I love this phrasing. The delicacy and precision of "poor dentition" over any one of the less kindly descriptions of gappy or discolored teeth.
The small dog has poor dentition. She was already lacking a few teeth when she first came to stay. The vet suggested that she'd probably spent some time gnawing on something metal, like a kennel. A nervous habit. (Sidebar fact: There's a parallel with horses, who have a truly weird behavior -- "cribbing" -- where they press their upper teeth on a solid surface, apply pressure, and then gulp air. No doubt there's something comforting about the practice, like fingernail-chewing.)
Also, though it squeezes at my heart to remember it, we helped loosen at least a couple of those teeth for her. She's got a spry way about her. When encouraged, she'll tear up her toys and haul ass around the house, all spring-loaded mischief. But the enthusiasm has a downside. At first, we did not notice that this fierce little tug-of-warrior was leaving the odd tooth fragment embedded in her fuzzy toy after an evening's frisk.
There she'd be, shivering a little with excitement, holding Cry-baby Lamb-chop clamped between her jaws, the light of battle still shining in her buggy eyes, despite the little smear of blood on the greyish fur of the toy. Like a kid refusing to admit chill after hours in the lake, she'd want us to continue yanking on the toy. She'd want to go on sliding on the hardwood with her back legs braced, growling.
Smiling her jack-o-lantern grin in a Platonic ideal of poor dentition.