The Relationship Between Bone Mineral Density Of The Mandibular Angle And Growth And Development In Health Children And Adolescents

Objective Bone mineral density(BMD) of different skeletal sites of body in health children and adolescents was measured by dual-energy X-ray absorptiometry(DXA). The correlations between the BMD of mandibular angle and basic physiological data(age,height, weight and BMI), and other skeletal sites(hand, femur, skull, subcranial skeleton and total body) was analyzed. The relationship between the BMD of mandibular angle and growth was to explored at the present study.Methods Eight hundred and thirty-nine health children and adolescents(422 males, 417females) aged 5-18 years in Guangzhou were divided into 14 groups according to ages each gender. Age, height, weight and BMI were recorded. The BMD of mandibular angle, hand, femur, skull, subcranial skeleton and total body were measured by DXA. Data was statistically analyzed.Results In 5-18 years of age, BMD of the mandibular angle increased from 0.708 g/cm2 to 1.348 g/cm2 in males, while 0.726 g/cm2 to 1.306 g/cm2 in females. The mandibular angle BMD of females increased rapidly from 11 to 15 years old, while it began to increase rapidly after the age of 13 in males and continued until 18 years old.The mandibular angle BMD of females was higher at 12-17 years old(P<0.05), and there was no difference between males and females at 5-11 and 18 years old(P>0.05). For both genders, the mandibular angle BMD was highly correlated with age(r=0.695, 0.796; P<0.01), height(r=0.642, 0.690; P<0.01), weight(r=0.638, 0.716;P<0.01); and was moderately correlated with BMI(r=0.405, 0.556; P<0.01). High correlation was also seen between the BMD of mandibular angle and that of otherskeletal sites(r=0.737-0.880, P<0.01). The correlations in females(r=0.786-0.872)was higher than that in males(r=0.737-0.831, P<0.01).Conclusions The mandibular angle BMD gradually increased with age and presented different growth rules between males and females. There was high correlation between mandibular angle BMD and age, height, weight and BMD of other skeletal sites in health children and adolescents. Mandibular angle BMD could reflect total body BMD and could be used to assess bone health in children and adolescents.