to cm away from the wound edge deeply into the wound It is then passed through the opposite side and reenters the wound parallel to the initial suture To avoid “buckling” and to provide some eversion of the wound edges, the skin must be entered perpendicularly, and the wound must be entered and exited at the same depth ( Fig 110.8 ) FIGURE 110.8 The horizontal mattress stitch is useful for closing the deep layer in shallow lacerations and in body areas with little subcutaneous tissue Certain dyed suture materials may cause a tattooing of the skin if placed in such a shallow position (From Grisham J Wound care In: Dieckmann RA, Fiser DH, Selbst SM, eds Illustrated Textbook of Pediatric Emergency & Critical Care Procedures St Louis, MO: Mosby; 1997:678, reprinted with permission.) The modified horizontal mattress stitch (half-buried) is often used to close a flap It is also called the corner stitch It relieves intrinsic tension and avoids vascular compromise when approximating the tip of the flap Using 5-0 or 6-0 sutures, the provider should enter intact skin across from the apex of the flap and exit the wound just below the subcuticular plane The needle should be brought to the tip of the flap, entering and exiting at the subcuticular plane Then, the needle is brought across the edge of the flap in the subcuticular plane and the skin is exited A knot should be tied in the usual manner and the tip of the flap brought to the apex of the wound ( Fig 110.9 ) Placing the needle in the flap edge first can be done to repair wounds in which there is ample perfusion to the flap The edge of the flap can then be moved back