Flat face
Page most recently updated 7 September 2026
This page focuses on flat face as a morphologic feature of conditions that may also be associated with psychiatric manifestations, such as psychosis, mania, autism spectrum disorder, ADHD, OCD, and self-injurious behaviours. The page begins with a clinical definition of flat face based on the standardized Elements of Morphology terminology, together with visual examples from the same source. This is followed by a list of conditions in which flat face has been described in association with psychiatric manifestations.
Of note, to optimize clinical utility, the list does not include conditions associated with intellectual disability in the absence of other psychiatric features.
Each condition listed below is linked to a dedicated page within this resource. These pages describe the psychiatric manifestations associated with each condition, as well as other morphologic and broader clinical features, allowing the differential diagnosis to be considered from multiple perspectives.
Flat face
Image credit: National Human Genome Research Institute (NHGRI), Elements of Morphology.
Definition
Subjective: Absence of concavity or convexity of the face when viewed in profile.
Comments: A useful guide is to imagine that a line connecting the glabella to the anterior most part of the mandible touches the top of the philtrum where it meets the base of the columella. The glabella is the most prominent point on the frontal bone above the root of the nose. If the superior philtrum is anterior to this line the face is convex, if the superior philtrum is posterior to this line the face is concave.
Conditions with potential psychiatric associations
Selected references and further reading — Morphologic lens
Allanson JE, Biesecker LG, Carey JC, Hennekam RCM. Elements of morphology: introduction. Am J Med Genet A. 2009;149A(1):2-5.
Hennekam RCM, Biesecker LG, Allanson JE, Hall JG, Opitz JM, Temple IK, Carey JC; Elements of Morphology Consortium. Elements of morphology: general terms for congenital anomalies. Am J Med Genet A. 2013;161A(11):2726-2733.
Jones KL, Jones MC, del Campo M. Smith's recognizable patterns of human malformation. 8th ed. Philadelphia: Elsevier; 2021.
Reardon W. The bedside dysmorphologist: a guide to identifying and assessing congenital malformations. 2nd ed. Oxford: Oxford University Press; 2016.