My name is Dr. Sook-Bin Woo,
and I am Associate Professor
at the Harvard School
of Dental Medicine.
The topic for this lecture is Pigmented,
Brown or Black Lesions
of the Oral Cavity.
Pigmentations can occur
from either an exogenous sources,
which means outside the body,
or from an endogenous source,
which means inside the body.
The most common exogenous sources
of pigmentation are foods
that we eat every day,
so things like coffee and tea
that we drink
will often cause staining of the teeth.
Other very common exogenous pigments
that can cause lesions
in the oral cavity include amalgam,
graphite, medications that are taken,
ritual tattoos that occur
in some cultures in the world,
as well as imbibing heavy metals
for whatever reason.
are those that are produced
by the cells within the body
and the two most common
are melanin pigment
produced by melanocytes,
which are often found on the skin
and also of coarse
within the oral epithelium
as well as blood-related pigments,
and these are related primarily
to the break down of red blood cells.
I just wanted to mention an interesting
chemical called homogentisic acid,
which is a phenolic acid
that is produced in the body
or accumulates in the body in patients
which is poorly controlled,
and this causes very dark pigmentation
of many organs in the body.
But we're not going
to talk about that today.
It's just sort of an interesting