Bone marrow mesenchymal stem cells on Matrigel: growing and changing / 中国组织工程研究

BACKGROUND: Matrigel as an extracellular matrix complex can facilitate cell proliferation, differentiation and collagen secretion in a cell culture system. OBJECTIVE: To establish a three-dimensional culture model of Matrigel combined with bone marrow mesenchymal stem cells (BMSCs) and to observe the morphology, proliferation and survival of BMSCs in the Matrigel three-dimensional culture model. METHODS: BMSCs were isolated and cultured by the whole bone marrow adherent method, followed by osteogenic and adipogenic induction and identification. The growth curve of passage 3 BMSCs was determined through the CCK-8 experiment. Passage 2 BMSCs were combined with Matrigel, and the morphology and proliferation of BMSCs were observed by hematoxylin-eosin staining under a phase contrast microscope. The viability of the cells was evaluated by the Live/Dead staining. RESULTS AND CONCLUSION: (1) BMSCs cultured by the whole bone marrow adherent method had the ability to differentiate into osteoblasts and adipocytes. (2) BMSCs exhibited an "S"-shaped growth curve, which was consistent with the growth characteristics of normal cells. (3) Under the phase contrast microscope, BMSCs cultured by the Matrigel model were extended and interconnected in a three-dimensional network growth state with good proliferation. The Matrigel gradually became soft and collapsed over time (7days) and a few cells were still in a network growth after 14 days. Hematoxylin-eosin staining results showed that the cell cytoplasm was larger at 4 days and the cells became thinned and mutually cross-linked at 7 days. (4) The active percentage of BMSCs in the Matrigel model was 92.57%, 95.54% and 97.37% at 1, 4, 7 days of culture, respectively. To conclude, BMSCs cultured on the Matrigel has good proliferation and high viability.

Mandibular-driven simultaneous maxillo-mandibular distraction for hemifacial microsomia with rapid prototyping technology / 中华整形外科杂志

<p><b>OBJECTIVE</b>To explore the clinical application of mandibular-driven simultaneous maxillo-mandihular distraction to correct hemifacial microsomia with rapid prototyping technology.</p><p><b>METHODS</b>The patient' s skull resin model was manufactured with rapid prototyping technology. The osteotomy was designed on skull resin model. According to the preoperative design, the patients underwent Le Fort I osteotomy and mandibular ramus osteotomy. The internal mandible distractor was embedded onto the osteotomy position. The occlusal titanium pin was implanted. Distraction were carried out by mandibular-driven simultaneous maxillo-mandihular distraction 5 days after operation.</p><p><b>RESULTS</b>The distraction in five patients was complete as designed. No infection and dysosteogenesis happened. The longest distance of distraction was 28 mm, and the shortest distance was 16 mm. The facial asymmetry deformity was significantly improved at the end of distraction. The ocelusal plane of patients obviously improved.</p><p><b>CONCLUSIONS</b>Rapid prototyping technology is helpful to design precisely osteotomy before operation. Mandibular-driven simultaneous maxillo-mandibular distraction can correct hemifacial microsomia. It is worth to clinical application.</p>

Quantitative analysis of craniofacial skeleton asymmetry by three-dimensional computed tomography / 中华整形外科杂志

<p><b>OBJECTIVE</b>To present a method of quantitative diagnosis of craniofacial skeleton deformities based on three-dimensional computed tomography (3D CT).</p><p><b>METHODS</b>20 cases with facial asymmetric deformities underwent 3D CT and the 3D images were reconstructed by Mimics 10.0 (Belgium). Anatomical landmarks were located and the coordinate of the landmarks obtained. Axial images of 1 patient with Romberg disease was used as representative case. The differences in the distance between the right landmarks and the left were calculated and analyzed.</p><p><b>RESULTS</b>The measurement results were not significantly different between two stages with an interval of 4 weeks ( P > 0.05), showing a reproducible resutls. The deviation of landmarks at facial midline increased gradually from upward to downward, reaching (2.63 +/- 0.54) mm at menton point. Paired landmarks showed asymmetry in three dimensions, especially gonion point on the left side, which was deviated 10.21 mm inward, 9.26 mm forward, 6.30 mm upward, compared to the opposite side.</p><p><b>CONCLUSIONS</b>The method of 3D CT quantitative analysis can provide precise information in the diagnosis and treatment planning of facial asymmetry deformity.</p>

Three-dimensional finite element analysis for different directions distraction at midface / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the biomechanical changes with different directions distraction at midface.</p><p><b>METHODS</b>An anteriorly directed 500 g force was applied to the floor of apertura piriforms in different directions to the occlusal plane. Three-dimensional finite element analysis was used to evaluate the biomechanical change of craniofacial complex.</p><p><b>RESULTS</b>As the force direction was moved downward, the sagittal distraction length of the craniofacial complex decreased and vertical movement changed from upward to downward. The craniofacial complex was moved anteriorly when the downward force was applied about 20-30 degrees to the occlusal plane. The forces could generate the uniform stress distribution in the craniofacial sutures and avoid counterclockwise rotation of the maxilla.</p><p><b>CONCLUSIONS</b>The craniofacial complex can be effectively distracted anteriorly when the downward force is applied to the floor of aperture piriforms in direction of 20-30 degrees to the occlusal plane.</p>

An ultrastructure study on the palatomaxillary suture of dog expanded by NiTi-SMA / 中华整形外科杂志

<p><b>OBJECTIVE</b>To explore the ultrastructure of the palate-maxillary sutures under tensile forces by transmission electron microscope (TEM).</p><p><b>METHODS</b>The Suture expanders were made in NiTi-Shape memory alloy (NiTi-SMA). The maximum force was 3.5 N. Fourteen 8-month old mongrel dogs were used in the study. They were divided into three groups, (1) experimental group, (2) control group, (3) sham group. In the experiment and control groups, an 8 mm wide cleft was made by surgery. The suture expanders were fixed onto the palatine bones of the experimental group. The dogs of the experimental group were executed after 3, 7, 14, 28, 56 days of suture expansion. The change of suture tissue was examined by TEM.</p><p><b>RESULTS</b>The cleft of the experiment group were closed at the ninth day of expansion. At the beginning, tissue rupture, exudation, death of fibroblasts, disruption of collagen and tear vessels were seen at the early stage of suture expansion. Then highly active functional manifestations were seen in both osteocytic and fibrocytic populations. At last, normal structure restored.</p><p><b>CONCLUSIONS</b>Cell types and functional condition could be distinguished clearly by TEM. It suggests that the suture expansion should be the process of tissue repair and regeneration. The suture cells response, especially, the osteogenic response were the major factor of increasing suture width.</p>

Application of thoracic skin flap with multiple blood supply in repair of tissue defects and deformities in jaw and neck / 中华烧伤杂志

<p><b>OBJECTIVE</b>To explore an appropriate measure to repair tissue defects and deformities in mandibulo-cervical region.</p><p><b>METHODS</b>Eighteen cases with severe tissue defects and deformity in jaw and neck were repaired with thoracic skin flap with multiple blood supply system in our unit from Jan. 2006 to Nov. 2008. Anterior cutaneous branch of transverse cervical artery, intercostal branch of internal thoracic artery and lateral thoracic artery were included in the pedicles.</p><p><b>RESULTS</b>All skin flaps survived, except in one patient in whom a small belb appeared at the distal end of the island flap with anterior cutaneous branch of transverse cervical artery, and it was healed after a few dressing changes. The functions and appearances were satisfactory after 6-month to 2-year follow-up, without showing secondary deformity.</p><p><b>CONCLUSIONS</b>The blood supply of thoracic skin flap is abundant and constant, which is an ideal method for repair of tissue defects and deformities in jaw and neck after taking into account some factors, such as the demand of the patient, general physical condition, and the size of the defect.</p>

Three-dimensional finite element analysis of craniofacial skeleton protraction at medium position / 中华整形外科杂志

<p><b>OBJECTIVE</b>The purpose of this study was to investigate the biomechanical changes of midface skeleton protraction at its medium position in the craniofacial complex, using the three-dimensional finite element method (FEM).</p><p><b>METHODS</b>A three-dimensional FEM model was developed from the CT scan images by the technologies of three-dimensional reconstruction, image processing and meshing. The protraction forces were applied to the following locations: the first molar, full maxillary arch, and the floor of aperture piriforms. Biomechanical changes from different position protraction were investigated by means of finite element analyses.</p><p><b>RESULTS</b>Protraction forces at the level of the floor of aperture piriforms produced a more forward movement of the upper maxilla in sagittal direction. Vertical and lateral displacements were less than those in loading with teeth or denture. Compressive stress on the radix nasi decreased obviously in midface skeleton protraction at its medium position.</p><p><b>CONCLUSIONS</b>Compared with traditional orthopedic protraction, midface skeleton protraction at its medium position could advance maxilla en bloc, decrease the counterclockwise rotation of the maxilla, and reduce the constriction of the anterior part of the palate.</p>

Suppositional sutural construction and application in the three-dimensional finite element model of craniofacial complex / 中华整形外科杂志

<p><b>OBJECTIVE</b>The purpose of this study was to explore suppositional sutural construction and protraction in the three-dimensional finite element model of craniofacial complex.</p><p><b>METHODS</b>Combining spiral CT scanning technology with the three-dimensional finite element method, three-dimensional FEM model of craniofacial complex was developed for analysis. In the model, craniofacial sutures were constructed through the MSC. Patran program and different mechanical properties of sutures were applied. Under the same loading condition, bone displacements of the maxilla were calculated.</p><p><b>RESULTS</b>A three-dimensional FE model of craniofacial complex, comprising teeth and craniofacial sutures, was developed. The displacement of the skeletal structures with sutures was significantly larger than that without sutures.</p><p><b>CONCLUSIONS</b>The construction of craniofacial sutures in the three-dimensional finite element model of craniofacial complex could improve the accuracy of finite element model, which set up good foundation for biomechanical studies of craniofacial complex.</p>