I want to applaud Thais Teixeria de Paiva and colleagues on their interesting and well-done article, “Influence of canine vertical position on smile esthetic perceptions by orthodontists and laypersons,” in the March 2018 issue of the AJO-DO (Paiva TT, Machado RM, Motta AT, Mattos CT. Influence of canine vertical position on smile esthetic perceptions by orthodontists and laypersons. Am J Orthod Dentofacial Orthop 2018; 153:371-6). The authors demonstrated that for both orthodontists and laypersons (60 in each group), the most attractive smile esthetics were found when the maxillary canines were at the standard (“natural”) vertical position and with 0.5 mm of intrusion (for those with or without gingival margin exposures); the less attractive smiles were those with 1.0 mm of maxillary canine extrusion and 1.0 mm of intrusion.

I have a comment for the authors, and this leads to a discussion of a future study. The target (morphed) photograph used in the study was of a man with a “nonconsonant” smile arc. It would be interesting to study the influence of esthetic perceptions when the maxillary canines are altered vertically in the target photograph with a “consonant” smile arc. The point about the target photograph possessing a “nonconsonant” vs “consonant” smile arc was not mentioned by the authors in their Discussion section. This could be a limitation of the study in the sense that the results could not be generalized to subjects with “consonant” smile arcs. If this suggested study is contemplated, a question comes to mind. The natural, standard vertical position of the maxillary canines with a “consonant” smile arc is intrusive/superior/upward compared with the standard vertical position with a “nonconsonant” smile arc, so would this make comparison of data between the 2 studies somewhat problematic?

Again, I commend the authors for their excellent work and contribution to the orthodontic literature.