Soft tissue dehiscence could result due to flap irritation as a result of, closure under tension, intraoperative or postoperative recipient site infection, postoperative edema, which in turns compromises stability of onlay bone blocks thus osseintegration of bone block. Any attempt of bone recontouring and resuturing fails since there is no vascular bed. Ideal requirements of barrier membranes are, they should be biological compatible, they must act as a barrier membrane, unwanted fibroblasts should be hindered from entrance while allowing diffusion of nutrients, tissue integration (biological adhesion), tissues should be able to grow into the membrane but not through it. Space maintainer, it should be sufficiently stiff, so as not to collapse into the underlying particulate bone under the pressure of soft tissue and it should be ease in its manipulation, adaptation and handling, as for example, collagen membrane. Some types of collagen membrane, contain some degrees of stretchability.
Is the use of collagen membrane on top of particulate bone mixture covered by onlay bone block in Maxilla better than the use of mixture of particulate bone covered by onlay bone block without the use of collagen membrane, in terms of bone quality and bone quantity?