Background: Low BMD is a common problem in major thalassaemia patient, but the use of DXA in chronic disease children with smaller bones, has some problems. Utilizing bone mineral apparent density (BMAD) helps in preventing this obstacle.  Testing the usefulness of this method in resolving the effects of bone size on BMD by comparing the BMD and BMAD of our thalassemics with results of our healthy ones, is our goal. Methods: Sample size was 110 cases with mean age of 9.6 ± 4.3 y/o and contained 73 males. Gauge of BMDs done by dual x-ray absorptiometry. Then BMAD was calculated. We did comparison of BMDs and BMADs results of thalassemic children with results of healthy Iranian pediatrics. Results: Mean of femoral BMD and BMAD, spinal BMD and BMAD was 0.579±0.134 g/cm2, 0.162±0.096 g/cm3, 0.563±0.118 g/cm2 and 0.107±0.015, respectively. When results of 9-18 patients compared with BMDs and BMADs of normal children, BMD of femur and BMD and BMAD of spine of patients found significantly lower (P-values,  0.003,  <0.001, <0.001, respectively). BMAD of femur of patients was not significantly different from normals. Conclusion: When bone mineral density of femur modifies by bone mineral apparent density formula, the remarkable difference between BMD of patients and normals; vanishes. Utilizing bone mineral apparent density helps in interpretation of femoral dual X-ray absorptiometry at least in thalassemic patients. As the results of vertebrae, after modification by calculating BMAD, remains significantly different, we cannot bring forward BMAD for mentioned aim in the spine of thalassemics.

Background: Normal bone structure is formed in childhood and adolescence. Any problem of bone formation at these stages will lead to significant osteoporosis and its complications in adulthood. Genetic factors are the most important factors in skeletal development. This study aimed to evaluate the bone mineral density and it's interfering factors in Iranian girls of Kawar of Fars.Materials and Methods: In this cross sectional study 235 healthy girls of Kawar of Fars aged 9-18 years old participated and they underwent Dual-energy X-ray Absorptiometry (DXA) scanning of lumbar spine, femoral neck and total body. The LMS method was applied to calculate smoothed BMC, BMD and BMAD for age related centiles.Results: Maximum accretion of BMC and BMD was at ages of 11 to 13 and according to 3rd, 25th, 50th, 75th and 97th percentile, BMC and BMD of all sites were increasing with a rather fixed rate up to the age of 15 and then after it increased very slowly.Conclusion: This study is the first study for normative data of BMC and BMD of Iranian girls and showed that BMC accretion of these girls was slower, but BMD accretion was greater than the girls of the other parts of the world. Absolute amount of bone mineral content in Iranian girls was lower than Indian, Lebanese and Asian girls of USA. Also weight and puberty were the two most important factors efficacious on BMD of the Iranian girls (of Kawar). Further research to evaluate the evolution of bone mineral density in Iranian children and adolescents is needed to identify the reasons for the significant differences in bone density values between our Iranian population and their Asian counterparts.