Dental aspects of hypophosphatasia: a case report, family study, and literature review.

The classic oral features of hypophosphatasia, namely, premature tooth loss and large pulp spaces, were found in a young adult woman with bone and joint pains. A study of 22 family members revealed several with dental abnormalities such as abnormal enamel, dentin, or cementum formation, decreased mandibular bone density, and abnormally large pulp spaces. Only the propositus' sister fulfilled the biochemical criteria for hypophosphatasia. Biochemical examination of an extracted tooth from this sister showed phosphate and alkaline phosphatase values that were 7 to 10 times lower than normal and reduced concentrations of the essential cofactors Zn++ and Co++. The spectrum of dental abnormalities is reviewed. This family study reveals that enamel hypoplasia, increased pulp spaces, and premature tooth loss are present not only in the deciduous but also in the permanent dentition. These findings should draw the dentist's attention to this condition.