The authors thank Ms. Makiko Kato for providing encouragement to complete this study. We also thank the Division of Experimental Animals and Medical Research Engineering, Nagoya University Graduate School of Medicine, for the housing of mice.

All experiments were carried out in accordance with protocols approved by the Animal Care and Use Committee of our institution. Sterilize all instruments prior to the procedure.
1. Preparation of a Mold for Creating the Custom-made Distractor
<ol>
	<li>Make two incomplete rings (outer diameter, 20 mm; inner diameter, 10 mm), which are a part of the distractor, with one sheet of paraffin wax (145 mm x 74 mm) using an Evans wax carver.
	<ol>
		<li>Make 4 of the same pieces. Use a wax spatula h...

<ol>
	<li>Watson, J. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Distraction+osteogenesis.">Distraction osteogenesis.</a> The Journal of the American Academy of Orthopaedic Surgeons. 14, 168-174 (2006).</li><li>Ilizarov, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+tension-stress+effect+on+the+genesis+and+growth+of+tissues:+Part+II.+The+influence+of+the+rate+and+frequency+of+distraction.">The tension-stress effect on the genesis and growth of tissues: Part II. The influence of the rate and frequency of distraction.</a> Clinical Orthopaedics and Related Research. 239, 263-285 (1989).</li><li>Wan, C., 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=Activation+of+the+hypoxia-inducible+factor-1+alpha+pathway+accelerates+bone+regeneration.">Activation of the hypoxia-inducible factor-1 alpha pathway accelerates bone regeneration.</a> Proceedings of the National Academy of Sciences of the United States of America. 105 (2), 686-691 (2008).</li><li>Fujio, M., 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=Stromal+cell-derived+factor-1+enhances+distraction+osteogenesis-mediated+skeletal+tissue+regeneration+through+the+recruitment+of+endothelial+precursors.">Stromal cell-derived factor-1 enhances distraction osteogenesis-mediated skeletal tissue regeneration through the recruitment of endothelial precursors.</a> Bone. 49 (4), 693-700 (2011).</li><li>Tong, L., 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=Focal+adhesion+kinase+expression+during+mandibular+distraction+osteogenesis:+evidence+for+mechanotransduction.">Focal adhesion kinase expression during mandibular distraction osteogenesis: evidence for mechanotransduction.</a> Plastic and reconstructive surgery. 111 (1), 211-222 (2003).</li><li>Rhee, S. T., El-Bassiony, L., Buchman, S. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extracellular+signal-+related+kinase+and+bone+morphogenetic+protein+expression+during+distraction+osteogenesis+of+the+mandible:+in+vivo+evidence+of+mechanotransduction+mechanism+for+differentiation+and+osteogenesis+by+mesenchymal+precursor+cells.">Extracellular signal- related kinase and bone morphogenetic protein expression during distraction osteogenesis of the mandible: in vivo evidence of mechanotransduction mechanism for differentiation and osteogenesis by mesenchymal precursor cells.</a> Plastic and reconstructive surgery. 117 (7), 2243-2249 (2006).</li><li>Isefuku, S., Joyner, C. J., Simpson, A. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+murine+model+of+distraction+osteogenesis.">A murine model of distraction osteogenesis.</a> Bone. 27 (5), 661-665 (2000).</li><li>Tay, B. K., Le, A. X., Gould, S. E., Helms, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Histochemical+and+molecular+analyses+of+distraction+osteogenesis+in+a+mouse+model.">Histochemical and molecular analyses of distraction osteogenesis in a mouse model.</a> Journal of Orthopaedic Research. 16 (5), 636-642 (1998).</li><li>Carvalho, R. 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=The+role+of+angiogenesis+in+a+murine+tibial+model+of+distraction+osteogenesis.">The role of angiogenesis in a murine tibial model of distraction osteogenesis.</a> Bone. 34 (5), 849-861 (2004).</li><li>Osawa, Y., 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=Activated+FGFR3+promotes+bone+formation+via+accelerating+endochondral+ossification+in+mouse+model+of+distraction+osteogenesis.">Activated FGFR3 promotes bone formation via accelerating endochondral ossification in mouse model of distraction osteogenesis.</a> Bone. 105, 42-49 (2017).</li></ol>

When a large animal is used as an experimental model, a ready-made extension device can be used, and it is easy to obtain good fixation and assess the extension operation itself and the extension amount. However, when a mouse is used as an experimental model, it is necessary to develop some or all of the equipment. Isefuku et al. and Tay et al. made the device and created a mouse model7,8. Carvahjo et al. adopted a method involving fixa...

Distraction osteogenesis (DO) is an established treatment method for a variety of skeletal disorders, such as limb length discrepancies, bone defects, and limb deformities1. This unique treatment strategy is based on the &#34;tension-stress principle&#34; proposed by Ilizarov. The method requires several days for latency, several weeks for active distraction, and several months for consolidation until the mature bone is formed2.
The local hypoxic conditions due to blockage of blood flow3,4 and mechanical stimulation5,6 are particularly important in the healing process of DO. Hypoxia-induced angiogenesis carries oxygen, nutrients, soluble factors and cells necessary for tissue repair locally through the blood flow. Mechanical stimulation by extension operation causes biological reactions such as differentiation of mesenchymal stem cells, bone formation, calcification and remodeling. Serial DO treatment allows the formation of not only hard tissues but also soft tissues, including nerves, muscles, blood vessels, and skin tissues, without the need for stem cell transplantation. Therefore, a DO model is considered to be an excellent model for analyzing the regeneration of various tissues.
Rabbits and dogs are the most widely used animals in basic research for DO; however, there are few analysis tools available for these animals. The use of a mouse DO model facilitates a more detailed analysis. It is particularly suitable for experiments using knockout mice. However, when using a mouse as an experimental animal, an extension device should be created. Here, we present a mouse tibial DO model developed using a custom-made distractor created using a dental laboratory tool and technique, which has been used in a previous study.

<table border="0" cellpadding="0" cellspacing="0" style="width:771px;" width="772">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:183px;">Paraffin wax</td>
			<td style="width:203px;">YAMAHACHI DENTAL MFG. CO.</td>
			<td style="width:147px;">-</td>
			<td style="width:239px;">For preparation a mold for resin rings</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:183px;">Labocone putty</td>
			<td style="width:203px;">GC Corporation</td>
			<td>-</td>
			<td>For preparation a mold for resin rings</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:183px;">Utility wax</td>
			<td style="width:203px;">GC Corporation</td>
			<td>-</td>
			<td>For preparation a mold for resin rings</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:183px;">Expansion screw</td>
			<td style="width:203px;">Ortho Dentaurum</td>
			<td style="width:147px;">600-301-30</td>
			<td>Component of custom-made distractor</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:183px;">Unifast III</td>
			<td style="width:203px;">GC Corporation</td>
			<td>-</td>
			<td style="width:239px;">Immediate polymerization resin Component of custom-made distractor</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:183px;">Ortho Crystal</td>
			<td style="width:203px;">NISSIN</td>
			<td>-</td>
			<td style="width:239px;">Transparent resin Component of custom-made distractor</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:183px;">25-gauge needle</td>
			<td style="width:203px;">TERUMO</td>
			<td style="width:147px;">NN-2516R</td>
			<td>For custom-made distractor</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:183px;">27-gauge needle</td>
			<td style="width:203px;">TERUMO</td>
			<td style="width:147px;">NN-2719S</td>
			<td>For custom-made distractor</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:183px;">ICR mouse</td>
			<td style="width:203px;">Chubu Kagaku Shizai Corporation</td>
			<td>-</td>
			<td>Experimental animal</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:183px;">Somnopentyl</td>
			<td style="width:203px;">Kyoritsu Seiyaku</td>
			<td>-</td>
			<td>Pentobarbital sodium salt</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:183px;">Isoflurane</td>
			<td style="width:203px;">FUJIFILM Wako Pure Chemical Corporation</td>
			<td style="width:147px;">099-06571</td>
			<td>Isoflurane inhalation solution</td>
		</tr>
	</tbody>
</table>

a mouse distraction osteogenesis model

Distraction osteogenesis (DO) is a surgical procedure that involves skeletal tissue regeneration without cell transplantation. A DO model consists of the following three phases: the latency phase after osteotomy and placement of the external distractor; the distraction phase, wherein the separated bone ends are gradually and continuously distracted; and the consolidation phase. This custom-made distractor used for DO is comprised of two incomplete acrylic resin rings and an expansion screw. The process was initiated by making a mold with silicone impression material and then creating the custom-made distractor. Dental resin was poured into the formwork made of silicone impression material, and it was allowed to polymerize to create the incomplete resin rings required for the custom-made distractor. These rings were fixed with an expansion screw using transparent resin. The custom-made distractor created via this approach was attached to the tibia of mice. The tibia was fixed to the device using one pair of 25 G needles proximally, one pair of 27 G needles distally, and acrylic resin. After a latency period of 5 days, distraction was initiated at a rate of 0.2 mm/12 h. The lengthening was continued for 8 days, resulting in a total gap of 3.2 mm. The mice were sacrificed 4 weeks after distraction. Bone formation in the distraction gap was confirmed using both radiography and histology.

Figures 1A and 1B present incomplete rings (outer diameter, 20 mm; inner diameter, 10 mm; thickness, 5 mm) with paraffin wax. Two wax patterns were embedded in silicone impression material, and a mold for the resin rings (Figure 1C) was formed. Polymerized resin was immediately poured into this mold, and resin rings were obtained (Figure 1D). A custom-made distra...

Watch this Scientific Journal Video about A Mouse Distraction Osteogenesis Model at JoVE.com

A Mouse Distraction Osteogenesis Model

We present a mouse tibial distraction osteogenesis model developed using a custom-made distractor. The use of a mouse as an analysis target is advantageous for advancing research.

Distraction osteogenesis (DO) is a surgical procedure that involves skeletal tissue regeneration without cell transplantation. A DO model consists of the ...

This method can help answer key questions in the hard and soft tissue regeneration field. The main advantage of this technique is that the use of a mouse allows for a detailed analysis of bone regeneration. Begin with a fully anesthetized adult mouse.Carefully shave and disinfect the surgical area with 10%iodine solution. Then, administer 0.5%lidocaine hydrochloride at the right lower limb. Then, after making a 15-millimeter longitudinal skin incision at the right lower leg with a number 15 scalpel, bluntly separate the underlying muscles, taking care not to remove all periosteum.Then, cut the fibula with scissors. Grasp the ankle with narrow, thin forceps, and use a 27-gauge needle to make a hole in the bone, about five millimeters from the heel. The needle should penetrate the skin, bone, and skin in that order.When the needle fully penetrates, cut the tip and root with a nipper so that the needle is about 15 millimeters. Make another hole in the same manner, about two to three millimeters proximal. Next, hold around the ankle, and pass a 25-gauge needle under the knee in the same manner.After the needle penetrates, cut the tip and root with a nipper. Make another hole in the same manner, about two to three millimeters distal. Place the custom-made distractor such that it is parallel to the extension direction.Fix the needles and device with enough polymerization dental resin to fill the grooves of the device. Wait for the polymerization to complete, which should take approximately five minutes. Then, while being very careful not to damage the surrounding tissues, cut the middle of the diaphysis of the tibia using a very thin cutting disc while applying a saline solution.Close the wound with a 4-0 nylon suture. Give subcutaneous injections of buprenorphine for analgesia immediately after surgery. There are various reports on the latency period and distraction rate, but here, representative protocols are shown.After a latency period of five days, begin the distraction procedure. For extension, use the pin attached to the rapid expansion screw. Move the pin in the direction of the yellow arrow attached to the extension screw.Hold the tail with the little finger and palm, and fix the extension device with the forefinger and thumb. Perform extension by moving the pin in the direction of the yellow arrow 0.2 millimeters for a one-quarter turn. Continue lengthening at the rate of 0.2 millimeters every 12 hours for eight days, which will result in a total gap of 3.2 millimeters.This image shows typical radiography findings at four weeks after distraction in the model. Newly formed bone is seen at the distraction site. Hematoxylin and eosin staining results are seen here.A newly formed bone bridge was observed, and the newly formed bone could be easily distinguished from the native bone. We presented a mouse tibial DO model developed using a custom-made distractor. The use of a mouse DO model facilitates a more detailed analysis.It is particularly suitable for experiments using knockout mice.

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Developmental Biology

6.1K Views.  Nagoya University Graduate School of Medicine. Questo metodo può aiutare a rispondere a domande chiave nel campo della rigenerazione dei tessuti duri e molli. Il principale vantaggio di questa tecnica è che l'uso di un topo consente un'analisi dettagliata della rigenerazione ossea. Inizia con un topo adulto completamente anestetizzato.Radere e disinfettare con cura l'area chirurgica con una soluzione di iodio al 10%. Quindi, somministrare lo 0,5% di cloridrato di lidocaina all'arto inferiore destro. Quindi, dopo aver fatto un'inc...