--- title: "Mouth Corner Position: What FaceIQ Labs Measures and How to Read It" description: "Mouth Corner Position is a FaceIQ Labs Harmony front-view measurement of the average vertical position of the mouth corners relative to the central mouth seam." canonical: "https://appear.faceiqlabs.com/support/harmony/mouth-corner-position" --- # Mouth Corner Position: What FaceIQ Labs Measures and How to Read It Mouth Corner Position is a FaceIQ Labs Harmony measurement taken on the front view. It is the mean of (mouth-center y − corner y) × photo scale: the average vertical position of both mouth corners relative to the central mouth seam. Negative means the corners sit below the seam; positive means above. ## Key facts - Mouth Corner Position is a front-view measurement in the mouth region of FaceIQ Labs' Harmony pillar. - Calculation: mean of (mouth-center y − corner y) × photo scale. - A negative value means the corners sit below the central mouth seam on average; a positive value means they sit above it. - It describes the resting direction of the mouth outline and is different from symmetry. - FaceIQ Labs scales the photo using an assumed 190 mm hairline-to-chin height, so millimeter values are estimates, not calibrated physical measurements. - FaceIQ Labs labels this a FaceIQ adaptation: a landmark-based description of facial shape. The linked research (Gibelli et al., 2015) has not directly validated this exact formula or its score. - A neutral expression is advised because the number is a contour measurement and does not describe mood. ## What does FaceIQ Labs measure for Mouth Corner Position? FaceIQ Labs measures Mouth Corner Position on a front-view photo as the mean of (mouth-center y − corner y) × photo scale. The result is the average vertical offset of the left and right mouth corners from the central mouth seam, which serves as the reference. The guide's schematic labels the left corner offset, right corner offset and central seam reference. ## What does a positive or negative Mouth Corner Position mean? In FaceIQ Labs' Mouth Corner Position measurement, a negative value means the mouth corners sit below the central mouth seam on average, and a positive value means they sit above it. This sign convention describes FaceIQ Labs' result and indicates the resting direction of the mouth outline. ## Is Mouth Corner Position the same as symmetry? No. FaceIQ Labs states that Mouth Corner Position differs from symmetry. It is an average describing the resting direction of the mouth outline, so both corners can be equally downturned, or opposite offsets on the two sides can cancel out and still produce an average near zero. ## How does FaceIQ Labs' worked example for Mouth Corner Position work? FaceIQ Labs gives two examples for Mouth Corner Position. Corners 1 mm and 3 mm above the center average +2 mm. Corners at +2 mm and −2 mm average zero despite the asymmetry. FaceIQ Labs notes these values only explain the calculation; they are not a target range and not measurements of its schematic. ## How accurate are the millimeter values for Mouth Corner Position? The millimeter values are approximate. FaceIQ Labs scales each photo using an assumed 190 mm hairline-to-chin height, so Mouth Corner Position results are estimates rather than calibrated physical measurements. The sign convention in the guide describes FaceIQ Labs' result. ## What expression should I use for the Mouth Corner Position photo? FaceIQ Labs advises a neutral expression for Mouth Corner Position. The number is a contour measurement of the mouth and does not describe mood, so it is meant to reflect the resting outline of the mouth rather than a smile or frown. ## Where does the Mouth Corner Position measurement come from? FaceIQ Labs labels Mouth Corner Position a FaceIQ adaptation: its own landmark-based description of facial shape. It links Gibelli et al. (2015), "A Quantitative Analysis of Lip Aesthetics: The Influence of Gender and Aging," which measured lip area, volume and thickness across sex and age groups. That paper is background only and has not directly validated this formula or its score. FaceIQ Labs says its score weights and reference ranges are model settings. ## Which other Harmony measurements are in the same mouth region? - Lip Thickness - Lower Lip to Upper Lip Ratio - Cupid's Bow Depth - Mouth-to-Nose Width Ratio - Interpupillary-Mouth Width Ratio - Chin-to-Philtrum Ratio ## Frequently asked questions ### What does a negative Mouth Corner Position value mean? On FaceIQ Labs, a negative value means the mouth corners sit below the central mouth seam on average, based on front-view photo landmarks. ### Does Mouth Corner Position measure facial symmetry? No. It is an average of the two corner offsets, so equally downturned corners or opposite offsets that cancel out are both possible. It describes resting mouth direction, not symmetry. ### Should I smile for the Mouth Corner Position measurement? No. FaceIQ Labs recommends a neutral expression, since this is a contour measurement and does not describe mood. ### Has FaceIQ Labs scientifically validated Mouth Corner Position? FaceIQ Labs describes it as its own landmark-based adaptation. The linked research (Gibelli et al., 2015) is background on lip morphology and has not directly validated this exact formula or score. ### Are the millimeter values real physical measurements? No. FaceIQ Labs scales the photo using an assumed 190 mm hairline-to-chin height, so the values are estimates, not calibrated physical measurements. ### Which pillar does Mouth Corner Position belong to? It belongs to FaceIQ Labs' Harmony pillar, as a front-view measurement in the mouth region. ## 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). 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