Development of a Novel Large-Animal Model for Craniofacial Microsomia: Proportional Skeletal Defects in Mandibular Ramus and Zygomatic Arch

Craniofacial microsomia (CFM) involves complex skeletal asymmetries, including mandibular and zygomatic arch deficiencies, leading to facial deformities and occlusal cant. Current animal models inadequately replicate these features, hindering the development of customized temporomandibular joint prostheses for CFM. This study aimed to develop a miniature pig model that mimics the proportional craniofacial skeletal defects observed in severe CFM, serving as a platform for future TMJ reconstruction studies. Three miniature pigs underwent preoperative CT imaging and digital surgical planning. Proportional mandibular ramus and zygomatic arch defects were created on the surgical side to reflect measurements from clinical CFM patients. Craniofacial morphology, masticatory efficiency, and maximum mouth opening (MMO) were assessed preoperatively and postoperatively at 3 and 13 weeks. At 13 weeks, craniofacial asymmetry closely resembled CFM. The ramus height and zygomatic arch surgical side to nonsurgical side ratios were reduced by 30% ( P = 0.003) and 52% ( P = 0.003), respectively, compared with preoperative values. Despite significant occlusal plane cant ( P = 0.011), maxillary height and chin deviation showed nonsignificant changes. Functional outcomes, including MMO and masticatory efficiency, were preserved. This model successfully replicates craniofacial skeletal defects characteristic of severe CFM. It offers a quantitative framework for testing TMJ prostheses, advancing reconstructive approaches for craniofacial deformities.