Thenasal bones are two small oblongbones, varying in size and form in different individuals; they are placed side by side at the middle and upper part of theface and by their junction, form thebridge of the upper one third of thenose.
There is heavyvariation in the structure of the nasal bones, accounting for the differences in sizes and shapes of the nose seen across different people. Angles, shapes, and configurations of both the bone and cartilage are heavily varied between individuals. Broadly, most nasal bones can be categorized as "V-shaped" or "S-shaped" but these are notscientific or medical categorizations. When viewinganatomical drawings of these bones, consider that they are unlikely to be accurate for a majority of people.[1]
The two nasal bones are joined at the midlineinternasal suture and make up thebridge of the nose.
Theouter surface isconcavo-convex from above downward, convex from side to side; it is covered by theprocerus andnasalis muscles, and perforated about its center by thenasal foramen, a small passageway for the transmission of a smallvein from the overlying soft tissues.
Theinner surface is concave from side to side, and is traversed from above downward, by a groove for the passage of a branch of thenasociliary nerve.
In primitivebony fish andtetrapods, the nasal bones are the most anterior of a set of four paired bones forming theroof of the skull, being followed in sequence by the frontals, theparietals, and thepostparietals. Their form in living species is highly variable, depending on the shape of the head, but they generally form the roof of the snout or beak, running from the nostrils to a position short of the orbits. In most animals, they are generally therefore proportionally larger than in humans or great apes, because of the shortened faces of the latter.Turtles, unusually, lack nasal bones, with theprefrontal bones of the orbit reaching all the way to the nostrils.[2]
