Scaphocephaly | |
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Boy with Scaphocephaly | |
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Specialty | Medical genetics |
Scaphocephaly, or sagittal craniosynostosis, is a type of cephalic disorder which occurs when there is a premature fusion of the sagittal suture. Premature closure results in limited lateral expansion of the skull resulting in a characteristic long, narrow head. [1] The skull base is typically spared. [2]
Scaphocephaly is the most common of the craniosynostosis conditions and accounts for approximately 50% of all craniosynostosis. [3] It is most commonly idiopathic (non-syndromic).
Non-syndromic
The underlying cause of the non-syndromic form is unknown. Over 100 mutations have been associated, including mutations in the FGFR genes. [4] Several potential risk factors have been identified for craniosynostosis include: [5]
Syndromic
Sagittal craniosynostosis is seen in many conditions and syndromes: [7]
Diagnosis of scaphocephaly is with physical exam, which may show characteristic features such as an elongated head in the anterior-posterior dimension, narrow head in the lateral dimension, and bony ridge at the vertex. [8]
Further evaluation with imaging may also be performed. Ultrasound may be used to detect fusion of the suture. CT scans may also be used to help with surgical planning and to diagnose associated hydrocephalus, which has been found to be present in 44% of cases in one study. [9] A measure of cephalic index may also be reduced, however the reliability of measurements may not be a reliable measure. [10]
Scaphocephaly can be classified into specific types, depending on morphology, position, and suture closure: [11]
This condition can be corrected by surgery if the child is young enough, typically within the first 3–6 months. [8] The goal of treatment is to correct intracranial pressure and repair bony deformities. [18] The decision to treat is multifactorial and should be performed at a center with an experienced craniofacial team. [19] In addition to the primary craniofacial surgeon, team members may include audiologists, dentists, otolaryngologists, neurosurgeons, plastic surgeons, and other supporting members. [19]
Surgery is generally aimed at removal of the fused sagittal suture to allow for lateral expansion of the skull. Surgical options include: [8]
The term, from Greek skaphe meaning 'light boat or skiff' and kephale meaning 'head', describes a specific shape of a long narrow head [23] that resembles a boat.
Say–Meyer syndrome is a rare X-linked genetic disorder that is mostly characterized as developmental delay. It is one of the rare causes of short stature. It is closely related with trigonocephaly. People with Say–Meyer syndrome have impaired growth, deficits in motor skills development and mental state.
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.
Brachycephaly is the shape of a skull shorter than average in its species. It is perceived as a cosmetically desirable trait in some domesticated dog and cat breeds, notably the pug and Persian, and can be normal or abnormal in other animal species.
Turricephaly is a type of cephalic disorder where the head appears tall with a small length and width. It is due to premature closure of the coronal suture plus any other suture, like the lambdoid, or it may be used to describe the premature fusion of all sutures. It should be differentiated from Crouzon syndrome. Oxycephaly is a form of turricephaly where the head is cone-shaped, and is the most severe of the craniosynostoses.
Plagiocephaly, also known as flat head syndrome, is a condition characterized by an asymmetrical distortion of the skull. A mild and widespread form is characterized by a flat spot on the back or one side of the head caused by remaining in a supine position for prolonged periods.
Trigonocephaly is a congenital condition due to premature fusion of the metopic suture, leading to a triangular forehead. The premature merging of the two frontal bones leads to transverse growth restriction and parallel growth expansion. It may occur as one component of a syndrome together with other abnormalities, or in isolated form. The term is from the Greek trigonon, "triangle", and kephale, "head".
Crouzon syndrome is an autosomal dominant genetic disorder known as a branchial arch syndrome. Specifically, this syndrome affects the first branchial arch, which is the precursor of the maxilla and mandible. Since the branchial arches are important developmental features in a growing embryo, disturbances in their development create lasting and widespread effects.
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.
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.
Saethre–Chotzen syndrome (SCS), also known as acrocephalosyndactyly type III, is a rare congenital disorder associated with craniosynostosis. 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 abnormalities of the hands and feet (syndactyly). Individuals with more severe cases of SCS may have mild to moderate intellectual 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.
Craniofacial surgery is a surgical subspecialty that deals with congenital and acquired deformities of the head, skull, face, neck, jaws and associated structures. Although craniofacial treatment often involves manipulation of bone, craniofacial surgery is not tissue-specific; craniofacial surgeons deal with bone, skin, nerve, muscle, teeth, and other related anatomy.
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.
The frontal suture is a fibrous joint that divides the two halves of the frontal bone of the skull in infants and children. Typically, it completely fuses between three and nine months of age, with the two halves of the frontal bone being fused together. It is also called the metopic suture, although this term may also refer specifically to a persistent frontal suture.
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.
Cranioplasty is a surgical operation on the repairing of cranial defects caused by previous injuries or operations, such as decompressive craniectomy. It is performed by filling the defective area with a range of materials, usually a bone piece from the patient or a synthetic material. Cranioplasty is carried out by incision and reflection of the scalp after applying anaesthetics and antibiotics to the patient. The temporalis muscle is reflected, and all surrounding soft tissues are removed, thus completely exposing the cranial defect. The cranioplasty flap is placed and secured on the cranial defect. The wound is then sealed.
Acrocephalosyndactyly is a group of congenital conditions characterized by irregular features of the face and skull (craniosynostosis) and hands and feet (syndactyly). Craniosynostosis occurs when the cranial sutures, the fibrous tissue connecting the skull bones, fuse the cranial bones early in development. Cranial sutures allow the skull bones to continue growing until they fuse at age 24. Premature fusing of the cranial sutures can result in alterations to the skull shape and interfere with brain growth. Syndactyly occurs when digits of the hands or feet are fused together. When polydactyly is also present, the classification is acrocephalopolysyndactyly. Polydactyly occurs when the hands or feet possess additional digits. Acrocephalosyndactyly is usually diagnosed after birth, although prenatal diagnosis is sometimes possible if the genetic variation is present in family members, as the conditions are typically inherited in an autosomal dominant pattern Treatment often involves surgery in early childhood to correct for craniosynostosis and syndactyly.
Muenke syndrome, also known as FGFR3-related craniosynostosis, is a human specific condition characterized by the premature closure of certain bones of the skull during development, which affects the shape of the head and face. First described by Maximilian Muenke, the syndrome occurs in about 1 in 30,000 newborns. This condition accounts for an estimated 8 percent of all cases of craniosynostosis.
McGillivray syndrome is a rare syndrome 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.
Craniosynostosis and dental anomalies is an autosomal recessive syndrome characterized by craniosynostosis, maxillary hypoplasia, and dental anomalies. Dental anomalies seen in this condition include malocclusion, delayed and ectopic tooth eruption, and/or supernumerary teeth. Syndactyly, clinodactyly, and other digit anomalies may also be present.
Leptocephaly is a rare form of complex craniosynostosis in which the sagittal and metopic suture simultaneously close. Leptocephaly is characterized by equal narrowing of the head and a tall and narrow head shape. Leptocephaly is usually nonsyndromic, but has been seen in individual cases such as Neu-Laxova syndrome.