Can anything be done to improve these dents and facial asymmetry? (Photos)

I am truly puzzled. The kind of cheek indentation seen in the photo is a rather ORDINARY volume deficit type problem that is routinely and easily treated with the use of a robust HA volumizing filler properly injected. What's more, treating the problem in the aforementioned way will likely also secondarily diminish the smile folds seen in the photo. You would be wise to consult with an experienced, board certified cosmetic dermatologist filler expert. In experienced hands, treatment should take about ten minutes, engender little to no significant downtime, give rise to immediate, on-the-spot results that will very likely elicit a "Wow!" reaction. So, don't be discouraged and go see an expert.

Only one side view posted photo not enough to compare sides. For that one area of denting might try short acting HA filler or a hyper diluted Radiesse/Sculptra combination. Expect fees to range from $500-$2000. But best to virtual consult with or repost photos to see comparable sides of face.