The fleshy external end of the nasal septum is called the
columella or columella nasi, and is made up of
cartilage and soft tissue. The nasal septum contains bone and
hyaline cartilage. It is normally about 2 mm thick. The nasal septum is composed of four structures: •
Maxillary bone (the crest) •
Perpendicular plate of ethmoid bone •
Septal nasal cartilage (i.e., quandrangular cartilage) •
Vomer bone The lowest part of the septum is a narrow strip of bone that projects from the maxilla and the
palatine bones, and is the length of the septum. This strip of bone is called the maxillary crest; it articulates in front with the septal nasal cartilage, and at the back with the vomer. The maxillary crest is described in the anatomy of the nasal septum as having a maxillary component and a palatine component.
Development of infant At an early period, the septum of the nose consists of a plate of cartilage, known as the
ethmovomerine cartilage. The posterosuperior part of this cartilage is
ossified to form the perpendicular plate of the
ethmoid; its anteroinferior portion persists as the septal cartilage, while the
vomer is ossified in the membrane covering its posteroinferior part. Two
ossification centers, one on either side of the middle line, appear about the eighth week of
fetal development in this part of the membrane, and hence the vomer consists primarily of two lamellae. About the third month, these unite below, and thus a deep groove is formed in which the cartilage is lodged. As growth proceeds, the union of the lamellae extends upward and forward, and at the same time, the intervening plate of cartilage undergoes absorption. By the onset of
puberty the lamellae are almost completely united to form a median plate, but evidence of the bilaminar origin of the bone is seen in the everted alae of its upper border and in the groove on its anterior margin. == Clinical significance ==