Final answer:
The three grasps used in expanded dental functions are the power grasp, for a firm grip involving all fingers; the precision grasp, using finger tips for fine motor tasks; and the lateral grasp, for stability and dexterity with the thumb and side of the index finger. These grasps are enhanced by movements like thumb opposition, allowing for effective manipulation of dental instruments.
Step-by-step explanation:
The three grasps commonly used by a dental operator or assistant when carrying out an expanded function are the power grasp, the precision grasp, and the lateral grasp. A power grasp is used when a firm grip is required, such as when handling dental instruments like forceps. This type of grasp involves using all fingers and the palm to firmly grip the object, which increases contact and the firmness of the hold. The precision grasp is more delicate and involves the tips of the fingers and thumb, typically utilized for tasks requiring fine motor skills, such as manipulating small objects or tools within the mouth. The lateral grasp, or pinch grasp, involves the thumb and the side of the index finger, and is used for tasks that require stability and dexterity, such as holding a dental mirror or scalpel.
An example of a power grasp could be when the operator firmly grips the handle of a dental scaler to remove plaque from a tooth surface. In contrast, a precision grasp might be used when placing a small amount of dental composite material onto the tip of a dental instrument. Lastly, a lateral grasp could be employed while holding a suction device during a dental procedure.
Movements like opposition of the thumb, particularly during precision and lateral grasps, enhance the ability to manipulate tools and perform delicate tasks effectively. The detailed mechanics of how these grasps involve the anatomy of the hand, such as the positioning of the metacarpal bones and the actions of the thumb's opposition, provide insight into the effectiveness of each grasp type.