Variations in dental arch morphology are outcomes of the complex adaptive system associated with the developmental variation of hypodontia

Abstract

Development of the human facial structures including the jaws and dentition occurs in a process that has the characteristics of a complex adaptive system (CAS) influenced by epigenetic, genetic and environmental factors. Earlier studies have suggested dental arch development to be reduced in size in subjects with hypodontia when compared with controls. Hypodontia is a variation of development and presents with a reduced number of teeth together with several other phenotypic changes. This study uses enhanced 3D imaging techniques to increase the accuracy of the measurements of dental arches. The sample consists of orthodontic patients, 60 with hypodontia (thirty males and thirty females), and 60 controls matched for age, gender and ethnicity. One operator using an Amann Girrbach Ceramill Map400 3D scanner recorded the 3D images from dental models. The 3D images were then viewed on MeshLab and the accuracy of the measurements were determined through repeat measurement of the same images; this was undertaken with intra-and inter-operator reproducibility. Ten repeat measurements were taken on 10 different models. Validation of the new system was undertaken by repeating the measurements using the standard 2D caliper technique. Arch dimension measurements were determined from distance between the left-hand side first molar to the right-hand side first molar. Similar measurements were also made for the inter-canine width. The results for average intraoperator measurements were 0.33 mm for the maxillary arch and 0.40 mm for the mandibular arch. The difference in average inter-operator reproducibility was also measured for inter-molar arch dimensions at 0.31 and 0.23 mm for maxillary and mandibular arches, respectively. This novel method provides an increased range of measurement of similar accuracy to standard techniques. This study will proceed to establish the variations on the 3D images between the hypodontia subjects and the control group.

"Dental Arch Dimensions in a Matched Pairs Study of Hypodontia Patients and Controls"

“…The matched pairs design and the pattern of congenitally missing teeth accords with previous studies [1,6,33]. The accuracy and validity of the 2D image analysis system used here has been established over a series of studies [7,12,28,33].The hypodontia patients included in the present study had significantly smaller arch circumference, arch length and intercanine width in the upper arch than controls. This agrees with the findings of Nelson et al [7] for their mild/moderate hypodontia group; in their severe hypodontia group the differences were greater.…”

“…The dental arches and the dentition are two closely related components of the stomatognathic system, which develop in anatomical proximity over an extended time period from early in utero to early adulthood. The dental arches and the dentition are both complex systems, whose development is determined by multiple interactions between genetic, epigenetic, and environmental factors [10][11][12]. Interactions continue as development progresses through cellular, soft tissue and mineralisation stages to the emergence of the mature phenotype [9].…”

Investigating the dentoalveolar complex in archaeological human skull specimens: Additional findings with large volume micro‐CT compared to standard methods

“…The information gained from detailed measurements and analysis of such images could increase the understanding of the impact of dental and oral health on the general health of an individual as well as provide data on the prevalence of craniofacial conditions in past populations. For example, there is evidence that in cases of hypodontia not only are the formed teeth and the dental arches affected but also the craniofacial complex (Kerekes‐Mathe et al, 2015; Patel et al, 2018).…”

“…For example, there is evidence that in cases of hypodontia not only are the formed teeth and the dental arches affected but also the craniofacial complex (Kerekes-Mathe et al, 2015;Patel et al, 2018).…”