Just read your NH nsfw hc, and in the 'body part' section you mentioned his teeth being the only part of himself he takes care off.
Now, my question to you then, would he mayhaps let his companion assist with the task of filing them, pherhaps even doing such a task for him.
(imagine if you will, a similar vibe to beard shaving with a barber's knife.
The file inside his mouth, opend and held open wide, such that they might have more room to work with, carefully holding himself in place, such that his teeth do not nick their hands.
They go about it methodologically enough that it is almost meditative, even as both they and he are aware that they could inflict harm on him with the tool in their hands, and he trusts that they won't, even if realistically, any injury they could cause heal in but mere moments time.
Every once in a while, they pause in their task to inspect their work, softly press upon the points with the pad of a finger, and along the sides of it to feel if they are smooth enough.
Were once they are satisfied with his upper jaw, they move onto his lower jaw, pressing down upon the tip of his his tounge, such that it is out of the way and won't be caught on the file as they work.
Finally they put down and away the file, and inspect their work with both hands, taking their time as they do, both out of a desire for their work to be up to his standards and preferences, as much as to watch the way he let's them manipulate his head as they wish, his lidded eyes watching them in turn.)
@twentyplusinterestsinatrenchcoat I thank you for the fic