1. Congenital factors: including hemifacial deformity, which leads to mandibular limb dysplasia, and the incidence rate is second only to cleft lip and palate with age. Hemifacial atrophy is characterized by soft tissue atrophy, also known as scleroderma. It also includes mandibular deviation, condyle hyperplasia on one side of mandible, abnormal proliferation of bone fiber or bone tumor.
2, acquired factors: unilateral chewing after tooth extraction, if you often chew food on one side, the other side will become smaller. Some people have a bad habit of sleeping, always sleeping on one side, so that soft tissue compression leads to a big face and a small face.
Big face and small face are more caused by congenital factors or diseases, genes and other factors, and less by acquired factors.