2van Zyl I, Geissberger M. Simulated shape design. Hel- ping patients decide their esthetic ideal[J]. J Am Dent Assoc, 2001, 132(8) : 1105-1109.
3Akarslan ZZ, Sadik B, Erten H, et al. Dental esthetic satisfaction, received and desired dental treatments for improvement of esthetics[J]. Indian J Dent Res, 2009, 20 (2) : 195-200.
4Gerritsen AE, Sarita P, Witter D J, et al. Esthetic per- ception of missing teeth among a group of Tanzanian a- dults[J]. Int J Prosthodont, 2008, 21(2):169-173.
5Goncalves LC, Comes VL, De Lima Lueas B, et aL Co- rrelation between the individual and the combined width of the six maxillary anterior teeth[J]. J Esther Restor Dent, 2009, 21 (3) : 182-192.
6Wolfart S, Quaas AC, Freitag S, et al. Subjective and objective perception of upper incisors[J]. J Oral Rehabil, 2006, 33 (7) : 489-495.
7Dong JK, Jin TH, Cho HW, et al. The esthetics of the smile: A review of some recent studies[J]. Int J Prostho- dont, 1999, 12(1):9-19.
8Duarte S Jr, Schnider P, Lorezon AP. The importance of width/length ratios of maxillary anterior permanent teeth in esthetic rehabilitation[J]. Eur J Esthet Dent, 2008, 3 (3) : 224-234.
9Murthy BV, Ramani N. Evaluation of natural smile: Go- lden proportion, RED or Golden percentage[J]. J Conserv Dent, 2008, 11 (1): 16-21.
10Ragain JC Jr, Johnston WM. Minimum color differences for discriminating mismatch between composite and tooth color[J]. J Esthet Restor Dent, 2001, 13(1):41-48.
