Nondestructive Microcomputed Tomography Evaluation of Mineral Density in Exfoliated Teeth with Hypophosphatasia.

Sachiko Hayashi-Sakai,Jun Sakai,Yutaka Nikkuni,Marie Soga,Takafumi Hayashi,Miwa Nakayama,Hideyoshi Nishiyama,Junko Shimomura-Kuroki,Makoto Sakamoto,Makiko Ike,Kouji Katsura,Taichi Kobayashi

doi:10.1155/2016/4898456

Sachiko Hayashi-Sakai, Jun Sakai + Show 10 more

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https://doi.org/10.1155/2016/4898456

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Abstract

Most cases of hypophosphatasia (HPP) exhibit early loss of primary teeth. Results of microcomputed tomography (micro-CT) analysis of teeth with HPP have rarely been reported. The purpose of the present study was to describe the mineral density distribution and mapping of exfoliated teeth from an HPP patient using micro-CT. Four exfoliated teeth were obtained from a patient with HPP. Enamel and dentin mineral densities of exfoliated teeth were measured on micro-CT. The mean values of enamel and dentin mineral densities in mandibular primary central incisors with HPP were 1.61 and 0.98 g/cm3, respectively. The corresponding values in the mandibular primary lateral incisors were 1.60 and 0.98 g/cm3, respectively. Enamel hypoplasia was seen in the remaining teeth, both maxillary and mandibular primary canines and first and second molars. Micro-CT enables nondestructive, noninvasive evaluation and is useful for studying human hard tissues obtained from patients.

Highlights

Hypophosphatasia (HPP) is a rare congenital metabolic bone disease with autosomal dominant or recessive inheritance
The disorder of HPP is caused by mutations to the tissuenonspecific alkaline phosphatase gene (TNSALP) and results in decreased serum alkaline phosphatase (ALP) levels and hard tissues with defective calcification
In previous studies of HPP, hypoplasia of cementum tissue was found to be responsible for early primary tooth loss in childhood HPP [1, 2, 6, 7], but few reports have examined exfoliated teeth of childhood HPP patients

Summary

Introduction

Hypophosphatasia (HPP) is a rare congenital metabolic bone disease with autosomal dominant or recessive inheritance. The disorder of HPP is caused by mutations to the tissuenonspecific alkaline phosphatase gene (TNSALP) and results in decreased serum alkaline phosphatase (ALP) levels and hard tissues with defective calcification. HPP is classified by the age at diagnosis into six clinical forms: (1) perinatal; (2) infantile; (3) childhood; (4) adult; (5) odonto-; and (6) a rare benign perinatal form [1,2,3,4,5]. The clinical picture shows a wide spectrum from dental abnormalities without skeletal manifestations in odonto-HPP to lethal skeletal hypomineralization in perinatal HPP [1, 2, 4]. A major dental feature of HPP is premature loss of dentition, which most commonly affects the incisors. In previous studies of HPP, hypoplasia of cementum tissue was found to be responsible for early primary tooth loss in childhood HPP [1, 2, 6, 7], but few reports have examined exfoliated teeth of childhood HPP patients

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