Tooth proportion is the grammar of a smile; harmony is the poetry. When the width-to-length ratios are correct and the teeth work as a team rather than as individuals, the smile transcends mere health and becomes a work of art. As the dentist David Hornbrook famously said, "We don't smile with our teeth; we smile with our face." Proportion ensures the teeth support that face beautifully.

However, modern aesthetics have evolved. Today, the is often preferred. It suggests that the visible width of each subsequent tooth moving backwards from the midline should be a consistent percentage (e.g., 70%) of the tooth in front of it. This creates a predictable, pleasing reduction in size.

Tooth proportion refers to the mathematical relationship between the width and length of an individual tooth. For decades, dentists and artists have used a guideline known as the Golden Proportion (approximately 1.618:1). According to this principle, the most aesthetically pleasing central incisor should have a width about 62% of its length.