Methodological approaches to studying dental arch morphology

Abstract

In order to develop a method for accelerated diagnostics of the dental arch gnathic type, we measured jaw cast models obtained from 213 people with an orthognathic bite, without congenital and/or acquired maxillofacial pathology. The difference between the actual and the calculated values of the inter-canine distance, which serves as a basis for the diagnostic method, was employed as a reference standard for mesognathic dental arches, where the triple selecting bias for the analysis of dental arches with physiological occlusion did not exceed 3 mm. The estimates for the inter-canine distance at various dental arch types (mesognathia, 39.62 +/- 1.24 mm; brachygnathia, 41.50 +/- 1.15 mm; dolichognathia, 34.54 +/- 1.64 mm) were obtained in view of the circle geometry, where the radius was identified by the ratio of the triple width sum of the three front teeth crowns (medial and lateral incisors and canines), to qr value (3.14). The dental arch anterior section height was half the circle radius. Inter-canine distance was calculated subject to the Pythagorean theorem. A width change (increase) exceeding 3 mm in the anterior section allowed attributing the dental arches to the brachygnathic type, while a decrease in the said index was considered typical of dolichognathia