Efficiency of ODI and APDI of Kim's cephalometric analysis in a Latin American population with skeletal open bite

ABSTRACT Objective: The objective of this research was to demonstrate the efficiency of the overbite depth indicator (ODI) and the anteroposterior dysplasia indicator (APDI) from Kim's cephalometric analysis, regarding the determination of the vertical and sagittal patterns of Latin American individuals. Methods: Two hundred lateral cephalometric radiographs were selected and divided into four study groups, with 50 radiographs each, for carrying out a cross-sectional study. The control group included radiographs of balanced individuals, and the other three groups had lateral cephalometric radiographs of subjects with Class I, II and III malocclusions and with skeletal open bite. After the pilot test was performed to calibrate the investigator, the ODI and APDI were measured. Descriptive statistics were performed and the one-way ANOVA with post-hoc Tukey HSD, or Kruskal-Wallis and Mann-Whitney U-test were used. Also a multiple linear regression was employed. Results: Statistically significant differences were found for the ODI of all groups (p< 0.001), except between Class I group (65.87 ± 4.26) and Class II open bite group (67.19 ± 3.58), both with similar values to each other. For APDI, statistically significant differences were also found for all groups (p< 0.001). However, no statistically significant differences were found between the balanced group (83.18 ± 1.71) and Class I group with skeletal open bite (81.78 ± 2.69). Conclusions: ODI and APDI are reliable indicators to evaluate the sagittal and vertical patterns of an individual, demonstrating their efficiency when a Latin American population was evaluated.

RESUMO Objetivo: o objetivo desta pesquisa foi demonstrar a eficácia do indicador de profundidade da sobremordida (ODI) e do indicador de displasia anteroposterior (APDI) da análise cefalométrica de Kim, no que diz respeito à determinação dos padrões vertical e sagital em indivíduos latino-americanos. Métodos: duzentas telerradiografias em norma lateral foram selecionadas e divididas em quatro grupos, com 50 radiografias cada, para a realização desse estudo transversal. O grupo controle incluiu radiografias de indivíduos com oclusão normal, e os outros três grupos incluíram, respectivamente, radiografias de indivíduos com má oclusão de Classe I, Classe II e Classe III, com mordida aberta esquelética. Após a realização de um estudo piloto para calibração do investigador, fez-se a medição do ODI e do APDI. Foram realizadas estatísticas descritivas e utilizados os testes ANOVA de uma via com post-hoc HSD de Tukey, ou teste de Kruskal-Wallis e teste U de Mann-Whitney. Também foi realizada uma regressão linear múltipla. Resultados: foram encontradas diferenças estatisticamente significativas para o ODI entre todos os grupos (p< 0,001), exceto entre os grupos Classe I (65,87 ± 4,26) e Classe II com mordida aberta (67,19 ± 3,58), ambos com valores semelhantes entre si. Para o APDI, também foram encontradas diferenças estatisticamente significativas entre todos os grupos (p< 0,001). Entretanto, não foi encontrada nenhuma diferença estatisticamente significativa entre o grupo controle (83,19 ± 1,71) e o grupo Classe I com mordida aberta esquelética (81,78 ± 2,69). Conclusões: tanto o ODI quanto o APDI são indicadores confiáveis para se avaliar os padrões sagital e vertical de um indivíduo, tendo sua eficácia comprovada para uso na população latino-americana estudada.

Study of the number of occlusal contacts in maximum intercuspation before orthodontic treatment in subjects with Angle Class I and Class II Division 1 malocclusion

OBJECTIVE: Define and compare numbers and types of occlusal contacts in maximum intercuspation. METHODS: The study consisted of clinical and photographic analysis of occlusal contacts in maximum intercuspation. Twenty-six Caucasian Brazilian subjects were selected before orthodontic treatment, 20 males and 6 females, with ages ranging between 12 and 18 years. The subjects were diagnosed and grouped as follows: 13 with Angle Class I malocclusion and 13 with Angle Class II Division 1 malocclusion. After analysis, the occlusal contacts were classified according to the established criteria as: tripodism, bipodism, monopodism (respectively, three, two or one contact point with the slope of the fossa); cuspid to a marginal ridge; cuspid to two marginal ridges; cuspid tip to opposite inclined plane; surface to surface; and edge to edge. RESULTS: The mean number of occlusal contacts per subject in Class I malocclusion was 43.38 and for Class II Division 1 malocclusion it was 44.38, this difference was not statistically significant (p>0.05). CONCLUSIONS: There is a variety of factors that influence the number of occlusal contacts between a Class I and a Class II, Division 1 malocclusion. There is no standardization of occlusal contact type according to the studied malocclusions. A proper selection of occlusal contact types such as cuspid to fossa or cuspid to marginal ridge and its location in the teeth should be individually defined according to the demands of each case. The existence of an adequate occlusal contact leads to a correct distribution of forces, promoting periodontal health.

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.