Agenesis of first and second permanent molar: Literature review and cases reports

Abstract

SUMMARY
Tooth agenesis is the absence of one or
more teeth in temporary or permanent dentition.
This anomaly in craniofacial malformations
is more frequent, that may occur as
an isolated anomaly or as part of a genetic
syndrome. The incidence of agenesis of
permanent teeth varies1.6-9.6%, excluding
third molars, while in primary dentition the
range is 0.5 to 0.9%. The factors that are
related to dental agenesis, are the genes and
signaling pathways. Specifically Pax9 has
been associated with the lack of permanent
molars. Agenesis of the first and second
permanent molars is not very common
but has been reported in the literature and
can be isolated or causing malocclusion.
Therefore, early diagnosis is essential to
establish a treatment plan to help guide the
eruption of other teeth and prevent sequel
due to agenesis. Four clinical cases are presented
of patients with agenesis of first and
second permanent molars to complement
the literature review.
Key words: Dental agenesis, first permanent
molars, second permanent molars,
malocclusion, organogenesis defect.