Changes In Skeletal Structure Research Articles

Chronic Excess Iodine Intake Inhibits Bone Reconstruction Leading to Osteoporosis in Rats

BackgroundAlthough iodine modulates bone metabolism in the treatment of thyroid disease, the effect of iodine intake on bone metabolism remains less known. ObjectiveThis study evaluated the effect of excess iodine intake in rats on bone reconstruction in the 6th and 12th month of intervention. MethodRats were treated with different doses of iodinated water: the normal group (NI, 6.15 μg/d), 5-fold high iodine group (5HI, 30.75 μg/d), 10-fold high iodine group (10HI, 61.5 μg/d), 50-fold high iodine group (50HI, 307.5 μg/d), and 100-fold high iodine group (100HI, 615 μg/d). Thyroid hormone concentrations were determined by a chemiluminescent immunoassay. Morphometry and microstructure of bone trabecula were observed by hematoxylin and eosin staining and microcomputed tomography, respectively. Alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) staining were performed to evaluate the activity of osteoblasts and osteoclasts, respectively. ResultsThe 24-h urine iodine concentration increased with iodine intake. The rats in the HI groups had higher serum thyroid-stimulating hormone and decreased serum free thyroxine concentrations in the 12th month than the NI group (all P < 0.05). The percentage of the trabecular bone area and osteoblast perimeter in the 100HI group were significantly lower than those in the NI group (P < 0.05). Increased structure model index was observed in the 50HI and 100HI groups compared with the NI group in the 6th month and increased trabecular separation in the 12th month (all P < 0.05). ALP and TRAP staining revealed osteoblastic bone formation was reduced, and the number of TRAP+ multinucleated cells decreased with increasing iodine intake. ConclusionsExcess iodine intake may increase the risk of hypothyroidism in rats. Chronic excess iodine intake can lead to abnormal changes in skeletal structure, resulting in reduced activity of osteoblasts and osteoclasts, which inhibits the process of bone reconstruction and may lead to osteoporosis.

Changes in the facial soft tissue profile after maxillary orthognathic surgery.

ObjectivesTo compare the changes of the soft tissue profile in relation to the displacement of the underlying hard structures in maxillary orthognathic surgery and to contribute to the esthetic prediction of the facial profile after surgical procedures.Materials and methodsWe analyzed the sagittal changes in the facial soft tissue profile related to surgical changes in skeletal structures after maxillary osteotomy in a retrospective study. The study sample comprised 115 adult patients between the ages of 18–50 years who had undergone maxillary orthognathic surgery and interdisciplinary orthodontic treatment at the Department of Orthodontics, Ludwig-Maximilians University of Munich, Germany. LeFort I osteotomy cases in both maxillary monognathic and bignathic osteotomy procedures were included. All subjects had received rigid fixation. A cephalometric analysis of presurgical and postsurgical cephalograms was performed and the correlations between hard tissue and soft tissue change ratios were evaluated using a bivariate linear regression analysis. A vertical line through the landmark sella (S) perpendicular to the nasion-sella line (NSL) served as the reference plane.ResultsThe subnasale (Sn) followed the A point (A) by 57%, the soft tissue A point (A′) followed the A point (A) by 73% and the upper lip, represented by the landmark labrale superius (Ls) followed the upper incisor (Is) by 73%; all three in a linear correlation with a mean prediction error of nearly 2 mm.ConclusionThe scatterplots show a linear correlation with a wide spread for all three pairs of reference points. The wide spread and the high prediction error of almost 2 mm indicate low predictability of the expected lip position and Sn.

Habitat influences skeletal morphology and density in the snailfishes (family Liparidae)

We tested the hypothesis that deep-sea fishes have poorly mineralized bone relative to shallower-dwelling species using data from a single family that spans a large depth range. The family Liparidae (snailfishes, Cottiformes) has representatives across the entire habitable depth range for bony fishes (0 m–> 8000 m), making them an ideal model for studying depth-related trends in a confined phylogeny. We used micro-computed tomography (micro-CT) scanning to test three aspects of skeletal reduction in snailfishes (50 species) across a full range of habitat depths: 1) reduction of structural dimensions, 2) loss of skeletal elements, and 3) reduction in bone density. Using depth data from the literature, we found that with increasing depth, the length of the dentary, neurocranium, and suborbital bones decreases. The ventral suction disk decreases width with increasing maximum habitat depth and is lost entirely in some deeper-living taxa, though not all. Although visual declines in bone density in deeper-living taxa were evident across full skeletons, individual densities of the lower jaw, vertebra, suction disk, hypural plate, and otoliths did not significantly decline with any depth metric. However, pelagic and polar taxa tended to show lower density bones compared to other species in the family. We propose that skeletal reductions allow snailfishes to maintain neutral buoyancy at great depths in the water column, while supporting efficient feeding and locomotion strategies. These findings suggest that changes in skeletal structure are non-linear and are driven not only by hydrostatic pressure, but by other environmental factors and by evolutionary ancestry, calling the existing paradigm into question.

Secular Changes in the Postcranial Skeleton of American Whites.

Secular change in height has been extensively investigated, but size and shape of the postcranial skeleton much less so. The availability of large, documented collections of nineteenth- and twentieth-century skeletons makes it possible to examine changes in skeletal structure over the past 150 years. We examined secular changes in long bone lengths and proportions, their allometric relationship to stature, and crosssectional properties of long bone shafts. Bone measurements and stature were organized into 10-year birth cohorts, ranging from 1840 to 1989. Variation among cohorts was tested by one-way ANOVA, and secular trend was examined visually by plotting mean measurements by birth decade. Allometry was examined by regressing log bone lengths onto log stature, using least squares regression. Allometry was also examined using the geometric mean of log bone lengths as the size variable. All bone lengths and stature showed positive secular change. Stature and the distal long bones showed the most pronounced changes. Proportions also changed, as revealed by the brachial and crural indices. Both indices increased, but the brachial index change was the most pronounced. Allometric relationships suggest that brachial index changes result from positive allometry of the radius and negative allometry of the humerus. Similar but less marked allometric relationships were found in the tibia and femur. Long bone shaft properties changed in the following ways: femur midshafts and tibia shafts at the nutrient foramen became more mediolaterally narrowed, and the femur became more mediolaterally thickened at the subtrochanteric level, approaching platymeria. All major long bones became more gracile. These remarkable changes in the postcranial skeleton are a response to the unparalleled changes in the environment in which modern Americans now live. Changes in growth resulting from plentiful and secure nutrition, reduced disease load, and marked reduction in bone loading from reduced activity levels are mainly responsible.

Teleost Skeletal Plasticity: Modulation, Adaptation, and Remodelling

The vertebrate skeleton is a plastic organ system and the skeleton of teleosts is no exception. Epigenetic factors during development influence skeletal anatomy, mechanical properties, and meristic characters. The adult teleost skeleton undergoes changes connected to mechanical adaptation, repair, mineral homeostasis, sexual maturation, and aging. Vestiges, rudiments, atavisms, hyperostotic bones, additional tooth rows, and variable numbers of vertebral bodies are prominent examples of variable characters. Morphological changes require changes of skeletal structures on the cellular level, including modulation, transdifferentiation, and remodelling. Alterations at the cellular level are best understood by acknowledging those characters that distinguish teleost skeletons from mammalian skeletons: (a) the absence of osteocytes in most species of teleosts; (b) abundant mononucleated osteoclasts that perform non-lacunar bone resorption; (c) a phosphorous- rather than a calcium-driven mineral homeostasis; and (d) a variety of tissue types intermediate between bone and cartilage. This brief account of teleost skeletal plasticity shows that the teleost skeleton is a lifelong plastic organ system. Using examples, also from our own studies, we provide examples of skeletal plasticity at various hierarchical levels.

On Recognizing Face Images With Weight and Age Variations

With the increase in age, there are changes in skeletal structure, muscle mass, and body fat. For recognizing faces with age variations, researchers have generally focused on the skeletal structure and muscle mass. However, the effect of change in body fat has not been studied with respect to face recognition. In this paper, we incorporate weight information to improve the performance of face recognition with age variations. The proposed algorithm utilizes neural network and random decision forest to encode age variations across different weight categories. The results are reported on the WhoIsIt database prepared by the authors containing 1109 images from 110 individuals with age and weight variations. The comparison with existing state-of-the-art algorithms and commercial system on WhoIsIt and FG-Net databases shows that the proposed algorithm outperforms existing algorithms significantly.

Cambios en la posición de las estructuras esqueléticas del complejo cráneo-cervical posterior a una cirugía ortognática

The aim of the present study was to conduct research on presence of changes in skeletal structures’ position of the cervical-cranial complex after treatment involving orthognatic surgery. 30 patient files were reviewed. Patients were afflicted with initial class I, II and III malocclusions which had been treated with orthognathic surgery. With the help of lateral skull X-rays, measurements were taken of pre- and post-surgical positions of vertebrae, hyoid bone, as well as skull rotation. It was found that patients subjected to combined surgery presented greater range of skull rotation changes in a posterior direction (p = 0.006). Female patients presented tendency to posterior skull rotation, and exhibited distance decrease from atlas to skull base (p = 0.23). In surgical patients, it is important to timely identify these skull rotation changes since they might elicit relapse of performed orthognathic surgery and/or occipital headache.

Assessment of bone feature parameters from lumbar trabecular skeletal patterns using mathematical morphology image processing

In this study, bone feature parameters were obtained from digital lumbar vertebral images to determine their potential usefulness in assessing binary trabecular skeletal patterns. The system consisted of a magnification radiographic technique, computed radiography (CR), microfocused X-ray computed tomography (mu-CT), and mathematical morphology image processing. A digital CR image was produced, using a ten-times magnified lumbar vertebral cancellous bone block (1.5 x 1.5 x 1.5 cm(3)). The information was then subjected to mathematical morphology image processing, to extract eight binary trabecular skeletal patterns having different continuities as the operation number ( n) increased. These skeletal patterns were used as test patterns and analyzed quantitatively by calculation of the skeletal pixel percentage (SKP) and star volume analysis (Vsk, volume of skeletal trabecular elements; Vsp, volume of nonskeletal elements). Then the binary skeletal pattern data were converted into the mu-CT format, using a general personal computer, and the images were quantitatively analyzed with mu-CT built-in image analysis software for microstructural indices, fractal dimension analysis, and node-strut analysis. The SKP and Vsk showed an expected decrease as n increased. Concurrently, the Vsp showed an expected increase as n increased. The skeletal thickness (Sk.Th) showed a constant value at n = 1 to 4 and n = 5 to 7, but decreased in a stepwise fashion at n = 1 and n = 5. The skeletal number (Sk.N), bone area fraction (B.Ar/T.Ar) and bone perimeter fraction (B.Pm/T.Ar), decreased as n increased. Skeletal space (Sk.Sp) and perimeter-to-area ratio (B.Pm/B.Ar) increased with increasing n. In the fractal dimension analysis, the values decreased with increasing n and showed changes similar to the image observations. In fact, the SKP, star volume analysis, Sk.N, B.Ar/T.Ar, B.Pm/T.Ar, Sk.Sp, and B.Pm/B.Ar all closely mirrored the observational analysis of the images. Linkage of the skeletal structure as functions of the following parameters could be quantitatively demonstrated. The parameters used were node (Nd) and terminus (Tm). Variations in the total strut length (TSL) and Tm could demonstrate quantitative changes in skeletal structure. These results indicate that the system consisting of a combination of a magnification radiographic technique, CR, mu-CT, and mathematical morphology image processing may be a useful tool for quantitative skeletal structure analysis and the structural assessment of lumbar vertebrae, for the assessment of skeletal structural changes. It is important to choose suitable parameters for the desired structural changes.

Skeletal development in two species of Tethya (Porifera, Demospongiae)

Changes in skeletal structure occurring in differently sized specimens of two species of Tethya (T. aurantium and T. citrina) were studied. In the two species, differences in sponge consistency were found to be affected by their radial strongyloxeas skeleton and by aster sheets reinforcing their collagenous ectosomes. In T. aurantium, body enlargement was enhanced by the production of new megasters, while in T. citrina a proliferation of strongyloxea bundles accompanied its growth. These differences are related to the different ecological strategies of the two species. In both species, strongyloxea length was clearly related to individual size.

Fetal alcohol syndrome: changes in craniofacial form with age, cognition, and timing of ethanol exposure in the macaque.

One component of the fetal alcohol syndrome (FAS) facial phenotype is a frontonasal anomaly characterized by a thin upper lip and a smooth philtrum. The expression of this anomaly can diminish with age and occurs infrequently in prenatal alcohol-exposed individuals. This study sought to explain these observations. Standardized craniofacial cephalograms of 18 nonhuman primates exposed weekly to ethanol or sucrose solution in utero were measured at ages 1, 6, 12, and 24 months to assess skeletal changes in craniofacial form with age, cognition, and timing of ethanol exposure. The data suggest that there may be a critical period for induction of alcohol-induced craniofacial alterations that occurs very early in gestation and is very short in duration (gestational days 19 or 20). The alterations were scarcely detectable at age 1 month, were most prominent at 6 months, and diminished progressively at 12 and 24 months in the macaque. The appearance and disappearance of the thin upper lip and smooth philtrum may be explained by underlying changes in skeletal structure with age. The infrequent occurrence of the FAS frontonasal anomaly may be explained, in part, by its short critical period of induction.

Steric control of reactivity: formation of oximes, benzodiazepinone N-oxides and isoxazoloquinolinones

Reaction of the alkenyl carbonyl compounds 1 with hydroxylamine can lead to the formation of the oximes 2, the benzodiazepinone N-oxides 3 or the isoxazoloquinolinones 5. The product(s) of reaction are shown to depend on the electronic nature of the terminal olefinic substituent R3 and the space filling capacity of the substituents R1, R2 and R4. When the olefinic centre is electron poor (R3 = CO2Et) ketocarbonyls convert exclusively to bicyclic nitrones 3 whereas aldehydes are more sensitive to subtle changes in skeletal structure and give rise to oximes 2, tricycles 5 or mixtures of both. For aldehyde and ketone substrates when the olefinic centre carries an aryl substituent (R3 = Ph) the primary product of reaction is the corresponding oxime which on thermal activation converts to the tricyclic isoxazoloquinolinones.

Jaws of adult culled ewes

SUMMARYThe jaws of 481 adult culled ewes were examined visually and radiographically for dental abnormality and changes in skeletal structure; the findings were correlated with ante-mortem body condition score and breed. Only two ewes had normal buccal morphology; the remainder of the sample showed a range of abnormalities which included loose and missing teeth, gingival hypertrophy, food-filled gingival pockets, ridging and shearing of the occlusal surfaces. There was a general loss of bone structure. Dental abnormality was not strongly correlated with breed but showed a significant relationship with radiographic assessment of bone density. Body condition did not appear to be adversely affected by dental disease. Skull dimensions and dental pad position were strongly associated with breed. The state of the incisor teeth alone was a poor indicator of cheek tooth condition.