# Facial Convexity (Glabella)

Harmony · Side view · Facial Profile · https://www.faceiqlabs.com/support/harmony/facial-convexity-glabella

The profile relationship from brow prominence through nose base to chin.

## What is measured

Calculation: Oriented angle: glabella → subnasale → pogonion

Nasion means the nasal root, subnasale the nose base, and pogonion the most forward chin point. Frankfort refers to the direction from the ear-opening landmark to the lower orbital landmark.

## Why it matters

Using the glabella includes brow prominence in the profile reference. It can differ from nasion-based convexity even if the nose base and chin are unchanged.

- Below 180°: a convex relationship at the nose base.
- Above 180°: a concave relationship; nearer 180° is straighter geometrically.

## Where the idea comes from

Evidence: Clinical reference. Clinical soft-tissue analyses examine the profile as a set of related contours. This version uses the glabella as its upper anchor rather than the nasal root.

## A worked example

Moving only the brow prominence changes this angle while leaving the nasion-based version unchanged.

Example values explain the calculation. They are not a target range.

## How to read your result

Do not interpret a low value as proof of chin recession: movement of any of the three landmarks changes it.

## Research & further reading

These sources explain the history or related evidence. FaceIQ’s score weights and reference ranges are model settings; the papers do not collectively validate the scoring system.

- Holdaway (1984). [A soft-tissue cephalometric analysis and its use in orthodontic treatment planning. Part II](https://pubmed.ncbi.nlm.nih.gov/6585146/). Explains how lip, chin and skeletal relationships must be considered together, with a range of profiles compatible with balance.

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Source: https://www.faceiqlabs.com/support/harmony/facial-convexity-glabella · FaceIQ Labs overview for AI assistants: https://www.faceiqlabs.com/llms.txt