INTRODUCTION
Axenfeld-Rieger syndrome (ARS) is a rare autosomal dominant disorder
with complete penetration and variable expressivity
(1). The first description of the
inherited syndrome was in 1935 by Rieger
(2, 3).
Different estimated incidence has been described 1:200.000
(2), 1:50.000 to 1:100.000
(1). 70% of the cases are inherited and
30% are arising de novo (4). ARS has
variable expressivity and it is considered to be a heterogeneous
disorder both morphologically and genetically
(2, 3,
5). There is not reported any racial or
sexual predilection (6,
7) and the syndrome has been described in
different ethnic groups, including Asia, Middle East, South and North
America, Africa and Europe (1).
ARS is a combination of anterior chamber cleavage syndrome and nonocular
abnormalities (8). Since 1989
(9) the term ARS has been used
collectively for, Axenfeld’s syndrome, Axenfeld’s anomaly, Rieger’s
anomaly and Rieger’s syndrome (10). An
overview is giving in table 1 with a description of the different
anomalies and syndromes according to Bender et al.
(10). ARS is characterized as a syndrome
with malformation of the anterior segment of the eye in combination with
a wide spectrum of non-ocular abnormalities such as dental, craniofacial
and somatic abnormalities. The wide range of clinical presentation and
developmental disturbances is described by many authors in the
literature (2-8,
11, 12)
and is listed in table 2. Hypodontia and failure of the periumbilical
skin to involute is most frequently seen
(3, 7,
8). A change in the periumbilical skin can
be wrongly diagnosed as umbilical hernia and lead to unnecessary surgery
(1).
Pathogenesis of ARS is assumed to be a genetic failure that results in
development disturbance in the late gestation period. A defect in the
ectodermal tissue due to a change in migration and differentiation of
the neural crest tissue is thought to be the cause
(8, 9). The
neural crest cells are responsible for the formation of the craniofacial
and ocular structures including bones, cartilage, dental papillae,
pituitary gland and the umbilical ring
(7). ARS is in the literature
(1, 13)
divided in to three different types, due to different genetic mutations
and deletions (14,
15) combined with different ocular and
systemic expressions see table 3.
The aim of this study is to present to two families with Axenfeld-Rieger
Syndrome, present their clinical findings, treatment of the dental
anomalies and dentofacial deformities.