At higher risk for oral
disease, Down patients
require specialized oral
TAYLOR SWISHER, BS, RDH;
HALEY PRYOR BS, RDH, EFDA; AND
DANIEL SCHURMAN, BS, RDH
Down syndrome is an intellectual disability
caused by changes in the DNA sequencing of
chromosome 21. The World Health Organization
estimates the worldwide incidence of Down
syndrome to be approximately one in 1,000 live
1 There are three types of Down syndrome.
The most common type is trisomy 21, which
occurs when there are three copies of chromosome 21 instead of two copies.
1 The next type is
translocation Down syndrome. Translocation
Down syndrome occurs when an extra part of
chromosome 21 breaks off and attaches, or translocates, to a different chromosome.
1 This type
accounts for a small percentage of people.
mosaic Down syndrome is a mixture or combination of the other two types.
1 Individuals with
mosaicism have three copies of chromosome 21
in some cells but not all.
1 These individuals may
have some but not all of the features of Down
syndrome, due to the presence of some cells with
the typical number of chromosomes.
Individuals with Down syndrome may have
physical features characteristic of the disorder.
Some physical signs of Down syndrome include
a small head; upward slanting eyes, often with