Congenital Choanal Atresia: Report of Three Cases Occurring in One Family

There have been over 500 cases of congenital choanal atresia reported in the literature,^1-3 but the cause of this developmental anomaly has continued to remain obscure. Several theories have been advanced concerning the mechanism of development,⁴ and among these are (1) continued dorsal growth of the nasal fossae in front of the nasopharynx, with a variable amount of mesenchymal tissue being caught between their epithelial surfaces⁵; (2) closure of the primitive nasal fossae by an epithelial plug, which then organizes forming a bony or membranous closure posteriorly⁶; (3) failure of development of the posterior end of the primitive posterior nares while there is a normal full development of the palate²; (4) failure of the buccopharyngeal membrane to be absorbed (this occurs in those cases of atresia which lie posterior to and against the posterior choanae),⁷ and (5) embryological overproduction of tissue in the region