[Use of autogenous cranial bone grafts for orbital floor reconstruction]

To evaluate the effects of autogenous calvarial bone grafts on treatment of the patients with defect of orbital floor from facial trauma.

During a 5-year period from April 1994 to April 1999, 34 patients ranging in age from 16 to 68 years (twenty males and fourteen females), who presented with orbital floor defects associated with other facial fractures were reconstructed by autogenous calvarial bone grafts. The surgical approach to the orbital floor involved a transconjunctival incision in 31 patients and a subciliary incision in 3 patients. After the orbital floor exploration, the bone graft was harvested through the coronal incision in 29 patients and the parietotemporal region incision in 5 patients. The bone graft was then fashioned to the appropriate size and configuration and fixed to the stable bone of the orbital floor with microplates or screws.

The surgical incisions healed well with a minimal scar. There were no infection, extrusion or other complications associated with autogenous calvarial bone graft. There were no cases of optic neuropathy, diplopia and enophthalmos. There was no morbidity in donor sites. One patient had slight ectropion, which lasted three months and became inconspicuous in six months. 8 cases with hypoesthesia of the infraorbital region returned the sensory function within 6 months. 6 patients with enophthalmos were partly corrected. The follow-up period ranged from 6 months to 5 years.

The orbital floor defects should be managed by early exploration to avoid later complications. The sequel, such as enophthalmos and dystopia or diplopia are much more difficult to correct after bony union. A vast array of autogenous and alloplastic materials have been used to reconstruct the defect of orbital floor. Autogenous bone graft reduces the risk of infection and extrusion. Cranial bone graft produces less donor site morbidity compared with other sites, non-visible scar as the incision is placed within the hair-bearing skin and the conjunctiva. The membranous bone from the skull has been shown to undergo less resorption and greater graft volume survival as compared to endochondral bone of the iliac crest or rib. Skull bone is an ideal source of bone graft in orbital reconstruction.