"The difficulty in defining nasal bone hypoplasia has historically lead to the development of various criteria, based on measurements such as BPD : nasal bone ratio 7, gestational age-adjusted nasal bone length, or a single cut-off definition (2.5 mm) 8."
Expected headings
"Associations"
"There is a spectrum of nasal bone hypoplasia, at one end of which is the relatively easily identified absent nasal bone. The other end of the spectrum is considerably harder to define, particularly when used as a screening tool (see below)."
"it relates to the phenotypical observation that individuals with Down syndrome have short noses; as well as a growing body of supportive radiological data"