Bone, aging

Perform x-ray of left wrist and hand for children over 1 year of age to estimate bone age (knee and ankle for children younger than 1 year of age). 

Perform imaging tests of the hypothalamic-pituitary region to detect structural or developmental anomalies. Perform x-ray to estimate bone age. 

The adult skeleton is periodically remodeled by transitory anatomic structures that contain juxtaposed osteoclast and osteoblast teams and that replace old bone with new bone. The purpose of this remodeling is both to prevent bone aging and repair the damage that occurs as well as to guarantee a contribution of minerals, especially calcium, to body cells for their correct function. In the last few years, due mainly to the research in molecular biology and cellular differentiation and to studies of genetically manipulated mice, it has been possible to discover many aspects both of the cellular and molecular bases of this bone remodeling as well as of the differentiation and function of the two main implied cell types osteoblasts and osteoclasts. 

Termine, J. D. and Posner, A. S. (1966). Infrared analysis of rat bone age dependency of amorphous and crystalline components. Science 153 1523-1525. 

The dosage may be gradually titrated upward at 6- to 12-month intervals as needed to achieve appropriate bone age advancement and eventual epiphyseal closure. Chronic dosing with 0.625 mg is sufficient to induce artificial cyclic menses with sequential progestin treatment and to maintain bone mineral density after skeletal maturity is achieved. 

Bone maturation Use cautiously in healthy males with delayed puberty. Monitor bone maturation by assessing bone age of the wrist and hand every 6 months. Carcinogenesis There are rare reports of hepatocellular carcinoma in patients receiving long-term therapy with androgens in high doses. 

Thyroid hormone also plays a major role in the maturation of bone. A deficiency of thyroid hormone in early life leads to both delay in and abnormal development of epiphyseal centers of ossification (epiphyseal dysgenesis). Hypothyroidism-induced impairment of linear growth can lead to dwarfism in which the Umbs are disproportionately short in relation to the trunk with the apparent bone age retarded in relation to chronological age. 

A 9-year-old boy with early puberty took oxandrolone for 22 months because of constitutional delay of growth. His height velocity increased above the 97th percentile and his bone age developed twice as fast as his chronological age. The oxandrolone was withdrawn, but his growth velocity did not decrease and his bone age continued to accelerate. 

A girl with floating harbor syndrome (short stature, delayed bone age, typical facies, and delayed speech development) received growth hormone from the age of 3.5 years for 14 months (83). At 6 years she developed an abnormal gait due to a tethered cord. 

Berg, S. (1963). The determination of bone age, in Methods of Forensic Science (R Lundquist, Ed.). New York Wiley and Sons, 231-252. 

E. Budyn, T. Multi-scale modeling of human cortical bone Aging and failure studies. Mat. Rsrch. Soc. Sym. Pro.- Mech. of Bio. Bio-Inspired Matls 975, 27-32 (2006)... 

Rittweger J, Gunga HC, Felensberg D, Kirsh KA. Muscle and bone-aging in space. J Gravit Physiol. 1999 6 P133-P136. 

In the first study, the patients had radiography of the left hand for bone age determination, and 12 had deferoxamine-induced long bone dysplasia (107). There was irregularity at the physeal-metaphyseal junction of the distal ulna (the site most frequently affected) and radius metaphyseal sclerosis was also common, especially of the ulna, but also of the radius, metacarpals, and phalanges. Radiolucent lesions occasionally accompanied metaphyseal sclerosis. In six patients with relatively mild lesions, the dysplastic changes had been missed or not mentioned. 

After Monitor bone age, calcium, parathyroid, phosphorus, renal function, glucose, growth rate, thyroid... 

Sizonenko PC, Paunier L. Hormonal changes in puberty III. Correlation of plasma dehy-droepiandrosterone, testosterone, FSH, and LH with stages of puberty and bone age in normal boys and girls and in patients with Addisons disease or hypogonadism or with premature or late adrenarche. J Clin Endocrinol Metab 1975 41 894-904. 

A drop of lidocaine is deposited in the gingival crevice so that the injection will be painless. Bilateral injection of 0.5-1 cm of 2% lidocaine without adrenaline (canine teeth or premolar-canine junction) anesthetizes the whole of the chin region (Figures 33.10, 33.11). The lidocaine should be injected in a line and slightly fanned. The older the patient, the further back the injection has to be, as the mental nerve foramen recedes as the bones age. 

Til. Thompson, R. G., Rodriguez, A., Kowarsid, A., Migeon, C. J., and Blizzard, R. M., Integrated concentration of human growth hormone correlated with plasma testosterone and bone age in preadolescent and adolescent males. /. Clin. Endocrinol. Metab. 35, 334-337 (1972). 

In the majority of girls with precocious puberty, no underlying cause is discernible. Such patients are likely to have a roentgenological bone age well in advance of their chronological age, while their serum alkaline phosphatase activities may reflect a period of rapid growth (S41). 

Hyperthyroidism. An increased growth rate, with advanced bone age, is a feature of hyperthyroidism in children, or hypothyroid children over-replaced with thyroxine. 

James is S years old and is much smaller than his classmates at. schtMtl. His growth rate has been monitored and has clearly dropped off markedly in the past year. He is an active child, and on extunination has normal body proportions. His mother and father are of average height. His bone age is that of a 3-year-old child. 

---