissues, nerve root injury, intra-spinal hematoma, etc.3,4,5); moreover, almost 50% of patients have local complications from traditional PVP with 95% of complications coming from cement leakage into surrounding tissue or embolization of paravertebral veins6. With the emergence of precision surgery, a 3-D printing guide template has been used in many spinal surgery operations7 because it can enhance the procedural accuracy, decreasing the difficulties and minimizing the operational risks. Here, we apply a 3-D printing guide template into the PVP to make the surgical procedure more precise and to decrease the rate of puncture-related complications. Compared with the traditional method, operations assisted by the 3D printing guide template have 1) increased surgical puncture accuracy, 2) minimized the radiation exposure during the operation, 3) shortened the surgical procedure time, and 4) decreased the probability of puncture-related complications.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>X-ray machine</td>
			<td>Company Philips</td>
			<td></td>
			<td>machine</td>
		</tr>
		<tr>
			<td>Magnetic resonance image machine</td>
			<td>Company GE</td>
			<td></td>
			<td>machine</td>
		</tr>
		<tr>
			<td>computer tomography</td>
			<td>Company GE</td>
			<td></td>
			<td>machine</td>
		</tr>
		<tr>
			<td>HORI 3D printing machine</td>
			<td>Company of Beijing Huitianwei Technology co. ltd.</td>
			<td></td>
			<td>machine</td>
		</tr>
		<tr>
			<td>Geomagic Design X</td>
			<td>3D Systems Company</td>
			<td></td>
			<td>software</td>
		</tr>
		<tr>
			<td>Materialise Interactive Medical Image Control System</td>
			<td>Materialise Company</td>
			<td></td>
			<td>software</td>
		</tr>
		<tr>
			<td>VertePort needle</td>
			<td>Stryker Company</td>
			<td></td>
			<td>operation appliance</td>
		</tr>
		<tr>
			<td>Spineplex</td>
			<td>Stryker Company</td>
			<td></td>
			<td>operation appliance</td>
		</tr>
		<tr>
			<td>Percutaneous Cement Delivery System</td>
			<td>Stryker Company</td>
			<td></td>
			<td>operation appliance</td>
		</tr>
		<tr>
			<td>Spirit Level Plus</td>
			<td>IOS App store</td>
			<td></td>
			<td>gradientor</td>
		</tr>
	</tbody>
</table>

three-dimensional printing guide template assisted percutaneous vertebroplasty (pvp)

Percutaneous vertebroplasty (PVP) is considered an effective treatment for the back pain caused by osteoporotic vertebral compression fracture. The accuracy of PVP mainly depends on the surgeons&#39; experience and multiple fluoroscopes during a traditional procedure. Puncture related complications were reported all over the world. To make the surgical procedure more precise and decrease the rate of puncture-related complications, our team applied a three-dimensional printing guide template to PVP to modify the traditional procedure. This protocol introduces how to model target vertebrae DICOM imaging data into three-dimensions in the software, how to simulate operation in this 3-D model, and how to use all of the surgical data to reconstruct a patient specific template for application. Using this template, surgeons can identify suitable puncture points accurately to improve the accuracy of the operation. The whole protocol includes: 1) diagnosis of the osteoporotic vertebral compression fracture; 2) acquisition of CT imaging of the target vertebra; 3) simulation of the operation in the software; 4) design and fabrication of the 3-D printing guide template; and 5) application of the template into an operation procedure.

Acquisition of CT images and digital modeling were performed in the hospital, while 3-D printing was performed in a 3-D printing company. Thirty minutes were needed to reconstruct the 3-D model from the CT images for the 3-D printing, and the 3-D printing company needed about 6 hours to print 2 guide templates out and send to the hospital.
The pre-operation images of the target vertebra of the patient were shown in <strong class...

Watch this Scientific Journal Video about Three-Dimensional Printing Guide Template Assisted Percutaneous Vertebroplasty PVP at JoVE.com

Three-Dimensional Printing Guide Template Assisted Percutaneous Vertebroplasty PVP

Herein, we present a three-dimensional printing guide template for percutaneous vertebraplasty. A patient with a T11 vertebral compression fracture was selected as a case study.

Three-Dimensional Printing Guide Template Assisted Percutaneous Vertebroplasty (PVP)

Percutaneous vertebroplasty (PVP) is considered an effective treatment for the back pain caused by osteoporotic vertebral compression fracture. The ...

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7.5K Views.  Capital Medical University. Herein, we present a three-dimensional printing guide template for percutaneous vertebraplasty. A patient with a T11 vertebral compression fracture was selected as a case study.

Video: Three-Dimensional Printing Guide Template Assisted Percutaneous Vertebroplasty PVP

Guide Wire Assisted Catheterization and Colored Dye Injection for Vascular Mapping of Monochorionic Twin Placentas

Monochorionic (MC) twin pregnancies are associated with significantly higher morbidity and mortality rates than dichorionic twins. Approximately 50% of MC twin pregnancies develop complications arising from the shared placenta and associated vascular connections1. Severe twin-to-twin syndrome (TTTS) is reported to account for approximately 20% of these complications2,3. Inter-twin vascular connections occur in almost all MC placentas and are related to the prognosis and outcome of these high-risk twin pregnancies. The number, size and type of connections have been implicated in the development of TTTS and other MC twin conditions. Three types of inter-twin vascular connections occur: 1) artery to vein connections (AVs) in which a branch artery carrying deoxygenated blood from one twin courses along the fetal surface of the placenta and dives into a placental cotyledon. Blood flows via a deep intraparenchymal capillary network into a draining vein that emerges at the fetal surface of the placenta and brings oxygenated blood toward the other twin. There is unidirectional flow from the twin supplying the afferent artery toward the twin receiving the efferent vein; 2) artery to artery connections (AAs) in which a branch artery from each twin meets directly on the superficial placental surface resulting in a vessel with pulsatile bidirectional flow, and 3) vein to vein connections (VVs) in which a branch vein from each twin meets directly on the superficial placental surface allowing low pressure bidirectional flow. In utero obstetric sonography with targeted Doppler interrogation has been used to identify the presence of AV and AA connections4. Prenatally detected AAs that have been confirmed by postnatal placental injection studies have been shown to be associated with an improved prognosis for both twins5. Furthermore, fetoscopic laser ablation of inter-twin vascular connections on the fetal surface of the shared placenta is now the preferred treatment for early, severe TTTS. 
Postnatal placental injection studies provide a valuable method to confirm the accuracy of prenatal Doppler ultrasound findings and the efficacy of fetal laser therapy6. Using colored dyes separately hand-injected into the arterial and venous circulations of each twin, the technique highlights and delineates AVs, AAs, and VVs. This definitive demonstration of MC placental vascular anatomy may then be correlated with Doppler ultrasound findings and neonatal outcome to enhance our understanding of the pathophysiology of MC twinning and its sequelae. Here we demonstrate our placental injection technique.

Vascular mapping of monochorionic (MC) twin placentas after birth provides a means for detailed demonstration of vascular connections between the twins&#x2019; circulations. 
Imbalance of these connections is thought to play a pivotal role in the development of complications of MC twinning including twin-to-twin transfusion syndrome.

Monochorionic (MC) twin pregnancies are associated with significantly higher morbidity and mortality rates than dichorionic twins. Approximately 50% of MC ...

Three-dimensional Imaging of Nociceptive Intraepidermal Nerve Fibers in Human Skin Biopsies

A punch biopsy of the skin is commonly used to quantify intraepidermal nerve fiber densities (IENFD) for the diagnosis of peripheral polyneuropathy 1,2. At present, it is common practice to collect 3 mm skin biopsies from the distal leg (DL) and the proximal thigh (PT) for the evaluation of length-dependent polyneuropathies 3. However, due to the multidirectional nature of IENFs, it is challenging to examine overlapping nerve structures through the analysis of two-dimensional (2D) imaging. Alternatively, three-dimensional (3D) imaging could provide a better solution for this dilemma.
In the current report, we present methods for applying 3D imaging to study painful neuropathy (PN). In order to identify IENFs, skin samples are processed for immunofluorescent analysis of protein gene product 9.5 (PGP), a pan neuronal marker. At present, it is standard practice to diagnose small fiber neuropathies using IENFD determined by PGP immunohistochemistry using brightfield microscopy 4. In the current study, we applied double immunofluorescent analysis to identify total IENFD, using PGP, and nociceptive IENF, through the use of antibodies that recognize tropomyosin-receptor-kinase A (Trk A), the high affinity receptor for nerve growth factor 5. The advantages of co-staining IENF with PGP and Trk A antibodies benefits the study of PN by clearly staining PGP-positive, nociceptive fibers. These fluorescent signals can be quantified to determine nociceptive IENFD and morphological changes of IENF associated with PN. The fluorescent images are acquired by confocal microscopy and processed for 3D analysis. 3D-imaging provides rotational abilities to further analyze morphological changes associated with PN. Taken together, fluorescent co-staining, confocal imaging, and 3D analysis clearly benefit the study of PN.

In order to study the changes of nociceptive intraepidermal nerve fibers (IENFs) in painful neuropathies (PN), we developed protocols that could directly examine three-dimensional morphological changes observed in nociceptive IENFs. Three-dimensional analysis of IENFs has the potential to evaluate the morphological changes of IENF in PN.

A punch biopsy of the skin is commonly used to quantify intraepidermal nerve fiber densities (IENFD) for the diagnosis of peripheral polyneuropathy 1,2. ...

Quantification of Breast Cancer Cell Invasiveness Using a Three-dimensional (3D) Model

It is now well known that the cellular and tissue microenvironment are critical regulators influencing tumor initiation and progression. Moreover, the extracellular matrix (ECM) has been demonstrated to be a critical regulator of cell behavior in culture and homeostasis in vivo. The current approach of culturing cells on two-dimensional (2D), plastic surfaces results in the disturbance and loss of complex interactions between cells and their microenvironment. Through the use of three-dimensional (3D) culture assays, the conditions for cell-microenvironment interaction are established resembling the in vivo microenvironment. This article provides a detailed methodology to grow breast cancer cells in a 3D basement membrane protein matrix, exemplifying the potential of 3D culture in the assessment of cell invasion into the surrounding environment. In addition, we discuss how these 3D assays have the potential to examine the loss of signaling molecules that regulate epithelial morphology by immunostaining procedures. These studies aid to identify important mechanistic details into the processes regulating invasion, required for the spread of breast cancer.

Quantification of Breast Cancer Cell Invasiveness Using a Three-dimensional 3D Model

This article provides detailed methodologies for the use of three-dimensional (3D) assays to quantify breast cancer cell invasion. Specifically, we discuss the procedures required to set up such assays, quantification, and data analysis, as well as methods to examine the loss of membrane integrity that occurs when cells invade.

It is now well known that the cellular and tissue microenvironment are critical regulators influencing tumor initiation and progression. Moreover, the ...

Accuracy in Dental Medicine, A New Way to Measure Trueness and Precision

Reference scanners are used in dental medicine to verify a lot of procedures. The main interest is to verify impression methods as they serve as a base for dental restorations. The current limitation of many reference scanners is the lack of accuracy scanning large objects like full dental arches, or the limited possibility to assess detailed tooth surfaces. A new reference scanner, based on focus variation scanning technique, was evaluated with regards to highest local and general accuracy. A specific scanning protocol was tested to scan original tooth surface from dental impressions. Also, different model materials were verified. The results showed a high scanning accuracy of the reference scanner with a mean deviation of 5.3 &#177; 1.1 &#181;m for trueness and 1.6 &#177; 0.6 &#181;m for precision in case of full arch scans. Current dental impression methods showed much higher deviations (trueness: 20.4 &#177; 2.2 &#181;m, precision: 12.5 &#177; 2.5 &#181;m) than the internal scanning accuracy of the reference scanner. Smaller objects like single tooth surface can be scanned with an even higher accuracy, enabling the system to assess erosive and abrasive tooth surface loss. The reference scanner can be used to measure differences for a lot of dental research fields. The different magnification levels combined with a high local and general accuracy can be used to assess changes of single teeth or restorations up to full arch changes.

Accuracy is a major demand in dental medicine. To verify accuracy, reference scanners are needed. This article presents a new reference scanner with an adjusted scanning method to acquire a broad variety of dental morphologies with high trueness and precision.

Reference scanners are used in dental medicine to verify a lot of procedures. The main interest is to verify impression methods as they serve as a base ...

Three-dimensional Co-culture Model for Tumor-stromal Interaction

Cancer progression (initiation, growth, invasion and metastasis) occurs through interactions between malignant cells and the surrounding tumor stromal cells. The tumor microenvironment is comprised of a variety of cell types, such as fibroblasts, immune cells, vascular endothelial cells, pericytes and bone-marrow-derived cells, embedded in the extracellular matrix (ECM). Cancer-associated fibroblasts (CAFs) have a pro-tumorigenic role through the secretion of soluble factors, angiogenesis and ECM remodeling. The experimental models for cancer cell survival, proliferation, migration, and invasion have mostly relied on two-dimensional monocellular and monolayer tissue cultures or Boyden chamber assays. However, these experiments do not precisely reflect the physiological or pathological conditions in a diseased organ. To gain a better understanding of tumor stromal or tumor matrix interactions, multicellular and three-dimensional cultures provide more powerful tools for investigating intercellular communication and ECM-dependent modulation of cancer cell behavior. As a platform for this type of study, we present an experimental model in which cancer cells are cultured on collagen gels embedded with primary cultures of CAFs.

Here we present a protocol to co-culture in three-dimensions, which is useful for investigating multicellular interactions and extracellular matrix-dependent modulation of cancer cell behavior. In this experimental model, cancer cells are cultured on collagen gels embedded with human cancer-associated fibroblasts.

Cancer progression (initiation, growth, invasion and metastasis) occurs through interactions between malignant cells and the surrounding tumor stromal ...

Three-Dimensional (3D) Tumor Spheroid Invasion Assay

Invasion of surrounding normal tissues is generally considered to be a key hallmark of malignant (as opposed to benign) tumors. For some cancers in particular (e.g., brain tumors such as glioblastoma multiforme and squamous cell carcinoma of the head and neck &#8211; SCCHN) it is a cause of severe morbidity and can be life-threatening even in the absence of distant metastases. In addition, cancers which have relapsed following treatment unfortunately often present with a more aggressive phenotype. Therefore, there is an opportunity to target the process of invasion to provide novel therapies that could be complementary to standard anti-proliferative agents. Until now, this strategy has been hampered by the lack of robust, reproducible assays suitable for a detailed analysis of invasion and for drug screening. Here we provide a simple micro-plate method (based on uniform, self-assembling 3D tumor spheroids) which has great potential for such studies. We exemplify the assay platform using a human glioblastoma cell line and also an SCCHN model where the development of resistance against targeted epidermal growth factor receptor (EGFR) inhibitors is associated with enhanced matrix-invasive potential. We also provide two alternative methods of semi-automated quantification: one using an imaging cytometer and a second which simply requires standard microscopy and image capture with digital image analysis.

Three-Dimensional 3D Tumor Spheroid Invasion Assay

Invasion of surrounding normal tissues is a defining characteristic of malignant tumors. We provide here a simple, semi-automated micro-plate assay of invasion into a natural 3D biomatrix that has been exemplified with a number of models of advanced human cancers.

Invasion of surrounding normal tissues is generally considered to be a key hallmark of malignant (as opposed to benign) tumors. For some cancers in ...

Three-dimensional Alginate-bead Culture of Human Pituitary Adenoma Cells

A three-dimensional culture method is described in which primary pituitary adenoma cells are grown in alginate beads. Alginate is a polymer derived from brown sea algae. Briefly, the tumor tissue is cut into small pieces and submitted to an enzymatic digestion with collagenase and trypsin. Next, a cell suspension is obtained. The tumor cell suspension is mixed with 1.2% sodium alginate and dropped into a CaCl2 solution, and the alginate/cell suspension is gelled on contact with the CaCl2 to form spherical beads. The cells embedded in the alginate beads are supplied with nutrients provided by the culture media enriched with 20% FBS. Three-dimensional culture in alginate beads maintains the viability of adenoma cells for long periods of time, up to four months. Moreover, the cells can be liberated from the alginate by washing the beads with sodium citrate and seeded on glass coverslips for further immunocytochemical analyses. The use of a cell culture model allows for the fixation and visualization of the actin cytoskeleton with minimal disorganization. In summary, alginate beads provide a reliable culture system for the maintenance of pituitary adenoma cells.

Three-dimensional culture in alginate beads, due to its simplicity and reproducibility, was chosen to maintain the pituitary adenoma cells. The procedures included an initial enzymatic digestion and mechanical dissociation of the tumor tissue, and the subsequent cell suspension was encapsulated in alginate beads.

A three-dimensional culture method is described in which primary pituitary adenoma cells are grown in alginate beads. Alginate is a polymer derived from ...

Three-Dimensional Printing of a Complex Aortic Anomaly

Complex congenital aortic anomalies include diverse types of malformations that may be clinically asymptomatic or present with respiratory or esophageal symptoms. These anomalies may be associated with other congenital heart diseases. It is hard to identify the accurate anatomic vessel location from two-dimensional imaging data, such as computed tomography. As an additive manufacturing method, three-dimensional (3-D) printing can covert the acquired imaging data into 3-D physical models. This protocol describes the procedure for modeling the volumetric DICOM imaging into 3-D data and printing it as an anatomically realistic 3-D model. Using this model, surgeons can identify the vessel location of complex aortic anomalies, which is helpful for pre-operative planning and intra-operative guidance.

Here, we present a protocol to use three dimensional printed models for pre-operative planning and intra-operative reorganization of complicated vascular locations when handling a congenital aortic anomaly.

Complex congenital aortic anomalies include diverse types of malformations that may be clinically asymptomatic or present with respiratory or esophageal ...

Three-Dimensional Collagen Matrix Scaffold Implantation as a Liver Regeneration Strategy

Liver diseases are the leading cause of death worldwide. Excessive alcohol consumption, a high-fat diet, and hepatitis C virus infection promote fibrosis, cirrhosis, and/or hepatocellular carcinoma. Liver transplantation is the clinically recommended procedure to improve and extend the life span of patients in advanced disease stages. However, only 10% of transplants are successful, with organ availability, presurgical and postsurgical procedures, and elevated costs directly correlated with that result. Extracellular matrix (ECM) scaffolds have emerged as an alternative for tissue restoration. Biocompatibility and graft acceptance are the main beneficial characteristics of those biomaterials. Although the capacity to restore the size and correct function of the liver has been evaluated in liver hepatectomy models, the use of scaffolds or some kind of support to replace the volume of the extirpated liver mass has not been assessed.
Partial hepatectomy was performed in a rat liver with the xenoimplantation of a collagen matrix scaffold (CMS) from a bovine condyle. Left liver lobe tissue was removed (approximately 40%), and an equal proportion of CMS was surgically implanted. Liver function tests were evaluated before and after the surgical procedure. After days 3, 14, and 21, the animals were euthanized, and macroscopic and histologic evaluations were performed. On days 3 and 14, adipose tissue was observed surrounding the CMS, with no clinical evidence of rejection or infection, as was vessel neoformation and CMS reabsorption at day 21. There was histologic evidence of an insignificant inflammation process and migration of adjacent cells to the CMS, observed with the hematoxylin and eosin (H&#38;E) and Masson&#39;s trichrome staining. The CMS was shown to perform well in liver tissue and could be a useful alternative for studying tissue regeneration and repair in chronic liver diseases.

Liver diseases are induced by many causes that promote fibrosis or cirrhosis. Transplantation is the only option for recovering health. However, given the scarcity of transplantable organs, alternatives must be explored. Our research proposes the implantation of collagen scaffolds in liver tissue from an animal model.

Liver diseases are the leading cause of death worldwide. Excessive alcohol consumption, a high-fat diet, and hepatitis C virus infection promote fibrosis, ...

Guided Endodontics: Three-Dimensional Planning and Template-Aided Preparation of Endodontic Access Cavities

Pulp canal obliterations (PCO) are often a consequence of dental trauma, such as luxation injuries. Even though dentin apposition is a sign of vital pulp, pulpitis or apical periodontitis may develop in the long term. Root canal treatment of teeth with severe PCO and pulpal or periapical pathosis is challenging for general practitioners and even for well-equipped endodontic specialists. To ensure detection of the calcified root canal and avoid excessive loss of tooth structure or root perforation, static navigation using templates ("Guided Endodontics") was introduced a few years ago. The general workflow includes three-dimensional imaging using cone-beam computed tomography (CBCT), a digital surface scan, and superimposition of both in a planning software. This is followed by virtual planning of the access cavity and the design of a template that will guide the drill to the desired target point. To do this, a true-to-scale virtual image of the drill must be placed in a way that the tip of the drill reaches the orifice of the calcified root canal. Once the template has been fabricated using computer-aided design and computer-aided manufacturing (CAD/CAM) or a 3D printer, guided preparation of the access cavity can be performed clinically. For research purposes, a postoperative CBCT image can be used to quantify the accuracy of the access cavity performed. This work aims to present the technique of static guided endodontics from imaging to clinical implementation.

Guided endodontics describes a template-aided approach for access cavity preparation. The procedure requires cone-beam computed tomography and a surface scan to produce a template. An incorporated sleeve guides the drill to the target point. This allows the preparation of minimally invasive endodontic access cavities in calcified teeth.

Pulp canal obliterations (PCO) are often a consequence of dental trauma, such as luxation injuries. Even though dentin apposition is a sign of vital pulp, ...