Dentin structure in familial hypophosphatemic rickets: benefits of vitamin D and phosphate treatment.
OBJECTIVE
To evaluate the outcome of 1-(OH) vitamin D and oral phosphate treatment on dentin structure in patients with familial hypophosphatemic rickets, and expression of SIBLINGs (a family of non-collagenous proteins involved in dentinogenesis) and osteocalcin.


METHODS
Seven patients with familial hypophosphatemic rickets (age 3-16 years) were studied before or during treatment. Deciduous and permanent teeth were prepared for scanning electron microscopy (SEM) analysis and immunohistochemistry.


RESULTS
Untreated or inadequately treated patients had necrotic teeth with impaired dentin mineralization including unmerged calcospherites and accumulation of non-collagenous proteins in wide interglobular spaces. Most of the primary incisors analyzed displayed fissures linking enamel subsurface to pulp horn. These elements may explain the bacterial penetration and dental abscesses despite the absence of carious lesions. Well-treated patients had healthy teeth with good dentin mineralization and little evidence of calcospherites.


CONCLUSIONS
Treatment of hypophosphatemic children with 1-(OH) vitamin D and oral phosphate insures good dentin development and mineralization, and prevents clinical anomalies such as the dental necrosis classically associated with the disease. Starting treatment during early childhood and good adherence to the therapy are mandatory to observe these beneficial effects.
Chaussain-Miller
C
C
Laboratoire Réparation et Remodelage des Tissus Oro-Faciaux, EA 2496 Groupe Matrices extracellulaires et Biominéralisation, Faculté de Chirurgie Dentaire, Université Paris 5, France. catherine.miller@univ-paris5.fr
Sinding
C
C
Septier
D
D
Wolikow
M
M
Goldberg
M
M
Garabedian
M
M
D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003790:Dental Pulp Necrosis / Q000188:drug therapy / Q000517:prevention & control; D003804:Dentin / Q000187:drug effects* / Q000473:pathology; D005260:Female; D006801:Humans; D007015:Hypophosphatemia, Familial / Q000150:complications / Q000188:drug therapy*; D008297:Male; D010710:Phosphates / Q000494:pharmacology / Q000627:therapeutic use*; D014807:Vitamin D / Q000494:pharmacology / Q000627:therapeutic use*; D014815:Vitamins / Q000494:pharmacology / Q000627:therapeutic use*
D010710:Phosphates; D014815:Vitamins; D014807:Vitamin D