Genotoxic evaluation of synthetic hydroxyapatite using mammalian bone marrow chromosome aberration test

Some of the beneficial biocompatible properties of hydroxyapatite [Ca10(PO4)6(OH)2]; the major component and an essential ingredient of normal bone and teeth, are that it is rapidly integrated into the human body and will bond to bone forming indistinguishable unions. But, before new materials are approved for medical use, mutagenesis systems to exclude cytotoxic, mutagenic or carcinogenic properties are applied worldwide. This study aimed to detect any chromosomal aberrations induced by the synthetic hydroxyapatite granules [Manufactured by Universiti Sains Malaysia, (USM) Penang, Malaysia] in the bone marrow cells of mice. The mitotic indices of the groups treated with synthetic hydroxyapatite granules did not show any significant difference as compared to the negative control group treated with distilled water. Also the groups of mice treated with synthetic hydroxyapatite granules and distilled water did not induce significant change in chromosome aberrations as compared to the positive control group treated with Mitomycin C. The mitotic indices and chromosomal analyses indicate that under the present test conditions, synthetic hydroxyapatite granules (manufactured by USM) are non cytotoxic and do not induce chromosome aberrations in the bone marrow cells of mice.

Nasalance scores of Malay (Kelantan dialect) in children with and without palatal cleft

This study was designed to obtain and compare the nasalance scores produced by normal Malay children and those with repaired palatal cleft. Data from 103 noncleft children and 27 children with repaired clefts were included. All children were of Malay origin with the Malay language (Kelantan dialect) as their first language. Two short and simple test stimuli were constructed in the Malay language; one resembled the Nasal Sentences and the other resembled the Zoo Passage (oral passage) used in nasometer testing. Nasalance scores were obtained with the Nasometer II model 6400 by Kay Elemetrics. Calibration of the nasometer and collection of data followed the recommended protocol outlined in the manual. Nasalance scores for the Oral Passage was significantly higher (p < 0.001) for the children with repaired palatal clefts when compared to scores for children without clefts. However, no differences in nasalance scores were detected between both groups for the Nasal Passage. The normative nasalance scores for Malay children with Kelantan dialect was established, which can be used as an objective reference in the management of Malay patients with resonance disorders.