The nasal bones are two small oblong bones situated at the upper part of the face and forming the bridge of the nose. Each bone is thicker and narrower above, thinner and broader below, and presents for examination two surfaces and four borders.
The facial surface is concave from above downward, convex from side to side, and near the centre is perforated by a small foramen, which transmits a small tributary to the facial vein. The posterior or nasal surface, covered in the recent state by mucous membrane, is concave laterally, and traversed by a longitudinal groove [sulcus ethmoidalis] for the anterior ethmoidal branch of the ophthalmic division of the fifth nerve. The short superior border is thick and serrated for articulation with the medial part of the nasal notch of the frontal. The inferior border is thin, and serves for the attachment of the lateral nasal cartilage. It is notched for the external nasal branch of the anterior ethmoidal nerve. The nasal bones of the two sides are united by their medial borders, forming the inter-nasal suture. The contiguous borders are prolonged backward to form a crest which rests on the frontal spine and the anterior border of the perpendicular plate of the ethmoid. The lateral border articulates with the frontal process of the maxilla.
Blood-supply of the nasal bone
Arteries are supplied to this bone by the nasal branch of the ophthalmic, the frontal, the angular, and the anterior ethmoidal arteries.
Articulations of the nasal bone
With the frontal, maxilla, ethmoid, and its fellow of the opposite side.
Ossification of the nasal bone
Each nasal bone is developed from a single center which appears about the eighth week in the membrane overlying the fronto-nasal cartilage. The cartilage, which is continuous with the ethmoid cartilage above and the lateral cartilage of the nose below, sub-sequently undergoes absorption as a result of the pressure caused by the expanding bone. A.t birth the nasal bones are nearly as wide as they are long, whereas in the adult the length is three times greater than the width.