ADEX Dental Hygiene Exam Prep

Answer: B - Trisomy 21 is Down syndrome. It is defined as a mental retardation disorder and is the most common chromosomal abnormality affecting 1 in 700 births, but varies with maternal age. Individuals with Down syndrome display a variety of abnormal features. A short list includes small brachycephalic skull, front flat facies, small nasomaxillary complex, ocular hypotelorism, and simian crease.