An anatomical study of the columella and the protruding premaxillae in a bilateral cleft lip and palate infant.

An anatomical reconstruction of the protruded premaxillary segment of an infant with bilateral cleft of the primary palate was made from serial histological sections and described in comparison with reconstruction columella, alar cartilages, nasal septum, and premaxillae of a neonatal control specimen. Most of the bilateral cleft abnormality was seen in the premaxillary bones which were advanced on the nasal septum and whose alveolar process protuded anteriorly into the columellar area. The medial crura of the alar cartilages and the nasal septum in the cleft specimen showed an essentially normal structure. Underdevelopment of the columbella was considered as primarily failure in the development of columellar skin caused by the invasive obstruction by the premaxillary bones.