A screwdriver having a retention mechanism for temporarily holding a screw in place on its tip while the screw is being positioned, rotated or removed. More particularly, a screwdriver with a cruciform head used in the installation and removal of bone screws during maxillofacial surgery.本發明係關於一種螺絲起子，其具有一用於在一螺絲釘被定位、旋轉或移除時將該螺絲釘暫時固持在其尖端上之適當位置的保持機構。更特定言之，本發明係關於一種具有一十字形頭部之螺絲起子，其在上頜面手術(maxillofacial surgery)期間用於接骨螺絲釘(bone screw)之安裝及移除。
