A flat facial profile, often described by clinicians as midface retrusion or midface hypoplasia, refers to a reduced projection in the central part of the face. This area includes the upper jaw (maxilla), cheekbones, and the region beneath the eyes. Instead of a gently convex or forward-jutting profile, the middle face appears underdeveloped, smaller than average, or positioned further back relative to the forehead and lower jaw. The causes stem from inherited traits, environmental factors during growth, and specific medical conditions.
The Role of Genetics and Ancestry
Inherited characteristics represent the most common reason for a specific facial profile, including one with reduced projection. Facial morphology is highly heritable, meaning the shape and size of your skull, jaw bones, and the relative position of your features are largely dictated by the genes passed down from your parents. Twin studies have shown that genetic factors can account for over 70% of the variation seen in many facial dimensions, such as facial depth and convexity.
The size of the maxilla and the forward growth of the midface are determined by a vast network of genes. If your parents or other close relatives have a similar profile, your facial structure is likely a normal genetic expression for your family line.
Ancestral background also plays a significant role in determining population-specific norms for facial structure. Certain populations, particularly those of East Asian descent, commonly exhibit a naturally flatter face in the transverse plane, which is an expected trait. A genetic profile can lead to a shorter maxilla or a more upright position of the front teeth, which contributes to the appearance of a recessed midface.
Developmental Factors Shaping Facial Structure
The way a person grows during childhood and adolescence significantly influences the final shape and projection of the face. The growth of the facial bones, especially the maxilla, is highly sensitive to external functional pressures, which can either guide forward growth or restrict it.
One of the most impactful developmental factors is chronic mouth breathing, often caused by obstructed airways due to enlarged tonsils, adenoids, or persistent allergies. When the mouth is habitually open to breathe, the tongue adopts a low resting posture in the floor of the mouth. This low tongue position removes the natural internal pressure that the tongue exerts on the roof of the mouth, which is necessary to guide the maxilla to grow wide and forward.
This lack of outward and forward force allows the cheeks’ external muscles to exert greater inward pressure, leading to a narrow upper jaw and a high, arched palate. The restricted horizontal and forward growth of the maxilla results in the characteristic appearance of a recessed midface and a steeper, longer facial profile.
The correct tongue resting position—known as the lingual resting position—is a major determinant of ideal midface development. When the tongue rests correctly, it stimulates the maxillary bone to expand and project forward, accommodating all teeth and supporting a harmonious profile. Early intervention, sometimes involving specialized orthodontic appliances for skeletal expansion, can help to widen the palate and encourage this forward growth, especially in growing children. The function of the chewing muscles is also relevant, as a diet that requires rigorous chewing applies forces to the facial bones that stimulate robust jaw development.
Medical Conditions Affecting Facial Profile
In a smaller number of cases, a flat or recessed facial profile is a defining characteristic of a specific medical or skeletal condition. These conditions are typically rooted in congenital issues or acquired trauma that directly interfere with the normal proliferation of bone cells in the midface.
A number of congenital syndromes are associated with midface hypoplasia, where the maxilla does not grow at the same rate as the lower jaw or the rest of the skull. Examples include certain craniosynostosis syndromes, such as Crouzon and Apert syndromes, where premature fusion of the skull sutures restricts the growth of the surrounding bones, including the midface. Other conditions, like Achondroplasia, are also characterized by midface retrusion due to defective bone formation.
Binder syndrome, or maxillonasal dysplasia, is a specific inherited abnormality that presents with a severe lack of projection in the mid-facial skeleton, resulting in an extremely flat nose and retruded maxilla. In these syndromic cases, the underdeveloped maxilla can make the lower jaw appear overly prominent, a condition referred to as relative prognathism.
Acquired issues, like severe facial trauma, can also lead to a flat profile if the maxilla is fractured and heals in a restricted, backward position, known as malunion. Children born with a cleft palate may experience restricted forward growth of the upper jaw, even after surgical repair, because the necessary bone fusion or scarring can inhibit subsequent natural expansion. These conditions usually require specialized treatment from a craniofacial team to address both the functional and aesthetic impacts of the inhibited growth.