While various classification systems have been proposed, only a few have found wide epidemiological and clinical acceptance. The classification of face anomalies proposed in this symposium was basically based on the SNOP and further subclassification according to severity and external or internal malformations was added. Severity of anomalies was devided into two groups, i. e. major and minor anomalies. Each anomaly was introduced into coding system according to classification of developmental mechanisms cited in SNOP coding manual. However, the anomalies which are developed by unknown mechanism were classified into additional item, as special organ anomaly, and the item, hyperplasia or excessive growth was added. Proposed classification was not completely satisfactory, but it was considered to be a relatively suitable for the epidemiological, or pathological or clinical statistics.
