Final answer:
The curve of spee is a 3-dimensional curve in dentistry that curves upward from anterior to posterior in the mouth.
Step-by-step explanation:
The curve of spee is a term used in dentistry to describe the curvature of the occlusal plane (the biting surface of the teeth) in the mouth. It is 3-dimensional and curves upward from anterior to posterior. This means that if you were to look at a side view of the mouth, the curved line representing the occlusal plane would be higher at the back of the mouth compared to the front.