the most used and predominant type of drill in surgery, and performs manually. It has an adjusted stopper based on the setting and where the bone is the most thickest to prevent plunging. Surgeons use this drill manually without any other procedures. Surgeons that use a hand-cranked drill often are required to employ a lot of upper body strength. Electric cranial drill The electric cranial drill is powered either by a battery or by electricity via wall sockets. Pneumatic cranial drill The pneumatic motor is known for its great speed, which makes surgery much easier and faster. It is driven by expanding compressed air. The use of this kind of mechanism has many advantages such as the ease of use through high peak velocities. Thanks to superior torque, this system has great performance and it is essential for complex revision operations. The surgical procedure is shorter than usual, so patients spend less time under anesthesia. Pneumatic high-speed craniotomes usually run at 40,000 to 80,000 rpm and have greatly facilitated intracranial approaches in neurosurgery. They are also employed to temporarily remove the vertebral arch in laminotomy. Scientific progress Technological progress to reduce surgery time and minimize risks for patients during surgery have been introduced in the field of cranial drills, primarily from machining. CAD/CAM CAD/CAM stands for computer-aided design/computer-aided manufacturing. In the medical field, as well, it is used by surgeons to simplify and ease surgeries: in the case of trepanning, a processor collects information from 2D images, and then turns them into 3D images. The processor codifies this information so that the drill can, without any trouble, pierce the correct portion of the skull. Photo gallery See also Instruments used in general surgery Retractor (medical) Surgical scissors Deep brain stimulation Intracranial pressure References Medical equipment Surgical instruments