Abstract Objective: To evaluate, by a three-dimensional study, the volumetric and integumentary effects of rapid maxillary expansion on the nose, in mouth breathing kids with maxillary hypoplasia, in the short term, assessing the possible interference of gender, growth and age on the results achieved. Methods: 120 mouth breathing patients with maxilla hypoplasia were divided into an Experimental Group treated by rapid maxillary expansion (n = 104, 62 males and 42 females, mean age 10.1 years, SD = 2.10, ranging from 5.1 to 13.9 years); and Control Group, constituted by 16 patients (9 males and 7 females, mean age 9.3 years, SD = 2.1 years, ranging from 6.1 to 13.2 years). Patients in the experimental group underwent multislice computed tomography examinations at two different times: (T1) pre-expansion and (T2) post-expansion. The control group was submitted to the same tests at the same time intervals. Six soft tissue variables of the nose were studied, besides the volume and area of the nasal cavity, and the measurement and comparison of data between T1 and T2 were performed using the Dolphin Imaging 11.7 Premium software. Results: The experimental group showed significant mean increases in all soft tissue variables studied (p < 0.005), yet there were no significant changes in the control group. In the comparison between groups, only inclination of the nasal dorsum did not present any significant change. Conclusion: Rapid maxillary expansion may alter the nasal shape and physiology, by anatomical changes in the nose soft tissues, making it an important aid in the treatment of mouth breathing in childhood. Level of evidence: The soft tissues of the nose play an important role in nasal shape and physiology and facial esthetics, and since they are directly related to the nasal valves, they are fundamental for maintenance and stability of the nasal breathing pattern.

Abstract Objective: The present prospective clinical study aimed to investigate the effects of rapid maxillary expansion on the airway, correlating airway volumes obtained on multi-slice computed tomography and polysomnography assessment of oxygen saturation and apnea/hypopnea index. Methods: Twenty-four patients (11 with obstructive sleep apnea and 13 with residual snoring, mean age 10.0 (1.8), were enrolled in the study. Each patient underwent multislice computed tomography and nocturnal polysomnography before rapid maxillary expansion and after removal of maxillary expansion after six months. Airway regions were segmented, and volumes were computed. Results: The increase in oropharyngeal volume was significant in both groups. Oxygen saturation and apnea/hypopnea index were not statistically significant. No correlation was found between total airway volume, oxygen saturation, and apnea/hypopnea index changes between the time points examined. Conclusions: This study showed that when rapid maxillary expansion is performed in individuals with sleep-disordered breathing, there were statistically significant differences in oropharyngeal volume between pre- and post-rapid maxillary expansion, but there was no correlation between oxygen saturation values and oropharyngeal volume increase. Level of evidence: The article is classified as Evidence Level 3 (Three).

RESUMO Objetivo: Analisar as variações do volume do palato duro em adultos com oclusão normal e diferentes tipos e padrões faciais, por meio de análise tridimensional em modelos digitais. Métodos: Os modelos das arcadas dentárias de 70 adultos caucasianos (28 homens, 42 mulheres), média de idade de 16,4 anos (DP 1,3 anos), foram digitalizados usando um scanner tridimensional (Delcam PowerSHAPE™, 2010, Birmingham, Reino Unido). Pontos próximos foram selecionados nas regiões gengival e cervical na superfície lingual dos dentes superiores, para analisar a morfologia palatina. Os padrões e tipos faciais e as medidas (largura, comprimento, altura, volume) do espaço no palato duro foram comparados por meio de análise de covariância (ANCOVA), com a idade como covariável e o sexo como variável independente, a um nível de significância de 5% (p< 0,05). Resultados: O presente estudo mostrou que as medidas de largura e comprimento foram semelhantes entre os tipos faciais mesofacial, dolicofacial e braquifacial, embora a altura e o volume do espaço no palato duro tenham sido ligeiramente menores nos indivíduos dolicofaciais, e tanto os indivíduos do Padrão I quanto do Padrão II não apresentaram alterações significativas para as quatro medidas. Os valores médios entre os padrões faciais foram: Padrão I - largura 38,31±2,59 mm, comprimento 37,44±2,42 mm, altura 17,03±2,42 mm, volume 10,52±1,72 mm3; Padrão II - largura 37,48±2,44 mm, comprimento 37,48±2,44 mm, altura 16,79±2,42 mm, volume 10,41±1,65 mm3 (p>0,05 para todas as variáveis). Conclusão: Não houve diferenças significativas para os padrões faciais e tipos faciais dos indivíduos comparados na amostra analisada.

ABSTRACT Objective: To analyze the variations of hard palate volume in adults with normal occlusion and different facial types and patterns, by using a three-dimensional analysis on digital casts. Methods: The dental casts of 70 Caucasian adults (28 men, 42 women), mean age of 16.4 years (SD 1.3 years), were scanned by using a tridimensional scanner (Delcam PowerSHAPE™, 2010, Birmingham, UK). Close points were selected in the gingival and cervical regions on the lingual surface of the maxillary teeth, to analyze palatal morphology. The facial patterns and types, and the measurements (width, length, height, volume) of the space on the hard palate were compared using analysis of covariance (ANCOVA), with age as the covariate, and sex as the independent variable. The significance level of 5% (p < 0.05) was adopted. Results: This study showed that the measurements of the width and length were similar among the mesofacial, dolichofacial and brachyfacial facial types, although the height and volume of the space on the hard palate were slightly smaller in dolichofacial individuals, and both Pattern I and Pattern II individuals showed no significant changes for the four measurements. The mean values among facial patterns were: Pattern I - width 38.31±2.59 mm; length 37.44±2.42 mm; height 17.03±2.42 mm and volume 10.52±1.72 mm3; Pattern II - width 37.48±2.44 mm; length 37.48±2.44 mm; height 16.79±2.42 mm and volume 10.41±1.65 mm3 (p>0.05 for all variables). Conclusion: There were no significant differences for the facial patterns and facial types of the individuals compared in the analyzed sample.