Evaluation of the palatal bone in different facial patterns for orthodontic mini-implants insertion: A cone-beam computed tomography study

ABSTRACT Objective: Evaluate the height, thickness and cortical density of the palatal bone of adults with different vertical facial patterns using Cone-Beam Computed Tomography (CBCT). Methods: This study analyzed 75 CBCTs of patients between 18 and 35 years old (45 men and 30 women). The CBCTs were classified into three groups based on their facial pattern: normodivergent, hypodivergent and hyperdivergent as determined from lateral cephalograms synthesized from the CBCTs. The height, cortical thickness and cortical density of the palatal bone were measured at 4, 8, 12, 16 and 20mm posterior to the incisive foramen, and at 3, 6 and 9mm lateral to the midpalatal suture. ANOVA with Tukey post-hoc tests were used for analysis of the data, at significance level of p< 0.05. Results: The hypodivergent pattern had a significant difference and the greatest height and cortical thickness of the palatal bone, followed by the hyperdivergent and the normodivergent patterns. No significant differences were found in minimum and maximum values of cortical density. Conclusion: The palatal bone is a favorable anatomical area to install different orthodontic temporary anchorage devices (TADs), where individuals with the hypodivergent vertical facial pattern have a higher height and cortical thickness of the palatal bone, followed by the hyperdivergent pattern and finally the normodivergent pattern. No significant differences in the cortical density of the palatal bone in the three facial patterns were found.

RESUMO Objetivo: Avaliar a altura, a espessura e a densidade cortical do osso palatino em adultos com diferentes padrões faciais verticais, utilizando a tomografia computadorizada de feixe cônico (TCFC). Métodos: O presente estudo analisou 75 TCFCs de pacientes com idades entre 18 e 35 anos (45 homens e 30 mulheres). As TCFCs foram classificadas em três grupos, de acordo com seus padrões faciais: normodivergentes, hipodivergentes e hiperdivergentes, conforme determinado na radiografia cefalométrica lateral reconstruída das TCFCs. Altura, espessura e densidade cortical do osso palatino foram aferidas a 4, 8, 12, 16 e 20 mm para posterior do forame incisivo e a 3, 6 e 9 mm lateralmente à sutura transpalatina. Os testes ANOVA e post-hoc de Tukey foram utilizados para análise dos dados, com nível de significância de p< 0,05. Resultados: O padrão hipodivergente apresentou uma diferença significativa e a maior altura e espessura cortical do osso palatino, seguido pelos padrões hiperdivergente e normodivergente. Nenhuma diferença estatisticamente significativa foi encontrada nos valores mínimos e máximos da densidade cortical. Conclusão: O osso palatino é uma área anatomicamente favorável para instalar diferentes dispositivos de ancoragem temporária. Indivíduos com padrão facial vertical hipodivergente apresentam maior altura e espessura cortical do osso palatino, seguido do padrão hiperdivergente e finalmente do padrão normodivergente. Não foi encontrada qualquer diferença significativa na densidade cortical do osso palatino entre os três padrões faciais.

Nasal septum changes in adolescent patients treated with rapid maxillary expansion

Objective: To analyze cone-beam computed tomography (CBCT) scans to measure changes in nasal septal deviation (NSD) after rapid maxillary expansion (RME) treatment in adolescent patients. Methods: This retrospective study involved 33 patients presenting with moderate to severe nasal septum deviation as an incidental finding. Out of these 33 patients, 26 were treated for transverse maxillary constriction with RME and seven, who did not undergo RME treatment, were included in the study as control group. CBCT scans were taken before appliance insertion and after appliance removal. These images were analyzed to measure changes in nasal septum deviation (NSD). Analysis of variance for repeated measures (ANOVA) was used. Results: No significant changes were identified in NSD regardless of the application or not of RME treatment and irrespective of the baseline deviation degree. Conclusion: This study did not provide strong evidence to suggest that RME treatment has any effect on NSD in adolescent patients; however, the results should be interpreted with caution, due to the small sample size and large variation amongst individual patient characteristics.

Objetivo: analisar imagens de tomografia computadorizada de feixe cônico (TCFC) para mensurar as alterações no desvio de septo nasal (DSN) após o tratamento com expansão rápida da maxila (ERM) em pacientes adolescentes. Métodos: o presente estudo retrospectivo incluiu 33 pacientes com desvio de septo nasal de moderado a severo, diagnosticado como um achado incidental. Dos 33 pacientes analisados, 26 tiveram a constrição maxilar transversal tratada por meio de ERM; 7 pacientes não foram submetidos à ERM, sendo incluídos no estudo como grupo controle. As imagens de TCFC foram obtidas antes da instalação do aparelho e após sua remoção, sendo analisadas para mensurar as alterações no DSN. A análise de variância para medidas repetidas (ANOVA) foi empregada. Resultados: não foram identificadas alterações significativas no DSN, independentemente da realização ou não do tratamento com ERM e do grau inicial de desvio. Conclusão: esse estudo não fornece evidências suficientes para sugerir que o tratamento com ERM produza qualquer efeito sobre o DSN em pacientes adolescentes. Porém, esses resultados devem ser interpretados com cautela, em virtude do tamanho reduzido da amostra e da grande variação das características individuais dos pacientes.

Reproducibility, reliability and validity of measurements obtained from Cecile3 digital models

The aim of this study was to determine the reproducibility, reliability and validity of measurements in digital models compared to plaster models. Fifteen pairs of plaster models were obtained from orthodontic patients with permanent dentition before treatment. These were digitized to be evaluated with the program Cécile3 v2.554.2 beta. Two examiners measured three times the mesiodistal width of all the teeth present, intercanine, interpremolar and intermolar distances, overjet and overbite. The plaster models were measured using a digital vernier. The t-Student test for paired samples and interclass correlation coefficient (ICC) were used for statistical analysis. The ICC of the digital models were 0.84 ± 0.15 (intra-examiner) and 0.80 ± 0.19 (inter-examiner). The average mean difference of the digital models was 0.23 ± 0.14 and 0.24 ± 0.11 for each examiner, respectively. When the two types of measurements were compared, the values obtained from the digital models were lower than those obtained from the plaster models (p < 0.05), although the differences were considered clinically insignificant (differences < 0.1 mm). The Cécile digital models are a clinically acceptable alternative for use in Orthodontics.