The Experiment That Expression Of BMP-9?OGF-1 In Different Periods Of Mandibular Callus Tissue

Objective: The subject aims to observe the histological changes of HE staining of bone callus specimens between mandibular fracture's fractured ends in different periods,and study the immunohistochemistry expression and significance of BMP-9 and IGF-1 in the process of bone fracture repair in different cycles,and provide experimental basis for studying the expression of BMP-9 and IGF-1 in mandibular fracture.Methods: From February 2018 to December 2019,30 patients(experimental group)who underwent mandibular fracture surgery in accordance with the inclusion criteria were selected from the Oral and Maxillofacial Surgery Department,Affiliated Stomatology Hospital of Zunyi Medical University.The callus tissue excised between the mandibular fracture's fractured ends was collected and divided into four groups according to the period from the mandibular fracture to receiving the surgery.It included 8 patients in one week after suffering mandibular fracture,10 patients in two weeks after mandibular fracture,8patients suffering three weeks' fracture and 4 patients suffering four weeks' fracture.One patient with square jaw deformity was selected and bilateral mandibular bone blocks removed during the surgery(control group)were collected.Preoperative subjects all agreed to this study and signed informed consent form.Histological changes of mandibular callus in different periods after mandibular fracture were observed by HE staining.Immunohistochemical staining with IGF-1 and BMP-9 as primary antibodies was performed in the experimental group,and the expression in different periods after fracture was observed.Mean optical density(MOD)of positive expression areas in different periods was measured by Image-Pro-Plus6.0 software.Statistical analysis was carried out by SPSS18.0 statistical software.All data statistics were expressed by mean standard deviation(x � s).The comparison among multiple groups of data was carried out by one-way analysis of variance,and the difference was statistically significant(P < 0.05).Results: 1.Observation results under HE staining microscope: In the first week after mandibular fracture,dilated capillary net was seen,the cavity wall was composed of fibrous connective tissue,and lymphocytes and fibroblasts infiltrated in the periphery.Inthe second week after fracture,new bone trabeculae and scattered chondrocytes can be seen,and lymphocyte and fibroblast infiltration can be observed in the surrounding connective tissue.In the third week,fibroblasts in fibrous connective tissue are in close contact with bone tissue and cartilage islands are increased.The fourth week: mature bone tissue,bone matrix deposition and new bone growth extending to the periphery can be seen.2.Immunohistochemistry Results: IGF-1 group: the MOD value in the first week after mandibular fracture was 0.149�0.021,the MOD value in the second week after mandibular fracture was 0.176�0.018,and the MOD value in the third week after fracture was0.236�0.024;MOD value in the fourth week after fracture was 0.184�0.016.BMP-9 group:MOD value in the first week after fracture was 0.084�0.002;MOD value in the second week was 0.095�0.007;The MOD value in the third week was 0.102 0.008;The MOD value in the fourth week after fracture was 0.082�0.003.In the control group,IGF-1 and BMP-9 were all negative in bilateral mandibular bone tissue.The MOD values of BMP-9and IGF-1 gradually increased in the first and second weeks,reached a peak in the third week,and declined in the fourth week.Besides,the expression difference of BMP-9 and IGF-1 in the second week after mandibular fracture is statistically significant(P < 0.05).The expression difference of BMP-9 and IGF-1 in the third week after fracture is statistically significant(P < 0.05).The expression difference of BMP-9 and IGF-1 in the fourth week after mandibular fracture is statistically significant(P < 0.05)compared with the second and third weeks after fracture.Conclusion: BMP-9 and IGF-1 are positively expressed in the bone callus tissue between the mandibular fracture's fractured ends in the early stage,and the average optical density value gradually increases in the first week and the second week,the third week reaches a peak value,and the fourth week decreases,which suggest that BMP-9 and IGF-1may play an important role in mandibular fracture repair.