Does Labial Orthodontic Appliance Affect Upper Lip Posture?

Objective: To assess changes in lips posture with and without bonded labial orthodontic appliances. Methods: Profile photographs of 33 patients were taken just before and just after debonding of labial brackets. Pictures were analyzed twice by a custom made analysis using "Viewbox” software. The validity of this new analysis was assessed in a preliminary study. A reference line was constructed between Center of Tragus and outer Canthus. The point where this elongated line intersected with the profile was coined Nasion-modified and served as the vertex point for angles used to evaluate the prominence of the lips. The final position of the lines was determined when they were tangent to the appropriate landmarks. ANOVA and t-test for paired differences were used. Results: The reproducibility of this photo-analysis was confirmed in the preliminary study, as no significant differences were found between the measurements (p<0.05). No statistically significant differences were found in lip prominence between pre and post debonding pictures (p<0.05). Conclusions: Our new photo-analysis showed that the presence of bonded orthodontic labial appliance has no effect on lip posture.