Hypophosphatasia: Evaluation of Size and Mineral Density of Exfoliated Teeth.

OBJECTIVE: Most cases of hypophosphatasia (HPP) exhibit early loss of primary teeth. Results of micro-computed tomography (micro-CT) analysis of teeth with HPP have not yet been reported. The purpose of the present study was to describe the size and mineral density distribution and mapping of exfoliated teeth with HPP using micro CT. STUDY DESIGN: Seven exfoliated teeth were obtained from a patient with HPP. Exfoliated teeth sizes were measured on micro CT images and mineral densities of the mandibular primary central incisors were determined. RESULTS: Partial dentures were fabricated for the patient to replace the eight primary teeth which had exfoliated. Most primary teeth sizes were within the normal range. The mean values of enamel and dentin mineral densities in teeth with HPP were 1.35 and 0.88 g/cm3, respectively, in the mandibular primary central incisors. CONCLUSION: Mineral density distribution and mapping revealed that the values in teeth with HPP were lower than the homonymous teeth controls in all regions from the crown to apex. Furthermore, it was demonstrated that the differences between HPP and controls were larger on the crown side and the differences tended to converge on the apex side. These results suggested that the present patient showed mild hypomineralization in the primary dentition.

[Recent features of parasites detected from clinical specimens].

It is generally considered that we have already been through with problems caused by various kinds of parasites which had once raged throughout the country. On the contrary to our common concept, we occasionally encounter some kinds of parasites in a laboratory as well as in clinical fields, which have become unfamiliar to us in these days. Parasitic diseases are in the first place, proper and limited to certain local regions, but the present situation has been greatly changed. Nowadays, specific parasites are no longer limited to polluted areas, but also they can be detected in any part of the world owing to facilitated transportations and a promoted international exchange of people. A recent gourmet boom is also one of the causes of infection as seen in anisakiasis. This study was conducted on the investigation of parasites detected from clinical specimens in our laboratory during the period from 1989 to 1993. 1) The following parasites were detected : (1) Strongyloides stercoralis, (2) Giardia lamblia, (3) Diphyllobothrium latum, (4) Schistosoma mansoni, (5) Entamoeba histolytica, (6) Necator americanus, (7) Isospora belli. 2) Strongyloides stercoralis was detected at the highest frequency. This result gives an account of high prevalence of the parasite among the inhabitants in Okinawa. In addition, the agar plate medium method which has been newly adopted has definitely led to far-advanced results for detection of this parasite. 3) Schistosoma mansoni and Necator americanus were found from foreigners one of whom was a Tanzanian and the other was a Dominican. 4) Isospora belli was found from those compromised cases such as ATL and AIDS.