Commonalities and evolutionary divergences of mandible shape ontogenies in rodents

2021 ◽  
Vol 34 (10) ◽  
pp. 1637-1652
Author(s):  
Morgane Dubied ◽  
Sophie Montuire ◽  
Nicolas Navarro
Keyword(s):  
Genetics ◽  
2004 ◽  
Vol 166 (4) ◽  
pp. 1909-1921
Author(s):  
Christian Peter Klingenberg ◽  
Larry J Leamy ◽  
James M Cheverud

Abstract The mouse mandible has long served as a model system for complex morphological structures. Here we use new methodology based on geometric morphometrics to test the hypothesis that the mandible consists of two main modules, the alveolar region and the ascending ramus, and that this modularity is reflected in the effects of quantitative trait loci (QTL). The shape of each mandible was analyzed by the positions of 16 morphological landmarks and these data were analyzed using Procrustes analysis. Interval mapping in the F2 generation from intercrosses of the LG/J and SM/J strains revealed 33 QTL affecting mandible shape. The QTL effects corresponded to a variety of shape changes, but ordination or a parametric bootstrap test of clustering did not reveal any distinct groups of QTL that would affect primarily one module or the other. The correlations of landmark positions between the two modules tended to be lower than the correlations between arbitrary subsets of landmarks, indicating that the modules were relatively independent of each other and confirming the hypothesized location of the boundary between them. While these results are in agreement with the hypothesis of modularity, they also underscore that modularity is a question of the relative degrees to which QTL contribute to different traits, rather than a question of discrete sets of QTL contributing to discrete sets of traits.


2021 ◽  
Vol 11 (5) ◽  
pp. 364
Author(s):  
Bingjiang Qiu ◽  
Hylke van der van der Wel ◽  
Joep Kraeima ◽  
Haye Hendrik Glas ◽  
Jiapan Guo ◽  
...  

Accurate mandible segmentation is significant in the field of maxillofacial surgery to guide clinical diagnosis and treatment and develop appropriate surgical plans. In particular, cone-beam computed tomography (CBCT) images with metal parts, such as those used in oral and maxillofacial surgery (OMFS), often have susceptibilities when metal artifacts are present such as weak and blurred boundaries caused by a high-attenuation material and a low radiation dose in image acquisition. To overcome this problem, this paper proposes a novel deep learning-based approach (SASeg) for automated mandible segmentation that perceives overall mandible anatomical knowledge. SASeg utilizes a prior shape feature extractor (PSFE) module based on a mean mandible shape, and recurrent connections maintain the continuity structure of the mandible. The effectiveness of the proposed network is substantiated on a dental CBCT dataset from orthodontic treatment containing 59 patients. The experiments show that the proposed SASeg can be easily used to improve the prediction accuracy in a dental CBCT dataset corrupted by metal artifacts. In addition, the experimental results on the PDDCA dataset demonstrate that, compared with the state-of-the-art mandible segmentation models, our proposed SASeg can achieve better segmentation performance.


2011 ◽  
Author(s):  
Seongho Seo ◽  
Moo K. Chung ◽  
Brian J. Whyms ◽  
Houri K. Vorperian

2019 ◽  
Vol 222 (12) ◽  
pp. jeb204867 ◽  
Author(s):  
Samuel Ginot ◽  
Anthony Herrel ◽  
Julien Claude ◽  
Lionel Hautier

2009 ◽  
Vol 96 (6) ◽  
pp. 725-730 ◽  
Author(s):  
Lionel Hautier ◽  
Pierre-Henri Fabre ◽  
Jacques Michaux
Keyword(s):  

Author(s):  
Boris Kryštufek ◽  
Georgy Shenbrot ◽  
Tina Klenovšek ◽  
Franc Janžekovič

Abstract We explore the pattern of spatial variation in mandibular morphology in relation to subspecific taxonomy in the dwarf fat-tailed jerboa, Pygeretmus pumilio. The unguided k-means clustering on mandible shape scores, partitioned populations into two clusters, corresponding to western and eastern populations. These clusters nearly perfectly matched the two subspecies groups (pumilio and potanini groups) recognized in an independent study based on the morphology of the glans penis. The mandible, although under environmental pressure, has retained a sufficient amount of taxonomic information to retrieve grouping closely resembling the one derived from a sexually selective trait. We recommend morphometrics of the mandible as a routine step in addressing variations in mammals at species and subspecies levels. We also stress the advantage of unsupervised k-clustering in testing null expectation in subspecies taxonomies. However, the power of this approach has its limitations and in our analysis, the k-clustering failed to retrieve subspecies in the potanini group.


2019 ◽  
Vol 488 (5) ◽  
pp. 576-580
Author(s):  
T. A. Mironova ◽  
V. B. Sycheva ◽  
A. A. Martynov ◽  
A. R. Gromov ◽  
D. S. Kostin ◽  
...  

For the first time, the analysis of the mandible shape in semispecies of common vole (Microtus arvalis) from the hybrid zone was carried out using geometric morphometry methods. High morphological variability of hybrids that were closer to the parent form Microtus obscurus than to M. arvalis was found. The main trends in the shape of the mandible, which locate mainly in the horizontal plane, are revealed.


2020 ◽  
Vol 223 (16) ◽  
pp. jeb224352 ◽  
Author(s):  
Colline Brassard ◽  
Marilaine Merlin ◽  
Claude Guintard ◽  
Elodie Monchâtre-Leroy ◽  
Jacques Barrat ◽  
...  

ABSTRACTPrevious studies based on two-dimensional methods have suggested that the great morphological variability of cranial shape in domestic dogs has impacted bite performance. Here, we used a three-dimensional biomechanical model based on dissection data to estimate the bite force of 47 dogs of various breeds at several bite points and gape angles. In vivo bite force for three Belgian shepherd dogs was used to validate our model. We then used three-dimensional geometric morphometrics to investigate the drivers of bite force variation and to describe the relationships between the overall shape of the jaws and bite force. The model output shows that bite force is rather variable in dogs and that dogs bite harder on the molar teeth and at lower gape angles. Half of the bite force is determined by the temporal muscle. Bite force also increased with size, and brachycephalic dogs showed higher bite forces for their size than mesocephalic dogs. We obtained significant covariation between the shape of the upper or lower jaw and absolute or residual bite force. Our results demonstrate that domestication has not resulted in a disruption of the functional links in the jaw system in dogs and that mandible shape is a good predictor of bite force.


2014 ◽  
Author(s):  
Martin Biosse Duplan ◽  
Rocco Federico Di ◽  
Yann Heuze ◽  
Emilie Gaudas ◽  
Davide Komla-Ebri ◽  
...  
Keyword(s):  

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