Coral

Source: Coral is harvested from a wide region of the Pacific and other tropical oceans. A number of coral genera have been collected for medicinal use, including Goniopora and Porites.

History: While coral has been used by the inhabitants of Pacific regions for cutting tools and as the basis of jewelry and amulets, it was not until the mid 1980s that its value in surgery was fully recognized. The natural material derived from the matrix of sea coral has been found to serve as an effective substrate for the growth of new bone in areas damaged by trauma or requiring reconstruction. Coral may be more durable than bone and appears to eliminate some of the complications inherent in traditional bone graft surgery.

Today, coral-based material is used to aesthetically enhance the facial skeleton in cosmetic surgery and is used as a surgical aid in maxillofacial reconstructive surgery.

Uses of Coral

Coral is used in cosmetic and reconstructive surgery and as a substrate for new bone growth.

Side Effects of Coral

Coral does not appear to be rejected or produce adverse effects.

Surgical Uses:

During surgery, the processed coral is shaped to fit the patient's facial structure. Sea coral has several advantages over human bone. Unlike traditional procedures that require the surgical removal of bonematrix from elsewhere in the patient's body (ie, hip) for grafting, coral implant requires only facial incision; it retains its shape well, and it provides a long-lasting matrix that closely resembles natural bone. In baboon studies, surgically made bone defects that were grafted with coral demonstrated substantial bone growth (p < 0.01) compared to bone grafts as early as 3 months after surgery, culminating with complete penetration of bone into the tridimensional porous spaces of the coral. Similar good results were observed when the material was implanted in the mandibles of rabbits. In dogs, bone regrowth in experimentally created proximal tibia defects demonstrated that the stereological distribution of regenerated bone in the porous hydroxyapatite was the same as in normal tibial bone; after 12 months. 66% of the surface of the coral was covered with new bone ingrowth.

Although experience is somewhat limited, published results suggest that in man, the use of coral in maxillofacial. surgery results in good bone conduction into the surgical site. Bone defects in man have been shown to heal rapidly following reconstruction with coral microgranules. Biopsies at 8 and 18 months showed good bone formation around the coral particles.

Toxicology: Follow-up of patients for 6 to 24 months found no deleterious host responses and good tolerabilit) to coral implants. To date, insufficient experience has been gained with the use of coral products to confirm their benefit in assisting bone growth in severely damagec weight-bearing bones.

Summary: Coral is now under investigation for its use in facial reconstructive surgery. The chemically modified coral exoskeleton provides a strong matrix for bone regeneration. The product does not appear to be associated with adverse effects or tissue rejection.