Luiz Carlos Gonçalves

Interalar Distance to Estimate the Combined Width of the Six Maxillary Anterior Teeth in Oral Rehabilitation Treatment

STATEMENT OF THE PROBLEM The faces architecture of dentate subjects has been studied to find a reliable guide for the selection of artificial anterior teeth. However, there is no consensus of data regarding a reference to estimate the width of artificial teeth. PURPOSE The purpose of this study was to analyze whether there is a consistent relationship between the interalar distance (IAD) and the combined mesiodistal width of the six maxillary anterior teeth. METHODS Standardized digital photographs of 81 dentate Brazilian subjects were included in the sample. They were 37 men and 44 women (age 17 to 33). Through image processing software, the IAD and the distance between the tips of the maxillary canines were measured when viewed from the frontal aspect. Accurate casts were made to quantify the distance between the distal surfaces of the maxillary canines on a curve, by use of a flexible millimeter ruler. Nonparametric statistics were performed to analyze the results (p < 0.05). RESULTS The IAD when compared with the width of the six maxillary anterior teeth, on a straight line and on a curve, presented a ratio of 0.914 and of 1.305, respectively. The Wilcoxon test showed no significant difference between the calculated width values and the mesiodistal width measured on a curve and on a straight line (p = 0.986). CONCLUSION The IAD, when increased by 31% of its value, can suggest the circumferential distance of the six maxillary anterior teeth. CLINICAL SIGNIFICANCE The width of the nose, when measured in digital photographs, can be utilized as a reliable guide for the selection of the maxillary anterior teeth width. It can improve the esthetic result of the oral rehabilitation treatment for the edentulous patient by offering a natural dentofacial relation.

Correlation between the individual and the combined width of the six maxillary anterior teeth.

PURPOSE There is a consensus in the community of dental research that the selection of undersized artificial maxillary anterior teeth offers an unnatural appearance to the denture. Several methods to select the adequate width of these teeth are of questionable validity, and many dentures have an obviously artificial appearance. This article assessed the relationship between the individual and the combined width of maxillary anterior teeth. MATERIALS AND METHODS Impressions were made of the anterior dentition of 69 dentate undergraduate students with rubber impression silicon, and casts were formed. The individual widths of the maxillary anterior teeth were measured by using a digital caliper (SC-6 digital caliper, Mitutoyo Corporation, Tokyo, Japan), and the combined width was registered by both adding the individual width and using a flexible millimeter ruler. RESULTS Students t-test showed significant differences between the analogous teeth and different sides of the maxillary dental arch (p = 0.001), with the exception of the central incisor (p = 0.984). Pearsons product moment correlation coefficient showed significant positive correlation between all the measurements compared (p = 0.000). Linear regression analysis concluded three mathematical equations to obtain the individual tooth width after measuring the combined width of the six maxillary anterior teeth by using a flexible millimeter ruler. CONCLUSIONS The individual tooth width can be determined if the combined width of the maxillary anterior teeth is obtained by using a flexible millimeter ruler.

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

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.