Angiogenesis in the human temporomandibular joint studied by immunohistochemistry for CD34 antigen

````The CD34 antigen is a sensitive marker of vascular endothelium and angi ogenesis. Thus, we examined the expression of CD34 in 20 human temporomandi bular joint (TMJ) samples with internal derangement and in 10 control speci mens by an immunohistological technique using paraffin-embedded tissue and specific anti-human CD34 monoclonal antibody. In the control specimens, CD3 4 was observed sporadically within the TMJ discs. On the other hand, in the internal derangement specimens, CD34 was found frequently in the walls of blood capillaries within the TMJ discs. In the synovial membrane, CD34 was detected frequently in the walls of many blood capillaries in both the cont rols and the internal derangement specimens. Indeed, CD34 expression in int ernal derangement specimens was more intense than in control specimens. In the posterior loose connective tissue of the bilaminar zone, and in the ant erior loose connective tissue between the upper and lower lamellae of the a nterior capsular wall, CD34 was detected in abundance in the walls of blood capillaries both of the controls and the internal derangement specimens. G enerally, CD34 was found rarely in the walls of large blood vessels. The pr esence of CD34 is suggested to be correlated with the process of angiogenes is induced by internal derangement of the TMJ.