Tjan A H, Miller G D, The J G
J Prosthet Dent. 1984 Jan;51(1):24-8. doi: 10.1016/s0022-3913(84)80097-9.
A survey of the characteristics of an open smile was conducted with 454 full-face photographs of randomly selected dental and dental hygiene students. Findings show that an average smile exhibits approximately the full length of the maxillary anterior teeth, has the incisal curve of the teeth parallel to the inner curvature of the lower lip, has the incisal curve of the maxillary anterior teeth touching slightly or missing slightly the lower lip, and displays the six upper anterior teeth and premolars. Consideration of the characteristics may be useful in improving the esthetics of restorations.
对随机挑选的454名牙科和口腔卫生专业学生的全脸照片进行了一项关于露齿微笑特征的调查。研究结果表明，平均微笑时上颌前牙露出大约全长，牙齿的切缘曲线与下唇的内曲线平行，上颌前牙的切缘曲线轻微接触或略微未接触到下唇，并露出六颗上前牙和前磨牙。考虑这些特征可能有助于改善修复体的美观。
