[Long-term outcome after frontal sinus obliteration with an ionomer bone substitute in the cat. I: Histological results].
BACKGROUND
Osteoplastic frontal sinus surgery in combination with sinus obliteration may occasionally be performed for indications such as severe sinus inflammations, extensive wall fractures involving the nasofrontal duct, or osteomas. The material most frequently used for this obliteration is autogenous adipose tissue. Autografts such as muscle, cartilage, and bone chips have been also recommended for this purpose. In order to avoid the surgical procedure required for harvesting an autograft from other body sites, alloplastic materials have been suggested for frontal sinus obliteration.


METHODS
In an animal study using cats, the mucous lining of the frontal sinus was removed, the nasofrontal duct sealed with semifluid ionomer cement, and the cavity filled up with a solid and porous ionomer-based microimplant.


RESULTS
Histological investigations were performed up to two years after surgery. Increasing obliteration of the sinus cavity by bone regeneration, starting from the sinus wall, as well as formation of connective tissue between the cement grains was detected as early as one month after implantation. Osteoblasts lining the osteoid layer were considered to be an indication of active bone regeneration. Osteogenesis inside the sinus cavity continuously progressed during the following months. Two years after implantation, osteoid and newly mineralized bone encircled the microimplants leading to an almost complete obliteration. There was no evidence for mucosal regeneration or foreign body reaction.


CONCLUSIONS
Because of its osteoconductive effect, biocompatibility, and biostability the ionomer-based microimplant is a suitable alloplastic material for frontal sinus obliteration.
Dazert
S
S
Universitäts-HNO-Klinik Würzburg.
Baier
G
G
D000818:Animals; D001861:Bone Regeneration / Q000502:physiology; D018786:Bone Substitutes; D002415:Cats; D003238:Connective Tissue / Q000473:pathology; D005260:Female; D005626:Frontal Sinus / Q000473:pathology / Q000601:surgery*; D005899:Glass Ionomer Cements; D008422:Materials Testing; D016348:Osseointegration / Q000502:physiology*; D014945:Wound Healing / Q000502:physiology
D018786:Bone Substitutes; D005899:Glass Ionomer Cements