Little is known about how the structures of connective tissue newly form during the wound-healing process. The authors investigated the repair process of excised skin wounds using alkali water cell maceration scanning electron microscopy. The development of the papillary dermis on the granulation surface proceeded toward the center of the wound, coupled with epidermis migration. No papillary dermis was evident on the granulation surface that had yet to be epithelialized. Finally, a layered structure as observed in normal dermis was reconstructed in the scar tissue. In other words, epidermis, basement membrane, and papillary dermis developed on the granulation surface accompanying epidermal migration, and reticular dermis as the result of maturation of granulation tissue. These findings demonstrate that both the papillary dermis and the reticular dermis develop differently after wounding, and that new papillary dermis and new epidermis develops as if completing “a unit” during the epithelialization process. The authors denote this unit the epithelialization unit.
A scanning electron microscopic study of healing excised rat wounds demonstrated early reformation of the reticular dermis. In contrast, the papillary dermis developed as a unit with the advancing epidermis.
From the *Department of Plastic and Reconstructive Surgery, National Defense Medical College, Tokorozawa, Saitama; and the †Department of Plastic and Reconstructive Surgery, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan.
Received April 21, 2003, and accepted for publication, after revision, July 25, 2003.
Presented in part at the 11th research council meeting of the Japan Society of Plastic and Reconstructive Surgery, 2001, Tokyo, Japan; and at the 32nd annual meeting of the Japan Society for Wound Healing, 2002, Fukuoka, Japan. Presented at a poster session at the 13th International Congress of Plastic, Reconstructive and Aesthetic Surgery, Sydney, Australia, 2003.
Reprints: Naoto Yamamoto, MD, Department of Plastic and Reconstructive Surgery, National Defense Medical College, 3–2, Namiki, Tokorozawa, Saitama, 359–8513, Japan. E-mail: firstname.lastname@example.org