Infraorbital sinus infections, which form the bulk of upper respirator
y tract infections in companion birds. are commonly encountered in cli
nical practice and often require medical and/or surgical management, T
he infraorbital sinus with its dorsal drainage into the nasal cavity m
akes it difficult to treat these infections, The sinus has various com
partments throughout the skull and subcutaneous tissue, As an aid in d
etermining the location and extent of the sinuses of the parrot and ma
caw. a corrosion cast of the infraorbital sinus was made, also, comput
ed tomography (CT) images of cadaver heads were completed at 2-mm scan
s, Prior to sectioning for sheet plastination, the infraorbital sinus
of one half of the imaged heads was injected with a mixture of colored
epoxy, The specimens were frozen (-25 degrees C) prior to sawing 2-mm
-thick sections which corresponded to the CT scans, The sections were
dehydrated, impregnated and sheets prepared using the standard E12 tec
hnique, The slices were used to identify the compartments of the infra
orbital sinuses and to aid identification of such on the CT images.