Comparison of mesiodistal tooth crown diameters and arch dimensions between modern Mongolians and Japanese

Abstract

The purposes of this study were to establish normative data for mesiodistal tooth crown diameters and arch dimensions in Mongolian adults and to compare them with those of Japanese adults. The study materials comprised dental casts of 100 modern Mongolian and 100 Japanese subjects (50 males, 50 females for each) with Angle Class I normal occlusion. The mean ages were 20 years 8 months for the Mongolian subjects and 20 years 0 months for the Japanese subjects. On the dental casts, the mesiodistal tooth crown diameters (excluding wisdom teeth) and dental arch dimensions were measured. The following arch dimensions were measured: inter-canine lingual, inter-premolar lingual, inter-molar lingual, inter-molar central, coronal arch length, basal arch length, and basal arch width. In the Mongolian samples, significant sex differences were noted, and most of the items were significantly larger in males than in females. Significant differences between the Mongolian and Japanese samples were mainly noted in the premolar and molar regions, rather than in the anterior region, and were significantly smaller in the Mongolian samples. In the Mongolian samples, the molar section widths and basal arch width and length were significantly larger in males and females compared with the Japanese samples. These results suggest that the tooth crown size and arch dimensions in the Mongolian samples differed from those in the Japanese samples, and that establishment of the clinical norm for Mongolian adults might be helpful in formulating treatment plans for Mongolian patients, given that these parameters are the basic tools for diagnosis.

Dental Implant Treatment with Computer-assisted Surgery for Bilateral Agenesis of Maxillary Lateral Incisors: A Case Report

“…Furthermore, even if the mesiodistal space is preserved by the presence of a deciduous tooth, there may still be insufficient space for implantation if there is agenesis of a maxillary lateral incisor. This is because the width of the crown of the maxillary lateral incisor in the permanent dentition is only 7.07±0.43 mm, making it the narrowest in the maxilla, although still wider than that in the primary dentition 4,13) . Earlier studies have noted that an implant fixture should be 1.5 to 2.0 mm away from adjacent teeth to avoid various complications, including damage to the root and peri-implant bone loss.…”

Dimensions of central incisors, canines, and first molars in subjects with Down syndrome measured on cone-beam computed tomographs

“…Although casts accurately represent the dental arches in 3 dimensions, they only allow measurement of crown dimensions. 3,8,9 Other 3-dimensional analysis tools developed in recent years, including stereophotogrammetry 2 and laser scanning, 8,10 allow more complex measurements, such as mesiodistal angulations. 8 Two-dimensional records include digital photographs, 11 panoramic x-rays, 12 and, in particular, periapical x-rays.…”

“…[2][3][4] In dentistry, tooth morphometry is used in disciplines as different as periodontology, 5 prosthetics, 6 and orthodontics. 7 Measurements in these morphologic studies have typically been made directly on jaw casts made from plaster or other stable materials.…”

Comparative study of the dental arch shape in young Brazilians with normal occlusion

“…23 The method applied in this study analyzed all data digitally, without the need for printed documents. The traditional dental casts were scanned and the measurements obtained through 3D images in specific software, as previously tested by Sousa et al 24 and reasoned by Fleming et al 25 In the literature the authors use different ways to obtain the measurements, directly over the dental casts using a caliper, [26][27][28] with photographic techniques, 29,30 photocopies or digitalized images, 6,10,19,21,31 and 3D digital casts. 20,23,[32][33][34] In order to determine the dental arches dimensions and shapes, some authors have chosen either one of the arches, the maxillary 19 or the mandibular, 14 and sometimes both of them.…”

“…20,23,[32][33][34] In order to determine the dental arches dimensions and shapes, some authors have chosen either one of the arches, the maxillary 19 or the mandibular, 14 and sometimes both of them. 28,30 In addition, several landmarks have been used such as clinical bracket points, 10,14-17 facial axis points, 20,33 center on the occlusal surface. 23 However, the anatomic structure chosen in this study was the incisal edge and cusp tip 11,12,18,32,[34][35][36][37] because it studied the dental not the alveolar arch characteristics and the sample consisted only of subjects with normal occlusion.…”