“…28 Cleft lip and palate, 29 hemifacial microsomia, 30 juvenile idiopathic arthritis, 31 Treacher Collins syndrome, 32 Albright syndrome, 33 Apert syndrome, Crouzon syndrome, 34 and craniosynostosis 35 are the common hereditary factors that lead to facial asymmetry and OC. Environmental factors affecting facial asymmetry and OC include facial trauma and fractures (prenatal and postnatal), 36 jaw cysts, and facial tumors as well as their surgical treatment, 37 teratogens, 38 hormonal disorders (such as gigantism or acromegaly), 39 Romberg syndrome, 40 posture, 41 temporomandibular joint (TMJ) ankylosis, 42 muscular disorders, 43 abnormal mouth breathing, habits such as finger or lip sucking, longterm bottle or pacifier use, pencil biting and nail biting, 44 tooth extraction and carries, 45 and incorrect use of force during orthodontic treatment or when using midline elastics. 46…”