Analysis of anterior dentoalveolar and perioral aesthetic characteristics and their impact on the decision to undergo a Phase II orthodontic treatment

Abstract

Researchers have conducted extensive studies regarding dentoalveolar factors that affect anterior dental aesthetics; however, there is no consensus regarding how these factors affect orthodontic treatment decisions. Only a few studies have included multiple factors simultaneously. Therefore, the objective was to investigate if there are identifiable dentofacial and perioral aesthetic factors that bias laypeople towards discontinuing treatment after a phase I treatment with this fixed class II corrector. An analysis of photos and dental casts of 60 children (23 males, 37 females) having received phase I orthodontic treatment with the Xbow appliance was conducted. Variables considered were incisor height and width measurements, incisor proportions, incisor angulations, vertical lip thickness, gingival/incisal display, smile width per cent, diastema, midline deviation, smile arc, gender, and use of a 2×4. A principal component analysis and a logistic regression were used to determine which factors related to a patient's likelihood of receiving further orthodontic treatment. Only the angulation of the right maxillary incisors was significantly related to a patient's likelihood (odds ratio 1.886 (1.004-3.466); P = 0.049) to proceed to phase II orthodontic treatment following phase I orthodontic treatment with the Xbow appliance. The odds of proceeding to phase II treatment were 86.6% greater with a one standard deviation increase in the angulation of the right central and lateral incisors. Other factors demonstrated trends but were not statistically significant. Sample in subgroups was small, excluded smiles that did not expose the upper incisor crowns significantly, smiles in real life are observed three-dimensionally, other factors outside the aesthetic measurements were not considered in the analysis. In this sample, the angulation of the maxillary right incisors was the most significant factor influencing the decision to undergo an orthodontic phase II.