Analysis of Crown Morphology and Gingival Shape in the Maxillary Anterior Dentition

2020 ◽  
Vol 40 (6) ◽  
pp. 925-931
Author(s):  
Chen Zhong ◽  
Xiao Yingzi ◽  
Lin Zhiqiang ◽  
Wang Peishuang ◽  
Zeng Yimin ◽  
...  
Keyword(s):  
2019 ◽  
Vol 53 (2) ◽  
pp. 106-118 ◽  
Author(s):  
Christopher Maier ◽  
Jelena Dumančić ◽  
Hrvoje Brkić ◽  
Zvonimir Kaić ◽  
Ivana Savić Pavičin ◽  
...  

2019 ◽  
Vol 169 (4) ◽  
pp. 646-663 ◽  
Author(s):  
Viktoria A. Krenn ◽  
Cinzia Fornai ◽  
Lisa Wurm ◽  
Fred L. Bookstein ◽  
Martin Haeusler ◽  
...  

1979 ◽  
Vol 159 (3) ◽  
pp. 331-341 ◽  
Author(s):  
Marvalee H. Wake ◽  
Gloria Z. Wurst
Keyword(s):  

Author(s):  
Andreas Rais ◽  
Martin Jacobs ◽  
Jan-Willem G. van de Kuilen ◽  
Hans Pretzsch

The current tendency towards the silvicultural promotion of mixed tree species has increased the variability in the crown structure within stands. This study shows how neighbouring trees can influence both the external crown features and internal wood properties of trees. Using terrestrial laser scanning, the crown features of 100 European beech trees, <i>Fagus sylvatica</i> L., from pure beech stands and mixed stands of beech with Douglas fir, Norway spruce, sessile oak and Scots pine were recorded. After felling and sawing, the dynamic modulus of elasticity was determined on 1623 boards from the two lower 4.1-m logs. Significant differences were found between beech trees from pure stands and those from beech–pine mixed stands in terms of crown volume (415 m<sup>3</sup> vs 766 m<sup>3</sup>), crown ratio (50.0% vs 71.5%), crown projection ratio (0.182 m cm<sup>−1</sup> vs 0.253 m cm<sup>−1</sup>) and branch angle (30.7° vs 54.1°). Multiple regression mixed models revealed significant relationships between timber stiffness and crown volume (-1.7 N mm<sup>−2</sup> m<sup>−3</sup>), crown ratio (-28.4 N mm<sup>−2</sup> %<sup>−1</sup>) and crown projection area (-9835 N mm<sup>−2</sup> m<sup>−1</sup> cm). Thus, the crown morphology of broad-leaved species reflects the tree’s long-term competitive status and suggests indicators for the assessment of mechanical–physical wood properties.


2019 ◽  
Vol 156 (9) ◽  
pp. 1618-1622 ◽  
Author(s):  
Romain Vullo ◽  
Nathalie Bardet ◽  
Emmanuel Gheerbrant ◽  
Nour-Eddine Jalil

AbstractA pycnodont premaxilla bearing a large incisiform tooth with an unusual crown morphology is described from the Palaeocene (Thanetian) phosphate deposits of Morocco. This peculiar tooth shows a broad, fan-shaped multicuspid crown with nine cusps, well adapted for benthic macroalgal scraping. This morph, assigned to a new species of Pycnodus (P. multicuspidatus sp. nov.), emphasizes the phenotypic plasticity of the group and documents an additional trophic specialization among Palaeogene pycnodontiform fishes. In the post-K/Pg boundary marine ecosystem of the Ouled Abdoun Basin, P. multicuspidatus sp. nov. may have opportunistically replaced Maastrichtian fish taxa with a similar front dentition and feeding behaviour, such as the putative specialized pycnodontiforms Stephanodus and Hadrodus.


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