Sirikururat, Papatpong, and Supranee Benjapupatthananan. 2019. “Relationship between smile line, gingival biotype, tooth shape, and gingival zenith of maxillary anterior teeth in a group of Thai young adults”. Mahidol Dental Journal 39 (2). Bangkok, Thailand:107-14. https://he02.tci-thaijo.org/index.php/mdentjournal/article/view/182102.