What is the angle formed where the upper and lower incisors meet?

The angle formed where the upper and lower incisors meet is known as the angle of incidence. This term is used in various contexts, including dentistry, to describe the angle at which two surfaces intersect. In the case of horse evaluation, particularly concerning their teeth, understanding the angle at which the incisors meet is critical. This relationship can provide insights into the horse's age, dental health, and how well the horse interacts with its environment in terms of feeding and biting.

The concept of the angle of incidence primarily pertains to how directly the upper incisors contact the lower incisors when the horse bites down. A proper angle can indicate healthy dental alignment, while deviations may suggest issues that could affect the horse's eating efficiency or overall dental hygiene.

Other options relate to different concepts in geometry or physics, but in the context of horse anatomy and evaluation, the angle of incidence is the most appropriate term for the situation described.