1. American Association of Orthodontics Orthodontic treatment contributes to good dental health for adults https://www.aaoinfo.org/adult-orthodontics
2. Kokich VG Adult Orthodontics in the 21st Century: Guidelines for Achieving Successful Results http://www.dentalxp.com/articles/Kokich-Adult%20Ortho%20in%20the%2021st%20Century.pdf
3. The importance of incisor positioning in the esthetic smile: the smile arc;Sarver;Am J Orthod Dentofacial Orthop,2001
4. Changes in smile parameters as perceived by orthodontists, dentists, artists, and laypeople;Gul-e-Erum;World J Orthod,2008
5. An esthetic evaluation of lip-teeth relationships present in the smile;Hulsey;Am J Orthod,1970