An Experimental Study Of Pathogenesis Similarity Between Traumatic Temporomandibular Joint Ankylosis And Heterotopic Ossification

Objective:The aim of this study was to explore the pathogenesis similarity between traumatic temporomandibular joint ankylosis(TMJA)and heterotopic ossification(HO).Reliable data were got to inspire new thoughts for prevention and treatment of traumatic TMJA.Methods:In this study,bone specimens of patients with traumatic TMJA and HO of joints(elbow,hip and knee joint)were chosen as experimental group A and B,with 30specimens in each group.All the patients were diagnosed and received surgical treatment in Zunyi medical college affiliated dental hospital and Zunyi medical college affiliated hospital.5 normal and complete coracoids were collected as control group C.All the studied subjects agreed to this study and signed the informed consent of clinical trials.Structural forms of bone specimens were detected by HE staining and expressions of BMP-2,BMP-4,CD34~+in Group A,B and C were detected by immunohistochemical inspection.And imaging expression features were compared to find differences.Experimental data differences were compared by SPSS17.0.Results:1.HE staining results:both experimental group A and B had mixed structural forms of calcified and uncalcified fibrous cartilage,fiber texture and blood capillary.Mature lamellar bones could be seen sometimes.Marrow cavity and osteoblastoma around it could be seen in mature bone texture;In soft tissue outside the joints of group A and B,there were mixed texture of muscle and new-born bones.And new vessels,muscle tissue,slender bone trabecula,fiberous callus,multinuclear giant cells could also been seen inside.Group C was covered by cortical bone,with a mature bone histomorphometry composed of cancellous bone,trabecular structure and blood capillary under it.No ossifying structure could be found inside soft tissue of joints.2.Immunohistochemistry results:It was mainly observed that experimentalgroup A and B had stronger BMP-2,BMP-4,CD34~+expression than control group C.Experimental group B had stronger BMP-2,BMP-4,CD34~+expression than positive ones in group C.Experimental group B had stronger BMP-2 expression than positive ones in group A.Experimental group A had stronger BMP-4,CD34~+expression than positive ones in group B.All the above difference had statistical significance(P<0.05).3.According to the comparison of image data between experimental group Aand B:imaging feature of both groups was that joint space disappeared to varying degrees or completely.Original joint areas were occupied by cancellous bone which had bone trabecula and covered by high-density cortical bone structure.This new formed structure was extremely similar to normal bone structure.In the soft tissue around the joint,there were cord-like,fascicular,stellate,reticulate,lamellar irregular high-density ossifications.Conclusion:Traumatic TMJA and HO had pathogenic similarities.