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Central nasoethmoidal complex
highlighted (yellow). Insert shows attachment of medial canthal ligament.
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Anatomic detail of medial
orbital wall.
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Coronal section of the interorbital
space in relation to the anterior fossa. Anatomic detail of ethmoidal
sinuses and nasal cavity. Arrow shows drainage route of the frontal
and ethmoidal sinuses.
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The naso-orbital-ethmoid
region consists of the cranium, nose,
orbit,
and maxilla. The structural
strength in this area comes primarily from the frontal
process as it extends down from the anterior cranium. The
medial
portion of the buttress and its associated
lamina
papyracea as well as the lacrimal bone,
and the ethmoid bone are thin,
fragile,
frequently comminuted, and displaced in
a medial direction. The more delicate nasal
bones are anterior to the medial portion of
the orbit and compose the
superior
most connection
to the frontal bone
laterally and articulate with the major portion
of the lacrimal bone and frontal process of
the maxilla. The
attachment
of the medial canthal tendon is in
this area of the frontal process and lacrimal
bone. The spaces posterior to the nasal complex are the ethmoidal
air cells. They are located centrally
and are vulnerable to injury. Because of their proximity
to the cribiform plate, their collapse and
displacement may be associated with CSF rhinorrhea,
pneumocephalus and injury to the nerves
of olfaction. Just
superior to the nasal bones and their junction with the frontal process
posteriorly lies the frontal sinus, which
is part of the internally pneumatized frontal bone. Associated fractures
of this area are common. The floor of the frontal sinus composes
a portion of the medial roof and is invariably involved in this injury. |
