Objective To evaluate the most acceptable lower anterior face height of male and female by orthodontic treatment seeking people. Methods Two hundred and thirty-two Chinese orthodontic seeking people of Guanghua Hospital of Stomatology of Sun Yat-sen University were randomly selected in this survey. An electronic questionnaire was designed with a set of male and female young Chinese adult images with changes of the lower anterior face height （while the middle anterior face height remains the same）. They were asked about the lowest, highest and optimal proportion（or so-called lower, higher and optimum limits respectively） between the lower anterior face height and the middle anterior face height（LAFH/MAFH） they could accept. All the findings of the proportion were analyzed by a statistic system. Results The lower limits’median value in regard to the LAFH/MAFH of male model and female model images was 0.8, this limit value for the male model’s was greater than the female model’s（P=0.039）; the higher limits’median value was 1.1, this limit value for the male model’s was less than the female model’s（Pfor orthodontist in treatments.
