2.1. Medical History: The patients were healthy
and were born at 38 weeks via an uncomplicated
Caesarean section delivery. The mother
developed food intolerance to dairy, wheat and
fructose during the pregnancy and also took
antibiotics during that time. During the first year
of life, the twins also developed allergies to
lactose and fructose and were given antibiotics
for repeated otitis media infections.
2.2. Dental History: A detailed history, extraoral
examination, intra oral examination and
radiographic evaluation were conducted.
Patient MB presented areas of white and
yellowish brown discoloration in the surface
enamel on teeth 21 and 46 (FDI Notation System),
respectively. The defective enamel appeared
to be of normal thickness and had a distinct
boundary demarcating it from the unaffected
enamel. The other FPMs and maxillary incisors
seemed unaffected.
A unilateral, left posterior crossbite was also
observed involving teeth 64-26 and 74-36 (Figs.
1-5).
Patient SB presented a similar white opacity on the
labial surface of tooth 21 in addition to yellowish
brown discoloration of the surface enamel in
teeth 16, 26, 36 and 46. SB also had a unilateral,
right posterior crossbite involving teeth 16-53
and 46-83 (Figs. 6-10).
In both cases the MIH-affected teeth were not
carious and there was no post eruptive breakdown
involved. The patients initially reported no pain or
sensitivity related to the MIH-affected teeth.
Both MB and SB had good oral hygiene and
reported brushing twice daily using fluoridated
to