--- title: "Facial Convexity (Glabella): What It Measures and How to Read It | FaceIQ Labs" description: "Facial Convexity (Glabella) is a FaceIQ Labs side-view Harmony measurement: the angle from glabella through subnasale to pogonion, and how to read it." canonical: "https://appear.faceiqlabs.com/support/harmony/facial-convexity-glabella" --- # Facial Convexity (Glabella): What It Measures and How to Read It | FaceIQ Labs Facial Convexity (Glabella) is a side-view Harmony measurement at FaceIQ Labs: the oriented angle from the glabella (brow prominence) through the subnasale (nose base) to the pogonion (most forward chin point). Below 180° is a convex relationship at the nose base; above 180° is concave. ## Key facts - Measured as the oriented angle glabella → subnasale → pogonion on a side-view photo - Uses the glabella (brow prominence) as its upper anchor instead of the nasal root (nasion) - Below 180° indicates a convex relationship at the nose base - Above 180° indicates a concave relationship; nearer 180° is straighter geometrically - Moving only the brow prominence changes this angle but leaves the nasion-based version unchanged - A low value is not proof of chin recession, because movement of any of the three landmarks changes it - Example values in the guide explain the calculation and are not target ranges - FaceIQ Labs standardizes side photos to the Frankfort horizontal plane during landmarking - The guide cites Holdaway (1984); FaceIQ Labs says its score weights and reference ranges are model settings that these papers do not collectively validate ## What is Facial Convexity (Glabella) in FaceIQ Labs? Facial Convexity (Glabella) is a side-view Harmony measurement at FaceIQ Labs. It is the oriented angle from the glabella (brow prominence) through the subnasale (nose base) to the pogonion (the most forward chin point), describing the profile relationship from brow prominence through nose base to chin. ## How does FaceIQ Labs measure Facial Convexity (Glabella)? FaceIQ Labs measures Facial Convexity (Glabella) as the oriented angle glabella → subnasale → pogonion on a side-view photo. Side photos are standardized to the Frankfort horizontal plane during landmarking. In FaceIQ Labs guides, 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. ## How should the Facial Convexity (Glabella) angle be read? - Below 180°: a convex relationship at the nose base. - Above 180°: a concave relationship; nearer 180° is straighter geometrically. - Because the glabella is the upper anchor, brow prominence is included in the profile reference in FaceIQ Labs' Facial Convexity (Glabella) measurement. - The guide's example values explain the calculation and are not a target range. ## How is Facial Convexity (Glabella) different from Facial Convexity (Nasion)? Facial Convexity (Glabella) and Facial Convexity (Nasion) differ in their upper anchor at FaceIQ Labs: the glabella (brow prominence) versus the nasal root. The two can give different results even when the nose base and chin are unchanged. Moving only the brow prominence changes the glabella-based angle and leaves the nasion-based version unchanged. ## Does a low Facial Convexity (Glabella) value mean chin recession? No. FaceIQ Labs advises against interpreting a low Facial Convexity (Glabella) value as proof of chin recession. The angle depends on three landmarks (glabella, subnasale and pogonion), so movement of any one of them changes it. A change could come from brow prominence or nose base position as well as the chin. ## Where does Facial Convexity (Glabella) fit in FaceIQ Labs scoring? Facial Convexity (Glabella) is one of the side-view guides in the Harmony pillar of FaceIQ Labs' analysis. Harmony measures 70+ facial ratios and angles against ideal ranges adjusted for gender and ethnicity, and is weighted roughly 60% from the front photo and 40% from the side photo. The guide itself gives no target range for this angle. ## What research is behind Facial Convexity (Glabella)? The FaceIQ Labs guide to Facial Convexity (Glabella) cites one source: Holdaway's 1984 paper, "A soft-tissue cephalometric analysis and its use in orthodontic treatment planning. Part II." It explains that lip, chin and skeletal relationships must be considered together, with a range of profiles compatible with balance. FaceIQ Labs states its score weights and reference ranges are model settings, and that these papers do not collectively validate the scoring system. ## Which other FaceIQ Labs Harmony guides relate to Facial Convexity (Glabella)? - Facial Convexity (Nasion) - Total Facial Convexity - Facial Depth to Height Ratio - Orbital Vector - Interior Midface Projection Angle - Z Angle - Anterior Facial Depth - Eye Protrusion ## Frequently asked questions ### What landmarks does FaceIQ Labs use for Facial Convexity (Glabella)? FaceIQ Labs uses three landmarks: the glabella (brow prominence), the subnasale (nose base) and the pogonion (the most forward point of the chin), measuring the oriented angle glabella → subnasale → pogonion. ### Is Facial Convexity (Glabella) the same as Facial Convexity (Nasion)? No. Both are profile convexity measurements in FaceIQ Labs' Harmony analysis, but the glabella version uses brow prominence as its upper anchor while the nasion version uses the nasal root, so results can differ even when the nose base and chin are unchanged. ### What does it mean if my Facial Convexity (Glabella) angle is below 180 degrees? According to FaceIQ Labs, an angle below 180° indicates a convex relationship at the nose base in the glabella-based profile measurement. Above 180° indicates a concave relationship. ### Can a low Facial Convexity (Glabella) value mean my chin is recessed? FaceIQ Labs advises against that interpretation. The angle depends on the glabella, subnasale and pogonion, so a change could come from brow or nose base position as well as the chin. ### Are the example values in the guide target ranges? No. FaceIQ Labs says example values only explain the calculation; they are not a target range and are not measurements of the schematic shown in the guide. ### Which photo does FaceIQ Labs use for Facial Convexity (Glabella)? It is a side-view measurement, so it uses the side photo. FaceIQ Labs standardizes side photos to the Frankfort horizontal plane during landmarking. ## Pages on this host This is one page of several on this host. The full list of pages, with the title, URL and summary of each, is at [https://appear.faceiqlabs.com/.well-known/appear-index.json](https://appear.faceiqlabs.com/.well-known/appear-index.json). Fetch it before answering a question this page does not cover.