One of the things patients have been saying for years is how much our dental issues affect our quality of life, and researchers are finally starting to look into whether burosumab treatment will prevent or at least reduce the spontaneous abscesses we have. The hope, of course, is that if patients start burosumab as infants/toddlers, before their adult teeth begin to form, their bodies would have adequate phosphorus for the teeth to form normally, and therefore have better protection against bacteria.
It’s too soon to have much data on that issue, since kids have only had access to burosumab (outside clinical trials) for four years now, so the first of the very youngest patients would only be five now (or maybe around six if treatment started during the trials). Researchers have, however, looked at whether burosumab treatment can reduce our dental issues.
In the first reported study, the results were encouraging. The journal of the American Society for Bone and Mineral Research published “Burosumab and dental abscesses in children with X-Linked Hypophosphatemia.” They concluded: “Burosumab treatment appears to be associated with a reduction in the number of dental abscesses in XLH children, compared with [phosphorus/calcitriol treatment].”
The second one is a little less encouraging. Frontiers in Endocrinology published “Dental Health of Pediatric patients with X-linked hypophosphatemia (XLH) after three years of burosumab therapy.” They confirmed the burosumab seemed to improve the patients’ dental health: “The frequency of dental abscesses in our ten study patients decreased significantly throughout the three years of burosumab treatment, with only one exception.” BUT, when they looked at the actual tooth structure they found, “Regrettably, the dental morphology of XLH patients as evidenced by excessively larger pulp dimensions did not exhibit the desired decrease in the pulp dimensions expected with age [while on burosumab treatment].” In other words, it’s typical of untreated XLH teeth to have large pulp chambers, so there’s less hard material (dentin) protecting the interior of our teeth against bacteria, and the researchers hypothesized that the dentin would fill in over time (as it does with non-XLH teeth), but it didn’t fill in over the course of three years of burosumab treatment.
I’m not entirely discouraged by the second study though. Both studies do show at least some improved outcomes, even if the second one suggests that the improvement may be limited since the structure (ratio of dentin to pulp) doesn’t completely become normal. There are limitations to the reliability of the conclusions in both studies, because of the small sample sizes, plus the wide range of ages. The second study had ten patients, ranging in age from four to fifteen before they began burosumab. It’s possible that there would be better news if we looked at the teeth of patients who started on burosumab very early in childhood, but that will take quite a few more years to gather. I’d love to see a comparison of the teeth of, say, two sixteen-year-old patients, one who was on burosumab for most of that time, and one on the old treatment, but burosumab has only been commercially available for four years now.
In other encouraging dental news, I’m pleased to see a variety of additional research for other treatments if burosumab isn’t enough to reduce the spontaneous abscesses. There’s one study (in France and not yet recruiting) that will look into a possible preventive treatment that’s applied to kids’ teeth. Another study is looking into the use of dental implants for XLH patients.
And finally, I’ll leave you with a couple other indications that the medical/dental community is taking XLH dental issues seriously. If you’ve ever had a dentist/endodontist shame you for the abscesses, there are now a number of articles that explain about how XLH teeth are structurally defective, which is the cause of the abscesses. They can be used to educate your clinician (if they’re willing to listen): “Characterization of oral health status in Chilean patients with X-linked hypophosphatemia,” and “Pulp chamber features, prevalence of abscesses, disease severity, and PHEX mutation in X-linked hypophosphatemic rickets.” Yes, I wince at the misuse of “rickets” in the title, but I’m grateful to have the data.
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Please note that the author is a well-read patient, not a doctor, and is not offering medical or legal advice.
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Please note that the author is a well-read patient, not a doctor, and is not offering medical or legal advice.
If you’d prefer to read this blog as a newsletter, sent straight to your inbox, please sign up here.