The effect of artificial cranial deformation on the incidence of wormian bones in the lambdoidal suture

One hundred and twenty adult and 80 human fetal skulls were examined to find the relationship (if any) between the presence of wormian bones in the lambdoidal suture and artificial deformation of the skull. Wormian bones occur in deformed and undeformed skulls with no significant differences. Wormian bones detected in fetal skulls preclude cultural deformation as an important factor in the formation of these bones. It is hypothesized that a genetic predisposition (genes allowing formation of secondary ossification centers) is present and that wormian bones are under direct genetic control regardless of the presence or absence of detectable cultural deformation.     

Test of the relationship between sutural ossicles and cultural cranial deformation: Results from Hawikuh,New Mexico

A number of researchers have hypothesized that the biomechanical forces associated with cultural cranial deformation can influence the formation of sutural ossicles. However, it is still difficult to make definitive conclusions about this relationship because the effects appear to be quite weak, and contradictory results have been obtained when specific sutures and deformation types are compared across studies. This research retests the hypothesis using a single archeological sample of lamdoidally deformed, occipitally deformed, and undeformed crania from Hawikuh, New Mexico (AD 1300–1680). Our results show no significant difference in either the prevalence or number of ossicles between deformed and undeformed crania, suggesting that the abnormal strains generated by cranial shape modification during infancy are not a factor in ossicle development for this population. One significant relationship was detected at the right lambdoid suture in crania with asymmetrical occipital deformation. Crania that were more deformed on the left side showed greater numbers of ossicles on the right side, but the effect was small. Furthermore, the relationship may well reflect a sampling error, due to the small number of crania with greater left side deformation and scorable right side lambdoid ossicles (n = 11). Although it is possible that forms of cranial deformation other than the posterior tabular types examined here may affect ossicle expression, our review of the literature suggests that the relationship in humans is complex and incompletely understood at this time. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.     

Comparative endocranial vascular changes due to craniosynostosis and artificial cranial deformation

The processes of craniosynostosis (premature fusion of one or more of the calvarial sutures) and artificial cranial deformation are similar since both can alter the shape of the craniofacial complex. Most research exploring these processes has focused on the ectocranium, although it is obvious that these processes also modify the endocranium. Endocranial changes due to either craniosynostosis or artificial cranial deformation have not been as thoroughly examined. Silicone rubber endocasts were made from 11 craniosynostotic archaeologically derived specimens from North and South America. For comparative purposes, endocasts were made from 22 normal and 17 occipitally deformed crania that were archaeologically derived from North and South America. With all samples, middle meningeal vessel patterns and venous sinus impressions were qualitatively and quantitatively analyzed. Depth, width, and convolution of the middle meningeal vessels were recorded, and the direction of vessel branches was noted. Both artificial cranial deformation and craniosynostosis altered the endocranial vasculature. Middle meningeal vessel and venous sinus impressions of the craniosynostotic group differed when compared to both the undeformed and artificially cranially deformed samples. Sinuses traversing under synostosed sutures became wider and deeper. In contrast, sinuses directly underneath the greatest artificial deformational stress were shallower, while there was compensatory enlargement of sinuses further away from the greatest deformational effects. Such compensatory enlargement also was shown by the high incidence of enlarged occipital/marginal sinuses in artificially deformed skulls. Increased intracranial pressure is hypothesized to be the cause of the venous sinus changes found in craniosynostotic individuals. Middle meningeal vessel patterns from craniosynostotic and artificially deformed specimens were similar in that their direction paralleled the direction of altered cranial growth. These findings demonstrate that the endocranial vasculature is developmentally plastic and responds to deformation in a predictable pattern. © 1996 Wiley-Liss, Inc.     

Intentional cranial deformation in the preColumbian populations of ecuador

Using 151 crania, 8 Preceramic, 86 Formative, 29 Regional Developmental, 28 Integration Period and some isolated skulls from Ecuador I can clarify some origins and diffusion of American cranial deformation. To Imbelloni's classification of Tabular erecta, Tabular obliqua, and Annular I add a new type, Cuneiform, marked by flattening of the entire occiput (not just the upper, membraneous-derived bone) without evidence of counter pressure in front. The Cuneiform type starts in Guayas about 2000 B.C. (perhaps the earliest in America) with diffusion to coastal Peru in Chavin times. Tabular erecta, of coastal origin between Manabi province and the Guyas river basin, about 1,000 B.C. , also spreads to coastal Peru. Tabular obliqua appears in Esmeraldas province probably from Mexico 2000 years ago, and diffuses south into Chile. Annular type starts early in the Southern Andes and appears late in the highlands of Ecuador.     

Artificial cranial deformation and the increased complexity of the lambdoid suture

Studies examining an association between artificial cranial deformation and the presence of wormian bones in the lambdoid suture have been inconclusive. Cranial deformation, however, does not seem to have a direct effect of increasing the sutural complexity of the pars lambdica of the lambdoid suture and also increasing the mean number of lambdoidal wormian bones, given their presence.     

The influence of experimental deformation on neurocranial Wormian bones in rats

Two hundred and twenty crania of Wistar rats were experimentally deformed. The growth of the anterior vault was restricted in one subgroup and the growth of the posterior vault was restricted in the second subgroup. Seventy-seven deformed animals survived up to the thirtieth day of age and were sacrificed. Both subgroups were compared with each other as well as with 37 surviving sham-operated animals and 51 controls, all samples being 30 days of age (group A). Additionally, 33 normal crania of animals sacrificed at 1, 10 and 20 days as well as 19 deformed crania of 10 and 20 days old were observed (group B). Chi-square and Z tests were employed. Wormian bones found in the skulls of normal growing rats apparently represent an epigenetic polymorphism. Higher frequencies of wormian bones were found in deformed crania than in sham-operated ones and controls. Experimental deformation may be an extra-genetic factor that affects the normal genetic expression of wormian bones. This concept is relevant to studies of human population differences based on discontinuous cranial traits.     

Effects of fronto-occipital artificial cranial vault modification on the cranial base and face.

Artificial reshaping of the cranial vault has been practiced by many human groups and provides a natural experiment in which the relationships of neurocranial, cranial base, and facial growth can be investigated. We test the hypothesis that fronto-occipital artificial reshaping of the neurocranial vault results in specific changes in the cranial base and face. Fronto-occipital reshaping results from the application of pads or a cradle board which constrains cranial vault growth, limiting growth between the frontal and occipital and allowing compensatory growth of the parietals in a mediolateral direction. Two skeletal series including both normal and artificially modified crania are analyzed, a prehistoric Peruvian Ancon sample (47 normal, 64 modified crania) and a Songish Indian sample from British Columbia (6 normal, 4 modified). Three-dimensional coordinates of 53 landmarks were measured with a diagraph and used to form 9 finite elements as a prelude to finite element scaling analysis. Finite element scaling was used to compare average normal and modified crania and the results were evaluated for statistical significance using a bootstrap test. Fronto-occipitally reshaped Ancon crania are significantly different from normal in the vault, cranial base, and face. The vault is compressed along an anterior-superior to posterior-inferior axis and expanded along a mediolateral axis in modified individuals. The cranial base is wider and shallower in the modified crania and the face is foreshortened and wider with the anterior orbital rim moving inferior and posterior towards the cranial base. The Songish crania display a different modification of the vault and face, indicating that important differences may exist in the morphological effects of fronto-occipital reshaping from one group to another.     

Effects of semi-group housing and floor type on pododermatitis,spinal deformation and bone quality in rabbit does

The most common housing system for reproduction rabbits, individual cage housing on a wire floor, is increasingly scrutinized because of its potential detrimental impact on animal welfare. We compared three types of housing: (1) individual cage housing on a wire floor (3952 cm²/doe, maximum roof height 63 cm, one 1000 cm² plastic footrest/doe), (2) semi-group housing on a wire floor (5000 cm²/doe, roofless, one 1000 cm² plastic footrest/doe) and (3) the same semi-group housing, but with a fully plastic slatted floor. In all housing systems, does had free access to an elevated platform. In the semi-group housing pens, four does were housed communally during 21 days of the reproduction cycle (to allow more space for locomotion and to increase opportunities for social contact), and individually during the other 21 days of the cycle (to minimize doe–doe and doe–kit aggression that peaks around kindling). In all, 24 Hycole does were included per system. The does entered the experiment at 203 days of age (after their first parity). The experiment consisted of four reproductive cycles, ending at 369 days of age. Pododermatitis was scored in cycles 1, 2 and 4. At the end of the 4^th cycle the does were euthanized and X-rays were taken to assess spinal deformation. Tibia and femur length, width and cortical thickness were determined and bone strength was assessed using a shear test, as a measure of bone quality. Although severe pododermatitis was absent, the prevalence of plantar hyperkeratosis (hair loss and callus formation) at the end of the 4^th cycle was much greater on the wire floor (65% and 68% for semi-group housing and individual cages, respectively) than on the plastic floor (5%, P<0.0001), even though the wire floors were equipped with a plastic footrest known to decrease hyperkeratosis. In contrast to our expectations, semi-group housing did not affect the prevalence of spinal deformations (P>0.10), but in line with our expectations bone quality was affected favourably by semi-group housing. The tibial cortex (and to a lesser extent the femoral cortex) was thicker in semi-group housing than in individual cages (1.45, 1.46 and 1.38 mm for semi-group housing on wire, semi-group housing on plastic and individual housing on wire, respectively, P=0.045). What this increase in cortical thickness means in terms of doe welfare requires further study, as it may reflect an increase in activity resulting either from increased space for locomotion, or from fleeing aggressive pen mates.     

Effects of fronto-occipital cranial reshaping on mandibular form.

Cultural reshaping (artificial deformation or modification) of the neurocranial vault provides an artificially increased range of morphological variability within which the relationship between the growing neurocranium and face can be investigated. We analyze crania which have been fronto-occipitally compressed to ascertain possible morphological effects on the mandible. We collected measures of mandibular breadth, length, and height from 82 modified (N = 48) and unmodified (N = 34) crania from a Peruvian Ancon series. Angle classification was also scored in order to investigate whether or not occlusal relationships were affected by neurocranial reshaping. Only intercondylar distance (posterior mandibular breadth) exhibited significant differences between unmodified and modified groups, though this difference was relatively small compared with vault deformation. The modified crania had a higher frequency of normal occlusion (Class I) than the unmodified crania. Increased intercondylar breadth in modified skulls is due to a cascade of effects which begin with a direct effect of the fronto-occipital deforming device on neurocranial shape (increased neurocranial width). The increase in mandibular breadth may be a compensatory response to increased cranial base breadth and maintains articulation between the cranial base and mandible. The increased posterior breadth, coupled with a slight decrease in mandibular depth, may contribute to the change in occlusal relationships suggested for this sample.     

Exploring artificial cranial deformation using elliptic Fourier analysis of Procrustes aligned outlines

The anatomical effects of artificial cranial deformation on the face and the base have been subject to various metric approaches, including standard linear as well as finite element techniques, and have produced controversial results (Antón [1989] Am. J. Phys. Anthropol. 79:253-267; Kohn et al. [1993] Am. J. Phys. Anthropol. 90:147-158). It can be argued that diverging observations partly result from methodological constraints. The present study compares samples of intentionally deformed and undeformed human crania, using elliptic Fourier analysis (EFA), a morphometric approach which has been shown to be particularly appropriate for characterizing the shape of two-dimensional outlines and associated shape changes. We improve the standard EFA approach by adding a preliminary orientation of the outlines following the rotation parameters of a Procrustes superimposition, using multiple homologous landmarks called control points. The results confirm that circumferentially deformed skulls exhibit modifications of the basioccipital region, together with increased anterior and inferior facial projection. However, the degree to which basioccipital flattening is modified in circumferentially deformed Peruvians was found to be less marked than changes observed in the face. Some of the modifications observed here can be related to morphological trends existing in the population from which our sample was taken. The observation of other modifications may be subject to methodological constraints of standard morphometric approaches.     

An in vitro comparison of bone deformation measured with surface and staple mounted strain gauges

Chicken tibiae were chosen as a model for human second metatarsals. Local surface bone deformation in a 4-point bending configuration was measured in vitro by both strain gauge instrumented staples and strain gauges bonded to the bone's cortical surface. A series of staple bridge dimensions (0.5, 0.6, 0.8 and 1.0 mm) was compared to test for staple influence on bone characteristics and greatest measurement validity and reliability. Thicker staple inhibition of bone deformation was the greatest but differences to thinner staples were not statistically significant (p>0.05). All staples except 0.5 mm had maximum deviations from linearity less than 1%. The 1.0 mm staple had an R² value of 0.992±0.006 plotted against the 4-point bending input force and 0.994±0.002 plotted against the surface strain gauge signal. The mean intraclass correlation coefficients (ICC) calculated with four input forces (30, 60, 90 and 120 N) and for loading and unloading conditions for the 0.5, 0.6, 0.8 and 1.0 mm staples were 0.75, 0.83, 0.87 and 0.92, respectively. Finally, the differences in slope of the staple strain gauge signal plotted against surface strain gauge signal between input force loading and unloading conditions (0.32), and between input compression and tension conditions (0.79) was least for the 1.0 mm staple which also resulted in the lowest standard deviations. These results suggested the appropriateness of the 1.0 mm staple for in vivo application.     

Deep-freeze preservation of cranial bones for future cranioplasty: nine years of experience in Soroka University Medical Center

Background Decompressive craniectomy is routinely performed in many neurosurgical centers to treat intracranial hypertension refractory to medical therapy as a result of head trauma, CVA or various brain tumors. When the patient survives his illness, cranioplasty with autologous bone graft or other reconstructive materials is considered to repair the skull defect. Objective This prospective study reviews the cases of decompressive craniectomies followed by later cranioplasty undertaken at our institute through the years 1996 and 2005 and describes the method used for preservation of removed bone flaps for future cranioplasty. Subjects and methods Sixty-eight patients underwent decompressive craniectomies since 1996. A protocol was designed to prepare the removed bone flaps for deep freeze preservation. After removal, the bone flaps were transferred to the skin bank at our institution within 6 h, gently rinsed using 1–3 liters of sterile saline (0.9% NaCl) supplemented with antibiotics (neomycin, 2 mM) with no dimethylsulfoxide (DMSO), then flaps were wrapped in two layers of sterile plastic coverage and preserved at −80°C. Results The patient’s population will be presented. Since 1996 we have performed 12 cranioplasties using deep-freeze preserved autologous bone graft. It took a rather long learning period, beginning with a single patient per year and continued with several others. Up to now, no case of infection, osteomyelitis or bone resorption following cranioplasty have occurred. Conclusion Deep-freeze preservation of autologous bone grafts to reconstruct skull defects after decompressive craniectomy is a useful procedure and has a low revision rate. N. Grossman: deceased 23 December 2006.     

Intentional cranial vault deformation and induced changes of the cranial base and face

Three morphologically distinct populations of Peruvian crania (n = 130) were metrically analysed to quantify changes resulting from intentional artificial vault deformation. Two of these samples are artificially deformed (anteroposterior [AP] and circumferential [C] types). Measurements taken from lateral radiographs demonstrated that alternative forms of the cranial base angle (N-S-Ba, planum angle, planum sphenoidale to plane of the clivus and PANG angle, planum sphenoidale to basion-sella plane) and the orbital and OANG angles (orbital roof to plane of the clivus and basion-sella plane, respectively) of both deformed groups increased while the angle S-Ba-O decreased significantly with respect to the undeformed (N) sample. Changes in the AP group are largely due to anteroinferior displacement of the basion-sella plane. Similar changes in group C are amplified by this group's posterosuperior frontal migration. This migration results in a relatively shallow orbit at the orbital plate/frontal squama interface. Unlike the deformation experienced by the external vault plates, the basion-sella plane orientation remains stable with respect to the Frankfort Horizontal. Additionally, nasal region measurements such as maximum nasal aperture breadth and nasal height were largely stable between each deformed group and the undeformed group. However, facial (bimaxillary and bizygomatic), basicranial, cranial, and frontal breadths decreased significantly from group AP to group N to group C. Thus, gross morphological facial changes between each undeformed group and the control group are largely accounted for by dimensional changes in peripheral structures. These results stress the importance of the dynamic interrelationship between the cranial vault and base in the development of the craniofacial complex.     

A mathematical model for mechanotransduction at the early steps of suture formation

Growth and patterning of craniofacial sutures is subjected to the effects of mechanical stress. Mechanotransduction processes occurring at the margins of the sutures are not precisely understood. Here, we propose a simple theoretical model based on the orientation of collagen fibres within the suture in response to local stress. We demonstrate that fibre alignment generates an instability leading to the emergence of interdigitations. We confirm the appearance of this instability both analytically and numerically. To support our model, we use histology and synchrotron X-ray microtomography and reveal the fine structure of fibres within the sutural mesenchyme and their insertion into the bone. Furthermore, using a mouse model with impaired mechanotransduction, we show that the architecture of sutures is disturbed when forces are not interpreted properly. Finally, by studying the structure of sutures in the mouse, the rat, an actinopterygian (Polypterus bichir) and a placoderm (Compagopiscis croucheri), we show that bone deposition patterns during dermal bone growth are conserved within jawed vertebrates. In total, these results support the role of mechanical constraints in the growth and patterning of craniofacial sutures, a process that was probably effective at the emergence of gnathostomes, and provide new directions for the understanding of normal and pathological suture fusion.     

Effects of 0.4 T rotating magnetic field exposure on density, strength, calcium and metabolism of rat thigh bones

The current study investigated the effects of 0.4 T rotary non-uniform magnetic field (RMF) exposure on bone density in ovariectomized (OVX) rats. Results showed that many bone indexes are significantly elevated after RMF exposure compared to the control OVX group and confirmed mechanistic evidence that strong magnetic field (MF) exposure could effectively increase bone density and might be used to treat osteoporosis. Synergy of daily RMF exposure (30 min a day for 30 days using an 8 Hz rotary 0.4 T MF) with calcium supplement tended to increase the indexes of thigh bone density, energy absorption, maximum load, maximum flexibility, and elastic deformation as compared to those of untreated OVX control group. Results also revealed that the indexes of alkaline phosphatase (ALP), serum phosphate, and serum calcium were higher in rats exposed to RMF with calcium than in the untreated OVX control group. Changes in bone mineral density (BMD) and bone mineral content (BMC) were observed in rats for three months including the first month RMF exposure. Bone density in rats exposed each day for 60 min increased during 1-month exposure and continued to increase during the post-exposure period. Furthermore, bone density and calcium content in rats exposed for 90 min daily decreased initially in the exposure month; however, ratio of increase was well above the control values by the end of the post-exposure period suggesting possible window and delayed effects. The study indicated that RMF exposure to both male and OVX female rats for 120 min a day over 15 day period should effectively promote increase of bone calcium contents (BCC) and bone-specific alkaline phosphatase (BAP) in rats thigh bone as well as a corresponding decrease in deoxypyridinoline crosslinks (DPD).     

Effects of long-term fixation on histological quality of undecalcified murine bones embedded in methylmethacrylate

While long-term fixation and storage of specimens is common and useful for many research projects, it is particularly important for space flight investigations where samples may not be returned to Earth for several months (International Space Station) or years (manned mission to Mars). We examined two critical challenges of space flight experimentation: the effect of long-term fixation on the quality of mouse bone preservation and the preservation of antigens and enzymes for both histochemical and immunohistochemical analyses, and how the animal/sample processing affects the preservation. We show that long-term fixation minimally affects standard histological staining, but that enzyme histochemistry and immunolabeling are greatly compromised. Further, we demonstrate that whole animal preservation is not as suitable as whole leg or stripped leg preservation for long-term fixation and all histological analyses. Overall, we recommend whole leg processing for long-term storage of bone specimens in fixative prior to embedding in plastic for histological examination.     

骨生苔藓在中国的新记录

在四川省马边大风顶国家级自然保护区的高山草甸上发现了生长在牦牛骨头上的苔藓。共有四种藓类植物:真藓科的真藓、刺叶真藓、丛藓科的短叶小石藓以及葫芦藓科的中华葫芦藓,它们都是顶蒴藓类。这是骨生苔藓植物在中国的首次记录报道。     

Effects of annular cranial vault modification on the cranial base and face

Artificial modification of the cranial vault was practiced by a number of prehistoric and protohistoric populations, frequently during an infant's first year of life. We test the hypothesis that, in addition to its direct effects on the cranial vault, annular cranial vault modification has a significant indirect effect on cranial base and facial morphology. Two skeletal series from the Pacific Northwest Coast, which include both nonmodified and modified crania, were used: the Kwakiutl (62 nonmodified, 45 modified) and Nootka (28 nonmodified, 20 modified). Three-dimensional coordinates of 53 landmarks were obtained using a diagraph, and 36 landmarks were used to define nine finite elements in the cranial vault, cranial base, and face. Finite element scaling was used to compare average nonmodified and average modified crania, and the significance of the results were evaluated using a bootstrap test. Annular modification of the cranial vault produces significant effects on the morphology of the cranial base and face. Annular modification in the Kwakiutl resulted in restrictions of the cranial vault in the medial-lateral and superior-inferior dimensions and an increase in anterior-posterior growth. Similar dimensional changes are observed in the cranial base. The Kwakiutl face is increased anterior-posteriorly and reduced anterior-laterally to posterior-medially. Similar effects of modification are observed in the Nootka cranial vault and cranial base, though not in the face. These results demonstrate the developmental interdependence of the cranial vault, cranial base, and face. © 1993 Wiley-Liss, Inc.     

Histological and immunochemical investigations on the organic substance present in human bones of the Iron Age

The Authors, after some preliminary remarks on the methods used, present the first results obtained from a series of histological and immunochemical investigations aimed at defining the presence and the components of the organic substance in human bones of the Iron Age. The first data reveal the existence of common antigenic points between the substances present in the bone extracts and some proteic components of the human serum.     

Assessing cranial plasticity in humans: The impact of artificial deformation on masticatory and basicranial structures

Artificial cranial deformations (ACD) are a widespread cultural practice found in numerous historical and prehistoric contexts. Their study can yield valuable insight into craniofacial growth, specifically into the interactions between neurocranial and basicranial modules. This study seeks to reinvestigate the presumed effect of ACD on basicranial and masticatory elements by applying a 3D geometric morphometric approach to CT scans. A total of 51 French and Bolivian skulls, representing anteroposterior and circumferential deformations and including undeformed individuals, were scanned, and 3D landmarks were submitted to between-group principal components analysis and two-block partial least-squares analysis. Our results illustrate changes in basicranial shape and in cranial base angles induced by ACD, as well as in masticatory geometry, namely in the relative position of the mandibular fossae. Furthermore, our findings highlight differential effects of the various deformation types, which suggest that patterns of covariation between modified vaults and their associated basicrania are more complex than previously assumed, thereby stressing the degree of plasticity in human craniofacial growth.