Plagiocephaly, also known as flat head syndrome, is a condition characterized by an asymmetrical distortion (flattening of one side) of the skull. It is characterized by a flat spot on the back or one side of the head caused by remaining in a supine position for too long.

"Plagiocephaly" is the word that is used to describe a diagonal asymmetry across the head shape. This word particularly describes a flattening which is to one side at the back of the head and there is often some facial asymmetry. Plagiocephaly divides into two groups: synostotic plagiocephaly, with one or more fused cranial sutures, and nonsynostotic (deformational) plagiocephaly. Surgical treatment of these groups includes the deference method; however, the treatment of deformational plagiocephaly is controversial. Brachycephaly describes a very wide head shape with a flattening across the whole back of the head.

Your baby's skull has seven bones. Normally, these bones don't fuse until around age 2, giving your baby's brain time to grow. Joints called cranial sutures, made of strong, fibrous tissue, hold these bones together. In the front of your baby's skull, the sutures intersect in the large soft spot (fontanel) on the top of your baby's head. Normally, the sutures remain flexible until the bones fuse. The signs of craniosynostosis may not be noticeable at birth, but they become apparent during the first few months of your baby's life. The symptoms differs from types of synostosis. First of all there is Sagittal synostosis (scaphocephaly). Premature fusion of the suture at the top of the head (sagittal suture) forces the head to grow long and narrow, rather than wide. Scaphocephaly is the most common type of craniosynostosis. The other one is called Coronal synostosis (anterior plagiocephaly). Premature fusion of a coronal suture — one of the structures that run from each ear to the sagittal suture on top of the head — may force your baby's forehead to flatten on the affected side. It may also raise the eye socket and cause a deviated nose and slanted skull. The Bicoronal synostosis (brachycephaly). When both of the coronal sutures fuse prematurely, your baby may have a flat, elevated forehead and brow.

Slight plagiocephaly is routinely diagnosed at birth and may be the result of a restrictive intrauterine environment giving a "diamond" shaped head when seen from above. If there is premature union of skull bones, this is more properly called craniosynostosis.

The incidence of plagiocephaly has increased dramatically since the advent of anti-Sudden Infant Death Syndrome recommendations for parents to keep their babies on their backs.

Data also suggest that the rates of plagiocephaly is higher among twins and multiple births, premature babies, babies who were positioned in the breech position or back-to-back, as well as babies born after a prolonged labour.

McGillivray syndrome is a very rare syndrome which is also known as a Craniosynostosis. It is characterized mainly by heart defects, skull and facial abnormalities and ambiguous genitalia. The symptoms of this syndrome are ventricular septal defect, patent ductus arteriosus, small jaw, undescended testes, and webbed fingers. Beside to these symptoms there are more symptoms which is related with bone structure and misshape.

McGillivray syndrome is a birth defect in which one or more of the joints between the bones of your baby's skull close prematurely, before your baby's brain is fully formed. When your baby has craniosynostosis, his or her brain cannot grow in its natural shape and the head is misshapen. It can affect one or more of the joints in your baby's skull. In some cases, craniosynostosis is associated with an underlying brain abnormality that prevents the brain from growing properly. Treating McGillivray usually involves surgery to separate the fused bones. If there is no underlying brain abnormality, the surgery allows baby’s brain to grow and develop in adequate space.

The cranium consists of three main sections including the base of the cranium (occipital bone), the face (frontal bone), and the top (parietal bones) and sides (temporal bone) of the head. Most of the bones of the cranium are permanently set into place prior to birth. However, the temporal and parietal bones are separated by sutures, which remain open, allowing the head to slightly change in shape during childbirth. The cranial sutures eventually close within the first couple of years following birth, after the brain has finished growing.

In individuals with SCS, the coronal suture separating the frontal bones from the parietal bones, closes prematurely (craniosynostosis), occasionally even before birth. If the coronal suture closes asymmetrically or unilaterally, then the face and forehead will form unevenly, from side-to-side. People with SCS have pointy, tower-like heads because their brain is growing faster than their skull, resulting in increased intracranial pressure (ICP) and causing the top of the head and/or forehead to bulge out to allow for brain growth. The face appears uneven, particularly in the areas of the eyes and cheeks, and the forehead appears wide and tall.

Because of the abnormal forehead, there is less space for the normal facial features to develop. This results in shallow eye sockets and flat cheekbones. The shallow eye sockets make the eyes more prominent or bulging and cause the eyes to be more separated than normal (hypertelorism). The underdeveloped eye sockets, cheekbones, and lower jaw cause the face to appear flat. Furthermore, the minor downward slant of the eyes along with the drooping eyelids (ptosis) adds to the overall unevenness of the face.

Brachycephaly (from Greek roots meaning "short" and "head") is the shape of a skull shorter than typical for its species. It is perceived as a desirable trait in some domesticated dog and cat breeds, such as pugs, and can be normal or abnormal in other animal species. In humans, the cephalic disorder is known as flat head syndrome, and results from premature fusion of the coronal sutures (see craniosynostosis) or from external deformation (see plagiocephaly). The coronal suture is the fibrous joint that unites the frontal bone with the two parietal bones of the skull. The parietal bones form the top and sides of the skull. This feature can be seen in Down syndrome.

In anthropology, human populations have been characterized as either dolichocephalic (long headed), mesaticephalic (moderate headed), or brachycephalic (short headed). The usefulness of the cephalic index was questioned by Giuseppe Sergi, who argued that cranial morphology provided a better means to model racial ancestry. The incidence of brachycephaly in people has increased since the advent of sudden infant death syndrome recommendations for parents to keep their babies on their backs. It is considered a cosmetic problem. Many pediatricians remain unaware of the issue and possible treatments. Treatments include regular prone repositioning of babies ("tummy time").

There are also cases of brachycephaly associated with plagiocephaly. Brachycephaly with plagiocephaly is positional and has become more prevalent since the "Back to Sleep" Campaign.The Back to Sleep campaign began in 1994 as a way to educate about ways to reduce the risk for sudden infant death syndrome (SIDS). The campaign was named for its recommendation to place healthy babies on their backs to sleep. Placing babies on their backs to sleep reduces the risk for SIDS, also known as "cot death" or "crib death." This campaign has been successful in promoting infant back sleeping and other risk-reduction strategies to parents, family members, child care providers, health professionals, and all other caregivers of infants, at a cost of increasing the incidence of this deformation of the head.

Brachycephaly also describes a developmentally normal type of skull with a high cephalic index, such as in snub-nosed breeds of dog such as pugs, Shih Tzus, and bulldogs or cats such as the Persian, Exotic and Himalayan.

Saethre–Chotzen syndrome (SCS), also known as Acrocephalosyndactyly type III is a rare congenital disorder associated with craniosynostosis (premature closure of one or more of the sutures between the bones of the skull). This affects the shape of the head and face, resulting in a cone-shaped head and an asymmetrical face. Individuals with SCS also have droopy eyelids (ptosis), widely spaced eyes (hypertelorism), and minor birth defects of the hands and feet (syndactyly). In addition, individuals with more severe cases of SCS may have mild to moderate mental retardation or learning disabilities. Depending on the level of severity, some individuals with SCS may require some form of medical or surgical intervention. Most individuals with SCS live fairly normal lives, regardless of whether medical treatment is needed or not.

The cranial malformations are the most apparent effects of acrocephalosyndactyly. Craniosynostosis occurs, in which the cranial sutures close too soon, though the child's brain is still growing and expanding. Brachycephaly is the common pattern of growth, where the coronal sutures close prematurely, preventing the skull from expanding frontward or backward, and causing the brain to expand the skull to the sides and upwards. This results in another common characteristic, a high, prominent forehead with a flat back of the skull. Due to the premature closing of the coronal sutures, increased cranial pressure can develop, leading to mental deficiency. A flat or concave face may develop as a result of deficient growth in the mid-facial bones, leading to a conditir prognathism. Other features of acrocephalosyndactyly may include shallow bony orbits and broadly spaced eyes. Low-set ears are also a typical characteristic of branchial arch syndromes.

All acrocephalosyndactyly syndromes show some level of limb anomalies, so it can be hard to tell them apart. However, the typical hand deformities in patients with Apert Syndrome distinguish it from the other syndromes.

The hands in patients with Apert syndrome always show four common features:

1. a short thumb with radial deviation

2. complex syndactyly of the index, long and ring finger

3. symbrachyphalangism

4. simple syndactyly of the fourth webspace

The deformity of the space between the index finger and the thumb may be variable. Based on this first webspace, we can differentiate three different types of handdeformation:

- Type I: Also called a "spade hand". The most common and least severe type of deformation. The thumb shows radial deviation and clinodactyly, but is separated from the index finger. The index, long and ring finger are fused together in the distal interphalangeal joints and form a flat palm. During the embryonic stage, the fusion has no effect on the longitudinal growth of these fingers, so they have a normal length. In the fourth webspace, we always see a simple syndactyly, either complete or incomplete.

- Type II: Also called a "spoon" or "mitten" hand. This is a more serious anomaly since the thumb is fused to the index finger by simple complete or incomplete syndactyly. Only the distal phalanx of the thumb is not joined in the osseous union with the index finger and has a separate nail. Because the fusion of the digits is at the level of the distal interphalangeal joints, a concave palm is formed. Most of the time, we see complete syndactyly of the fourth webspace.

- Type III: Also called the "hoof" or "rosebud" hand. This is the most uncommon but also most severe form of hand deformity in Apert syndrome. There is a solid osseous or cartilaginous fusion of all digits with one long, conjoined nail. The thumb is turned inwards and it is often impossible to tell the fingers apart. Usually proper imaging of the hand is very difficult, due to overlap of bones, but physical examination alone is not enough to measure the severity of deformation

Cleidocranial dysostosis is a general skeletal condition so named from the collarbone (cleido-) and cranium deformities which people with it often have.

People with the condition usually present with a painless swelling in the area of the clavicles at 2–3 years of age. Common features are:

- Clavicles (collarbones) can be partly missing leaving only the medial part of the bone. In 10% cases, they are completely missing. If the collarbones are completely missing or reduced to small vestiges, this allows hypermobility of the shoulders including ability to touch the shoulders together in front of the chest. The defect is bilateral 80% of the time. Partial collarbones may cause nerve damage symptoms and therefore have to be removed by surgery.

- The mandible is prognathic due to hypoplasia of maxilla (micrognathism) and other facial bones.

- A soft spot or larger soft area in the top of the head where the fontanelle failed to close, or the fontanelle closes late.

- Bones and joints are underdeveloped. People are shorter and their frames are smaller than their siblings who do not have the condition.

- The permanent teeth include supernumerary teeth. Unless these supernumeraries are removed they will crowd the adult teeth in what already may be an underdeveloped jaw. If so, the supernumeraries will probably need to be removed to make space for the adult teeth. Up to 13 supernumarary teeth have been observed. Teeth may also be displaced. Cementum formation may be deficient.

- Failure of eruption of permanent teeth.

- Bossing (bulging) of the forehead.

- Open skull sutures, large fontanelles.

- Hypertelorism.

- Delayed ossification of bones forming symphysis pubis, producing a widened symphysis.

- Coxa vara can occur, limiting abduction and causing Trendelenburg gait.

- Short middle fifth phalanges, sometimes causing short and wide fingers.

- Vertebral abnormalities.

- On rare occasions, brachial plexus irritation can occur.

- Scoliosis, spina bifida and syringomyelia have also been described.

Other features are: parietal bossing, basilar invagination (atlantoaxial impaction), persistent metopic suture, abnormal ear structures with hearing loss, supernumerary ribs, hemivertebrae with spondylosis, small and high scapulae, hypoplasia of illiac bones, absence of the pubic bone, short / absent fibular bones, short / absent radial bones, hypoplastic terminal phalanges.

Carpenter Syndrome belongs to a group of rare genetic disorders known as acrocephalopolysyndactyly, abbreviated ACPS (RN, 2007). There were originally five types of ACPS, but this number has been decreased because they have been found to be closely related to one another or to other disorders (Paul A. Johnson, 2002).

The most common physical manifestation of Carpenter Syndrome is early fusing of the fibrous cranial sutures which results in an abnormally pointed head. The fusion of the skull bones is evident from birth (National Organization for Rare Disorders, Inc., 2008). Babies’ mobile cranial bones form a cone shape as the pass through the birth canal and soon thereafter return to a normal shape; however, a baby affected by carpenter syndrome maintains a cone shaped head.

A baby affected by Carpenter Syndrome will also display malformations of the face. An individual affected by the syndrome may have broad cheeks, a flat nasal bridge, and a wide upturned nose with abnormally large nasal openings. Their ears will most commonly be low, unevenly set, and malformed in structure. In addition to these facial abnormalities, individuals also have an underdeveloped maxilla and/ or mandible with a highly arched and narrow palate which makes speech a very difficult skill to master. Teeth are usually very late to come in and will be undersized and spaced far apart (Carpenter Syndrome-description).

Other physical abnormalities often associated with Carpenter Syndrome include extra digits. Extra toes are more commonly seen than fingers. Often both the toes and fingers are webbed, a process that occurs before the sixth week gestational period. Often their digits will be abnormally short, and the fingers are commonly missing an interphalangeal joint. Roughly half of the babies born with Carpenter Syndrome have some type of heart defect, and seventy five percent of individuals with this disease will experience some degree of development delay due to mild mental retardation (Carpenter Syndrome-description).

The primary diagnostic factor is a malformation of the skull. The two most common types of craniosynostosis are sagittal and bicoronal. Sagittal craniosynostosis manifests itself by causing a long narrow skull, resembling a football. It is quantitatively determined by measuring the anterior to posterior (front to back) diameter of the skull. An increased A-P diameter indicates a malformed fusion of the sagittal suture. Individuals affected with sagittal craniosynostosis have narrow, prominent foreheads and the back of the head is much larger than normal. The “soft spot” is very small or missing altogether with this particular type of craniosynostosis.

The second common type of skull malformation is bicoronal craniosynostosis is characterized by a wide, short skull. In this particular type of craniosynostosis the A-P diameter is smaller than in normal individuals. These individuals have malformed eye sockets and foreheads. The eye sockets are much smaller than normal and often cause visual impairment. Complications may include damage to the optic nerve, resulting in a decrease in visual clarity, bulging eyeballs as a result of shallow eye orbits which usually causes some sort of damage to the cornea (the outer layer of the eye). Bicoronal craniosynostosis may also result in widely spaced eyes and narrowing of the sinuses and tear ducts that may result in inflammation of the mucous membranes of the exposed portion of the eye.

In addition to the previously named complications of bicoronal craniosynostosis, many babies will also be affected by hydrocephalus, more commonly known as water on the brain. Hydrocephalus results in increased pressure on the brain which can cause permanent brain damage if not treated promptly. An abnormally highly arched palate is also seen in affected individuals causing dental problems and the thrusting forward of the lower jaw. Individuals affected by Carpenter syndrome often experience cutaneous syndactyly (fusion of the digits) or polydactyly (presence of extra digits) of the toes more often than fingers. Individuals also have short fingers.Approximately one third of individuals born with Carpenter Syndrome have a type of heart defect. Commonly seen heart defects may include: narrowing of the pulmonary artery, transposition of the major blood vessels, or the presence of an abnormally large vena cava, which delivers blood back to the heart from the head, neck, and upper limbs. The testes of males affected by Carpenter Syndrome may also fail to descend (Paul A. Johnson, 2002).

There are two problems that may occur during development that cause acrania.

Brachycephaly can be corrected with a cranial remolding orthoses (helmet) which provide painless total contact over the prominent areas of the skull and leave voids over the flattened areas to provide a pathway for more symmetrical skull growth. Treatment generally takes 3–4 months, but varies depending on the infant's age and severity of the cranial asymmetry.

However studies by scientists in the Netherlands have found there was no significant difference over time between infants treated with helmets and infants left untreated. All parents of infants treated with helmets confirmed negative side effects including skin irritation and sweating.

This study focused only on patients with mild to moderate cases, the participation rate was only 21%, and there was a 73% reporting of fitting issues, calling into question the validity of the study. Incorrectly fit devices cannot be expected to yield results. Additionally, independent published research that examined the effectiveness of helmet therapy conclude that as many as 95% of

patients demonstrate an improvement in head shape symmetry following helmet therapy, and the American Orthotics and Prosthetics Association (AOPA) has serious concerns about the relevance and validity of this study.

Acrania is a rare congenital disorder that occurs in the human fetus in which the flat bones in the cranial vault are either completely or partially absent. The cerebral hemispheres develop completely but abnormally. The condition is frequently, though not always, associated with anencephaly. The fetus is said to suffer from acrania if it meets the following criteria: the fetus should have a perfectly normal facial bone, a normal cervical column but without the fetal skull and a volume of brain tissue equivalent to at least one third of the normal brain size.

There are four main signs of acalvaria: absence of the flat bones of the cranial vault, absence of the dura mater and muscles associated with it, skull abnormalities, and the absence of a skull cap. This condition can be diagnosed prior to birth using ultrasonography. Physicians often use magnetic resonance imaging to confirm the diagnosis because in utero, acalvaria is sometimes confused with anencephaly or encephalocele. A distinguishable difference is that with anencephaly, the cerebral hemispheres are missing, but with acalvaria, all parts of the cerebrum are usually present and developed, whereas parts of the calvarium are missing.

In addition to small palpebral fissures, features include epicanthus inversus (fold curving in the mediolateral direction, inferior to the inner canthus), low nasal bridge, ptosis of the eyelids and telecanthus.

Cleidocranial dysostosis (CCD), also called cleidocranial dysplasia, is a birth defect that mostly affects the bones and teeth. The collarbones are typically either poorly developed or absent, which allows the shoulders to be brought close together. The front of the skull often does not close until later, and those affected are often shorter than average. Other symptoms may include a prominent forehead, wide set eyes, abnormal teeth, and a flat nose. Symptoms vary among people; however, intelligence is typically normal.

The condition is either inherited from a person's parents or occurs as a new mutation. It is inherited in an autosomal dominant manner. It is due to a defect in the RUNX2 gene which is involved in bone formation. Diagnosis is suspected based on symptoms and X-rays with confirmation by genetic testing. Other conditions that can produce similar symptoms include mandibuloacral dysplasia, pyknodysostosis, osteogenesis imperfecta, and Hajdu-Cheney syndrome.

Treatment includes supportive measures such as a device to protect the skull and dental care. Surgery may be performed to fix certain bone abnormalities. Life expectancy is generally normal.

It affects about one per million people. Males and females are equally commonly affected. Modern descriptions of the condition date to at least 1896. The term is from "cleido" meaning collarbone, "cranial" meaning head, and "dysostosis" meaning formation of abnormal bone.

Blepharophimosis syndrome is an autosomal dominant characterized by blepharophimosis (horizontal shortening of the palpebral fissures), ptosis (upper eyelid drooping, usually with the characteristics of congenital ptosis), epicanthus inversus (skin folds by the nasal bridge, more prominent lower than upper lid), and telecanthus (widening of the distance between the medial orbital walls). This syndrome is caused by mutations in the FOXL2 gene, either with premature ovarian failure (BPES type I) or without (BPES type II). It may also be associated with lop ears, ectropion, hypoplasia of superior orbital rims, and hypertelorism.

Acalvaria is a rare malformation consisting of absence of the calvarial bones, dura mater and associated muscles in the presence of a normal skull base and normal facial bones. The central nervous system is usually unaffected. The presumed pathogenesis of acalvaria is faulty migration of the membranous neurocranium with normal placement of the embryonic ectoderm, resulting in absence of the calvaria but an intact layer of skin over the brain parenchyma. In other words, instead of having a skull cap protecting the brain, there is only skin covering it. The size of the area that is missing the skull cap can vary from case to case. In extreme cases, the entire top part of the cranium that is dome-shaped may be absent.

Binder's Syndrome/Binder Syndrome (Maxillo-Nasal Dysplasia) is a developmental disorder primarily affecting the anterior part of the maxilla and nasal complex (nose and jaw). It is a rare disorder and the causes are unclear.

The characteristics of the syndrome are typically visible. The syndrome involves hypoplasia of variable severity of cartilaginous nasal septum and premaxilla. It includes complete total absence of the anterior nasal spine. There are also associated anomalies of muscle insertions of the upper lip and the nasal floor and of the cervical spine. Affected individuals typically have an unusually flat, underdeveloped midface (midfacial hypoplasia), with an abnormally short nose and flat nasal bridge. They have an underdeveloped upper jaw, relatively protruding lower jaw with anterior mandibular vertical excess and a Class III skeletal and dental (reverse overjet) profile. They have a small frontal sinus and global facial imbalance.

Treatment is encouraged as early as possible with posteroanterior traction on the maxilla and, at about age 8, reinsertion of the nasolabial muscles onto the anterior border of the cartilaginous system. Many who have a severe case of the disorder undergo plastic surgery or orthodontic treatment for cosmetic reasons.

The clinical presentation of HFM is quite variable. The severity may depend on the extent of the area with an insufficient blood supply "in utero", and the gestational age of the fetus at which this occurs. In some people, the only physical manifestation may be a small and underdeveloped external ear. In more severe cases, multiple parts of the face may be affected. Some people with HFM may have sensorineural hearing loss and decreased visual acuity or even blindness.

Goldenhar syndrome can be thought of as a particularly severe form of HFM, in which extracranial anomalies are present to some extent. Some of the internal organs (especially the heart, kidneys, and lungs) may be underdeveloped, or in some cases even absent altogether. The affected organs are typically on the same side as the affected facial features, but bilateral involvement occurs in approximately 10% of cases. Deformities of the vertebral column such as scoliosis may also be observed in Goldenhar syndrome.

While there is no universally accepted grading scale, the OMENS scale (standing for Orbital, Mandible, Ear, Nerves and Soft tissue) was developed to help describe the heterogeneous phenotype that makes up this sequence or syndrome.

Intellectual disability is not typically seen in people with HFM.

Facial features found in this syndrome include

- dolichocephaly

- hypertelorism

- ptosis

- microretrognathia

- high arched palate

- long flat philtrum

- low set ears

Non facial features of this syndrome include

- hyperextensibility

- hypotonia

- lateral meningoceles

The lateral meningocoles are a common finding in this syndrome. They may be associated with neurological abnormalities and result in bladder dysfunction and neuropathy.

Hemifacial microsomia (HFM) is a congenital disorder that affects the development of the lower half of the face, most commonly the ears, the mouth and the mandible. It usually occurs on one side of the face, but both sides are sometimes affected. If severe, it may result in difficulties in breathing due to obstruction of the trachea—sometimes even requiring a tracheotomy. With an incidence in the range of 1:3500 to 1:4500, it is the second most common birth defect of the face, after cleft lip and cleft palate. HFM shares many similarities with Treacher Collins syndrome.

The following are symptoms characteristic with individuals having the disorder. Individuals may display some, most, or all of these symptoms throughout the course of their life, though symptoms may vary with each patient.

- Abnormal hair (coarse, thick, brittle)

- Calvarial hypomineralization (soft skull)

- Y-shaped cataracts by 1–2 years of age

- Skeletal defects

- Hypertelorism (wide-set eyes)

- Facial dysmorphisms

- Late-closing fontanels

- Abnormal accumulation of proteins in the endoplasmic reticulum

- Scoliosis

- Broad forehead, nose

- Missing, small teeth or abnormal teeth positioning

- Poor skull calcification

- Flat foot

- Motor delay

- Abnormal vertebrae

- Prominent forehead and brow

- High nose bridge

- Capillary hemangioma

- Delayed tooth eruption

- Long upper lip groove

- Large mouth

- High arched palate

- Narrow hips and rib cage

- Thin lips

- Narrow and sloping shoulders

- Hyperpigmentation

- Hyperextensible joints

Onset of the disease is in neonatal development and infancy, and symptoms tend to become evident soon after birth.