Effect of zinc-defi cient nutrition on craniofacial bone growth in rats

Abstract

Background: Zinc (Zn) is an essential nutrient that is required in humans and animals for the
growth, development, and maintenance of healthy bones. The aim of this study is to investigate the
effects of zinc-defi cient nutrition on the dental, mandibular, maxillary, and cranial dimensions of rats.
Materials and Methods: This experimental study was carried out on 14 male Wistar rats. The
rats were randomly divided into two groups. Group I rats were fed with a Zn-defi cient (ZD)
diet, and Group II rats with a Zn-containing (ZC) diet. All the rats on the experimental diet were
killed at the end of the fourth week and their blood samples were taken. The serum Zn levels
were measured by an atomic absorption spectrophotometer. Radiographic assessment of the jaw
bone density was done at the end of the study. Subsequently, the fi nal measurements were made
on the dry skulls, the mandibles, and teeth in both the groups. Statistical evaluation was performed
by the student’s t-test and repeated measures analysis. The difference between the groups was
considered statistically signifi cant if P < 0.05.
Results: The ZD group showed a signifi cantly lower value in body weight (P < 0.05), serum level
of zinc (P < 0.0001), and radiographic bone density of the mandible (P = 0.02). With regard to the
craniofacial parameters, a signifi cant difference was observed only in the length of the clinical crowns
of the teeth (L13), which were longer in group II as compared to group I (P = 0.03).
Conclusion: This study confi rmed that changes in zinc intake could not affect the growth of
craniofacial structures. Also, it might change the radiographic bone density of the mandible.
Key Words: Craniofacial bones, rats, zinc defi ciency