가토의 두개안면골봉합선의 견고한 고정이 골성장에 미치는 영향

Abstract

Plate and screw fixation has had a profound effect on the recent development of craniofacial surgery. Rigid fixation of the facial skeleton by using plate and screw has become routine in adults, many craniofacial surgeons have expanded its use to the pediatric patient. The effects of microplate and screw fixation on subsequent craniofacial growth, however, have not been qualified in infancy and childhood. Sixty white male rabbits, 4 weeks old and weighing 400 gm, were divided into 5 groups. Each group contains 12 rabbits. Group 1 was control and group 2 was sham. They operated periosteal elevation to the right of the midline over the nasal and frontal bone. Group 3: 2-hole microplate and screws were placed in the right nasofrontal suture. Group 4: 2-hole microplate and screws were placed in the right nasomaxillary suture. Group 5: microplates and screws were placed in the right nasofrontal and nasomaxillary suture. All rabbits were killed at 18 weeks postoperatively. We analyzed the changes in morphology to the result of differences in growth between the operated and unoperated group by direct osteometry on dry skull preparations, and the structures of the constrained suture were analysed under light microscopy. Periosteal elevation alone (sham group) showed no discenible change in the shape of craniofacial bone except localized periosteal thickening. Nasofrontal suture plating showed periosteal thickening and bony resorption around the plate, nasal flattening of plated side, an increase in the width of the nasal bone on the plated side, a slight nasal deviation (mean 2.0 degrees) to the plated side, and frontal displacement of microplate and screws. Nasomaxillary suture plating showed periosteal thickening and bony resorption around the plate, nasal flattening of plated side, a decrease in the width of the nasal bone on the plated side, and nasal displacement of microplate and screws. Nasofrontal and nasomaxillary suture plating showed periosteal thickening and bony resorption around the plate, nasal depression of plated side, a decrease in the width of the nasal bone on the plated side, a significant nasal deviation (mean 5.2 degrees) to the plated side, and frontal and nasal displacement of microplates and screws. The findings of this study show that the use of microplate and screw fixation of the growing craniofacial skeleton in the rabbit model leads to little evidence of localized growth retardation. But their use in the pediatric population should be viewed cautiously, because secondary growth disturbances can be produced with the use of these fixation devices. Careful observation of early and late growth is mandatory when microplates are used in the pediatric patient. It is recommended that the plates and screws are removed as soon as possible their bony union. Key Words: Craniofacial growth ,Rigid fixation ,Osteometry