As well as the high incidence of oral clefts, the number of children born with craniofacial deformities in Vietnam is also very high. Clinicians believe this is related to factors such as environmental pollution caused by the use of chemical agents during the Vietnam War, and the low standard of living which means that most pregnant mothers are poorly nourished.
除了唇顎裂的發生率高，越南顱顏畸形兒的出生率也頗驚人，臨床經驗認為，這和當年越戰遭受生化攻擊，導致環境污染，以及因為貧窮，懷孕母親多半營養不良等因素有關。