Wormian bones

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Wormian bones
(Sutural bones)
Wormian bones.svg
Wormian bones compared to a normal skull
Wormian bones.jpg
Skull of a 21-year-old man with Wormian bones
Details
Identifiers
Latin ossa suturale
TA98 A02.1.00.043
TA2 831
FMA 59327
Anatomical terms of bone

Wormian bones, also known as intrasutural bones or sutural bones, [1] are extra bone pieces that can occur within a suture (joint) in the skull. These are irregular isolated bones that can appear in addition to the usual centres of ossification of the skull and, although unusual, are not rare. [2] They occur most frequently in the course of the lambdoid suture, which is more tortuous than other sutures. They are also occasionally seen within the sagittal and coronal sutures. A large wormian bone at lambda is often called an Inca bone (os incae), [3] due to the relatively high frequency of occurrence in Peruvian mummies. Another specific Wormian bone, the pterion ossicle, sometimes exists between the sphenoidal angle of the parietal bone and the great wing of the sphenoid bone. [4] They tend to vary in size and can be found on either side of the skull. Usually, not more than several are found in a single individual, but more than one hundred have been once found in the skull of a hydrocephalic adult.

Contents

Wormian bones are a marker for some diseases and important in the primary diagnosis of brittle bone disease: osteogenesis imperfecta . [5]

Wormian bones may also be seen in: [6]

Derivation of the name

Wormian bones are named for Ole Worm, professor of anatomy at Copenhagen, 15881654. He taught Latin, Greek, physics and medicine. His description of the extra-sutural bones contributed to the science of embryology.

Additional image

See also

Related Research Articles

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The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone, however two parts are more prominent: the cranium and the mandible. In humans, these two parts are the neurocranium (braincase) and the viscerocranium that includes the mandible as its largest bone. The skull forms the anterior-most portion of the skeleton and is a product of cephalisation—housing the brain, and several sensory structures such as the eyes, ears, nose, and mouth. In humans, these sensory structures are part of the facial skeleton.

<span class="mw-page-title-main">Fontanelle</span> Anatomical feature of the infant human skull

A fontanelle is an anatomical feature of the infant human skull comprising soft membranous gaps (sutures) between the cranial bones that make up the calvaria of a fetus or an infant. Fontanelles allow for stretching and deformation of the neurocranium both during birth and later as the brain expands faster than the surrounding bone can grow. Premature complete ossification of the sutures is called craniosynostosis.

<span class="mw-page-title-main">Occipital bone</span> Saucer-shaped membrane bone situated at the back and lower part of the cranium

The occipital bone is a cranial dermal bone and the main bone of the occiput. It is trapezoidal in shape and curved on itself like a shallow dish. The occipital bone overlies the occipital lobes of the cerebrum. At the base of the skull in the occipital bone, there is a large oval opening called the foramen magnum, which allows the passage of the spinal cord.

<span class="mw-page-title-main">Osteogenesis imperfecta</span> Group of genetic disorders that mainly affect the bones

Osteogenesis imperfecta, colloquially known as brittle bone disease, is a group of genetic disorders that all result in bones that break easily. The range of symptoms—on the skeleton as well as on the body's other organs—may be mild to severe. Symptoms found in various types of OI include whites of the eye (sclerae) that are blue instead, short stature, loose joints, hearing loss, breathing problems and problems with the teeth. Potentially life-threatening complications, all of which become more common in more severe OI, include: tearing (dissection) of the major arteries, such as the aorta; pulmonary valve insufficiency secondary to distortion of the ribcage; and basilar invagination.

<span class="mw-page-title-main">Apert syndrome</span> Congenital disorder of the skull and digits

Apert syndrome is a form of acrocephalosyndactyly, a congenital disorder characterized by malformations of the skull, face, hands and feet. It is classified as a branchial arch syndrome, affecting the first branchial arch, the precursor of the maxilla and mandible. Disturbances in the development of the branchial arches in fetal development create lasting and widespread effects.

<span class="mw-page-title-main">Craniosynostosis</span> Premature fusion of bones in the skull

Craniosynostosis is a condition in which one or more of the fibrous sutures in a young infant's skull prematurely fuses by turning into bone (ossification), thereby changing the growth pattern of the skull. Because the skull cannot expand perpendicular to the fused suture, it compensates by growing more in the direction parallel to the closed sutures. Sometimes the resulting growth pattern provides the necessary space for the growing brain, but results in an abnormal head shape and abnormal facial features. In cases in which the compensation does not effectively provide enough space for the growing brain, craniosynostosis results in increased intracranial pressure leading possibly to visual impairment, sleeping impairment, eating difficulties, or an impairment of mental development combined with a significant reduction in IQ.

<span class="mw-page-title-main">Skull fracture</span> Medical condition

A skull fracture is a break in one or more of the eight bones that form the cranial portion of the skull, usually occurring as a result of blunt force trauma. If the force of the impact is excessive, the bone may fracture at or near the site of the impact and cause damage to the underlying structures within the skull such as the membranes, blood vessels, and brain.

<span class="mw-page-title-main">Carpenter syndrome</span> Medical condition

Carpenter syndrome, also called acrocephalopolysyndactyly type II, is an extremely rare autosomal recessive congenital disorder characterized by craniofacial malformations, obesity, syndactyly, and polydactyly. Acrocephalopolysyndactyly is a variation of acrocephalosyndactyly that presents with polydactyly.

<span class="mw-page-title-main">Sagittal suture</span> Midline joint between the parietal bones of the skull

The sagittal suture, also known as the interparietal suture and the sutura interparietalis, is a dense, fibrous connective tissue joint between the two parietal bones of the skull. The term is derived from the Latin word sagitta, meaning arrow.

<span class="mw-page-title-main">Lambdoid suture</span> Connective tissue between the parietal bones and the occipital bone of the skull

The lambdoid suture is a dense, fibrous connective tissue joint on the posterior aspect of the skull that connects the parietal bones with the occipital bone. It is continuous with the occipitomastoid suture.

<span class="mw-page-title-main">Dentinogenesis imperfecta</span> Medical condition

Dentinogenesis imperfecta (DI) is a genetic disorder of tooth development. It is inherited in an autosomal dominant pattern, as a result of mutations on chromosome 4q21, in the dentine sialophosphoprotein gene (DSPP). It is one of the most frequently occurring autosomal dominant features in humans. Dentinogenesis imperfecta affects an estimated 1 in 6,000-8,000 people.

An osteochondrodysplasia, or skeletal dysplasia, is a disorder of the development of bone and cartilage. Osteochondrodysplasias are rare diseases. About 1 in 5,000 babies are born with some type of skeletal dysplasia. Nonetheless, if taken collectively, genetic skeletal dysplasias or osteochondrodysplasias comprise a recognizable group of genetically determined disorders with generalized skeletal affection. These disorders lead to disproportionate short stature and bone abnormalities, particularly in the arms, legs, and spine. Skeletal dysplasia can result in marked functional limitation and even mortality.

<span class="mw-page-title-main">Dentin dysplasia</span> Medical condition

Dentin dysplasia (DD) is a rare genetic developmental disorder affecting dentine production of the teeth, commonly exhibiting an autosomal dominant inheritance that causes malformation of the root. It affects both primary and permanent dentitions in approximately 1 in every 100,000 patients. It is characterized by the presence of normal enamel but atypical dentin with abnormal pulpal morphology. Witkop in 1972 classified DD into two types which are Type I (DD-1) is the radicular type, and type II (DD-2) is the coronal type. DD-1 has been further divided into 4 different subtypes (DD-1a,1b,1c,1d) based on the radiographic features.

<span class="mw-page-title-main">Fibrous joint</span> Fixed joints between bones held together by dense, fibrous tissue

In anatomy, fibrous joints are joints connected by fibrous tissue, consisting mainly of collagen. These are fixed joints where bones are united by a layer of white fibrous tissue of varying thickness. In the skull the joints between the bones are called sutures. Such immovable joints are also referred to as synarthroses.

Type I collagen is the most abundant collagen of the human body, consisting of around 90% of the body's total collagen in vertebrates. Due to this, it is also the most abundant protein type found in all vertebrates. Type I forms large, eosinophilic fibers known as collagen fibers, which make up most of the rope-like dense connective tissue in the body. Collagen I itself is created by the combination of both a proalpha1 and a proalpha2 chain created by the COL1alpha1 and COL1alpha2 genes respectively. The Col I gene itself takes up a triple-helical conformation due to its Glycine-X-Y structure, x and y being any type of amino acid. Collagen can also be found in two different isoforms, either as a homotrimer or a heterotrimer, both of which can be found during different periods of development. Heterotrimers, in particular, play an important role in wound healing, and are the dominant isoform found in the body.

<span class="mw-page-title-main">Pycnodysostosis</span> Genetic disease

Pycnodysostosis, is a lysosomal storage disease of the bone caused by a mutation in the gene that codes the enzyme cathepsin K. It is also known as PKND and PYCD.

<span class="mw-page-title-main">Tricho–dento–osseous syndrome</span> Medical condition

Tricho–dento–osseous syndrome (TDO) is a rare, systemic, autosomal dominant genetic disorder that causes defects in hair, teeth, and bones respectively. This disease is present at birth. TDO has been shown to occur in areas of close geographic proximity and within families; most recent documented cases are in Virginia, Tennessee, and North Carolina. The cause of this disease is a mutation in the DLX3 gene, which controls hair follicle differentiation and induction of bone formation. All patients with TDO have two co-existing conditions called enamel hypoplasia and taurodontism in which the abnormal growth patterns of the teeth result in severe external and internal defects. The hair defects are characterized as being rough, course, with profuse shedding. Hair is curly and kinky at infancy but later straightens. Dental defects are characterized by dark-yellow/brownish colored teeth, thin and/or possibly pitted enamel, that is malformed. The teeth can also look normal in color, but also have a physical impression of extreme fragility and thinness in appearance. Additionally, severe underbites where the top and bottom teeth fail to correctly align may be present; it is common for the affected individual to have a larger, more pronounced lower jaw and longer bones. The physical deformities that TDO causes become more noticeable with age, and emotional support for the family as well as the affected individual is frequently recommended. Adequate treatment for TDO is a team based approach, mostly involving physical therapists, dentists, and oromaxillofacial surgeons. Genetic counseling is also recommended.

<span class="mw-page-title-main">Bruck syndrome</span> Medical condition

Bruck syndrome is characterized as the combination of arthrogryposis multiplex congenita and osteogenesis imperfecta. Both diseases are uncommon, but concurrence is extremely rare which makes Bruck syndrome very difficult to research. Bruck syndrome is thought to be an atypical variant of osteogenesis imperfecta most resembling type III, if not its own disease. Multiple gene mutations associated with osteogenesis imperfecta are not seen in Bruck syndrome. Many affected individuals are within the same family, and pedigree data supports that the disease is acquired through autosomal recessive inheritance. Bruck syndrome has features of congenital contractures, bone fragility, recurring bone fractures, flexion joint and limb deformities, pterygia, short body height, and progressive kyphoscoliosis. Individuals encounter restricted mobility and pulmonary function. A reduction in bone mineral content and larger hydroxyapatite crystals are also detectable Joint contractures are primarily bilateral and symmetrical, and most prone to ankles. Bruck syndrome has no effect on intelligence, vision, or hearing.

<span class="mw-page-title-main">Kleeblattschaedel</span> Medical condition

Kleeblattschaedel is a rare malformation of the head where there is a protrusion of the skull and broadening of the face. This condition is a severe type of craniosynostosis.

<span class="mw-page-title-main">Wormian bone-multiple fractures-dentinogenesis imperfecta-skeletal dysplasia syndrome</span> Medical condition

Wormian bone-multiple fractures-dentinogenesis imperfecta-skeletal dysplasia syndrome is a rare genetic bone disorder which is characterized by the presence of wormian bones in the skull, dentinogenesis imperfecta, recurrent bone fractures, hypertelorism, and eye puffiness. This disorder is unique from osteogenesis imperfecta because of the presence of cortical defects and the absence of defective collagen or osteopenia. It is not exactly known whether this condition is autosomal dominant or autosomal recessive.

References

  1. radiopaedia.org Saladin, Kenneth (August 2006). Anatomy & Physiology: The Unity of Form & Function (4th ed.). McGraw-Hill. ISBN   0-07-331608-3.
  2. Gray, Henry; Warren Harmon Lewis (1918). Anatomy of the Human Body. Lea & Febiger.
  3. Parente, K; Mercado-Deane, MG; Brummund, T (2001). "Radiological Case of the Month". Archives of Pediatrics & Adolescent Medicine. 155 (6): 731–2. doi:10.1001/archpedi.155.6.731. PMID   11386967 . Retrieved 2008-11-02.
  4. Dr. Akram Abood Jaffar. "Sutural bones". Archived from the original on 2009-10-21.
  5. Glorieux FH, "Osteogenesis Imperfecta", Best Practice & Research Clinical Rheumatology. 22:1, pp. 85–100. 2008
  6. Wormian Bones: Differential Diagnosis #6, The Radiology Blog, published April 27, 2012