Catharine Wright wrote:

 >I have had discolored teeth since I was an infant.  I am now 25 years old.
 >We could never precisely pinpoint the cause or find a cure

Discolored teeth is one of the possible symptoms of undiagnosed celiac
disease. I tried finding a web page listing this. While lots of pages note
the relationship, none were as well laid out as an article I have in my
files. So here is that one:

 From the Canadian Celiac Association's "Celiac News" dated Spring '94:

Excerpts from "Update" Nov. 93, a publication of the College of Dental
Surgeons of British Columbia. Reprinted with permission.

Children with celiac disease often reveal pathognomonic enamel defects
systematically and chronologically in all four quadrants. Dentists can play
an important role in screening patients possibly suffering from celiac disease.

Patients with symmetrical enamel hypoplasia in permanent teeth should be
advised to seek serologic screening using sensitive and/or invasive tests
for evidence of small bowel mucous villous atrophy.

Celiac Disease as Classified by Enamel Defects are:

Grade 0: No defect.

Grade I: Defect in colour of enamel only; single or multiple cream, yellow
or brown opacities with clearly defined or diffused margins; all or part of
the enamel surface is without a natural glaze.

Grade II: Minor structural defects; rough enamel surface, horizontal
grooves or shallow pits, light opacities and/or discoloration may be found;
or part of the enamel surface is without a natural glaze.

Grade III: Evident structural defects; all or part of the enamel surface is
rough with deep horizontal grooves of varying width; may have large
vertical pits; large opacities of strong and varying discoloration.

Grade IV: Severe structural defects; the shape of the tooth may be abnormal
with cusp tips sharply pointed and/or the incisal edges unevenly thinned
and roughened; margins of the lesions are well defined and strongly discoloured.