The Journal of Clinical Endocrinology and Metabolism recently ran an article co-written by Scientific Advisory Board member Thomas O. Carpenter, MD, entitled "Conventional Therapy in Adults with X-Linked Hypophosphatemia: Effects on Enthesopathy and Dental Disease." You can read the abstract here http://press.endocrine.org/doi/full/10.1210/JC.2015-2199 The remainder of the article is behind a paywall, but your doctor will likely be able to access it if you provide that link. Also, the link will take you to instructions for requesting a copy from the publisher.
The conclusion of the article: "Treatment [with phosphorus and a vitamin D metabolite) in adulthood may not promote or prevent enthesopathy [calcification of soft tissues]; however, it may be associated with a lower risk of experiencing severe dental disease." J. Clin. Endocrinol. Metab 100: 3625-3632, 2015.
Accompanying that article was a commentary piece by another SAB member, Michale J. Econs, MD, entitled "Conventional Therapy in Adults with XLH improves Dental Manifestations, But Not Enthesopathy." Again, you can read a portion of it (and find instructions for obtaining a full copy) here: http://press.endocrine.org/doi/abs/10.1210/jc.2015-3229
While the conclusion (that conventional treatment of adults is unlikely to reduce the risk of enthesopathy) is less than encouraging, the good news is that the article and the commentary both document the fact that adults with XLH do, indeed, have ongoing symptoms, i.e., dental abscesses and enthesopathy. Getting this fact on record, in peer-reviewed, highly regarded medical journals is a slow process, but one that is critical for educating physicians who seldom see an XLHer and are unaware of the adult symptoms.