**9. Surgical technique**

As mentioned before, donor site reconstruction following cranial bone grafting involves the use of thin bone chip lamellae that are harvested from the cranial bone that is adjacent to the donor site.

We have successfully performed this procedure in more than 200 patients in a 15-year period. This reconstruction technique is applicable to mild-to-moderate donor site defects, and is useful for treating in both, split- and full-thickness donor site defects.

An initial Z-type scalp incision is made, followed by subperiosteal dissection to create a periosteal cover for the grafted bone chips. The galea over the periosteum is preserved to ensure that the periosteal blood supply is adequate. The use of subperiosteal dissection is essential in order to close the reconstructed donor site. Following graft harvesting of the cranial bone, thin cranial bone lamellae are harvested from the adjacent cranial bone by using a curved chisel (**Illustration 2** and **Photo 5**). The bone dust and small bone chips that are obtained during harvesting are collected and also used for reconstruction. The thin harvested bone chips are placed in the donor site cavity to over-correct the defect. Then, a block of gelatin sponge is placed over the bone grafts to avoid displacement during the operation. The procedure is completed by closing the periosteum and skin in separate layers.

Among the patients we have treated, the reconstructed defects initially appeared to be undercorrected, which prompted us to modify our procedure by overfilling the cavity with cranial bone chips.

As a craniofacial surgeon, I observed my mentors Henry Kawamoto and Ian Jackson perform cranial bone graft harvesting. My main concern was that patients might not accept the appearance of the donor site defect, especially when the procedure was performed for esthetic reasons. I described a technique of nasal bony reconstruction and performed it in a large number of patients. My initial experience with this procedure demonstrated that there was poor patient acceptance of the cranial bone grafting procedure owing to the presence of a defect at the donor site. Therefore, I reconstructed the donor site defect using tiny bone chips that are harvested from the cranial bone that is adjacent to the donor site. After the procedure was introduced, a higher proportion of my patients accepted the use of cranial bone grafts. The bone dust and small bone chips that are obtained during harvesting are also collected and placed in the donor site cavity, along with the tiny harvested bone chips. Overcorrection is advised to account for the potential dead spaces between the bone chips. Several reports have described reconstructing the donor site following full-thickness cranial bone grafting by splitting another full-thickness bone graft or using a split graft.

In our experience, reconstructing split-thickness and full-thickness donor sites with cranial bone chips is a simple, safe, and satisfying procedure. This technique is useful to fill the donor site during cranial bone grafting, which is a concern for esthetic surgeons.
