& ltp> As far as plastic surgery is concerned, it is not a major operation to correct adult flat head with bone cement, but it requires high skills from doctors. & lt/p & gt； & ltp> Operationally, a small incision of 3~4 cm will be made in the skin above the scalp, and bone cement will be injected between the fascia and the bone, that is, outside the skull, which will not have any effect on the brain. & lt/p & gt； & ltp style = \ " text-align:center \ " & gt； & ltimg src = \ "/uploadfile/image/2019161576459075737583.png \" title = \ "case of Korean sculpture hospital \" alt = \ ""height = \ " 163 \ " border = \ " 0 \ " vspace = \ " 0 \ " style = \ " width:400 px； Height:163 px; \ "/>； & lt/p & gt； & ltp> As far as the safety of materials is concerned, bone cement has been used in clinic for decades, and its safety is beyond doubt as a substitute for bones in surgery. & lt/p & gt； & ltp> The reason why this operation is not a major operation is mainly because the operation time is short, about 45 minutes to an hour, which is similar to rhinoplasty or double eyelid surgery. However, due to the characteristics of bone cement, it takes about 2-3 minutes to form after injection into the head, and the bone cement will be completely stiff in about 5 minutes, so it cannot be formed at this time, so the technical requirements for surgeons are very strict. & lt/p & gt； & ltp style = \ " text-align:center \ " & gt； & ltimg src = \ "/uploadfile/image/20191216/1576459076364056.png \" title = \ "schematic diagram of bone cement \" alt = Height: 365px \ "/>; & lt/p & gt； & ltp> So as long as doctors are skilled and experienced, the operation is generally not difficult and the safety is more guaranteed. & lt/p & gt； Science popularization of<p> related knowledge;