Effect of zinc-deficient nutrition on craniofacial bone growth in rats

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-deficient 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-deficient (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 final 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 significant if P < 0.05. RESULTS: The ZD group showed a significantly 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 significant 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 confirmed that changes in zinc intake could not affect the growth of craniofacial structures. Also, it might change the radiographic bone density of the mandible.