The pen grasp resembles the position commonly used to hold a pen or pencil and is widely used for most operative instruments.
The modified pen grasp is like the pen grasp except the operator uses the pad of the middle finger on the handle of the instrument. Some operators prefer this method since they feel it provides more strength and stability in some procedures.
The palm grasp is used for bulky instruments. It is commonly used for surgical forceps, dental dam clamp forceps, straight chisels, and the A/W syringe.
The palm thumb, or thumb to nose grasp, is used by the assistant for holding the oral evacuator. The operator may use this with instruments that require a more vertical movement.