A steep mandibular plane angle is characterized by a significant incline of the lower jawbone’s rear portion. It’s measured as the angle formed between the occlusal plane and a line drawn from the gonion to the menton. A steeper angle typically indicates a more prominent and defined jawline, creating a stronger and more angular facial appearance. This feature is often associated with a stronger bite force and an increased risk of temporomandibular joint (TMJ) disorders.