scholarly journals Geometric morphometric investigation of craniofacial morphological change in domesticated silver foxes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Timothy M. Kistner ◽  
Katherine D. Zink ◽  
Steven Worthington ◽  
Daniel E. Lieberman
Keyword(s):  
Three Dimensional ◽  
Cranial Base ◽  
Craniofacial Morphology ◽  
Wild Populations ◽  
Linear Measurements ◽  
Skeletal Morphology ◽  
Geometric Morphometric ◽  
Domestication Syndrome ◽  
Morphometric Investigation ◽  
Unselected Population

AbstractTo test the effects of domestication on craniofacial skeletal morphology, we used three-dimensional geometric morphometrics (GM) along with linear and endocranial measurements to compare selected (domesticated) and unselected foxes from the Russian Farm-Fox Experiment to wild foxes from the progenitor population from which the farmed foxes are derived. Contrary to previous findings, we find that domesticated and unselected foxes show minimal differences in craniofacial shape and size compared to the more substantial differences between the wild foxes and both populations of farmed foxes. GM analyses and linear measurements demonstrate that wild foxes differ from farmed foxes largely in terms of less cranial base flexion, relatively expanded cranial vaults, and increased endocranial volumes. These results challenge the assumption that the unselected population of foxes kept as part of the Russian Farm-Fox experiment are an appropriate proxy for ‘wild’ foxes in terms of craniofacial morphology and highlight the need to include wild populations in further studies of domestication syndrome to disentangle the phenotypic effects of multiple selection pressures. These findings also suggest that marked increases in docility cannot be reliably diagnosed from shape differences in craniofacial skeletal morphology.

Three-Dimensional Assessment of Craniofacial Features in Patients With Down Syndrome During the Mixed Dentition Period: A Case-Control Study

2021 ◽  
pp. 105566562199818
Author(s):  
Hideomi Takizawa ◽  
Masahiro Takahashi ◽  
Koutaro Maki
Keyword(s):  
Down Syndrome ◽  
Three Dimensional ◽  
Cranial Base ◽  
Craniofacial Morphology ◽  
Mixed Dentition ◽  
Linear Measurements ◽  
3 Dimensional ◽  
Anterior Nasal Spine ◽  
Craniofacial Features ◽  
And Control

Objectives: Down syndrome (DS) is a common congenital chromosomal disorder related to trisomy 21. Lateral cephalometric radiography studies have shown that patients with DS have characteristic craniofacial morphology; however, no 3-dimensional analysis studies have been performed to investigate the craniofacial features, including volumetric aspects, of patients with DS. The present study was performed to evaluate the craniofacial features, including volumetric aspects, of patients with DS and to compare these findings with control participants using cone beam computed tomography (CBCT). Materials and Methods: The study sample consisted of 12 patients with DS and 12 control participants. All participants were examined by means of CBCT; the resulting images were used for evaluation of maxillary and mandibular volume, cranial base, and craniofacial measurements. Differences between patients with DS and control participants were statistically analyzed using Student t test. Results: Compared to control participants, patients with DS exhibited statistically significant reductions in maxillary and mandibular volumes. Both sagittal and axial cranial base linear measurements were shorter in patients with DS than in control participants. In contrast, the cranial base angle was enhanced in patients with DS, compared with control participants. Moreover, condylion (Co)–gnathion, anterior nasal spine–menton, and Co-subspinale (point A) measurements were shorter in patients with DS than in control participants; the sella–nasion–mandibular plane angle was significantly reduced in patients with DS, compared with control participants. Conclusion: Our results suggest that patients with DS have distinct skeletal volume and craniofacial morphology features, relative to individuals without DS.

Morphometric analysis of the palatal shape and arch dimension in subjects with palatally displaced canine

2019 ◽  
Vol 41 (5) ◽  
pp. 460-467 ◽  
Author(s):  
Manuela Mucedero ◽  
Matteo Rozzi ◽  
Alessia Milazzo ◽  
Paola Cozza
Keyword(s):  
Morphometric Analysis ◽  
Shape Change ◽  
Three Dimensional ◽  
Study Groups ◽  
3D Models ◽  
Permanent Teeth ◽  
Control Group ◽  
Linear Measurements ◽  
Geometric Morphometric ◽  
Maxillary Arch

Summary Objectives The aim of this study is to analyse the morphological variations of the palate shape and maxillary arch dimension in a group of subjects with unilaterally or bilaterally impacted maxillary canines compared with a control group, using three-dimensional (3D) geometric morphometric. Materials The subject of this study consisted of pre-treatment records of 46 (18 males and 28 females) patients with one or both canines palatally displaced. A control group of 26 subjects was selected from a list of orthodontic patients at the same dental hospital. The subjects were divided in two study groups: unilateral palatally displaced canine (UPDC) and bilateral palatally displaced canine (BPDC). Study casts were scanned to analyse the palate’s shape and maxillary arch dimension. The 3D geometric morphometric analysis was used to study the entirety of the shape of the palate. The virtual 3D models were measured with a specific software to analyse the maxillary arch dimension. (VAM, Vectra; Canfield Scientific, Fairfield, New Jersey, USA). Results When comparing the groups with the geometric morphometrics analysis, no significant palatal shape change was found. For the analysis of linear measurements, only a significant reduction of intercanine width was found in the UPDC and BPDC groups when compared with the control subjects. Conclusions Patients with palatally displaced permanent canine showed no maxillary transverse constriction or variation in palatal vault morphology but the absence of permanent teeth was associated with a reduction in the intercanine width.

Morphometric analysis of the palatal shape and arch dimension in subjects with buccally displaced canine

2019 ◽  
Vol 42 (5) ◽  
pp. 544-550
Author(s):  
Manuela Mucedero ◽  
Matteo Rozzi ◽  
Giulia Di Fusco ◽  
Carlotta Danesi ◽  
Paola Cozza
Keyword(s):  
Three Dimensional ◽  
Segment Length ◽  
Control Group ◽  
Linear Measurements ◽  
Clinical Factor ◽  
Geometric Morphometric ◽  
Morphometric Variation ◽  
Morphological Variations ◽  
Palatal Vault ◽  
Maxillary Arch

Summary Objectives To analyse morphological variations of the palate shape and maxillary arch dimension between a group of subjects with unilaterally or bilaterally buccally impacted maxillary canines and a control group (CG) by means of 3D geometric morphometric (GMM). Materials Pre-treatment records of 50 subjects (16 males and 34 females; mean age 13.9 years ± 1.8) with one or both canines buccally displaced were collected retrospectively. A CG of 50 subjects was selected from a list of orthodontic patients at the same dental hospital. The experimental group, buccally displaced canine (BDC) was divided in two groups: unilateral buccally displaced canine (UBDC) and bilateral buccally displaced canine (BBDC). To analyse the palate’s shape and maxillary arch dimension, study casts were scanned. To study the entirety of the palatal shape, 3D GMM analysis was used. To analyse the maxillary arch dimension, the virtual three-dimensional models were measured with a specific software (VAM, Vectra, Canfield Scientific, Fairfield, New Jersey, USA). Results When comparing the groups with the GMM analysis, patients with BDC showed a statistically significant narrower and higher palatal vault. About the analysis of linear measurements, the intercanine width, the anterior and posterior segment length were significantly smaller in BDC, UBDC, and BBDC subjects when compared with the controls and there were no differences between UBDC versus BBDC groups. Conclusions Patients with buccally displaced permanent canine tended to have maxillary transverse constriction and variation in palatal vault morphology. The morphometric variation of the palatine vault and arch dimensions can be considered a clinical factor associated with the presence of BDC.

Effect of Premature Sagittal Suture Closure on Craniofacial Morphology in a Prehistoric Male Hopi

1994 ◽  
Vol 31 (5) ◽  
pp. 385-396 ◽  
Author(s):  
Luci Ann P. Kohn ◽  
Michael W. Vannier ◽  
Jeffrey L. Marsh ◽  
James M. Cheverud
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Cranial Base ◽  
Craniofacial Morphology ◽  
Cranial Vault ◽  
Normal Male ◽  
Scaling Analysis ◽  
Sagittal Suture ◽  
Normal Individuals ◽  
Suture Closure

Scaphocephaly is caused by premature sagittal suture closure. It restricts medial-lateral growth of the cranial vault which appears longer and narrower than normal. We examined how this natural malformation affected morphology of the cranial base and face. A prehistoric adult male Hopi with scaphocephaly was compared to 19 normal male Hopi (Old Walpi Series, Field Museum of Natural History, Chicago, IL). Three-dimensional coordinates of 53 landmarks were recorded on the cranial vault, cranial base, and face. Finite element scaling analysis was used to test for significant differences between the scaphocephalic and normal Individuals in craniofacial morphology. Finite element scaling results indicated that scaphocephaly has a profound effect on cranial vault morphology. However, morphology of the cranial base and face were only slightly affected and, typically, are within the normal range of variation for the sample. An abnormality in the cranial base Is not associated with scaphocephaly in this individual.

scholarly journals A developmentally descriptive method for quantifying shape in gastropod shells

2020 ◽  
Vol 17 (163) ◽  
pp. 20190721
Author(s):  
J. Larsson ◽  
A. M. Westram ◽  
S. Bengmark ◽  
T. Lundh ◽  
R. K. Butlin
Keyword(s):  
Empirical Studies ◽  
Three Dimensional ◽  
Shell Shape ◽  
Large Set ◽  
Littorina Saxatilis ◽  
Shape Variation ◽  
Gastropod Shell ◽  
Geometric Morphometric ◽  
Wide Range ◽  
Descriptive Method

The growth of snail shells can be described by simple mathematical rules. Variation in a few parameters can explain much of the diversity of shell shapes seen in nature. However, empirical studies of gastropod shell shape variation typically use geometric morphometric approaches, which do not capture this growth pattern. We have developed a way to infer a set of developmentally descriptive shape parameters based on three-dimensional logarithmic helicospiral growth and using landmarks from two-dimensional shell images as input. We demonstrate the utility of this approach, and compare it to the geometric morphometric approach, using a large set of Littorina saxatilis shells in which locally adapted populations differ in shape. Our method can be modified easily to make it applicable to a wide range of shell forms, which would allow for investigations of the similarities and differences between and within many different species of gastropods.

scholarly journals An In Vivo 3D Micro-CT Evaluation of Tooth Movement After the Application of Different Force Magnitudes in Rat Molar

2009 ◽  
Vol 79 (4) ◽  
pp. 703-714 ◽  
Author(s):  
Carmen Gonzales ◽  
Hitoshi Hotokezaka ◽  
Yoshinori Arai ◽  
Tadashi Ninomiya ◽  
Junya Tominaga ◽  
...  
Keyword(s):  
Tooth Movement ◽  
Three Dimensional ◽  
Element Model ◽  
Longitudinal Change ◽  
Micro Ct ◽  
Linear Measurements ◽  
Center Of Rotation ◽  
Ct Evaluation ◽  
Space Width

Abstract Objective: To investigate the precise longitudinal change in the periodontal ligament (PDL) space width and three-dimensional tooth movement with continuous-force magnitudes in living rats. Materials and Methods: Using nickel-titanium closed-coil springs for 28 days, 10-, 25-, 50-, and 100-g mesial force was applied to the maxillary left first molars. Micro-CT was taken in the same rat at 0, 1, 2, 3, 10, 14, and 28 days. The width of the PDL was measured in the pressure and tension sides from 0 to 3 days. Angular and linear measurements were used to evaluate molar position at day 0, 10, 14, and 28. The finite element model (FEM) was constructed to evaluate the initial stress distribution, molar displacement, and center of rotation of the molar. Results: The initial evaluation of PDL width showed no statistical differences among different force magnitudes. Tooth movement was registered 1 hour after force application and gradually increased with time. From day 10, greater tooth movement was observed when 10 g of force was applied. The FEM showed that the center of rotation in the molar is located in the center of five roots at the apical third of the molar roots. Conclusion: The rat's molar movement mainly consists of mesial tipping, extrusion of distal roots, intrusion of mesial root, palatal inclination, and mesial rotation. Although the initial tooth movement after the application of different force magnitudes until day 3 was not remarkably different, 10 g of force produced more tooth movement compared with heavier forces at day 28.

scholarly journals Three-dimensional craniofacial morphology in unilateral cleft lip and palate

2014 ◽  
Vol 56 (2) ◽  
pp. 165-172 ◽  
Author(s):  
Eyas Abuhijleh ◽  
Halise Aydemir ◽  
Ufuk Toygar-Memikoğlu
Keyword(s):  
Cleft Lip ◽  
Cleft Lip And Palate ◽  
Three Dimensional ◽  
Craniofacial Morphology

scholarly journals Three-dimensional positional assessment of glenoid fossae and mandibular condyles in patients with Class II subdivision malocclusion

2017 ◽  
Vol 87 (6) ◽  
pp. 847-854 ◽  
Author(s):  
Juliana Macêdo de Mattos ◽  
Juan Martin Palomo ◽  
Antonio Carlos de Oliveira Ruellas ◽  
Paula Loureiro Cheib ◽  
Manhal Eliliwi ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Sella Turcica ◽  
Class Ii ◽  
Cranial Base ◽  
Class Ii Malocclusion ◽  
Computed Tomographic ◽  
Anterior Cranial Base ◽  
Condylar Position ◽  
Male Patients ◽  
Anterior Posterior

ABSTRACT Objectives: To test the null hypotheses that the positions of the glenoid fossae and mandibular condyles are identical on the Class I and Class II sides of patients with Class II subdivision malocclusion. Materials and Methods: Retrospective three-dimensional (3D) assessments of the positions of the glenoid fossae and mandibular condyles were made in patients with Class II malocclusion. Relative to a fiducial reference at the anterior cranial base, distances from the glenoid fossae and condyles were calculated in pretreatment cone beam computed tomographic scans of 82 patients: 41 with Class II and 41 with Class II subdivision malocclusions. The 3D distances from glenoid fossae to sella turcica in the X (right-left), Y (anterior-posterior), Z (inferior-superior) projections were calculated. Results: Patients with Class II malocclusion displayed a symmetric position of the glenoid fossae and condyles with no statistically significant differences between sides (P > .05), whereas patients with Class II subdivision showed asymmetry in the distance between the glenoid fossae and anterior cranial base or sella turcica (P < .05), with distally and laterally positioned glenoid fossae on the Class II side. (P < .05). Male patients had greater distances between glenoid fossae and anterior cranial fossae (P < .05). The condylar position relative to the glenoid fossae did not differ between the two malocclusion groups nor between males and females (P > .05). Conclusions: The null hypotheses were rejected. Patients with Class II subdivision malocclusion displayed asymmetrically positioned right- and left-side glenoid fossae, with a distally and laterally positioned Class II side, although the condyles were symmetrically positioned within the glenoid fossae.

scholarly journals Tooth-size discrepancy: A comparison between manual and digital methods

2014 ◽  
Vol 19 (4) ◽  
pp. 107-113 ◽  
Author(s):  
Gabriele Dória Cabral Correia ◽  
Fernando Antonio Lima Habib ◽  
Carlos Jorge Vogel
Keyword(s):  
Three Dimensional ◽  
Diagnostic Tools ◽  
Tooth Size ◽  
Digital Models ◽  
Linear Measurements ◽  
Length Discrepancy ◽  
Technological Advances ◽  
Size Discrepancy ◽  
Digital Methods ◽  
Plaster Models

INTRODUCTION: Technological advances in Dentistry have emerged primarily in the area of diagnostic tools. One example is the 3D scanner, which can transform plaster models into three-dimensional digital models. OBJECTIVE: This study aimed to assess the reliability of tooth size-arch length discrepancy analysis measurements performed on three-dimensional digital models, and compare these measurements with those obtained from plaster models. MATERIAL AND METHODS: To this end, plaster models of lower dental arches and their corresponding three-dimensional digital models acquired with a 3Shape R700T scanner were used. All of them had lower permanent dentition. Four different tooth size-arch length discrepancy calculations were performed on each model, two of which by manual methods using calipers and brass wire, and two by digital methods using linear measurements and parabolas. RESULTS: Data were statistically assessed using Friedman test and no statistically significant differences were found between the two methods (P > 0.05), except for values found by the linear digital method which revealed a slight, non-significant statistical difference. CONCLUSIONS: Based on the results, it is reasonable to assert that any of these resources used by orthodontists to clinically assess tooth size-arch length discrepancy can be considered reliable.

scholarly journals Accuracy of digital dental models and three-dimensional printed dental models in linear measurements and Bolton analysis

F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 180
Author(s):  
William Suryajaya ◽  
Maria Purbiati ◽  
Nada Ismah
Keyword(s):  
Treatment Planning ◽  
Interobserver Reliability ◽  
Intraclass Correlation ◽  
Three Dimensional ◽  
3D Printer ◽  
Intraoral Scanner ◽  
Linear Measurements ◽  
Dental Model ◽  
Dental Models ◽  
Digital Dental Models

Background: Due to advances in digital technology, it is possible to obtain digital dental models through intraoral scanning. The stereolithographic data collected from the scanner can subsequently be printed into a three-dimensional dental model in resinic material. However, the accuracy between digital dental models and printed dental models needs to be evaluated since it might affect diagnosis and treatment planning in orthodontic treatment. This study aimed to evaluate the accuracy of digital models scanned by a Trios intraoral scanner and three-dimensional dental models printed using a Formlabs 2 3D printer in linear measurements and Bolton analysis. Methods: A total of 35 subjects were included in this study. All subjects were scanned using a Trios intraoral scanner to obtain digital study models. Stereolithographic data from previous scanning was printed using a Formlabs 2 3D printer to obtain printed study models. Mesiodistal, intercanine, intermolar, and Bolton analysis from all types of study models were measured. The intraclass correlation coefficient was used to assess intraobserver and interobserver reliability. All data were then statistically analyzed. Results: The reliability tests were high for both intraobserver and interobserver reliability, which demonstrates high reproducibility for all measurements on all model types. Most of the data compared between study models showed no statistically significant differences, though some data differed significantly. However, the differences are considered clinically insignificant. Conclusion: Digital dental models and three-dimensional printed dental models may be used interchangeably with plaster dental models for diagnostic and treatment planning purposes. Keywords: Accuracy, 3D printing, digital dental model, printed dental model.

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