Assessment of changes in smile after rapid maxillary expansion

Abstract

INTRODUCTION: This study evaluated changes in the smile characteristics of patients with maxillary constriction submitted to rapid maxillary expansion (RME). METHODS: The sample consisted of 81 extraoral photographs of maximum smile of 27 patients with mean age of 10 years, before expansion and 3 and 6 months after fixation of the expanding screw. The photographs were analyzed on the software Cef X 2001, with achievement of the following measurements: Transverse smile area, buccal corridors, exposure of maxillary incisors, gingival exposure of maxillary incisors, smile height, upper and lower lip thickness, smile symmetry and smile arch. Statistical analysis was performed by analysis of variance (ANOVA), at a significance level of 5%. RESULTS: RME promoted statistically significant increase in the transverse smile dimension and exposure of maxillary central and lateral incisors; maintenance of right and left side smile symmetry and of the lack of parallelism between the curvature of the maxillary incisal edges and lower lip border. CONCLUSIONS: RME was beneficial for the smile esthetics with the increase of the transverse smile dimension and exposure of maxillary central and lateral incisors.<br>INTRODUÇÃO: esse estudo avaliou as alterações das características do sorriso de pacientes com atresia maxilar submetidos à expansão rápida da maxila (ERM). MÉTODOS: a amostra consistiu de 81 fotografias extrabucais do sorriso máximo de 27 pacientes, com idade média de 10 anos, antes da expansão e aos três e seis meses após a fixação do parafuso expansor. As análises das fotografias foram realizadas por meio do programa Cef X 2001, e as seguintes medidas foram analisadas: dimensão transversal do sorriso, corredores bucais, quantidade de exposição dos incisivos superiores, exposição gengival dos incisivos superiores, altura do sorriso, espessuras dos lábios superior e inferior, simetria e arco do sorriso. As alterações no sorriso durante as diferentes fases foram avaliadas por meio da análise de variância (ANOVA), seguida pelo teste de comparações múltiplas de Bonferroni, com nível de significância de 5%. RESULTADOS: a ERM promoveu aumento estatisticamente significativo da dimensão transversal do sorriso e da quantidade de exposição dos incisivos centrais e laterais superiores; manutenção da simetria entre os lados direito e esquerdo e da falta de paralelismo entre a curvatura das bordas dos incisivos superiores e a do lábio inferior. CONCLUSÃO: a ERM beneficiou a estética do sorriso com o aumento da dimensão transversal do sorriso e da quantidade de exposição dos incisivos centrais e laterais superiores

<p>Clinical effectiveness of orthodontic treatment on smile esthetics: a systematic review</p>

“…The authors also showed that rapid palatal expansion decreases the exposure of buccal corridors after treatment. On the contrary, Carvalho et al17 showed that buccal corridors remain unchanged after rapid palatal expansion. The authors evaluated 27 patients in 3 different time frames: T1, before expansion; T2, 3 months after expansion; and T3, 6 months after expansion.…”

“…Extraction biomechanics seem to be of the most important concern for researchers regarding their influence on smile esthetics 38–18. Palatal expanders also have been connected to have an effect on the smile,20,17 followed by self-ligating brackets15 and intrusion devices 21…”

“…The change in the curvature of the smiling was found to be related more significantly to the magnitude of difference in the inclination between the pre-treatment anterior occlusal plane and the functional occlusal plane than to the change in the inclination of the maxillary incisors2. The change in the maxillary intercanine width did not influence the curvature significantlyModerateCarvalho et al (2012)17Cohort27 subjects (15 females, 12 males); mean age 10 years+3 monthsRME palatal expander81 extraoral photographs of maximum smile before expansion and 3–6 months after fixation of the expanding screwRME was beneficial for the smile esthetics and resulted in an increase of the transverse smile dimension and exposure of maxillary central and lateral incisors. However, lip thickness and buccal corridors remained unchangedModerateTauheed et al (2012)18Cohort57 subjects (45 males, 12 females);31 non-extraction,26 extraction; age12–30 yearsExtractionsStudy model analysis;digital pictures analysis pre and post orthodontic treatmentGolden proportions were improved after orthodontic treatment.There was a significant difference between the post-treatment micro-esthetic values between non-extraction and extraction groups.…”

The Effects of Maxillary Expansion on the Soft Tissue Facial Profile

“…Although the dental and skeletal effects of expansion using dental or skeletal anchorage are well documented, little information is available concerning the overlying soft tissue changes following these treatment modalities. The authors who have analyzed soft tissue changes associated with RME and SARME were more interested with naso-maxillary region ( 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ). They reported modifications in cheek, upper lip and nasal morphology which were explained majorly by the transversal enlargement of the maxilla, except for few studies ( 19 , 23 ) reporting that RME did not have significant clinical effects on the nose.…”

“…The authors who have analyzed soft tissue changes associated with RME and SARME were more interested with naso-maxillary region ( 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ). They reported modifications in cheek, upper lip and nasal morphology which were explained majorly by the transversal enlargement of the maxilla, except for few studies ( 19 , 23 ) reporting that RME did not have significant clinical effects on the nose. Furthermore, it has been pointed out that the immediate maxillary advancement with downward and backward mandibular rotation during maxillary expansion could have an effect on the patients’ soft tissue profiles ( 24 , 25 , 26 , 27 , 28 , 29 , 30 ).…”