Vault Deformation Research Articles

Maxillary changes and occlusal traits in crania with artificial fronto‐occipital deformation

Artificial fronto-occipital deformation of the cranial vault was typical of pre-Columbian cultures in the central Andean coastal regions. We have studied the influence of this deformation on maxillary and mandibular morphology. Measurements were performed on 86 adult Ancon skulls with anteroposterior deformation. Undeformed skulls from the area of Makatampu (n = 52) were used as the control group. To explore the influence of the deformity on occlusion, the skulls were categorized using the Angle classification and the alignment of the interincisor midline. In the group of deformed skulls, there was an increase in lateral growth of the vault and of the base of the skull (P < 0.001), giving rise to a greater interpterygoid width of the maxilla (P < 0.001), and an increase in the transverse diameter of the palatal vault. The mandible presented an increase in the length of the rami (P < 0.001) and in the intercondylar width, with no alteration of mandibular length. The deformed skulls had normal (class I) occlusion, with no displacement of the midline. The difference in the asymmetry index between the two groups was not statistically significant. Artificial fronto-occipital deformation of the cranial vault provoked compensatory lateral expansion of the base that was correlated with the transverse development of the maxilla and mandible. Occlusion and sagittal intermaxillary position were not affected by the cranial deformity. These results provide evidence of the integration between the neurocranium and the viscerocranium in craniofacial development, and support the hypothesis of a compensatory effect of function.

A look at Mayan artificial cranial deformation practices: morphological and cultural aspects [RETRACTED

Induced deformation of the cranial vault is one form of permanent alteration of the body that has been performed by human beings from the beginning of history as a way of differentiating from others. These procedures have been observed in different cultures, but were particularly widespread in Mesoamerica. The authors examined and reviewed the historical and anthropological literature of intentional deformation practices in Mayan culture. The Mayans performed different types of cranial deformations and used different techniques and instruments to deform children's heads. The most remarkable morphological alteration is seen in the flattening of the frontal bone. Some archeological investigations link deformation types with specific periods. This article provides a glance at the cultural environment of the Mayans and demonstrates the heterogeneity of this interesting cultural phenomenon, which has changed over time.

Deformation mechanism of a shallow double-arch tunnel in a sloping rock mass

The Fuxi double arch tunnel was constructed through a faulted rock mass of metasandstones overlain by slope debris. The paper describes the geological setting, highlighting the poor quality of the ground in the portal area. Following the construction of the exploratory tunnels, the concentrated overburden stress beneath the pillars caused severe deformation and cracking in the tunnel and in the slope above. An integrated analysis was carried out, taking into account the change in stress related to the excavation of the tunnels, the asymmetric pressures and the nature of the fractured overburden. This indicated that control of the tunnel vault deformation was a key step to controlling the deformation of the whole portal area. As a consequence, some additional support was provided to the central pillar prior to the construction of the main tunnels and the secondary lining was installed at an early stage.

Artificial cranial deformation in Pleistocene Australians: the Coobool Creek sample

Several authors have suggested that some Pleistocene Australian crania have been altered by artificial cranial deformation. The large sample from Coobool Creek has featured prominently in this debate. The present study reevaluates the evidence for artificial cranial deformation in this population using both a larger cranial sample and a more comprehensive set of measurements than those used in earlier work on this subject. Additionally, random expectation statistics are used to calculate statistical significance for these examinations. The results of this study agree with prior work indicating that a portion of this sample shows evidence for artificial deformation of the cranial vault. Many Coobool Creek crania display strong shape similarities with a population of known deformed individuals from New Britain. Coobool Creek crania 1, 41, 65, and 66 show the strongest evidence for deformation, but several other individuals from this sample also show clear evidence for culturally manipulated changes in cranial shape. This project provides added support for the argument that at least some Pleistocene Australian groups were practicing artificial cranial deformation.

The influence of artificial cranial vault deformation on the expression of cranial nonmetric traits: Its importance in the study of evolutionary relationships

Nonmetric cranial traits have been commonly used in evolutionary relationship studies. They develop during the growth and development of an individual, and for this reason its expression presents different sources of genetic and nongenetic variation. However, the use of these features in evolutionary relationship studies carries the implicit assumption that much of the nonmetric trait variation is essentially genetic. Among the nonheritable factors, cranial vault deformation has been the most studied in human populations. Because of the widespread distribution and elevated rate of artificial cranial vault deformation found in America, and the importance of nonmetric traits in evolutionary relationship studies in this area, the objectives of this paper are as follows: (a) to study the influence of artificial cranial vault deformation on the presence of nonmetric traits within samples of human craniofacial remains; and (b) to establish artificial cranial vault deformation influence on evolutionary relationships between local populations on a regional scale. Our results indicate that artificial cranial vault deformations alter the variation and covariation of metric and nonmetric traits in some samples. Wormian bones, placed in cranial vault sutures, are the most influenced by this factor. However, our results suggest that when all nonmetric traits were used the artificial cranial vault deformation did not influence the basic pattern of variation among samples. The exclusion or inclusion of wormians bones in evolutionary relationships analysis did not modify the results, but using only wormians bones lead to inconsistent results indicating that these traits have little value on these kind of studies.

MEF2C Transcription Factor Controls Chondrocyte Hypertrophy and Bone Development

Chondrocyte hypertrophy is essential for endochondral bone development. Unexpectedly, we discovered that MEF2C, a transcription factor that regulates muscle and cardiovascular development, controls bone development by activating the gene program for chondrocyte hypertrophy. Genetic deletion of Mef2c or expression of a dominant-negative MEF2C mutant in endochondral cartilage impairs hypertrophy, cartilage angiogenesis, ossification, and longitudinal bone growth in mice. Conversely, a superactivating form of MEF2C causes precocious chondrocyte hypertrophy, ossification of growth plates, and dwarfism. Endochondral bone formation is exquisitely sensitive to the balance between MEF2C and the corepressor histone deacetylase 4 (HDAC4), such that bone deficiency of Mef2c mutant mice can be rescued by an Hdac4 mutation, and ectopic ossification in Hdac4 null mice can be diminished by a heterozygous Mef2c mutation. These findings reveal unexpected commonalities in the mechanisms governing muscle, cardiovascular, and bone development with respect to their regulation by MEF2 and class II HDACs.

Relationship between anteroposterior cranial vault deformation and mandibular morphology in a pre-Columbian population

An externally applied force to the cranial vault has been reported to affect the growth of the facial skeleton. However, the effect on the mandible is unclear. The purpose of this study was to investigate the relationship between anteroposterior cranial vault deformation and mandibular morphology. The study sample included 44 women's crania with intact faces and bases that were excavated from archaeological sites in the Azapa Valley in northern Chile. The crania were divided into anteroposterior deformation (AP) and undeformed (U) groups according to frontal, parietal, and occipital curvatures. The sizes of the cranial vault, middle face, and mandible were measured with calipers. Lateral cephalograms were taken and analyzed according to a conventional method. Cranial base angle, bizygomatic breadth and upper facial height, bicondylar breadth, anterior breadth, and mandibular body length were significantly larger, and the mandibular angle was significantly smaller, in the AP group than in the U group. The anteroposteriorly shorter and wider cranial deformation caused by externally applied forces in infancy might affect the bone-remodeling process of the mandibular angle, leading to a smaller mandibular angle in adulthood.

Brain tissue deforms similarly to filled elastomers and follows consolidation theory

Slow, large deformations of human brain tissue—accompanying cranial vault deformation induced by positional plagiocephaly, occurring during hydrocephalus, and in the convolutional development—has surprisingly received scarce mechanical investigation. Since the effects of these deformations may be important, we performed a systematic series of in vitro experiments on human brain tissue, revealing the following features. (i) Under uniaxial (quasi-static), cyclic loading, brain tissue exhibits a peculiar nonlinear mechanical behaviour, exhibiting hysteresis, Mullins effect and residual strain, qualitatively similar to that observed in filled elastomers. As a consequence, the loading and unloading uniaxial curves have been found to follow the Ogden nonlinear elastic theory of rubber (and its variants to include Mullins effect and permanent strain). (ii) Loaded up to failure, the “shape” of the stress/strain curve qualitatively changes, evidencing softening related to local failure. (iii) Uniaxial (quasi-static) strain experiments under controlled drainage conditions provide the first direct evidence that the tissue obeys consolidation theory involving fluid migration, with properties similar to fine soils, but having much smaller volumetric compressibility. (iv) Our experimental findings also support the existence of a viscous component of the solid phase deformation. Brain tissue should, therefore, be modelled as a porous, fluid-saturated, nonlinear solid with very small volumetric (drained) compressibility.

Artificial cranial deformation in newborns in the pre-Columbian Andes

Artificial deformation of the neonatal cranial vault is one form of permanent alteration of the body that has been performed by the human being from the beginning of history as a way of differentiating from others. These procedures have been observed on all continents, although it became widespread practice among the aborigines who lived in the Andean region of South America. It has been suggested that the expansion of this practice started with the Scythians from their original settlements in central Asia and spread toward the rest of Asia and Europe, and it is believed that Asiatic people carried this cultural custom to America when they arrived on the current coasts of Alaska after crossing the Strait of Behring. The practice of deforming newborn heads was present in the whole of the American continent, from North America to Patagonia, but cranial molding in neonates was most widely practiced in the Andean region, from Venezuela to Guyana, Colombia, Ecuador, Peru, Bolivia, Chile, and Argentina. Intentional deformation of the head in neonates was carried out in different ways: by compression of the head with boards and pads; by compression with adjusted bindings; or by restraining the child on specially designed cradle-boards. The purpose of head shaping varied according to culture and region: while in certain regions it was a symbol of nobility or separated the different social groups within society, in others it served to emphasize ethnic differences or was performed for aesthetic, magical or religious reasons. There is no evidence of any neurological impairment among indigenous groups who practiced cranial deformations in newborns.

Intentional cranial vault deformation in a Slavonic population from the medieval cemetery in Devín (Slovakia)

A case of skull deformation is presented in a young individual (probably a girl), from Devin Castle dated to the Early Medieval Period (10th–12th centuries ad). The cause of deformation could be the result of developmental disease—turricephaly, or as a result of trauma in early childhood. X-rays did not confirm the hypothesis of turricephaly. According to the classificatory system of artificial deformations our specimen belongs to the circumferential type. This kind of deformation is common in the Migration Period in our territory but unique in the Early Middle Ages. Copyright © 1999 John Wiley & Sons, Ltd.

Artificial cranial deformation and fossil Australians revisited

Based on cranial characters shared byHomo erectusin Java andHomo sapiensin Australia, Australasia is widely considered the strongest case for a regional origin of modern humans. However, artificial vault deformation has been suggested to be the cause of “archaic” characters such as frontal recession in key fossil Australian crania. We use log–log plots of cranial arc versus chord measurements and we score nonmetric traits often thought to be associated with artificial deformation to make systematic comparisons across groups and deformation types to identify universal consequences of artificial deformation. Based on our large comparative sample (n=588) apparatus-deformed crania have flatter frontals and occipitals and usually more angulated parietals in the sagittal plane than undeformed crania, regardless of deformation type. Fossil Australian samples exhibit evidence of both undeformed and deformed individuals. The sample from Coobool Creek provides evidence that undeformed individuals had more rounded frontals than recent Australians. However, many individuals from Coobool Creek, Kow Swamp, and Nacurrie exhibit modification of one or more cranial contours. The Kow Swamp individuals in particular plot with deformed crania from all regions. In addition, the frequency of hyperostotic traits such as bregmatic eminence, metopic and sagittal keels inH. sapiensis influenced by both artificial deformation and pathological hypervascularity/hyperostosis. Thus it is unwise to use cranial contours and these nonmetric traits to infer genetic relatedness between Fossil Australians and IndonesianH. erectus.

Treatment of Positional Plagiocephaly with Dynamic Orthotic Cranioplasty

Dynamic orthotic cranioplasty (DOC) was developed to treat asymmetrical head shape of a nonsynostotic origin, which is defined by the term positional plagiocephaly. These positional deformations have been found to correlate with a number of environmental factors. Infants with positional plagiocephaly may exhibit complex multistructural asymmetry affecting the cranial vault, face, and skull base, or expression may be local in nature. Between 1988 and 1993, we performed DOC on 124 infants with positional plagiocephaly. Through clinical, anthropometric, radiographic, and statistical evaluation, we found that DOC corrects positional deformation of the cranial vault, skull base, and upper face, with no evident relapse following treatment. The design and the global approach to deformation address a wide spectrum of abnormal head shapes. The procedure is dynamic and customized, and it does not rely on passive growth alone for improvement.

Sutural complexity in artificially deformed human (Homo sapiens) crania

The pattern of complexity of cranial sutures is highly variable both among and within species. Intentional cranial vault deformation in human populations provides a controlled natural experiment by which we were able to quantify aspects of sutural complexity and examine the relationship between sutural patterns and mechanical loading. Measures of sutural complexity (interdigitation, number, and size of sutural bones) were quantified from digitized tracings of 13 sutures and compared among three groups of crania (n = 70) from pre-European contact Peru. These groups represent sample populations deformed in 1) anteroposterior (AP) and 2) circumferential (C) directions and 3) an undeformed population. Intergroup comparisons show few differences in degree or asymmetry of sutural interdigitation. In the few comparisons which show differences, the C group is always more interdigitated than the other two while the AP group has more sutural bones. The sutures surrounding the temporal bone (sphenotemporal, occipitotemporal, and temporoparietal) most frequently show significant differences among groups. These differences are related to the more extreme binding of C type deformation and are consistent with hypothesized increases in tension at coronally oriented sutures in this group. The larger number of sutural bones in the AP group is consistent with the general broadening of the cranium in this group and with experimental evidence indicating the development of ossicles in areas of tension. We suggest that so few changes in sutural complexity occurred either because the magnitude of the growth vectors, unlike their direction, is not substantially altered or because mechanisms other than sutural growth modification are responsible for producing the altered vault shapes. In addition, the presence of fontanelles in the infant skulls during binding and the static nature of the binding may have contributed to the similarity in complexity among groups.

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.

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.

Cranial base morphology in association with intentional cranial vault deformation: By R. William McNeill and George N. Newton. Am. J. Phys. Anthrop. 23: 241–254, September, 1965

Cranial base morphology in association with intentional cranial vault deformation: By R. William McNeill and George N. Newton. Am. J. Phys. Anthrop. 23: 241–254, September, 1965

Cranial base morphology in association with intentional cranial vault deformation.

AbstractComparison of vault and basal dimensions in 86 Amerind crania revealed that artificial deformation is associated with elevation of frontal orbital processes and temporal petrous crests, restriction of normal downward rotation of foramen magnum, and flattening of mid‐saggital cranial base. Circumferentially deformed crania were modified to a greater degree than antero‐posteriorly deformed skulls. While degree of basal deformation was dependent upon type of vault deformation, this study could not demonstrate the existence of a relationship between type of vault deformation and direction of cranial base modification.