Hypophosphatasia (HPP) is an inherited bone disease caused by mutation of the alkaline phosphatase, biomineralization associated (ALPL) gene and is characterized by bone hypomineralization and/or early exfoliation of primary teeth. Dental manifestations can lead to the diagnosis of milder types of HPP. The purpose of this paper is to report the case of two patients with growth and development problems who were referred to a dental clinic due to early exfoliation of primary teeth and were subsequently diagnosed with childhood HPP with bone symptoms. Early diagnosis of HPP and management of growth and development are important, as HPP is a progressive disease. When dentists detect early exfoliation of the mandibular incisors before four years of age, they should refer the patient for investigation of HPP. Growth and development should be closely monitored in patients with early primary tooth exfoliation.