Musculoskeletal System - Skull Development: Difference between revisions

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[[File:Fetal_head_lateral.jpg|thumb|alt=12 week fetal skull|300px|Fetal Head (12 weeks) showing cartilage (blue) and bone (red)]]
[[File:Fetal_head_lateral.jpg|thumb|alt=12 week fetal skull|300px|Fetal Head (12 weeks) showing cartilage (blue) and bone (red)]]


The Skull is a unique skeletal structure in several ways: embryonic cellular origin (neural crest), form of ossification (intramembranous and endochondrial) and flexibility (fibrous sutures). The cranial vault (which encloses the brain) bones are formed by intramembranous ossification. While the bones that form the base of the skull are formed by endochondrial ossification. The bones enclosing the brain have large flexible fibrous joints (sutures) which allow firstly the head to pass through the birth canal and secondly postnatal brain growth. (See also notes on [[Head Development]])
The {{skull}} is a unique skeletal structure in several ways: embryonic cellular origin ({{neural crest}} and {{mesoderm}}), form of ossification (intramembranous and ) and flexibility (fibrous sutures). The cranial vault (which encloses the brain) bones are formed by {{intramembranous ossification}}. While the bones that form the base of the skull are formed by {{endochondral ossification}}.


Ossification
* {{endochondral ossification}} - ethmoid, basi sphenoid, basi occipital, petrous temporal
* {{intramembranous ossification}} - facial skeleton (nasals, maxillae, premaxillae, zygomatic, mandible) and cranial vault (frontal, parietal, and squamous temporal)


In humans, ossification continues postnatally, through puberty until mid 20's and in old age the sutures separating the vault plates are often completely ossified.
The bones enclosing the brain have large flexible fibrous joints (sutures) which allow firstly the head to pass through the birth canal and secondly postnatal brain growth. (See also notes on [[Head Development]]) In humans, ossification within the skull continues postnatally, through puberty until mid 20's and in old age the sutures separating the vault plates are often completely ossified.




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[[:Category:Skull|Category:Skull]] | [[Head Development]] | [[Palate Development]] | [[Joint Development - Temporomandibular Joint|Temporomandibular Joint]]
[[:Category:Skull|Category:Skull]] | {{head}} | {{neural crest}} | {{palate}} | {{temporomandibular joint}} | {{joint}}


{{Musculoskeletal Links}}
{{Musculoskeletal Links}}
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* '''Transcriptional analysis of human cranial compartments with different embryonic origins'''<ref name="PMID26188427"><pubmed>26188427</pubmed></ref> "Previous investigations suggest that the embryonic origins of the calvarial tissues (neural crest or mesoderm) may account for the molecular mechanisms underlying sutural development. The aim of this study was to evaluate the differences in the gene expression of human cranial tissues and assess the presence of an expression signature reflecting their embryonic origins. Of six paired comparisons, frontal and parietal compartments (distinct tissue types of calvaria, either bone or intrasutural mesenchyme) had the most different gene expression profiles despite being composed of the same tissue type (bone). Transcriptional profiles of two groups of tissues, frontal and metopic compartments vs. parietal and sagittal compartments, suggest differences in proliferation, differentiation and extracellular matrix production. Our data suggest that in the second trimester of human foetal development, a gene expression signature of neural crest origin still exists in frontal and metopic compartments while gene expression of parietal and sagittal compartments is more similar to mesoderm."
* '''Review - A comprehensive review of the anterior fontanelle: embryology, anatomy, and clinical considerations.'''{{#pmid:28396968|PMID28396968}} "Fontanelles are a regular feature of infant development in which two segments of bone remain separated, leaving an area of fibrous membrane or a "soft spot" that acts to accommodate growth of the brain without compression by the skull. Of the six fontanelles in the human skull, the anterior fontanelle, located between the frontal and parietal bones, serves as an important anatomical diagnostic tool in the assessment of impairments of the skull and brain and allows access to the brain and ventricles in the infant. The diagnostic value of the anterior fontanelle, through observation of its shape, size, and palpability, makes the area of significant clinical value."
* '''The BMP Ligand Gdf6 Prevents Differentiation of Coronal Suture Mesenchyme in Early Cranial Development'''<ref><pubmed>22693558</pubmed></ref> "Growth Differentiation Factor-6 (Gdf6) is a member of the Bone Morphogenetic Protein (BMP) family of secreted signaling molecules. Previous studies have shown that Gdf6 plays a role in formation of a diverse subset of skeletal joints. In mice, loss of Gdf6 results in fusion of the coronal suture, the intramembranous joint that separates the frontal and parietal bones. .... Therefore, although BMPs are known to promote bone formation, Gdf6 plays an inhibitory role to prevent the osteogenic differentiation of the coronal suture mesenchyme."
 
* '''Epigenetic control of skull morphogenesis by histone deacetylase 8'''<ref><pubmed>19605684</pubmed></ref> "Histone deacetylases (Hdacs) are transcriptional repressors with crucial roles in mammalian development. Here we provide evidence that Hdac8 specifically controls patterning of the skull by repressing a subset of transcription factors in cranial neural crest cells. Global deletion of Hdac8 in mice leads to perinatal lethality due to skull instability, and this is phenocopied by conditional deletion of Hdac8 in cranial neural crest cells. Hdac8 specifically represses the aberrant expression of homeobox transcription factors such as Otx2 and Lhx1. These findings reveal how the identity and patterning of vertebrate-specific portions of the skull are epigenetically controlled by a histone deacetylase."
* '''Expression of five frizzleds during zebrafish craniofacial development.'''<ref><pubmed>19595791</pubmed></ref> "Wnt/Planar Cell Polarity (PCP) signaling is critical for proper animal development. ...Frizzled (Fzd) homologues are Wnt receptors ...Closer examination revealed that fzd7b is expressed in the neural crest and the mesodermal core of the pharyngeal arches and in the chondrocytes of newly stacked craniofacial cartilage elements. However, fzd7a is only expressed in the neural crest of the pharyngeal arches and fzd8a is expressed in the pharyngeal endoderm."
* '''Skull Abnormalities - Craniosynostosis'''<ref><pubmed>17132737</pubmed>| [http://www.pnas.org/cgi/content/abstract/103/49/18603 PNAS Link]</ref> "Craniosynostosis, the fusion of one or more of the sutures of the skull vault before the brain completes its growth, is a common (1 in 2,500 births) craniofacial abnormality, approximately 20% of which occurrences are caused by gain-of-function mutations in FGF receptors (FGFRs). ...These experiments show that attenuation of FGFR signaling by pharmacological intervention could be applied for the treatment of craniosynostosis or other severe bone disorders caused by mutations in FGFRs that currently have no treatment."
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{| class="wikitable mw-collapsible mw-collapsed"
{| class="wikitable mw-collapsible mw-collapsed"
! More recent papers
! More recent papers &nbsp;
|-
|-
| [[File:Mark_Hill.jpg|90px|left]] {{Most_Recent_Refs}}
| [[File:Mark_Hill.jpg|90px|left]] {{Most_Recent_Refs}}


Search term: [http://www.ncbi.nlm.nih.gov/pubmed/?term=Skull+Embryology ''Skull Embryology'']
Search term: [http://www.ncbi.nlm.nih.gov/pubmed/?term=Skull+Embryology ''Skull Embryology''] | [http://www.ncbi.nlm.nih.gov/pubmed/?term=Skull+Development ''Skull Development''] | [http://www.ncbi.nlm.nih.gov/pubmed/?term=Mandible+Development ''Mandible Development'']
 
|}
{| class="wikitable mw-collapsible mw-collapsed"
! Older papers &nbsp;
|-
| {{Older papers}}
* '''Transcriptional analysis of human cranial compartments with different embryonic origins'''{{#pmid:26188427|PMID26188427}} "Previous investigations suggest that the embryonic origins of the calvarial tissues (neural crest or mesoderm) may account for the molecular mechanisms underlying sutural development. The aim of this study was to evaluate the differences in the gene expression of human cranial tissues and assess the presence of an expression signature reflecting their embryonic origins. Of six paired comparisons, frontal and parietal compartments (distinct tissue types of calvaria, either bone or intrasutural mesenchyme) had the most different gene expression profiles despite being composed of the same tissue type (bone). Transcriptional profiles of two groups of tissues, frontal and metopic compartments vs. parietal and sagittal compartments, suggest differences in proliferation, differentiation and extracellular matrix production. Our data suggest that in the second trimester of human foetal development, a gene expression signature of neural crest origin still exists in frontal and metopic compartments while gene expression of parietal and sagittal compartments is more similar to mesoderm."
 
* '''The BMP Ligand Gdf6 Prevents Differentiation of Coronal Suture Mesenchyme in Early Cranial Development'''{{#pmid:22693558|PMID22693558}} "Growth Differentiation Factor-6 (Gdf6) is a member of the Bone Morphogenetic Protein (BMP) family of secreted signaling molecules. Previous studies have shown that Gdf6 plays a role in formation of a diverse subset of skeletal joints. In mice, loss of Gdf6 results in fusion of the coronal suture, the intramembranous joint that separates the frontal and parietal bones. .... Therefore, although BMPs are known to promote bone formation, Gdf6 plays an inhibitory role to prevent the osteogenic differentiation of the coronal suture mesenchyme."
 
* '''Epigenetic control of skull morphogenesis by histone deacetylase 8'''{{#pmid:19605684|PMID19605684}} "Histone deacetylases (Hdacs) are transcriptional repressors with crucial roles in mammalian development. Here we provide evidence that Hdac8 specifically controls patterning of the skull by repressing a subset of transcription factors in cranial neural crest cells. Global deletion of Hdac8 in mice leads to perinatal lethality due to skull instability, and this is phenocopied by conditional deletion of Hdac8 in cranial neural crest cells. Hdac8 specifically represses the aberrant expression of homeobox transcription factors such as Otx2 and Lhx1. These findings reveal how the identity and patterning of vertebrate-specific portions of the skull are epigenetically controlled by a histone deacetylase."


<pubmed limit=5>Skull Embryology</pubmed>
* '''Expression of five frizzleds during zebrafish craniofacial development.'''{{#pmid:19595791|PMID19595791}} "Wnt/Planar Cell Polarity (PCP) signaling is critical for proper animal development. ...Frizzled (Fzd) homologues are Wnt receptors ...Closer examination revealed that fzd7b is expressed in the neural crest and the mesodermal core of the pharyngeal arches and in the chondrocytes of newly stacked craniofacial cartilage elements. However, fzd7a is only expressed in the neural crest of the pharyngeal arches and fzd8a is expressed in the pharyngeal endoderm."
 
* '''Skull Abnormalities - Craniosynostosis'''{{#pmid:17132737|PMID17132737}} "Craniosynostosis, the fusion of one or more of the sutures of the skull vault before the brain completes its growth, is a common (1 in 2,500 births) craniofacial abnormality, approximately 20% of which occurrences are caused by gain-of-function mutations in FGF receptors (FGFRs). ...These experiments show that attenuation of FGFR signaling by pharmacological intervention could be applied for the treatment of craniosynostosis or other severe bone disorders caused by mutations in FGFRs that currently have no treatment."
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==Fetal Skull ==
==Fetal Skull ==
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<div id="Mandible Development"></div>
==Mandible Development==
==Mandible Development==
[[File:Pharyngeal_arch_cartilages.jpg|thumb|Meckel's cartilage]]
[[File:Pharyngeal_arch_cartilages.jpg|thumb|Meckel's cartilage]]
Meckel's cartilage, located within the first pharyngeal arch mandibular prominence, forms a cartilage "template" besides which the mandible develops by the process of intramembranous ossification. It is important to note that this cartilage template does not ossify (endochondral ossification) but provides a transient structure where the mandible will form, and later degenerates.
Meckel's cartilage, located within the first pharyngeal arch mandibular prominence, forms a cartilage "template" besides which the {{mandible}} bone develops by the process of intramembranous ossification. It is important to note that this cartilage template does not ossify (endochondral ossification) but provides a transient structure where the mandible will form, and later degenerates.


See also the 1957 historic paper on temporomandibular joint development.<ref name=Moffatt1957>{{Ref-Moffatt1957}}</ref>
===Embryonic and Fetal Mandible===
===Embryonic and Fetal Mandible===
<gallery>
<gallery>
File:Gray0178.jpg|Embryo CRL 24 mm (outer aspect, about [[Carnegie stage 22]])
File:Low1909 fig01.jpg|embryo 18 mm
File:Gray0179.jpg|Embryo CRL 24 mm (inner aspect, about [[Carnegie stage 22]])
File:Low1909 fig02.jpg|embryo 24 mm
File:Gray0180.jpg|Embryo CRL 95 mm (outer aspect, about [[Fetal_Development_-_12_Weeks|Fetal week 12]], GA week 14)
File:Gray0178.jpg|Embryo 24 mm (outer aspect, about [[Carnegie stage 22]])
File:Gray0181.jpg|Embryo CRL 95 mm (inner aspectt, about [[Fetal_Development_-_12_Weeks|Fetal week 12]], GA week 14)
File:Gray0179.jpg|Embryo 24 mm (inner aspect, about [[Carnegie stage 22]])
File:Low1909 fig03.jpg|embryo 28 mm
File:Low1909 fig04.jpg|fetus 43 mm
File:Low1909 fig05.jpg|fetus 65 mm
File:Low1909 fig06.jpg| fetus 55 mm
File:Low1909 fig07.jpg|fetus 95 mm
File:Gray0180.jpg|fetus  95 mm (outer aspect, about [[Fetal_Development_-_12_Weeks|Fetal week 12]], {{GA}} week 14)
File:Gray0181.jpg|fetus 95 mm (inner aspectt, about [[Fetal_Development_-_12_Weeks|Fetal week 12]], {{GA}} week 14)
File:Low1909 plate01.jpg|human 18-24-95 mm
</gallery>
</gallery>


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{{Mandible images}}
{{Mandible images}}


:'''Links:''' [[Musculoskeletal_System_-_Temporomandibular Joint|Temporomandibular Joint Development]]
==Neurocranium==
==Neurocranium==
===Frontal bone===
===Frontal bone===
* neural crest origin
* neural crest origin
* requires Msx1 and Dlx5<ref><pubmed>20824629</pubmed></ref>
* requires Msx1 and Dlx5{{#pmid:20824629|PMID20824629}}
===Parietal bone===
===Parietal bone===
* paraxial mesoderm origin
* paraxial mesoderm origin
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At the molecular level, accelerated suture intramembranous ossification can be mediated through a dual role of β-catenin in both the expansion of osteoprogenitors and the maturation of osteoblasts.<ref><pubmed>17113065</pubmed></ref> These researchers also show that disruption of Axin2/β-catenin signaling alters the regulation of the downstream transcription target, cyclin D1, in the canonical Wnt pathway.<ref><pubmed>21108844</pubmed></ref>
At the molecular level, accelerated suture intramembranous ossification can be mediated through a dual role of β-catenin in both the expansion of osteoprogenitors and the maturation of osteoblasts.{{#pmid:17113065|PMID17113065}} These researchers also show that disruption of Axin2/β-catenin signaling alters the regulation of the downstream transcription target, cyclin D1, in the canonical Wnt pathway.{{#pmid:21108844|PMID21108844}}
===Computed Tomography Views===
===Computed Tomography Views===
{|
{|
| [[File:Skull CT normal sutures.jpg|600px]]
| [[File:Skull CT normal sutures.jpg|600px]]


Skull CT Vertex, later and basal views.<ref name="PMID21431034"><pubmed>21431034</pubmed>| [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3056371 PMC3056371] | [http://www.ijri.org/article.asp?issn=0971-3026;year=2011;volume=21;issue=1;spage=49;epage=56;aulast=Khanna Indian J Radiol Imaging.]</ref>
Skull CT Vertex, later and basal views.{{#pmid:21431034|PMID21431034}}
| valign=top|
| valign=top|
'''Sutures and Fontanels'''
'''Sutures and Fontanels'''
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== Abnormalities==
== Abnormalities==


There are several skull deformities caused by premature fusion ('''synostosis''') of different developing skull sutures. Suture abnormalities are classified as either "simple" (only one suture involved) or "compound" (two or more sutures involved).  
There are several skull deformities caused by premature fusion ('''synostosis''') of different developing skull sutures. Suture abnormalities are classified as either "simple" (only one suture involved) or "compound" (two or more sutures involved). Failure of neural (brain) development may also result in acrocephaly of the skull.




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The CT images shown below are from a recent review of skull abnormalities.<ref name="PMID21431034"><pubmed>21431034</pubmed>| [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3056371 PMC3056371] | [http://www.ijri.org/article.asp?issn=0971-3026;year=2011;volume=21;issue=1;spage=49;epage=56;aulast=Khanna Indian J Radiol Imaging.]</ref>
The CT images shown below are from a recent review of skull abnormalities.{{#pmid:21431034|PMID21431034}}
|}
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=== Craniosynostosis ===
=== Craniosynostosis ===
Attenuation of signaling pathways stimulated by pathologically activated FGF-receptor 2 mutants prevents craniosynostosis.<ref><pubmed>17132737</pubmed></ref> "Craniosynostosis, the fusion of one or more of the sutures of the skull vault before the brain completes its growth, is a common (1 in 2,500 births) craniofacial abnormality, approximately 20% of which occurrences are caused by gain-of-function mutations in FGF receptors (FGFRs). ...These experiments show that attenuation of FGFR signaling by pharmacological intervention could be applied for the treatment of craniosynostosis or other severe bone disorders caused by mutations in FGFRs that currently have no treatment."
Attenuation of signaling pathways stimulated by pathologically activated FGF-receptor 2 mutants prevents craniosynostosis.{{#pmid:17132737|PMID17132737}} "Craniosynostosis, the fusion of one or more of the sutures of the skull vault before the brain completes its growth, is a common (1 in 2,500 births) craniofacial abnormality, approximately 20% of which occurrences are caused by gain-of-function mutations in FGF receptors (FGFRs). ...These experiments show that attenuation of FGFR signaling by pharmacological intervention could be applied for the treatment of craniosynostosis or other severe bone disorders caused by mutations in FGFRs that currently have no treatment."
 
See also {{Crouzon syndrome}}.


====Dolichocephaly and scaphocephaly====
====Dolichocephaly and scaphocephaly====
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(c) Longitudinal splitting of the nails is frequent.
(c) Longitudinal splitting of the nails is frequent.
|-
|-
| Craniofrontonasal syndrome<ref><pubmed>15166289</pubmed>| [http://www.pnas.org/content/101/23/8652.full PNAS Link]</ref>
| Craniofrontonasal syndrome{{#pmid:15166289|PMID15166289}}
| '''Links:''' [http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=304110 OMIM - Craniofrontonasal Syndrome]
| '''Links:''' [http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=304110 OMIM - Craniofrontonasal Syndrome]
|}
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===Crouzon syndrome===
Crouzon syndrome (craniofacial dysostosis) rare genetic disorder also characterized by premature closure of cranial sutures. Cranial and facial malformations vary, ranging from mild to potentially severe, including among members of the same family ({{autosomal dominant}}). The syndrome is caused by mutations in one of the FGFR genes, most commonly FGFR2.


:'''Links:''' [https://www.omim.org/entry/176943 OMIM - FGFR2]
== Skull Histology ==
== Skull Histology ==
A histological image of a skull bone formation by Intramembranous ossification.
A histological image of a skull bone formation by Intramembranous ossification.
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===Reviews===
===Reviews===
{{#pmid:1522265}}
{{#pmid:9482048}}
{{#pmid:7813156}}


<pubmed>1522265</pubmed>
{{#pmid:7813157}}
<pubmed>9482048</pubmed>
<pubmed>7813156</pubmed>
<pubmed>7813157</pubmed>
<pubmed>8266985</pubmed>


{{#pmid:8266985}}
===Articles===
===Articles===


<pubmed>14504503</pubmed>
{{#pmid:14504503}}




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</gallery>
</gallery>


===Historic Images===
===Historic===
[[Embryology_History|Historic Embryology]]
[[Embryology_History|Historic Embryology]]


{| class="wikitable mw-collapsible mw-collapsed"
{| class="wikitable mw-collapsible mw-collapsed"
! [[Book_-_Manual_of_Human_Embryology_11E|1910 Development of the Skeleton]]
! Johns Hopkins Fetal Skull Collection (1918–1951) &nbsp;
|-
|{{Johns Hopkins Fetal Skull Collection simplified table}}
|}
 
{| class="wikitable mw-collapsible mw-collapsed"
! [[Book_-_Manual_of_Human_Embryology_11E|1910 Development of the Skeleton]] &nbsp;
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{| class="wikitable mw-collapsible mw-collapsed"
{| class="wikitable mw-collapsible mw-collapsed"
! [[Paper - The skull of a human fetus of 40 mm 1|1914 Human Fetus 40 mm Skull]]
! [[Paper - The skull of a human fetus of 40 mm 1|1914 Human Fetus 40 mm Skull]] &nbsp;
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{| class="wikitable mw-collapsible mw-collapsed"
{| class="wikitable mw-collapsible mw-collapsed"
! [[Book_-_Contributions_to_Embryology_Carnegie_Institution_No.48|1921 43 mm Fetal Skull]]
! [[Book_-_Contributions_to_Embryology_Carnegie_Institution_No.48|1921 43 mm Fetal Skull]] &nbsp;
|-
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{| class="wikitable mw-collapsible mw-collapsed"
{| class="wikitable mw-collapsible mw-collapsed"
! [[Anatomy_of_the_Human_Body_by_Henry_Gray#1_Development|1918 Gray's Anatomy]]
! [[Anatomy_of_the_Human_Body_by_Henry_Gray#1_Development|1918 Gray's Anatomy]] &nbsp;
|-
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* '''intramembranous ossification''' - bone formation from a membrane where no pre-existing cartilage is found, such as the calvarial vault component.
* '''intramembranous ossification''' - bone formation from a membrane where no pre-existing cartilage is found, such as the calvarial vault component.
* '''neurocranium''' -  the portion of the skull that surrounds the brain. Ossification of bones in cranial base (endochondral) and vault (intramembranous).
* '''neurocranium''' -  the portion of the skull that surrounds the brain. Ossification of bones in cranial base (endochondral) and vault (intramembranous).
* '''opisthion''' - anatomical region located on the occipital bone, located at the midpoint of the posterior margin of the foramen magnum.
* '''opisthion''' - anatomical region located on the occipital bone, located at the midpoint of the posterior margin of the foramen magnum.
* '''posterior fontanel''' - developing skull region that closes by about 3 months postnatally.
* '''posterior fontanel''' - developing skull region that closes by about 3 months postnatally.
* '''primary craniosynostosis''' - an intrinsic defect in a suture.
* '''primary craniosynostosis''' - an intrinsic defect in a suture.
* '''secondary craniosynostosis''' - premature closure of normal sutures due to systemic and metabolic (hyperthyroidism, hypercalcemia, hypophosphatasia, vitamin D deficiency, renal osteodystrophy, Hurler's Syndrome, sickle cell disease and thalassemia) and those that can affect brain growth.  
* '''secondary craniosynostosis''' - premature closure of normal sutures due to systemic and metabolic (hyperthyroidism, hypercalcemia, hypophosphatasia, vitamin D deficiency, renal osteodystrophy, Hurler's Syndrome, sickle cell disease and thalassemia) and those that can affect brain growth.  
* '''simple craniosynostosis''' - premature fusion involving only one suture.
* '''simple craniosynostosis''' - premature fusion involving only one suture.
* '''synostosis''' - premature fusion.
* '''synostosis''' - premature fusion.
* '''viscerocranium''' - facial skeleton and some anterior neck structures.
* '''viscerocranium''' - facial skeleton and some anterior neck structures.


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* '''PubMed Health''' [http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002557 Craniosynostosis]
* '''PubMed Health''' [http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002557 Craniosynostosis]
* Johns Hopkins Fetal Skull Collection (1918–1951) - collection was begun by Adolph Hans Schultz (1891–1976) - fetal, stillbirths, newborns, and infants up to approximately one year of age. Collection of 112 specimens was transferred to the [https://www.cmnh.org/phys-anthro/collection-database Cleveland Museum of Natural History] on a permanent loan in 1973.
{{Johns Hopkins Fetal Skull Collection simplified collapse table}}




{{Glossary}}
{{Glossary}}


{{Footer}}
{{Footer}}


[[Category:System Development]] [[Category:Skull]] [[Category:Axial Skeleton]]
[[Category:System Development]] [[Category:Skull]] [[Category:Axial Skeleton]]

Revision as of 10:03, 19 June 2019

Embryology - 28 Mar 2024    Facebook link Pinterest link Twitter link  Expand to Translate  
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Introduction

12 week fetal skull
Fetal Head (12 weeks) showing cartilage (blue) and bone (red)

The skull is a unique skeletal structure in several ways: embryonic cellular origin (neural crest and mesoderm), form of ossification (intramembranous and ) and flexibility (fibrous sutures). The cranial vault (which encloses the brain) bones are formed by intramembranous ossification. While the bones that form the base of the skull are formed by endochondral ossification.

Ossification

The bones enclosing the brain have large flexible fibrous joints (sutures) which allow firstly the head to pass through the birth canal and secondly postnatal brain growth. (See also notes on Head Development) In humans, ossification within the skull continues postnatally, through puberty until mid 20's and in old age the sutures separating the vault plates are often completely ossified.


In the entire skeleton, early ossification occurs in the jaw and at the ends of long bones (More? see movie developing mouse). Osteoblasts manufacture bone and are derived from ectomesenchymal in origin. (More? see lineage below). Flexible fibrous sutures allow growth of the brain to be accomodated by calvarial plate growth. Recent studies have show that noggin (a BMP antagonist) is involved in closure of these sutures.


Developmentally and clinically there are several abnormalities associated with skull growth and palate development. These abnormalities can furthermore impact on other systems such as neural, sensory, respiratory and nutritional functions.


Category:Skull | head | neural crest | palate | temporomandibular joint | joint

Musculoskeletal Links: Introduction | mesoderm | somitogenesis | limb | cartilage | bone | bone timeline | bone marrow | shoulder | pelvis | axial skeleton | skull | joint | skeletal muscle | muscle timeline | tendon | diaphragm | Lecture - Musculoskeletal | Lecture Movie | musculoskeletal abnormalities | limb abnormalities | developmental hip dysplasia | cartilage histology | bone histology | Skeletal Muscle Histology | Category:Musculoskeletal
Historic Embryology - Musculoskeletal  
1853 Bone | 1885 Sphenoid | 1902 - Pubo-femoral Region | Spinal Column and Back | Body Segmentation | Cranium | Body Wall, Ribs, and Sternum | Limbs | 1901 - Limbs | 1902 - Arm Development | 1906 Human Embryo Ossification | 1906 Lower limb Nerves and Muscle | 1907 - Muscular System | Skeleton and Limbs | 1908 Vertebra | 1908 Cervical Vertebra | 1909 Mandible | 1910 - Skeleton and Connective Tissues | Muscular System | Coelom and Diaphragm | 1913 Clavicle | 1920 Clavicle | 1921 - External body form | Connective tissues and skeletal | Muscular | Diaphragm | 1929 Rat Somite | 1932 Pelvis | 1940 Synovial Joints | 1943 Human Embryonic, Fetal and Circumnatal Skeleton | 1947 Joints | 1949 Cartilage and Bone | 1957 Chondrification Hands and Feet | 1968 Knee
Historic Embryology
1910 Textbook Skull | 1910 Textbook Skull Images | 1910 30mm Embryo Skull | 1921 Human Brain Vascular | 1923 Head Subcutaneous Plexus | 1919 21mm Embryo Skull | 1920 Human Embryo Head Size | 1921 43 mm Fetal Skull | 1915 The Monotreme Skull | Historic Disclaimer

Some Recent Findings

Historic images of the skull by Vesalius
  • Review - A comprehensive review of the anterior fontanelle: embryology, anatomy, and clinical considerations.[1] "Fontanelles are a regular feature of infant development in which two segments of bone remain separated, leaving an area of fibrous membrane or a "soft spot" that acts to accommodate growth of the brain without compression by the skull. Of the six fontanelles in the human skull, the anterior fontanelle, located between the frontal and parietal bones, serves as an important anatomical diagnostic tool in the assessment of impairments of the skull and brain and allows access to the brain and ventricles in the infant. The diagnostic value of the anterior fontanelle, through observation of its shape, size, and palpability, makes the area of significant clinical value."
More recent papers  
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Search term: Skull Embryology | Skull Development | Mandible Development

Older papers  
These papers originally appeared in the Some Recent Findings table, but as that list grew in length have now been shuffled down to this collapsible table.

See also the Discussion Page for other references listed by year and References on this current page.

  • Transcriptional analysis of human cranial compartments with different embryonic origins[2] "Previous investigations suggest that the embryonic origins of the calvarial tissues (neural crest or mesoderm) may account for the molecular mechanisms underlying sutural development. The aim of this study was to evaluate the differences in the gene expression of human cranial tissues and assess the presence of an expression signature reflecting their embryonic origins. Of six paired comparisons, frontal and parietal compartments (distinct tissue types of calvaria, either bone or intrasutural mesenchyme) had the most different gene expression profiles despite being composed of the same tissue type (bone). Transcriptional profiles of two groups of tissues, frontal and metopic compartments vs. parietal and sagittal compartments, suggest differences in proliferation, differentiation and extracellular matrix production. Our data suggest that in the second trimester of human foetal development, a gene expression signature of neural crest origin still exists in frontal and metopic compartments while gene expression of parietal and sagittal compartments is more similar to mesoderm."
  • The BMP Ligand Gdf6 Prevents Differentiation of Coronal Suture Mesenchyme in Early Cranial Development[3] "Growth Differentiation Factor-6 (Gdf6) is a member of the Bone Morphogenetic Protein (BMP) family of secreted signaling molecules. Previous studies have shown that Gdf6 plays a role in formation of a diverse subset of skeletal joints. In mice, loss of Gdf6 results in fusion of the coronal suture, the intramembranous joint that separates the frontal and parietal bones. .... Therefore, although BMPs are known to promote bone formation, Gdf6 plays an inhibitory role to prevent the osteogenic differentiation of the coronal suture mesenchyme."
  • Epigenetic control of skull morphogenesis by histone deacetylase 8[4] "Histone deacetylases (Hdacs) are transcriptional repressors with crucial roles in mammalian development. Here we provide evidence that Hdac8 specifically controls patterning of the skull by repressing a subset of transcription factors in cranial neural crest cells. Global deletion of Hdac8 in mice leads to perinatal lethality due to skull instability, and this is phenocopied by conditional deletion of Hdac8 in cranial neural crest cells. Hdac8 specifically represses the aberrant expression of homeobox transcription factors such as Otx2 and Lhx1. These findings reveal how the identity and patterning of vertebrate-specific portions of the skull are epigenetically controlled by a histone deacetylase."
  • Expression of five frizzleds during zebrafish craniofacial development.[5] "Wnt/Planar Cell Polarity (PCP) signaling is critical for proper animal development. ...Frizzled (Fzd) homologues are Wnt receptors ...Closer examination revealed that fzd7b is expressed in the neural crest and the mesodermal core of the pharyngeal arches and in the chondrocytes of newly stacked craniofacial cartilage elements. However, fzd7a is only expressed in the neural crest of the pharyngeal arches and fzd8a is expressed in the pharyngeal endoderm."
  • Skull Abnormalities - Craniosynostosis[6] "Craniosynostosis, the fusion of one or more of the sutures of the skull vault before the brain completes its growth, is a common (1 in 2,500 births) craniofacial abnormality, approximately 20% of which occurrences are caused by gain-of-function mutations in FGF receptors (FGFRs). ...These experiments show that attenuation of FGFR signaling by pharmacological intervention could be applied for the treatment of craniosynostosis or other severe bone disorders caused by mutations in FGFRs that currently have no treatment."

Fetal Skull

The Images below show the combined endochondral and intramembranous ossification that is occurring in early fetal development (week 12).

In the first 2 images the bone cartilage is shown in blue and the new bone in red.

Note the difference in appearance between the upper and lower jaw (maxilla and mandible), the currently cartilage base of the skull (chondrocranium) and the cranial vault (neurocranium).

Fetal head lateral.jpg

Fetal head lateral view

Fetal head medial.jpg

Fetal head medial view

Fetal head section 01.jpg

Fetal head section

This mid-line section through the fetal head shows features of the developing skull and the brain, face and mouth.
  • Neural
    • developing brain and brainstem.
    • lamina terminalis (site of anterior neuropore closure).
    • fourth ventricle.
    • developing pituitary sitting in the sella turcica.
  • Musculoskeletal
    • cartilage - septum of the nose.
    • bone - ossifying nasal concha.
    • bone - palate roof of mouth.
    • cartilage - soft palate back of mouth.
    • cartilage - base of skull and vertebra.
    • muscle - tongue, attached note foramen cecum.
    • bone - mandible.
    • cartilage - developing hyoid and thyroid bones.

Mandible Development

Meckel's cartilage

Meckel's cartilage, located within the first pharyngeal arch mandibular prominence, forms a cartilage "template" besides which the mandible bone develops by the process of intramembranous ossification. It is important to note that this cartilage template does not ossify (endochondral ossification) but provides a transient structure where the mandible will form, and later degenerates.

See also the 1957 historic paper on temporomandibular joint development.[7]

Embryonic and Fetal Mandible

Birth to Adult Mandible

Postnatal human mandible growth icon.jpg
 ‎‎Mandible Growth
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Postnatal human mandible growth 1.gif

Animated GIF

Mandible Development: Week 8 outer view | Week 8 inner view | Week 12 outer view | Week 12 inner view | Week 12 Head outer view | Week 12 Head inner view | Birth | Childhood | Adult | Old Age | Small Animation | Large Animation | Muscle Attachments | Mandible Ossification | 1909 Mandible | embryo 18 mm | embryo 24 mm | embryo 28 mm | fetus 43 mm | fetus 65 mm | fetus 55 mm | fetus 95 mm | human 18-24-95 mm | Skull Development | Head Development


Links: Temporomandibular Joint Development

Neurocranium

Frontal bone

  • neural crest origin
  • requires Msx1 and Dlx5[8]

Parietal bone

  • paraxial mesoderm origin


Skull Views

Skull anterior.gif Skull superior.gif Skull lateral view.gif Bailey139.jpg
anterior view superior view lateral view lateral view
showing anterior fontenelle, sutures, mandible showing anterior fontenelle, sutures showing suture, mandible newborn skull

Skull Fontanels and Sutures

Adult Skull

The bones enclosing the brain have large flexible fibrous joints (sutures) which allow firstly the head to compress and pass through the birth canal and secondly to postnatally expand for brain growth. (More? Molecular Skull Sutures) These sutures gradually fuse at different times postnatally, firstly the metopic suture in infancy and the others much later. Abnormal fusion (synostosis) of any of the sutures will lead to a number of different skull defects, leading to disruption of brain development. (More? Abnormal Synostosis) In old age all these sutures are generally completely fused and ossified.


Skull Fontanels

The newborn skull has 6 fontanels (fontanelles) the most obvious are the anterior and posterior fontanels that close at different times postnatally.
  • posterior fontanel closes at about 3 months
  • anterior fontanel closes at about 18 months
Newborn Skull Fontanels

Newborn Skull Fontanels (CT, vertex view)

At the molecular level, accelerated suture intramembranous ossification can be mediated through a dual role of β-catenin in both the expansion of osteoprogenitors and the maturation of osteoblasts.[9] These researchers also show that disruption of Axin2/β-catenin signaling alters the regulation of the downstream transcription target, cyclin D1, in the canonical Wnt pathway.[10]

Computed Tomography Views

Skull CT normal sutures.jpg

Skull CT Vertex, later and basal views.[11]

Sutures and Fontanels

  • a - Metopic suture
  • b - coronal sutures
  • c - sagittal suture
  • d - lambdoid suture
  • e - squamosal suture
  • f - anterior fontanel
  • g - posterior fontanel
  • h - sphenoidal fontanel
  • i - mastoid fontanel

coronal suture

Skull CT normal sutures 01.jpg

lambdoid suture

Skull CT normal sutures 02.jpg

metopic suture begins at nose and runs superiorly to meet sagittal suture and fuses during infancy (fusion beginning at 3 months and completes by 6 to 8 months of age) before all other cranial sutures.

sagittal suture

Cranial Base Synchondroses

In the base of the skull there can also be found a number of synchondrosis, "cartilage sutures", that are the last to close and have a role in the ongoing growth of the postnatal skull. Synchondrosis is a type of cartilaginous joint in which the cartilage is usually converted into bone before adult life. It has been compared in appearance to a long bone growth plate, but is bipolar rather than unipolar in structure.


These sutures also lost at different times in postnatal development:

  • Inter-sphenoidal – around birth
  • Spheno-ethmoidal – 6-7 yrs
  • Spheno-occipital – 12-15 yrs


Fetal Head Growth

Fetal head growth circumference graph02.jpg Fetal head growth circumference graph01.jpg

Abnormalities

There are several skull deformities caused by premature fusion (synostosis) of different developing skull sutures. Suture abnormalities are classified as either "simple" (only one suture involved) or "compound" (two or more sutures involved). Failure of neural (brain) development may also result in acrocephaly of the skull.


Oxycephaly.jpg
Oxycephalus (historic image from Hess, 1922)
* craniosynostosis premature cranial suture fusion, results in an abnormal skull shape, blindness and mental retardation.
  • oxycephaly (tower skull) results from premature coronal suture synostosis.
  • plagiocephaly results from asymmetric coronal suture synostosis, incidence is approximately 1 in 300 live births.
  • lambdoid synostosis results from premature lambdoid suture synostosis, a rare abnormality (incidence is approximately 3 in 100,000 live births) which displaces ear posteriorly towards the fused suture.
  • caphocephaly results from premature sagittal suture synostosis.
  • trigoncephaly (wedge skull) results from metopic suture synostosis.



The CT images shown below are from a recent review of skull abnormalities.[11]

Craniosynostosis

Attenuation of signaling pathways stimulated by pathologically activated FGF-receptor 2 mutants prevents craniosynostosis.[6] "Craniosynostosis, the fusion of one or more of the sutures of the skull vault before the brain completes its growth, is a common (1 in 2,500 births) craniofacial abnormality, approximately 20% of which occurrences are caused by gain-of-function mutations in FGF receptors (FGFRs). ...These experiments show that attenuation of FGFR signaling by pharmacological intervention could be applied for the treatment of craniosynostosis or other severe bone disorders caused by mutations in FGFRs that currently have no treatment."

See also Crouzon syndrome.

Dolichocephaly and scaphocephaly

Skull CT abnormal 01.jpg
Dolichocephaly and scaphocephaly

(premature fusion of the sagittal suture)


Brachycephaly and anterior plagiocephaly

(Greek, brakhu = short) (Greek plagios = oblique)

  • brachycephaly - premature bicoronal fusion
  • anterior plagiocephaly - unicoronal fusion

Leads to a restriction of anterior-posterior calvarial growth and relatively unaffected biparietal growth.

Skull CT abnormal 02.jpg Skull CT abnormal 03.jpg


Skull Turricephaly

Skull CT abnormal 04.jpg


Skull Trigonocephaly

Skull CT abnormal 07.jpg

(Greek, trigonos = three angles) This abnormality results from the premature fusion of the metopic suture occurring before 6 months (3-9 months) of age.

Skull Oxycephaly

Skull CT abnormal 08.jpg

Images show oxycephaly from severe sagittal and coronal synostoses (arrowheads).

Craniofrontonasal Syndrome

Craniofrontonasal syndrome (CFNS) is a human X-linked developmental disorder caused by a mutation in ephrin-B1 affecting mainly females. Characterised by abnormal development of cranial and nasal bones, craniosynostosis (premature coronal suture fusion), and other extracranial anomalies (limb polydactyly and syndactyly).

Craniofrontonasal syndrome.jpg (a) Facial view showing marked hypertelorism, divergent squint, and central nasal groove (subject age, 1 year).


(b) Three-dimensional computed tomographic skull reconstruction (subject age, 8 months) showing right unicoronal synostosis, lateral displacement of orbits, and central defect between frontal bones. Note bony ridge at site of obliterated right coronal suture (arrowhead); the left coronal suture is patent (arrow). f, frontal bone; p, parietal bone.


(c) Longitudinal splitting of the nails is frequent.

Craniofrontonasal syndrome[12] Links: OMIM - Craniofrontonasal Syndrome

Crouzon syndrome

Crouzon syndrome (craniofacial dysostosis) rare genetic disorder also characterized by premature closure of cranial sutures. Cranial and facial malformations vary, ranging from mild to potentially severe, including among members of the same family (autosomal dominant). The syndrome is caused by mutations in one of the FGFR genes, most commonly FGFR2.


Links: OMIM - FGFR2

Skull Histology

A histological image of a skull bone formation by Intramembranous ossification.

Intramembranous ossification centre.jpg

Adult Skull

Adult Skull MRI Links: Skull Development - MRI
Adult Skull Movie 1 icon.jpg
 ‎‎Viscerocranium
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Adult Skull Movie 2 icon.jpg
 ‎‎Temporal Bones
Page | Play
Adult Skull Movie 3 icon.jpg
 ‎‎Occipital - Frontal
Page | Play
Adult Skull Movie 4 icon.jpg
 ‎‎Parietal-Zygomatic
Page | Play


References

  1. D'Antoni AV, Donaldson OI, Schmidt C, Macchi V, De Caro R, Oskouian RJ, Loukas M & Shane Tubbs R. (2017). A comprehensive review of the anterior fontanelle: embryology, anatomy, and clinical considerations. Childs Nerv Syst , 33, 909-914. PMID: 28396968 DOI.
  2. Homayounfar N, Park SS, Afsharinejad Z, Bammler TK, MacDonald JW, Farin FM, Mecham BH & Cunningham ML. (2015). Transcriptional analysis of human cranial compartments with different embryonic origins. Arch. Oral Biol. , 60, 1450-60. PMID: 26188427 DOI.
  3. Clendenning DE & Mortlock DP. (2012). The BMP ligand Gdf6 prevents differentiation of coronal suture mesenchyme in early cranial development. PLoS ONE , 7, e36789. PMID: 22693558 DOI.
  4. Haberland M, Mokalled MH, Montgomery RL & Olson EN. (2009). Epigenetic control of skull morphogenesis by histone deacetylase 8. Genes Dev. , 23, 1625-30. PMID: 19605684 DOI.
  5. Sisson BE & Topczewski J. (2009). Expression of five frizzleds during zebrafish craniofacial development. Gene Expr. Patterns , 9, 520-7. PMID: 19595791 DOI.
  6. 6.0 6.1 Eswarakumar VP, Ozcan F, Lew ED, Bae JH, Tomé F, Booth CJ, Adams DJ, Lax I & Schlessinger J. (2006). Attenuation of signaling pathways stimulated by pathologically activated FGF-receptor 2 mutants prevents craniosynostosis. Proc. Natl. Acad. Sci. U.S.A. , 103, 18603-8. PMID: 17132737 DOI.
  7. Moffatt BC. The prenatal development of the human temporomandibular joint. (1957) Carnegie Instn. Wash. Publ. 611, Contrib. Embryol., 36: .
  8. Chung IH, Han J, Iwata J & Chai Y. (2010). Msx1 and Dlx5 function synergistically to regulate frontal bone development. Genesis , 48, 645-55. PMID: 20824629 DOI.
  9. Liu B, Yu HM & Hsu W. (2007). Craniosynostosis caused by Axin2 deficiency is mediated through distinct functions of beta-catenin in proliferation and differentiation. Dev. Biol. , 301, 298-308. PMID: 17113065 DOI.
  10. Mirando AJ, Maruyama T, Fu J, Yu HM & Hsu W. (2010). β-catenin/cyclin D1 mediated development of suture mesenchyme in calvarial morphogenesis. BMC Dev. Biol. , 10, 116. PMID: 21108844 DOI.
  11. 11.0 11.1 Khanna PC, Thapa MM, Iyer RS & Prasad SS. (2011). Pictorial essay: The many faces of craniosynostosis. Indian J Radiol Imaging , 21, 49-56. PMID: 21431034 DOI.
  12. Twigg SR, Kan R, Babbs C, Bochukova EG, Robertson SP, Wall SA, Morriss-Kay GM & Wilkie AO. (2004). Mutations of ephrin-B1 (EFNB1), a marker of tissue boundary formation, cause craniofrontonasal syndrome. Proc. Natl. Acad. Sci. U.S.A. , 101, 8652-7. PMID: 15166289 DOI.

Reviews

Shah M, Ross JS, VanDyke C, Rudick RA, Goodkin DE, Obuchowski N & Modic MT. (1992). Volume T1-weighted gradient echo MRI in multiple sclerosis patients. J Comput Assist Tomogr , 16, 731-6. PMID: 1522265

Stelnicki EJ, Mooney MP, Losken HW, Zoldos J, Burrows AM, Kapucu R & Siegel MI. (1997). Ultrasonic prenatal diagnosis of coronal suture synostosis. J Craniofac Surg , 8, 252-8; discussion 259-61. PMID: 9482048

Ocampo RV & Persing JA. (1994). Sagittal synostosis. Clin Plast Surg , 21, 563-74. PMID: 7813156

Vander Kolk CA & Carson BS. (1994). Lambdoid synostosis. Clin Plast Surg , 21, 575-84. PMID: 7813157

Cohen MM. (1993). Sutural biology and the correlates of craniosynostosis. Am. J. Med. Genet. , 47, 581-616. PMID: 8266985 DOI.

Articles

Weinzweig J, Kirschner RE, Farley A, Reiss P, Hunter J, Whitaker LA & Bartlett SP. (2003). Metopic synostosis: Defining the temporal sequence of normal suture fusion and differentiating it from synostosis on the basis of computed tomography images. Plast. Reconstr. Surg. , 112, 1211-8. PMID: 14504503 DOI.


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Search July 2010 "Skull Development" All (15473) Review (1231) Free Full Text (1634)

Search Pubmed: Skull Development

Additional Images

Historic

Historic Embryology

Johns Hopkins Fetal Skull Collection (1918–1951)  
Johns Hopkins Fetal Skull Collection (1918–1951) - Simplified | Simplified Collapse | Full | Skull Development
Specimen Schultz Number Schultz Number (Old) Sex Race Ted Combs Age 1 Ted Combs Age 2 Ted Combs Notes
JH 001 6 Blank Male B 5-6 IU Left Occipital Condyle Missing 7/01 JR
JH 002 15 253 Male B 7 IU
JH 003 18 Blank Male B 11 PN LEFT GREATER WING MAY HAVE BEEN BROKEN
JH 004 34 394 Male B 12 PN ENTIRE BASICRANIUM FUSED
JH 005 35 361 Male B 10 IU
JH 006 36 258 Male B 7 IU ADOLF H SCHULTZ DRAWING INCLUDED
JH 007 38 269 Male B 10-11 IU IMPROPER OSSIFICATION OF DORSUM STELLA
JH 008 51 Blank Male B 5 IU NOT ALL BONES BELONG HERE
JH 009 56 271 Male B 10 IU
JH 010 58 340 Male B 9-10 IU
JH 011 62 Blank Male B 0 Newborn
JH 012 67 322 Male B 0 Newborn MOLAR BUDS INCLUDED
JH 013 69 299 Male? B 9 IU CHECK SEX
JH 014 71 323 Male B 0 Newborn
JH 015 78 298 Male B 8 IU IMPROPER OSSIFICATION OF THE STELLA TURCICA
JH 016 83 Blank Male B 7 IU
JH 017 91 334 Male B 10 IU
JH 018 96 310 Male B 10 IU SQUAMOUS PORTION OF OCCIPITAL IN 2 PIECES
JH 019 109 315 Male B 10 IU EXTRA BROKEN MALLEUS INCLUDED
JH 020 110 257 Male B 6 IU TEMPORALS POORLY OSSIFIED
JH 021 111 342 Male B 3 PN
JH 022 126 367 Male B 10 IU
JH 023 135 250 Male B 8 IU VERY YOUNG
JH 024 137 285 Male B 8 IU
JH 025 139 400 Male B 0 Newborn
JH 026 144 Blank Male B 10 IU "Two right lateral occipital bones and no left

JR 7/12/2001"

JH 027 147 391 Male B 2 PN LEFT FRONTAL IS THE ONLY BONE PRESENT.
JH 028 155 355 Male B 0 Newborn
JH 029 159 273 Male B 9 IU
JH 030 161 367 Male B 0 Newborn
JH 031 164 359 Male B 2 PN MANDIBLE ONCE FUSED, NOW BROKEN"
JH 032 178 483 Male B 15 PN MaleOST OF BASICRANIUM FUSED
JH 033 184 365 Male B 2 PN
JH 034 189 377 Male B 3 PN
JH 035 2 306 Female B 0 Newborn MANDIBLE WAS FUSED: NOW BROKEN
JH 036 8 Blank Female B 9 IU
JH 037 14 236 Female B 5 IU
JH 038 17 Blank Female B 14 PN ADOLF H SCHULTZ DRAWING INCLUDED
JH 039 44 298 Female B 8 IU EXTRA MALLEUS
JH 040 45 Blank Female B 0 Newborn POOR OSSIFICATION OF THE CALVARIA
JH 041 53 440 Female B 12 PN WHOLE SKULL BADLY OSSIFIED
JH 042 57 366 Female B 2 PN
JH 043 59 Blank Female B 8 IU
JH 044 61 340 Female B 9 IU INCOMPLETE
JH 045 63 340BUG!!! Female B 12 PN TEETH BELONG TO JH 05. BAD BONE.
JH 046 70 345 Female B 3 PN
JH 047 75 364 Female B 0 Newborn
JH 048 84 Blank Female B 8 IU
JH 049 86 341 Female B 2 PN
JH 050 88 294 Female B 8 IU
JH 051 101 290 Female B 8 IU
JH 052 107 Blank Female B 8 IU
JH 053 118 311 Female B 9 IU NASAL BONES FUSED
JH 054 120 252 Female B 8 IU
JH 055 121 276 Female B 6 IU
JH 056 122 313 Female B ? ? TWO FRONTALS FROM TWO SPECIMENS (SIDES IN DISPUTE) EAR OSSICLES WITH SMALL....(?)
JH 057 127 307 Female B 10 IU
JH 058 132 354 Female B 4 PN
JH 059 149 290 Female B 8 IU
JH 060 150 2825 Female B See Note See Note Age estimated as 8 months to Newborn
JH 061 169 340 Female B 0 Newborn
JH 062 172 283 Female B 7 IU
JH 063 185 345 Female B 10 IU
JH 064 190 331 Female B 2 PN
JH 065 191 256 Female B 5-6 IU
JH 066 10 240 Male W 5 IU
JH 067 20 Blank Male W 0 Newborn Reported missing by JR 7/001
JH 068 40 Blank Male W 2 PN
JH 069 48 340 Male W 7 IU
JH 070 49 274 Male W 6-7 IU
JH 071 74 332 Male W 10 IU
JH 072 77 336 Male W 10 IU
JH 073 89 344 Male W 9 IU
JH 074 92 279 Male W 6 IU
JH 075 105 Blank Male W 6 IU
JH 076 108 280 Male W 9 IU
JH 077 129 340 Male W 1 PN
JH 078 131 364 Male W 9 IU
JH 079 136 363 Male W 9 IU
JH 080 138 355 Male W 3 PN KERKRING'S CENTER OBSERVED
JH 081 141 347 Male W 2 PN MANDIBLE ONCE FUSED NOW BROKEN
JH 082 143 326 Male W 0 Newborn EXTRA MALLEUS INCLUDED
JH 083 146 320 Male W 9 IU THREE PARIETAL FRAGMENTS
JH 084 151 353 Male W 3 PN
JH 085 156 364 Male W 2 PN
JH 086 157 288 Male W 8 IU
JH 087 162 374 Male W 9 IU
JH 088 166 382 Male W 4 PN MANY TOOTH FRAGMENTS
JH 089 171 380 Male W 10 IU NASAL BONES FUSED
JH 090 179 Blank Male W 3 PN
JH 091 186 373 Male W 9 IU
JH 092 188 Blank Male W 8 IU
JH 093 192 328 Male W 7 IU KERKRING'S CENTER OBSERVED
JH 094 13 Blank Female W 0 Newborn TEETH FRAGMENTS
JH 095 23 352 Female W 4 PN TYMPANIC MEMBRANE INTACT
JH 096 43 268 Female W 5 IU ADOLF H SCHULTZ DRAWING INCLUDED
JH 097 47 313 Female W 8 IU ONE BONE FRAGMENT - SQUAMOUS TYPE
JH 098 64 364 Female W 3 PN
JH 099 95 350 Female W 4 PN HYDROCEPHALIC
JH 100 100 365 Female W 0 Newborn
JH 101 114 396 Female W 5 PN MANDIBLE ONCE FUSED NOW BROKEN
JH 102 116 400 Female W 2 PN TEETH NOT COUNTED
JH 103 117 290 Female W 7 IU TWO TOOTH BUDS
JH 104 128 368 Female W 5 PN TOOTH FRAGMENTS
JH 105 134 Blank Female W 9 IU EAR OSSICLES PRESENT - NO COUNT
JH 106 148 290 Female W 8 IU EAR OSSICLES PRESENT - NO COUNT
JH 107 160 60 Female W 2 PN EAR OSSICLES PRESENT - NO COUNT
JH 108 167 372 Female W 1 PN EAR OSSICLES PRESENT - NO COUNT
JH 109 168 316 Female W 8 IU EAR OSSICLES PRESENT - NO COUNT
JH 110 170 331 Female W 0 Newborn EAR OSSICLES PRESENT - NO COUNT
JH 111 175 342 Female W 10 IU EAR OSSICLES PRESENT - NO COUNT
JH 112 194 317 Female W 8 IU
Johns Hopkins Fetal Skull Collection (1918–1951) - The collection was begun by Adolph Hans Schultz (1891–1976) - fetal, stillbirths, newborns, and infants up to approximately one year of age. Collection of 112 specimens was transferred to the Cleveland Museum of Natural History on a permanent loan in 1973.
1910 Development of the Skeleton  
1914 Human Fetus 40 mm Skull  

Macklin CC. The skull of a human fetus of 40 mm 1. (1914) Amer. J Anat. 16(3): 317-386. Macklin CC. The skull of a human fetus of 40 mm 2. (1914) Amer. J Anat. 16(3): 387-426.

1921 43 mm Fetal Skull  
1918 Gray's Anatomy  

Terms

  • anterior fontanel - developing skull region that closes by about 20 months postnatally.
  • basion - anatomical region on the basiocciput located at the midpoint between the anterior margin and posterior margin (opisthion) of the foramen magnum.
  • compound craniosynostosis premature suture fusion involving two or more sutures.
  • craniosynostosis - (craniostenosis) the premature fusion of cranial sutures.
  • dermatocranium - (membranous) skull calvarial vault develops from intramembranous ossification.
  • harlequin eye - a term used to describe the prominent bilateral elliptical orbits of the skull seen in brachycephaly.
  • endochondral ossification - bone formation from a pre-existing cartilage template, such as the chondrocranium.
  • intramembranous ossification - bone formation from a membrane where no pre-existing cartilage is found, such as the calvarial vault component.
  • neurocranium - the portion of the skull that surrounds the brain. Ossification of bones in cranial base (endochondral) and vault (intramembranous).
  • opisthion - anatomical region located on the occipital bone, located at the midpoint of the posterior margin of the foramen magnum.
  • posterior fontanel - developing skull region that closes by about 3 months postnatally.
  • primary craniosynostosis - an intrinsic defect in a suture.
  • secondary craniosynostosis - premature closure of normal sutures due to systemic and metabolic (hyperthyroidism, hypercalcemia, hypophosphatasia, vitamin D deficiency, renal osteodystrophy, Hurler's Syndrome, sickle cell disease and thalassemia) and those that can affect brain growth.
  • simple craniosynostosis - premature fusion involving only one suture.
  • synostosis - premature fusion.
  • viscerocranium - facial skeleton and some anterior neck structures.

External Links

External Links Notice - The dynamic nature of the internet may mean that some of these listed links may no longer function. If the link no longer works search the web with the link text or name. Links to any external commercial sites are provided for information purposes only and should never be considered an endorsement. UNSW Embryology is provided as an educational resource with no clinical information or commercial affiliation.

  • Johns Hopkins Fetal Skull Collection (1918–1951) - collection was begun by Adolph Hans Schultz (1891–1976) - fetal, stillbirths, newborns, and infants up to approximately one year of age. Collection of 112 specimens was transferred to the Cleveland Museum of Natural History on a permanent loan in 1973.
Johns Hopkins Fetal Skull Collection (1918–1951)  
Johns Hopkins Fetal Skull Collection (1918–1951) - Simplified | Simplified Collapse | Full | Skull Development
Specimen Schultz Number Schultz Number (Old) Sex Race Ted Combs Age 1 Ted Combs Age 2 Ted Combs Notes
JH 001 6 Blank Male B 5-6 IU Left Occipital Condyle Missing 7/01 JR
JH 002 15 253 Male B 7 IU
JH 003 18 Blank Male B 11 PN LEFT GREATER WING MAY HAVE BEEN BROKEN
JH 004 34 394 Male B 12 PN ENTIRE BASICRANIUM FUSED
JH 005 35 361 Male B 10 IU
JH 006 36 258 Male B 7 IU ADOLF H SCHULTZ DRAWING INCLUDED
JH 007 38 269 Male B 10-11 IU IMPROPER OSSIFICATION OF DORSUM STELLA
JH 008 51 Blank Male B 5 IU NOT ALL BONES BELONG HERE
JH 009 56 271 Male B 10 IU
JH 010 58 340 Male B 9-10 IU
JH 011 62 Blank Male B 0 Newborn
JH 012 67 322 Male B 0 Newborn MOLAR BUDS INCLUDED
JH 013 69 299 Male? B 9 IU CHECK SEX
JH 014 71 323 Male B 0 Newborn
JH 015 78 298 Male B 8 IU IMPROPER OSSIFICATION OF THE STELLA TURCICA
JH 016 83 Blank Male B 7 IU
JH 017 91 334 Male B 10 IU
JH 018 96 310 Male B 10 IU SQUAMOUS PORTION OF OCCIPITAL IN 2 PIECES
JH 019 109 315 Male B 10 IU EXTRA BROKEN MALLEUS INCLUDED
JH 020 110 257 Male B 6 IU TEMPORALS POORLY OSSIFIED
JH 021 111 342 Male B 3 PN
JH 022 126 367 Male B 10 IU
JH 023 135 250 Male B 8 IU VERY YOUNG
JH 024 137 285 Male B 8 IU
JH 025 139 400 Male B 0 Newborn
JH 026 144 Blank Male B 10 IU "Two right lateral occipital bones and no left

JR 7/12/2001"

JH 027 147 391 Male B 2 PN LEFT FRONTAL IS THE ONLY BONE PRESENT.
JH 028 155 355 Male B 0 Newborn
JH 029 159 273 Male B 9 IU
JH 030 161 367 Male B 0 Newborn
JH 031 164 359 Male B 2 PN MANDIBLE ONCE FUSED, NOW BROKEN"
JH 032 178 483 Male B 15 PN MaleOST OF BASICRANIUM FUSED
JH 033 184 365 Male B 2 PN
JH 034 189 377 Male B 3 PN
JH 035 2 306 Female B 0 Newborn MANDIBLE WAS FUSED: NOW BROKEN
JH 036 8 Blank Female B 9 IU
JH 037 14 236 Female B 5 IU
JH 038 17 Blank Female B 14 PN ADOLF H SCHULTZ DRAWING INCLUDED
JH 039 44 298 Female B 8 IU EXTRA MALLEUS
JH 040 45 Blank Female B 0 Newborn POOR OSSIFICATION OF THE CALVARIA
JH 041 53 440 Female B 12 PN WHOLE SKULL BADLY OSSIFIED
JH 042 57 366 Female B 2 PN
JH 043 59 Blank Female B 8 IU
JH 044 61 340 Female B 9 IU INCOMPLETE
JH 045 63 340BUG!!! Female B 12 PN TEETH BELONG TO JH 05. BAD BONE.
JH 046 70 345 Female B 3 PN
JH 047 75 364 Female B 0 Newborn
JH 048 84 Blank Female B 8 IU
JH 049 86 341 Female B 2 PN
JH 050 88 294 Female B 8 IU
JH 051 101 290 Female B 8 IU
JH 052 107 Blank Female B 8 IU
JH 053 118 311 Female B 9 IU NASAL BONES FUSED
JH 054 120 252 Female B 8 IU
JH 055 121 276 Female B 6 IU
JH 056 122 313 Female B ? ? TWO FRONTALS FROM TWO SPECIMENS (SIDES IN DISPUTE) EAR OSSICLES WITH SMALL....(?)
JH 057 127 307 Female B 10 IU
JH 058 132 354 Female B 4 PN
JH 059 149 290 Female B 8 IU
JH 060 150 2825 Female B See Note See Note Age estimated as 8 months to Newborn
JH 061 169 340 Female B 0 Newborn
JH 062 172 283 Female B 7 IU
JH 063 185 345 Female B 10 IU
JH 064 190 331 Female B 2 PN
JH 065 191 256 Female B 5-6 IU
JH 066 10 240 Male W 5 IU
JH 067 20 Blank Male W 0 Newborn Reported missing by JR 7/001
JH 068 40 Blank Male W 2 PN
JH 069 48 340 Male W 7 IU
JH 070 49 274 Male W 6-7 IU
JH 071 74 332 Male W 10 IU
JH 072 77 336 Male W 10 IU
JH 073 89 344 Male W 9 IU
JH 074 92 279 Male W 6 IU
JH 075 105 Blank Male W 6 IU
JH 076 108 280 Male W 9 IU
JH 077 129 340 Male W 1 PN
JH 078 131 364 Male W 9 IU
JH 079 136 363 Male W 9 IU
JH 080 138 355 Male W 3 PN KERKRING'S CENTER OBSERVED
JH 081 141 347 Male W 2 PN MANDIBLE ONCE FUSED NOW BROKEN
JH 082 143 326 Male W 0 Newborn EXTRA MALLEUS INCLUDED
JH 083 146 320 Male W 9 IU THREE PARIETAL FRAGMENTS
JH 084 151 353 Male W 3 PN
JH 085 156 364 Male W 2 PN
JH 086 157 288 Male W 8 IU
JH 087 162 374 Male W 9 IU
JH 088 166 382 Male W 4 PN MANY TOOTH FRAGMENTS
JH 089 171 380 Male W 10 IU NASAL BONES FUSED
JH 090 179 Blank Male W 3 PN
JH 091 186 373 Male W 9 IU
JH 092 188 Blank Male W 8 IU
JH 093 192 328 Male W 7 IU KERKRING'S CENTER OBSERVED
JH 094 13 Blank Female W 0 Newborn TEETH FRAGMENTS
JH 095 23 352 Female W 4 PN TYMPANIC MEMBRANE INTACT
JH 096 43 268 Female W 5 IU ADOLF H SCHULTZ DRAWING INCLUDED
JH 097 47 313 Female W 8 IU ONE BONE FRAGMENT - SQUAMOUS TYPE
JH 098 64 364 Female W 3 PN
JH 099 95 350 Female W 4 PN HYDROCEPHALIC
JH 100 100 365 Female W 0 Newborn
JH 101 114 396 Female W 5 PN MANDIBLE ONCE FUSED NOW BROKEN
JH 102 116 400 Female W 2 PN TEETH NOT COUNTED
JH 103 117 290 Female W 7 IU TWO TOOTH BUDS
JH 104 128 368 Female W 5 PN TOOTH FRAGMENTS
JH 105 134 Blank Female W 9 IU EAR OSSICLES PRESENT - NO COUNT
JH 106 148 290 Female W 8 IU EAR OSSICLES PRESENT - NO COUNT
JH 107 160 60 Female W 2 PN EAR OSSICLES PRESENT - NO COUNT
JH 108 167 372 Female W 1 PN EAR OSSICLES PRESENT - NO COUNT
JH 109 168 316 Female W 8 IU EAR OSSICLES PRESENT - NO COUNT
JH 110 170 331 Female W 0 Newborn EAR OSSICLES PRESENT - NO COUNT
JH 111 175 342 Female W 10 IU EAR OSSICLES PRESENT - NO COUNT
JH 112 194 317 Female W 8 IU
Johns Hopkins Fetal Skull Collection (1918–1951) - The collection was begun by Adolph Hans Schultz (1891–1976) - fetal, stillbirths, newborns, and infants up to approximately one year of age. Collection of 112 specimens was transferred to the Cleveland Museum of Natural History on a permanent loan in 1973.


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Cite this page: Hill, M.A. (2024, March 28) Embryology Musculoskeletal System - Skull Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Musculoskeletal_System_-_Skull_Development

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© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G