Histochemical analysis of enzymes involved in the formation and metabolism of the nasal septal cartilage.

Formation of the nasal septal cartilage in prenatal and neonatal rats was studied histologically and by histochemistry to determine the manner, degree and participation of the nasal septal cartilage in midface growth and in bone formation of the face. Chondrogenesis of the nasal septal cartilage started at the 13th embryonic day, premaxillary and vomerin bone formation at the 14th embryonic day and endochondral bone formation of the septo-presphenoid area at the 17th embryonic day. After differentiation of the nasal septal cartilage, this cartilage supported ethmoid bone formation by endochondal ossification in the septo-presphenoid area. Nasal septal cartilage showed intense activity of lactate dehydrogenase, NADH2-diaphorase and a moderate activity of acid phosphatase, whereas premaxillary and vomerin bone showed intense activity of alkaline phosphatase. Osteoblasts showed intense activity of alkaline phosphatase, lactate dehydrogenase and NADH2-diaphorase and osteoclasts showed intense activity of acid phosphatase. During the embryonal period growth of the nasal septal cartilage could occur in an ethmoido-rostral direction supported by endochondral ossification and growth in length and height supported by apposition and interstitial growth.