The nasal bridge is the narrow ridge running along the top part of the nose. It begins at the point between the eyes and continues downward to the area just before the nose begins to flare out and become the nostrils. An abnormal size and shape to the nose’s bridge can indicate a genetic disease or fetal alcohol syndrome.
The bridge of the nose, along with the tip of the nose and the nostrils are the most prominent external features of the nose. Formed by the meeting of two plate-like nasal bones, the nasal bridge is the pitched roof over the nose. This area provides support, protection and structure to the internal parts of the nose.
Many birth defects are characterized by a broad or low bridge. A broad bridge will have a larger than normal angle where the two, slanted nasal bones meet. In this situation, the nose will appear very wide just below the eyes. A low nose bridge, often referred to as saddle nose, will curve inward rather than run flat along the top of the nose. Fragile X syndrome, Down syndrome and fetal alcohol syndrome are all characterized by a broad or low bridge.
Fragile X syndrome is a genetic condition caused by mutation on the X chromosome of the FMR1 gene. Along with a broad nasal bridge, this disease manifests with other abnormal physical features, such as a long, thin face with a conspicuous chin, large head, flat feet and loose joints, as well as mental retardation and autistic-like behavior. Use of alcohol during pregnancy, resulting in fetal alcohol syndrome, can produce not only a low nasal bridge but also wide-set eyes with drooping eyelids, genital deformities, cleft lip and heart defects.
Down syndrome is a genetic abnormality in which the person typically has an extra chromosome 21 resulting in a total of 47 rather than the usual 46 chromosomes. This extra chromosome is responsible for dysmorphic attributes of the face and hands, mental retardation and defects of the heart common with Down syndrome. The abnormal nasal bridge characteristic of Down syndrome is so prominent that it is often used as a marker for the disease in fetal sonograms.
The nasal bridge can be altered cosmetically with rhinoplasty or with ornamentation. Rhinoplasty can be used to narrow a broad nose or reshape a low bridge. Ornamentation of the nose can be performed by piercing the nostril, septum or the bridge of the nose. The bridge of the nose is pierced by pinching together the skin over the bridge and piecing the skin.