1 Introduction Unilateral craniofacial microsomia (UCM), also known as first and second branchial arch syndrome, is a congenital malformation characterised by unilateral deficiencies of hard and soft tissues, including the temporomandibular joint, mandibular ramus, masticatory muscles, and the ear [1], [2]. UCM is the second most common congenital craniofacial anomaly after cleft lip and palate, with an estimated prevalence of approximately 1 in 3,500–5,600 live births [2].