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>

Viscoelasticity of porcine acellular dermal matrix / 医用生物力学

Objective To evaluate the viscoelastic properties of porcine acellular dermal matrix (PADM) by comparison and analysis on physical parameters of the skin. Methods Full-thickness skin defects were performed on the back of white rabbits as wound models, and randomly divided these wounds into 3 groups according to different methods of skin grafting: PADM group (autogenous skin and PADM were grafted to the surface of the wound), TS group (autogenous skin was grafted in situ), NS group (normal skin as the control). Experiments on the stress-strain relationship of the implanted skin in the three groups were conducted. Results The curves of stress relaxation, creep, and stress-strain relationship showed that under a given stress, PADM group had the lowest strain, NS group had the highest strain, while the strain of TS group was in between the PADM and NS group. Conclusions The skin viscoelasticity mechanical model is a four-parameter solid model. When the skin wounds are grafted by using PADM which may have poor elasticity, its recovery capacity after deformation is also poor, and this is in agreement with the clinical results.

Effect of different concentration of tamoxifen ointment on the expression of TGF-beta2 of hypertrophic scar at rabbit ears / 中华整形外科杂志

<p><b>OBJECTIVE</b>To observe the effect of different concentration of Tamoxifen ointment on the fibroblasts and transforming growth factor (TGF-beta2) of hypertrophic scar at rabbit ears, so as to explore the possibility of treatment of hypertrophic scar with Tamoxifen.</p><p><b>METHODS</b>The hypertrophic scar model was established in 96 New Zealand rabbits' ears. The wounds were divided into four groups (A, B, C and D), with 144 wounds in each group. Different concentration of tamoxifen ointment (0.5%, 1%, 2%) was topically administered in groups A, B and C respectively, and blank ointment in group D. On postoperative day 30, 60 and 90, the scar samples were harvested. The scar thickness, scar histological change and the content of TGF-beta2 were detected.</p><p><b>RESULTS</b>(1) On the 30th day after operation, the difference of scar tissue thickness among groups A, D and B, C reached statistical significance (group A, D < group B < group C). However, there was a contrary tendency in fibroblasts density and TGF-beta2 content of the scar tissue simultaneously. (2) On 60th, 90th day after injury, there was statistical difference in scar thickness, fibroblasts density and the content of TGF-beta2 in scar of four groups (P < 0.05). The content of TGF-beta2 in group A, B, C, D was (43.97 +/- 3.63) microg/L, (41.92 +/- 3.91) microg/L, (36.69 +/- 4.15) microg/L, (54.90 +/- 4.71) microg/L, respectively, on 60th day; and (45.69 +/- 2.63) microg/L, (40.43 +/- 3.87) microg/L, (38.76 +/- 3.24) microg/L, (52.59 +/- 4.92) microg/L, respectively, on 90th day. The fibroblasts density of scar in groups A, B, C, D was (4392.07 +/- 327.84) point/mm2, (4208.57 +/- 329.76) point/mm2 (4 033.44 +/- 427.91) point/mm2, (4863.03 +/- 387.98) point/mm2, respectively, on 60th day; and (4418.41 +/- 432.52) point/mm2, (4077.65 +/- 386.70) point/mm2, (3844.53 +/- 354.29) point/mm2, (4838.64 +/- 390.52) point/mm2, respectively, on 90th day. The content of TGF-beta2 and fibroblasts density of scar were lined up as group D > group A > group B > group C (P < 0.05).</p><p><b>CONCLUSIONS</b>Topical Tamoxifen can reduce the content of TGF-beta2 and fibroblast, decrease fibroblasts density and the formation of hypertrophic scar at rabbit ears. It offers a new way for the treatment of the hypertrophic scar.</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>

Treatment strategies for mass burn casualties / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Mass burn casualties are always a great challenge to a medical team because a large number of seriously injured patients were sent in within a short time. Usually a high mortality is impending. Experiences gained from successful treatment of the victims may be useful in guiding the care of mass casualties in an armed conflict.</p><p><b>METHODS</b>Thirty-five burn victims in a single batch, being transferred nonstop by air and highway from a distant province, were admitted 48 hours post-injury. All patients were male with a mean age of (22.4 +/- 8.7) years. The burn extent ranged from 4% to 75% ((13.6 +/- 12.9)%) total body surface area. Among them, thirty-two patients were complicated by moderate and severe inhalation injury, and tracheostomy had been performed in 15 patients. Decompression incisions of burn eschar on extremities were done in 17 cases before transportation. All the thirty-five patients arrived at the destination smoothly via 4-hour airlift and road transportation. Among them, twenty-five patients were in critical condition.</p><p><b>RESULTS</b>These thirty-five patients were evacuated 6 hours from the scene of the injury, and they were transferred to a local hospital for primary emergency care. The patients were in very poor condition when admitted to our hospital because of the severe injury with delayed and inadequate treatment. Examination of these patients at admission showed that one patient was suffering from sepsis and multiple organ dysfunction syndrome. Dysfunction of the heart, lung, liver, kidney, and coagulation were all found in the patients. Forty-eight operations were performed in the 23 patients during one month together with comprehensive treatment, and the function of various organs was ameliorated after appropriate treatment. All the 35 patients survived.</p><p><b>CONCLUSIONS</b>A well-organized team consisting of several cooperative groups with specified duties is very important. As a whole, the treatment protocol should be individualized, basing on the extent of the injury and the care that the patient had received at the spot. During airlift, the stretchers should be arranged perpendicular to the longitudinal axis of the cabin. The treatment protocol in our hospital consisted mainly of prompt effective relief of all life-threatening complications, followed by early closure of burn wounds, appropriate use of anti-infection therapy, emphasis on nutritional support, correction of metabolic disorders, alleviation of immunosuppression, correction of coagulopathy, and effective support and protection of organ function.</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>

Repairing of lower eyelid ectropion with expanded flap / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the effect of reconstruction of lower eyelid ectropion with expanded flap.</p><p><b>METHODS</b>Fourty patients with lower eyelid ectropion were reconstructed using tissue expander. The volume of the smallest expander was 30 ml, and that of the biggest one was 150 ml. The expand time was from 2-months to 3-months, then advancement or transposition flaps were created and employed in the defected lesion where the scar was removed just in one operation.</p><p><b>RESULTS</b>All patients have been followed up for 2-year with satisfactory results and no recurrences was appearance.</p><p><b>CONCLUSIONS</b>Application of expander reasonable may get satisfactory result in reconstruction of lower eyelid ectropion. The incision in donor site is hidden and the symptom seldom recurs.</p>

Differential display of homeobox gene expressions in the normal, wounded human fetal and adult skins by DNA microarray / 中华整形外科杂志

<p><b>OBJECTIVE</b>To explore the differential expression of homeobox genes in the normal, wounded human fetal and adult skins and its significance in fetal scarless healing.</p><p><b>METHODS</b>Gene chips containing 14 000 human genes were used to investigate homeobox gene expressions of the normal, wounded human fetal and adult skins.</p><p><b>RESULTS</b>There were significant differences between the expression of homeobox genes, especially for PRX-2, HOXB13, HOXB6 and HOXB7.</p><p><b>CONCLUSIONS</b>The homeobox gene is in close relation to developmental biology. The different expressions and changes of homeobox genes in the normal, wounded human fetal and adult skin may be a primary cause of different wound healing between fetal and adult skin.</p>

The role of tyrosine phosphorylation proteins in procollagen gene expression of fibroblasts in wound healing / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the role of adhesion between fibronectin and fibroblasts in wound healing as well as tyrosine phosphorylation proteins in procollagen mRNA expression.</p><p><b>METHODS</b>The level of proalpha1 (I) mRNA and tyrosine phosphorylation protein were detected employing the techniques of RT-PCR and immunoblotting. After inhibition of tyrosine kinases, herbimycin A was added to the medium to block the pathway of tyrosine phosphorylation, the changes of procollagen mRNA and tyrosine phosphorylation proteins were further investigated.</p><p><b>RESULTS</b>The adhesion between fibroblasts and fibronectin in wound healing not only induced the production of 98kd and 65kd tyrosine phosphorylation protein, but also enhanced obviously the expression of procollagen alpha1 (I) mRNA. When the pathway of tyrosine phosphorylation was blocked, the level of procollagen alpha1 (I) mRNA lowered remarkably, accompanied by the decrease of 98kd, 65kd tyrosine phosphorylation proteins.</p><p><b>CONCLUSION</b>The adhesion between fibronectin and fibroblasts plays an important role in expression increase of procollagen mRNA during wound healing, in the process of which tyrosine phosphorylation is a key step.</p>

The significance and the expression of homeobox genes during human burn wound healing / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the expression of several homeobox genes during the wound healing in fetal and adult skin and their roles in fetal scarless wound healing.</p><p><b>METHODS</b>The expressions of PRX-2, HOXB13, HOX2.2 and HOX2.3 during wound healing in fetal and adult skin were determined with in situ hybridization.</p><p><b>RESULTS</b>(1) PRX-2 positive expression could be identified in normal fetal and adult skin, especially in the fetus. But there was difference in location sites of the genes. The positive expression in normal fetal skin was mainly found in the peripheral cells at the hair shafts within dermal papilla layers and was also found in the epithelium. Nevertheless, weak positive expression of PRX-2 was found in the epithelial basal layer cells in normal adult skin but not in dermal tissue. There was strong positive expression of the PRX-2 in the tissue around the wound in fetus but not of that in adults except the epithelial basal layers. (2) Positive expression of HOXB13 could be identified in both normal fetal and adult skins. And the expression was concentrated mainly in hair follicle cells in the dermis and in the basal layer cells in the epithelium. Furthermore, the expression became weak after trauma, especially in fetal skin. (3) The positive expression of HOX2.2 and HOX2.3 in normal fetal skin was observed mainly in the whole layer of the epithelium and especially in the epithelial basal layers. Weak positive expression could be found in the dermis and strong expression found in the tissue near the wound. But there was no positive expression of the HOX genes in normal adult skin and wounds.</p><p><b>CONCLUSION</b>The difference in the HOX expression in fetal and adult skin wound healing might be the key factor leading to different wound healing. Homeobox genes might be closely related with the developmental biology.</p>

A comparative study of PDGF and EGF expression in skin wound healing between human fetal and adult / 中华整形外科杂志

<p><b>OBJECTIVE</b>To explore the differences of PDGF and EGF expression in the wound healing between fatal and adult.</p><p><b>METHODS</b>With the established animal model of fetal scarless healing and the adult samples, an immunohistochemical technique was used to evaluate the expression of PDGF and EGF in the normal adult skin, normal fetal skin, and the process of their wound healing.</p><p><b>RESULTS</b>1. The expression of the PDGF was not found in the fetal skin, but a mild amount of the PDGF was shown in the epidermis and the upper dermal layer 12 hours and 1 day after the wounding process. In the normal adult skin, expression of PDGF was shown in the dermal fibroblasts, macrophagocytes and blood capillaries, and a strong expression was presented during its wound healing process. 2. In the fetal skin, the expression of the EGF was seen in the epidermis, hair follicles, sebaceous glands and sweat glands, but there were no markedly changes during the wound healing. In the adult skin, a positive stain of the EGF was shown in the basal layer of the epidermis while the mild stain in hair follicles and sweat glands. The level of the expression became gradually decreasing with the time going in the wounded adult skin.</p><p><b>CONCLUSION</b>The different expression of growth factors between fetal and adult skin in wound healing may be one of the important reasons that the fetal wound could produce scarless healing.</p>