What is Crouzon
Syndrome is a hereditary condition diagnosed based on a
pattern of cranial and facial malformations. The basic
identifiable sign of Crouzon Syndrome, present also in
many similar disorders, is premature fusion of the
sutures. Facial symptoms include small eye sockets,
midface hypoplasia, and vertically compressed nasal
passages (giving the nose a "beaked" appearance).
Non-craniofacial symptoms are also sometimes present.
Crouzon (usually pronounced "krooz-on") Syndrome is
sometimes also called craniofacial dysostosis or
Crouzon's disease, though these terms are no longer
What are the
wide range of symptoms have been attributed to Crouzon
Syndrome, but the standard craniofacial symptoms are:
premature fusion of sutures, a "flat" sphenoid bone,
exophthalmos (protruding eyes), a hypoplasic midface/small
palate with subsequently compressed nasal passages, and
a large jaw. Severity of all Crouzon symptoms varies
from case to case.
Premature Fusion of Sutures.
The basic, and usually most dangerous, effect of
Crouzon Syndrome is premature fusion of the sutures. The
two sutures involved are usually the two coronal
sutures, although this is not always the case; when the
two coronal sutures are the only two fused, this leads
to an abnormally high forehead. The condition is usually
referred to as acrocephaly. There have been cases, in
Crouzon Syndrome, of a wide variety of sutural fusions.
Regardless of the type of cranial vault deformation,
surgery is almost always necessary to allow the brain
room to grow. There are, however, a wide variety of
surgeries available which generally leave the patient
with a relatively normal skull shape and full bone
In most cases of
Crouzon Syndrome, the sphenoid bones (the temples) are
"flattened". Although this is generally one of the
criteria employed to diagnose Crouzon Syndrome, it is
not usually a terribly noticeable or debilitating
craniofacial symptom (despite its proximity to various
sensitive craniofacial areas); it's a good thing, too,
because it is virtually impossible to surgically
The most obvious and distinctive facial symptom of
Crouzon Syndrome is exophthalmos (protruding eyes). It
is pretty much impossible to fully correct by surgery,
although procedures exist to reduce its severity.
Exophthalmos is probably the Crouzon symptom most likely
to get a child teased on a playground, but is usually
otherwise benign. Personal experience has taught this
author that exophthalmos sometimes becomes less marked
as the patient grows older.
In Crouzon Syndrome, the
midface (maxilla and nasopharynx) does not naturally
"grow out" as far as it does in most people; it's
smaller and located slightly further back in the face.
This, combined with the unusually large lower jaw (see
below), causes the upper teeth to be out of alignment
with the lower teeth. The size and location of the
nasopharynx causes vertical compression of the nasal
passages, often leading to a reduced airflow through
nose breathing. The vertical compression of the nasal
passages is generally referred to as "Croupert", because
it occurs frequently both in Crouzon and Apert
syndromes. Procedures exist to "pull out" the midface,
although such procedures are fairly lengthy and
Another facial symptom
common in Crouzon is the large jaw. This (by contrast)
causes the midface hypoplasia to appear worse than it
is, and also leads the lower teeth to be further out of
alignment with the upper. The large jaw is probably the
Crouzon symptom most easily correctable by surgery.
What are some other common
Syndrome frequently causes disorders related to auditory
canals which may lead to hearing loss. Sleep apnea is
also extremely common.
Once reported in textbooks
as a condition unassociated with non-craniofacial
deformities, it has now been linked to other symptoms as
well. Among them are vertebral malformations (curvature
or subluxation of the spine), digital fusion, and
ankylosis of the elbow joints.
complications have been reported whose presence in
Crouzon patients may or may not be coincidental (such as
valve blockages, mitral valve disorders, eye disorders,
respiratory dysfunctions, and serious spinal
deformities). Specialists are still trying to isolate
the symptoms caused by Crouzon Syndrome from symptoms
caused by unrelated conditions.
What are "Type I" and "Type II"?
Type I Crouzon Syndrome
consists only of craniofacial symptoms; Type II includes
both craniofacial and non-craniofacial symptoms.
Can Crouzon Syndrome be
Current medical literature seems to have reached the
consensus that a child, in a situation where one parent
has Crouzon Syndrome, has roughly a fifty percent chance
of being born with the condition.
Can Crouzon Syndrome occur
"spontaneously", without a family history of the
it frequently does. Statistics seem to suggest that
Crouzon Syndrome occurs spontaneously in twenty-five to
fifty percent of cases.
WHAT KIND OF SURGERY IS USED TO TREAT
Premature fusion of the sutures.
The premature fusion of
the sutures is generally corrected as soon as reasonably
possible after birth, to prevent potential brain damage.
Depending upon the severity of cranial deformation,
several options are available. Virtually all surgical
options involve removal and replacement of the cranial
vault to relieve pressure; the removal of cranial bone
is called a craniectomy. Craniectomies may be partial
(wherein only some bone, usually a strip, is removed
from the skull and replaced) or full (wherein the entire
skull is removed, fragmented, and put back in place to
grow together). The latter is referred to as a
morcellation craniectomy. Skull shape is maintained
through external molds; thanks to a procedure invented
twenty years ago, called lateral canthal advancement,
one may have a partial or full craniectomy and still
maintain a normal skull shape.
Exophthalmos is difficult to
treat. Various procedures exist, orbital surgeries and
non-orbital surgeries. Non-orbital surgeries are
performed with minimal interference with the eye socket
proper, focusing instead on the bone surrounding the eye
socket. For example, surgery in which one grafts bone to
the browline or cheekbone would not involve surgery in
the orbits proper. Orbital surgery involves actually
placing the eyes further back in the orbits or changing
Often times exophthalmos is
caused by prematurely fused shallow orbits; through
surgery, the bone of the orbits can be removed and
allowed to reossify. In some cases, however, the shallow
orbits are due to a tight craniofacial structure and
removing the orbital bones may accomplish little.
The large jaw.
As Crouzon symptoms go, the
large jaw is remarkably easy to treat. Surgical
advancements have led to a scarless lower jaw reduction
wherein portions of the mandible are actually removed
via incisions made inside the mouth. The jaw is then
held together by wires and the bone allowed to heal.
Common Type II symptoms.
The author is still
researching surgeries used to treat Type II symptoms,
but hopes to finish this section within the very near
What is Crouzon Syndrome similar
Crouzon Syndrome and Apert Syndrome are remarkably
similar. Both involve cranial vault fusion (usually of
the same sutures, nonetheless) and midface hypoplasia
(leading to vertically compressed nasal passages which,
because they occur in basically the same fashion in both
conditions, are referred to as "Croupert").
There are, however, some qualifying differences between
the two conditions. Apert Syndrome is more likely to
involve non-craniofacial deformations (digital fusion is
extremely common); further, while most Crouzon cases are
hereditary, most Apert cases are not.
Like Crouzon Syndrome, Saethre-Chotzen involves
premature cranial vault fusion. Whereas the premature
synostosis causing Crouzon's maxillary hypoplasia is
central to the face, however, Saethre-Chotzen's facial
anomalies tend to be more localized and vary greatly
from individual to individual. Rather than exophthalmos,
Saethre-Chotzen patients tend to have "drooping" upper
eyelids. Saethre-Chotzen is also marked by non-facial
conditions such as fusion of skin tissue, short digits,
and various skeletal malformations.
While Carpenter (Carpenter's) Syndrome was technically
discovered in 1901, it was not widely diagnosed until
1966. It involves premature cranial vault synostosis,
leading generally to severe acrocephaly (resulting very
often in mental retardation). Varying eyelid and digital
anomalies are also common.
Pfeiffer Syndrome involves premature cranial vault
synostosis of both coronal sutures, whereas in Crouzon
Syndrome other sutures may be the culprit. Like Crouzon
Syndrome, however, Pfeiffer Syndrome causes midface
hypoplasia. Pfeiffer Syndrome is also identified by
unusually wide thumbs and fusion of the soft and/or
connective tissue in the hands.
Waardenburg Syndrome involves a cleft palate,
displacement of the eyelids, partial albinism, a broad
septum, deafness, and various limb defects. Premature
cranial vault synostosis is not, however, a common
effect of the condition.
Treacher-Collins Syndrome (also known as Franceschetti-Klein
Syndrome or mandibulofacial dysostosis) was first noted
in 1846, although clear diagnostic criteria were not
established until 1949. It is marked by maxillary and
mandibular hypoplasia, outer ear malformations, and
various eyelid malformations.