Facial profile and nasolabial angle-upper incisor relationship: effects of miniscrew-anchored maxillary protraction therapy in adolescents.

OBJECTIVES

To evaluate the effects of miniscrew-anchored maxillary protraction on the soft tissue profile, focusing on facial convexity and the correlation between upper incisor position and the nasolabial angle.

MATERIALS AND

METHODS

Twenty growing patients with skeletal Class III malocclusion and maxillary deficiency were treated with a Hyrax hybrid expander and a mandibular anchorage bar supported by two miniscrews. Class III elastics were worn from the maxillary molars to the bar, fitting the miniscrews between the incisors and canines, and a facemask was used only at night. Soft tissue effects were assessed using lateral radiographs and standardized profile photographs before (T1) and after (T2) treatment. Measurements were obtained with Dolphin software. The Wilcoxon paired test compared changes, and Pearson correlation assessed the association between incisor position and nasolabial angle.

RESULTS

The final sample included 17 subjects (mean age: 12.3 years, SD = 1.2). Lip position and H.NB angle increased significantly (P < .05), whereas the nasolabial angle and facial convexity decreased (P < .05). A negative correlation was observed between the nasolabial angle and upper incisor position (P < .05).

CONCLUSIONS

Miniscrew-anchored maxillary protraction improved the facial profile by reducing concavity. Upper incisor advancement was associated with a decrease in the nasolabial angle, confirming the influence of dental movement on soft tissue balance.