Abstract
Seven adult platyrrhine monkeys (Cebus apella) of both sexes, had their right zygomatic bone fractured and displaced by surgery. After a time lapse of 7 months, they were sacrificed, macerated, and the crania were studied by means of radiography, the split-line technique, and scanning electron microscopy.
The changes on the operated side, observable by radiography, consisted mainly of a discrete disorganization of the zygomatic bone trabeculae and diminution of the radiopacity of the lateral-inferior margin of the orbit, of the zygomaticoalveolar crest and of a line that accompanied the zygomaticomaxillary suture.
The split-line technique, applied to the operated osseous region, demonstrated a fibrous disarrangement of the body of the zygomatic bone and of the fractured and repaired areas. At the level of the zygomatico temporal and zygomaticomaxillary sutures, the split-lines converged to the extremity of the involved processes (those which showed volumetric increases) and did not pass along the other side, as on the normal side. The convergence of the lines associated with the volumetric increase displayed an adaptation to the concentration of mechanical forces in the extremity of each process.
Scanning electron microscopy of superficial areas of the decalcified and nondecalcified zygomatic bone revealed changes on the operated side compared to the control one. These included irregular and disorganized compact bone showing depression, micro-elevations and irregular foramina, still evidencing a fibrillar arrangement without a defined structural pattern as regards the architectural orientation.
