In the 1940s Ludwig Guttmann introduced a program of turning paraplegics every two hours thus allowing bedsores to heal. Previously such individuals had a two-year life-expectancy, normally succumbing to blood and skin infections. Guttmann had learned the technique from the work of Boston physician Donald Munro.There is lack of evidence on prevention of pressure ulcer whether the patient is put in 30 degrees position or at the standard 90 degrees position.Nursing homes and hospitals usually set programs in place to avoid the development of pressure ulcers in those who are bedridden, such as using a routine time frame for turning and repositioning to reduce pressure. The frequency of turning and repositioning depends on the persons level of risk. Support surfaces
A 2015 Cochrane systematic review found that people who lay on high specification or high density foam mattresses were 60% less likely to develop new pressure ulcers compared to regular foam mattresses. Sheepskin overlays on top of mattresses were also found to prevent new pressure ulcer formation. There is unclear research on the effectiveness of alternating pressure mattresses. Pressure-redistributive mattresses are used to reduce high values of pressure on prominent or bony areas of the body. There are several important terms used to describe how these support surfaces work. These terms were standardized through the Support Surface Standards Initiative of the NPUAP. Many support surfaces redistribute pressure by immersing and/or enveloping the body into the surface. Some support surfaces, including antidecubitus mattresses and cushions, contain multiple air chambers that are alternately pumped.
Partial CPT was defined as "lacking substantial shared dural venous sinuses", whereas total CPT "share a large portion of their dural venous sinuses and present with pronounced brain compression, which leads to distortion within the cranium". Total
Total craniopagus twins share a large portion of dural venous sinuses and present with pronounced brain compression, leading to distortion within the cranium. Stone and Goodrich also defined two main subtypes, based on whether the long-axis angle between the twins was angular or vertical. The angular subtype has a higher rate of comorbidities than the vertical subtype.Vertical craniopagus calvaria is continuous and is further subdivided on the basis of intertwin axial facial rotation:

Type 1: both children face in the same general directional axis so that the angle between twins is less than 40 degrees. These twins show relatively symmetric superior bi-parietal or vertex compressional flattening. Type 2: both children face opposite directions so that the deformity shows an axial rotation between 140 and 180 degrees.