[Effect of the discontinuity of the zygomatic arch on facial growth in young rats].

The results of experimental studies on the zygomatic arch during the growth period, through excisions or fractures, are controversial. In this study, the effect of a discontinuity of the zygomatic arch on facial growth was experimentally evaluated, without tissual damage or deviations. One-month-old rats were submitted to a surgical procedure in order to obtain a one-milimeter-wide discontinuity of the right zygomatic arch. The left side served as a control. After three months, the rats were sacrificed, their skull and hemimandibles were dissected, and radiographs were obtained. Cephalometric measurements were carried out in order to assess the dimensions of the infratemporal fossa, maxilla and mandible, by means of a computer system. There was no significant difference between the experimental and control sides as to the measurements pertaining to the maxilla and mandible. Significant difference was observed in the anteroposterior length of the infratemporal fossa. It was concluded that the consequences of a discontinuity of the zygomatic arch on facial growth are restricted to the structure itself.