OBJECTIVETo study the edentulous patients facio-maxillary characters, and discuss the base of recording jaw relation by swallowing action.

METHODSForty-three edentulous patients were included in this study, age ranged from 57 to 70 yr, with new comfortable full dentures. Two lateral cephalograms for one patient were taken by SIRONA digital X-ray dental system, one of which was centric occlusion with full denture, another was the end position of swallowing action without denture.

RESULTSThe vertical facial dimensions of male were a little more than that of female. The ratio of lower front facial height/upper front facial height was about 6/5, angle S-N-Po was about 78 approximately 80 degrees. These data may be useful for dentists to make diagnoses if the jaw relation is right or not. Both in vertical or anterior-posterior (horizontal) dimension, the differences between two groups (two actions in one patient) were not significant. It showed that two positions of two actions were the same.

CONCLUSIONSThe SIRONA digital X-ray dental system for cephalometry was swift, and had its own characters. The way of swallowing and occluding is one of efficient methods to record the jaw relation of edentulous patients veraciously and naturally.