Early partial monolateral zygomatic arch defect leads to unilateral craniofacial malformation

This study used reconstructed three-dimensional imaging to examine the influence of early partial monolateral zygomatic arch defect on the craniofacial development in a minipig model.

Five 7-week-old Chinese minipigs were used in this study. Each of them underwent skull radiography, three-dimensional computed tomography (CT), and surgery at 8 weeks of age. Bilateral zygomatic arches were randomized and divided into the experimental side and the control side. A standard 2-cm-long zygomatic arch defect was made by an electric drill on the experimental side. The contralateral side was left intact. One of them underwent skull radiography and three-dimensional CT 2, 4, 8, and 12 weeks after surgery. The other 3 minipigs underwent scanning 4, 8, and 12 weeks after surgery. The bone defect was observed by radiography and three-dimensional CT. All three-dimensional CT data were examined by Mimics 10.01 software, and three-dimensional images were reconstructed. The length of both zygomatic arches, the length and width of the skull, and the hemicranial angles of both sides were measured and compared.

The zygomatic arch developed to a summit at approximately 20 weeks of age. The zygomatic arch length of the experimental side is longer than that of the control side at each time point after surgery. The hemicranial angle of the experimental side is less than that of the control side at each time point after surgery.

Early partial monolateral zygomatic arch defect accelerates its growth in the sagittal plane and impedes the hemicranial growth in the coronal plane. Early reconstruction of zygomatic arch defect may be essential to minimize the developmental craniofacial malformation in children.