3d Images for Automated Digital Odontometry

Abstract

Abstract. Improvements of existing and development of new non-contact measurement techniques, especially for surfaces of complex spatial shape, allow involvement of various disciplines into advanced technological reality. These improvements have two major directions. The first, being more obvious, refers to introduction of accurate digital 3D images in spheres where real objects have become subjects of traditional study, techniques or manufacturing technologies. The other direction deals with substantial methodological improvements, as they become possible only with introduction of the above-mentioned techniques. Among such is the division of physical anthropology, of dentistry and other disciplines related to dental studies, – odontometry, or measurements of teeth. Traditional odontometry, by turning into automated digital odontometry, becomes a method of accurate and objective morphological assessments in dentistry and anthropology, including palaeoanthropology. As a new method, automated digital odontometry requires interpretations of dental morphology (applicable in digital techniques), accurate 3D images of teeth and software based on 3D and 2D image analysis suitable for automated measurements. The mentioned factors are particularly important for this method due to its inapplicability on real objects. Thus various approaches to obtaining digital images are discussed in the context of their quality and conformity with the studied material and odontometric technique, which currently includes automated orientation algorithms setting locations for principal morphological structures and measurement algorithms themselves, likewise functioning in an automated mode.

Automated Digital Odontometry: Measurement Data Analyses in Cases of Complicated Dental Morphology

“…We should also mention that all of the studied upper teeth are wider that the lower molar from Fofanovo, not including its comparable sizes of vestibular cusp (5,65 mm), which is predominantly due to pronounced outer slope (contour length -5,32 mm); however, due to morphology of the masticatory system and orthognathic closure pattern of upper and lower teeth, it is more correct to compare lower vestibular cusps with upper oral. Another significant part of odontometric data referring to this study subject, as well an extension of our previous studies (Gaboutchian et al, 2019), are angular measurements. And here as well we can find support for the observed dental morphology: the sharpest angle among oral cusp belongs to 1.7 C2 (82,8º).…”

“…As can be seen, odontological study of the morphological feature has been traditionally held in the nature of descriptive objectivityas non-metric. Previously these teeth have been studied through angular measurement (Gaboutchian et al, 2019), and the parameters were found to be effective for comparisons with teeth not representing this morphological feature. However, more profound measurements can be performed for odontological analysis of trait expression degree in anthropological research through implementing automated digital odontometry.…”

“…Image obtaining methods may vary for aDo application; however scanning accuracy is highly appreciated as it influences directly the measurement results (Gaboutchian and Knyaz, 2019). Initially our 3D imaging experience started with photogrammetry and structured lighting for plaster models of dental arches, nevertheless other scanning methods have been tested and were found to be more suitable for odontological studies of unique palaeoanthropological material.…”

3d Reconstruction and Image Processing of Anthropological Archaeological Findings

“…Thus automated digital odontometry is the other approach to measurements of teeth in the current study, or even not teeth but rather their 3D images. Fully automated algorithms based on morphological interpretations allow orientation, sectioning and measurements of a wide variety of different linear, angular, area parameters as well as calculation of coefficients and parameter ratios (Gaboutchian et al, 2017, Gaboutchian et al, 2019. Landmark setting on 3D surfaces and 2D contours does not require much effort or profound skills in odontometry or anthropology from the operator.…”

New Approach to Dental Morphometric Research Based on 3D Imaging Techniques

“…Thus, they are not intended for scanning teeth unless opaque spray is applied (but it is preferable to avoid contamination either in case of intraoral procedures or for scanning palaeoanthropological findings). As an alternative, there are examples of successful application of intraoral scanners which were initially designed for clinical use in dental practice [39][40][41][42].…”