Upon obtaining an in-depth history, many of these patients will reveal that they had premature loss of their deciduous teeth [ is characterized by premature exfoliation of fully rooted primary teeth and/or severe dental caries, often not associated with abnormalities of the skeletal system.The anterior deciduous teeth are more likely to be affected and the most frequent loss involves the incisors .However, it should be noticed that these clinical subtypes overlap, for instance infantile and childhood hypophosphatasia share some clinical symptoms, and patients with adult hypophosphatasia often had some clinical symptoms already in childhood.].These spurs are often diagnostic for hypophosphatasia.The symptoms are highly variable in their clinical expression, which ranges from stillbirth without mineralized bone to early loss of teeth without bone symptoms.Depending on the age at diagnosis, six clinical forms are currently recognized: perinatal (lethal), perinatal benign, infantile, childhood, adult and odontohypophosphatasia.In the lethal perinatal form, the patients show markedly impaired mineralization .In the prenatal benign form these symptoms are spontaneously improved.
There is also a predilection for chondrocalcinosis and marked osteoarthropathy later in life.Hypercalcemia also is present, explaining in part a history of irritability, poor feeding, anorexia, vomiting, hypotonia, polydipsia, polyuria, dehydratation, and constipation.Increased excretion of calcium may lead to renal damage.Dental X-rays show reduced alveolar bone, enlarged pulp chambers and root canals.
Although the only clinical feature is dental disease, biochemical findings are generally indistinguishable from those in patients with mild forms of hypophosphatasia (adult and childhood).
In infants who survive, there is often spontaneous improvement in mineralization and remission of clinical problems, with the exception of craniosynostosis .