<unk>  can be fundamentally classified by their level of complexity, the types of tissues present, or by their blood supply. Complexity<unk>  can be classified according to level of complexity. The surgeon should choose the least complex type that will achieve the desired effect, a concept known as the reconstructive ladder. Local<unk>  Local<unk>  are created by freeing a layer of tissue and then stretching the freed layer to fill a defect. This is the least complex type of<unk> and includes advancement<unk> , rotation<unk> , and transposition<unk> , in order from least to most complex. With an advancement<unk>  incisions are extended out parallel from the wound, creating a rectangle with one edge remaining intact. This rectangle is freed from the deeper tissues and then stretched (or advanced) forward to cover the wound. The<unk> is disconnected from the body except for the uncut edge which contains the blood supply which feeds in horizontally. A rotation<unk> is similar except instead of being stretched in a straight line, the<unk> is stretched in an arc. The more complex transposition<unk> involves rotating an adjacent piece of tissue, resulting in the creation of a new defect that must then be closed. Regional<unk>  Regional or interpolation<unk>  are not immediately adjacent to the defect. Instead, the freed tissue "island" is moved over or underneath normal tissue to reach the defect to be filled, with the blood supply still connected to the donor site via a pedicle. This pedicle can be removed later on after new blood supply has formed, e.g., PMMC, DP<unk>  for head and neck defects, TRAM for breast reconstruction. Distant<unk>  Distant<unk>  are used when the donor site is far from the defect. These are the most complex class of<unk>  Direct or tubed<unk>  involve having the<unk> connected to both the donor and recipient sites simultaneously, forming a bridge. This allows blood to be supplied by the donor site while a new blood supply from the recipient site is formed. Once this happens, the "bridge" can be disconnected from the donor site if necessary, completing the transfer. A free<unk> has the blood supply cut and then reattached microsurgically to a new blood supply at the recipient site. Tissue type Here are some of the more common classifications by tissue type: * Cutaneous<unk>  contain the full thickness of the skin and superficial fascia and are used to fill small defects. * Fasciocutaneous<unk>  add subcutaneous tissue and deep fascia, resulting in a more robust blood supply and ability to fill a larger defect. * Musculocutaneous<unk>  further add a layer of muscle to provide bulk that can fill a deeper defect. * Muscle<unk>  can provide bulk or functional muscle. If skin cover is needed, a skin graft can be placed over it. * Bone<unk>  are used to replace bone, such as in jaw reconstruction. Vascular Classification based on blood supply to the<unk>  * Axial<unk>  are supplied by a named artery and vein. This allows for a larger area to be freed from surrounding and underlying tissue, leaving only a small pedicle containing the vessels. * Reverse-flow<unk>  are a type of axial<unk> in which the supply artery is cut on one end and blood is supplied by backwards flow from the other direction. * Random<unk>  are simpler and have no named blood supply. Rather, they are supplied by generic vascular networks. * Pedicled<unk>  remain attached to the donor site via a pedicle that contains the blood supply, in contrast to a free<unk> as described under Classification by complexity.
Flap 
Bridge 
Wart
Caul
Periwound
Welt 
Trip 
Hair