In Holdaway's analysis, how far should the nasion to pogonion line (H line) ideally be from the upper lip?

Holdaway's analysis is a well-known cephalometric assessment used in orthodontics to evaluate facial balance and aesthetics, particularly in relation to the profile. The H line, which is drawn from the nasion (the bridge of the nose) to the pogonion (the most forward point on the chin), serves as a reference line for assessing the position of both the upper lip and the chin.

According to Holdaway's criteria, the ideal position for the upper lip is 2-4 mm in front of the H line. This means that a value of 9 mm ahead of the H line for the upper lip would indicate that the lip is positioned sufficiently forward, contributing to a more favorable aesthetic appearance.

In orthodontic treatment planning, achieving this ideal position can enhance facial aesthetics and is often a target for achieving better facial harmony. Treatment may involve various orthodontic modalities to reposition the teeth and supporting structures to achieve this balance. Being in the ideal range ensures not just an attractive profile, but also functional attributes like dental occlusion and lip closure.

The rationale behind the measurement and this ideal distance is based on empirical observations of facial harmony among various populations, often seen as foundational in orthodontic criteria for achieving optimal facial outcomes.