Cleft lip, nose, and palate: the nasal septum as the pacemaker for midfacial growth.

The need to be aware of the dynamics of cartilage development and growth is encountered by surgeons whenever they attempt to correct craniofacial defects such as unilateral or bilateral cleft lip/cleft palate or midfacial injuries after trauma. Within the craniofacial region, the nasal septal cartilage and the sphenoethmoidal and sphenooccipital cranial synchondroses are distinguished from other craniofacial cartilages in possessing intrinsic growth potential. Indeed, growth of the nasal septal cartilage outstrips the growth of other skeletal and soft tissues in the midface to such an extent that it is the pacemaker for growth of the face and anterior portion of the skull. We revisit and reinforce the importance of the nasal septum as pacemaker with analysis of 3 classes of evidence: in vivo growth of the nasal septum in nonhuman mammalian models; composition and in vitro growth of nasal septal cartilage or chondrocytes; and experience from the surgical repair of unilateral or bilateral facial clefts.