Distance between the medialis angles of the eyes as an anatomical parameter for tooth selection

Abstract

During the construction of a removable prosthesis, the lack of pre-extractions records turns the selection of artificial maxillary anterior teeth into a complex procedure. The aim of this study was to identify a mathematical relation between the anterior dental segment and the distance between the medialis angles of the eyes, for selecting the suitable width of the six maxillary anterior teeth. Standardized digital images of 80 dentate Brazilian subjects were used to measure both facial and oral structures when viewed from the frontal aspect through an image processing program. Accurate casts were made to measure on a curve the distance between the maxillary canines. Parametric statistics was performed to analyse the results (P < 0.05). The distance between the medialis angles of the eyes showed no significant difference according to gender (P < 0.108). The Pearson Product Moment Correlation Coefficient showed significant positive correlation between the distance between the medialis angles of the eyes and all variables compared. After the linear regression analysis, mathematical formulae and biometric ratios were concluded to estimate the combined width of the six maxillary anterior teeth from the measurement of the distance between the medialis angles of the eyes. The distance between the medialis angles of the eyes measured through photogrammetry can be a reliable guide for tooth selection.

The significance of biometric parameters in determining anterior teeth width

“…Discussions on this topic are very present in the contemporary professional literature 2,7,8,[11][12][13][14][15][16][17][18][19][20][21][22] . Reviews of the recent scientific literature reveal studies that were carried out using different methodology and sample size, different face and natural teeth parameters 8, 10, 11-13, 15, 19, 20 , casts 5, 16-18, 21, 22 , or photographs 5,14,16,17,20 , as well as various types of gauges which makes the comparison of results very difficult.…”

“…Authors of many recent studies suggest observing people's facial measurements in order to obtain objective guidelines for anterior teeth width selection, and measuring distances between certain reference points of the face 5,[8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] . These points are, as a rule, easily located, although their exact position is often defined differently by different authors.…”

“…These anatomical parameters are: bizygomatic width (BZW) 5, 10, 11 , interpupillary distance (IPD) 5,8,10,11,16 , intercommissural distance (ICMD) 19,22 , interalar width (IAW) 5,8,11,14,16,[19][20][21][22] , which is defined as the distance between the widest points of the ala of the nose, inner canthal distance (ICD) 9,10,[12][13][14][15][16][17]22 which is defined as the distance between the medial angles of the palpebral fissures, width of the upper lip philtrum (PHULW) 9 and nose length (NL) [20][21][22] . These anatomical parameters are: bizygomatic width (BZW) 5, 10, 11 , interpupillary distance (IPD) 5,8,10,11,16 , intercommissural distance (ICMD) 19,22 , interalar width (IAW) 5,8,11,14,16,[19][20][21][22] , which is defined as the distance between the widest points of the ala of the nose, inner canthal distance (ICD) …”

Relación entre distancia intercantal y ancho de dientes anterosuperiores en jóvenes chilenos

“…4 Esta medida se considera normal entre 28mm y 35mm demostrándose como una de las más estables en el individuo sin presentar diferencias según sexo, raza o edad. 3 Diversos reportes han encontrado una relación entre la DIC y la distancia mesiodistal de los dientes anterosuperiores en población Brasileña 5 , Indú 3 y Saudí. 1 Sin embargo, considerando el origen mixto de la población sudamericana producto de las diferentes migraciones y los altos niveles de flujo de genes característicos de la región, se sugiere un patrón morfológico dental único para la población andina sudamericana.…”

“…La razón entre DIC y los seis dientes anterosuperiores son, en general, menor en comparación a los resultados previos. 1,2,4,5 Los resultados obtenidos difieren con lo presentado en otras poblaciones estudiadas. Este aspecto puede explicarse por la población mixta que caracteriza a Sudamérica debido al constante mestizaje de la zona incluyendo la población Chilena.…”