Comparing grappling ability of extant Ursids

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I posted these data with regards to Canines comparison between Polar bears and Brown bears on a different forum some times ago, will copy it here.

1. Canines:
See Per Christiansen (2008) Table 2 for data on the canines of several species of Ursid.
   
Here are some relevant comparisons that I would make:

a. Canines Crown Height: I use Canine Height / Skull Length to make body-size-adjusted crown height comparison
Polar Bear: 0.133
Brown Bear: 0.132

Summary: When body size is adjusted, the crown height of these two bears are comparable.

b. Canine Crown Bending Strength: I will compare bending strengths at two points, at the alveolus and at 45% of crown height.
I use the following calculation to make body size-adjusted canine bending strength:

Sml(Avl) * 10^4 / Skull Length^2: size-adjusted bending strength about medial-lateral axis at the alveolus.
I use squared Skull Length to adjust for square-cube law since strength values Sml and Sap are measured in mm^2. The 10^4 is added there to make the values not to 'decimal' (i hope that makes sense)

Polar Bear: 2.084
Brown Bear: 1.948

Sap(Avl) * 10^4 / Skull Length^2: size-adjusted bending strength about anterior-posterior axis at the alveolus.
Polar Bear: 1.515
Brown Bear: 1.335

Sml(45%) * 10^4 / Skull Length^2: size-adjusted bending strength about medial-lateral axis at 45% of crown height.
Polar Bear: 1.014
Brown Bear: 1.186


Sap(45%) * 10^4 / Skull Length^2: size-adjusted bending strength about anterior-posterior axis at 45% of crown height.
Polar Bear: 0.887
Brown Bear: 0.961

Summary: Polar Bear's canines are stronger proximally (at alveolus). Brown Bear's canines are stronger distally (at 45% of crown height). This is probably due to the fact polar bear's canines are thicker at the alveoli but then become sightly more tapered distally.

c. Canine Root Strength, determined by canine root surface area:
See Alejandro Pérez-Ramos et al (2018) Table 2.
   
The value Ca RA-sa is relevant to our purposes because it is size-adjusted.
Polar Bear 1: 0.40
Polar Bear 2: 0.43
Brown Bear: 0.38

Summary: when size is adjusted, Polar bears have thicker, an thus more reinforced canines root. Reply