What are the observable characteristics of epithelialization?

"WOUNDS WITH LOSS OF SKIN Acute, traumatic injuries that result in loss of skin - such as a full-thickness burn, a deep abrasion, or avulsion - will pass through the same phases of healing. However, wound closure requires two additional biological mechanisms: epithelial migration and wound contraction. a. Epithelialization As soon as the biochemical and cellular substrates for healing are assembled and bacterial contamination falls below 105 organisms/gm, the epithelium begins to proliferate and migrate across the wound surface. If the wound is a superficial burn or abrasion, the epithelium will spread quickly from sweat glands and hair follicles, covering entire wound surface within 10 to 14 days. When full thickness skin has been lost, epithelium can migrate only from the wound margins. Epithelialization is very slow process, and is often insufficient for timely wound closure. Furthermore, epithelium migrates without an accompanying dermal layer, and is therefore vulnerable to injury. The histology of migratory epithelium often appears neoplastic. A chronic wound that is not closed for many years might in time become a malignant ulcer, named for the French surgeon, Marjolin, who first described this complication of a longstanding surface defect. Reconstructive surgeons who manage extensive wounds learn not to depend exclusively on epithelialization, except for the smallest or most superficial of injuries. Instead, they use grafts or flaps for wound closure."