The goal of this study was to determine, through a longitudinal follow-up, whether sex influences bone adaptation during simulated weightlessness. Twelve-week-old male and female Wistar rats were hindlimb unweighted for 2 wk, and the time course of bone alteration was monitored in vivo by means of densitometry and unbiased three-dimensional quantitative microcomputed tomography at 7 and 14 days...

A two-dimensional finite element model of a mandibular quadrant was used to examine differences in magnitude of the principal stresses from the placement of three- and four-unit bridges. The area of interest spanned the first premolar to the second molar. Loading conditions were (i) vertical and distributed and (ii) 30 degrees to the vertical and concentrated. The principal stresses were calcul...

Intermittent treatment with parathyroid hormone (PTH) increases bone formation and prevents bone loss in hindlimb-unloaded (HLU) rats. However, the mechanisms of action of PTH are incompletely known. To explore possible interactions between weight bearing and PTH, we treated 6-mo-old weight-bearing and HLU rats with a human therapeutic dose (1 microg.kg(-1).day(-1)) of human PTH(1-34) (hPTH). C...

OBJECTIVE To investigate the influence of decreased mechanical loading on the density and mechanical properties of the cancellous bone of the human mandibular condyle. DESIGN Destructive compressive mechanical tests were performed on cancellous bone specimens.Background. Reduced masticatory function in edentate people leads to a reduction of forces acting on the mandible. As bone reacts to it...

OBJECTIVE The study tested the hypothesis that females who sustain stress fractures of cancellous bone have decreased bone density. DESIGN A retrospective, controlled, cross-sectional study. SETTING The setting of the study was a tertiary care center for Women's Sports Medicine. PATIENTS 20 female patients under the age of 40 who had suffered a stress fracture and who had a positive diagn...

Age-related functional changes of bone is not well understood. The effect of aging on bone response to a low calcium feeding was studied using senescent rats. Male Wistar rats aged 23 to 28 months were fed either a low calcium diet (0.05% Ca, 0.35% P) or a normal calcium diet (0.5% Ca, 0.35% P) by using a pair feeding technique. They were sacrificed at intervals of 6, 9, and 20 days. Bone miner...

Bone mineral density [BMD] generally correlates with bone strength. BMD testing is used to assess bone density and diagnose osteoporosis. The correlation between CT numbers and mechanical property estimated from cortical bone were found to be low (r2<0.2) and cancellous bone were found to be higher (r2>0.6). The specific relationship depending on the types of bone, that predict elastic module f...

Introduction The use of morselized impacted cancellous allografts for hip arthroplasty revision surgery shows results which seem to differ dramatically from other kinds of allografting (1,2). In structural cancellous allografts, bone ingrowth is usually limited to 2-3 mm (3), whereas the whole of morselized impacted grafts seem to be remodelled in several cases as judged by radiography (1,4). I...