Genesis Metopic synostosis occurs in about 0.67 to 14 per 10,000 births. It accounts for 10% to 20% of patients, making it the third most common type of craniosynostosis in the clinic. It is characterized by trigonocephaly, lateral supraorbital retrusion, and hypotelorism. Like sagittal synostosis, metopic synostosis occurs more frequently in males, with a 2 to 6.5:1 male:female ratio reported with no maternal or paternal age…

Genesis Coronal craniosynostosis is the second most common type of craniosynostosis, accounting for 20% to 30% of cases. Constraint-induced unilateral coronal craniosynostosis can be secondary to early descent of the fetal head into a constraining position or aberrant fetal lie or can be caused by constraint within a bicornuate uterus. The majority (67% to 71%) of unilateral coronal craniosynostosis is right-sided, and this nonrandom predilection may…

Genesis Early descent of the fetal head into the maternal pelvis (as early as 4 to 6 weeks before delivery) with fetal head entrapment that results in biparietal constraint is considered the most common cause of sagittal craniostenosis. This mode of genesis is shown in Figure 29-1 . Synostosis limits lateral cranial expansion, resulting in dolichocephaly with progressive frontal and/or occipital prominence ( Fig. 30-1 ),…

Genesis The term craniostenosis (literally translating as “cranial narrowing”) is used to describe the abnormal head shape that results from premature fusion of one or more sutures, whereas craniosynostosis is the process of premature sutural fusion that results in craniostenosis. The term craniosynostosis is used more widely, perhaps in an effort to distinguish deformational nonsynostotic head shapes from those caused by underlying sutural synostosis, but the…

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Genesis Brachycephaly translates literally to “short head” and refers to a head that is shortened in the anteroposterior dimension and wide between the biparietal eminences when viewed from above. The most frequent cause of brachycephaly is constant supine positioning during infancy ( Fig. 27-1 ). The increasing prevalence of brachycephaly in recent years is a consequence of the success of efforts to prevent sudden infant death…

Genesis The postmortem diagnosis of sudden infant death syndrome (SIDS) was introduced midway through the twentieth century, but its association with infant sleeping position was not established until the 1990s. Sudden infant death syndrome is considered to have a multifactorial basis whereby some infants are born with risk factors that make them more vulnerable to dying during infancy. African-American and Native American infants are more than…

Genesis Plagiocephaly , which literally translates from the Greek term plagio kephale as “oblique head,” is a term used to describe asymmetry of the head shape when viewed from the top ( Fig. 25-1 ). It is a nonspecific term that has been used to describe head asymmetry caused by either premature sutural fusion or postnatal head deformation resulting from a positional preference; hence, modifying terms…

Genesis The term torticollis is derived from the Latin terms torus , meaning “twisted,” and collum , meaning “neck,” and it refers to the posture that results from the head being twisted and turned to one side. This is most often caused by a congenital asymmetry in the length and/or strength of the sternocleidomastoid (SCM) muscles on each side of the neck, which must be distinguished…

Genesis Congenital compression of the chin against either the chest or intrauterine structures may limit the growth of the jaw before birth, and when asymmetric, jaw retrusion is more commonly left-sided ( Fig. 23-1 ). If the compression is of prolonged duration, there may be pressure indentation or skin necrosis on the upper thoracic surface. As shown in Fig. 23-1 , one deformational cause of asymmetric…

Genesis Overfolding of the upper helix and/or other parts of the cartilaginous auricle are common constraint-related deformations, as is flattening of the ear against the head ( Figs. 22-1 and 22-2 ). Prolonged constraint of the external ear may also result in asymmetric overgrowth of the ear. Ear enlargement is commonly observed on the side opposite the muscular torticollis in torticollis-plagiocephaly deformation sequence ( Fig. 22-3…

Genesis A small nose may result from constraint-related limitation of nasal growth in a face presentation, transverse lie or from compression resulting from a small uterine cavity. A compressed nose is also a feature of oligohydramnios and severe crowding, such as can occur in a bicornuate uterus ( Fig. 21-1 ). Infants born to mothers with a bicornuate uterus have about a fourfold greater risk of…

Genesis Scoliosis is the most common deformity of the spine, and it is defined as a lateral curvature of the spine that is 10 degrees or greater on a standing coronal radiographic image. Congenital scoliosis is caused by a failure of vertebral segmentation, which may lead to progressive spinal deformity with growth. Neuromuscular scoliosis is caused by central nervous system dysfunction (e.g., spastic quadriplegia), peripheral neuromuscular…

Genesis Pectus excavatum and pectus carinatum are the most common abnormalities of the thorax. The incidence of pectus excavatum is between 1 and 8 per 1000 persons, and pectus carinatum is two to four times less frequent than pectus excavatum, with a significant male to female excess for both pectus carinatum and pectus excavatum. If no features of an underlying disorder are detected, then the pectus…

Genesis Lung hypoplasia implies an abnormal reduction in the weight and/or volume of the lung without the absence of any of its lobes; this condition is different from agenesis or aplasia of the lungs. Lung hypoplasia can result from various phenomena. During the fourth week of gestation, the laryngotracheal groove forms in the esophageal portion of the endotracheal tube, and shortly thereafter lung development begins with…

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Genesis Eventration of the diaphragm is defined as the abnormal elevation of the diaphragm. It may originate from a congenital defect or may be acquired. Congenital eventration is a rare developmental abnormality characterized by muscular aplasia or hypoplasia of the diaphragm. Acquired eventration is caused by injury to the phrenic nerve with resultant paralysis and elevation of the entire diaphragm. The paralysis may be secondary to…

Genesis The frequency of brachial plexus palsy has been decreasing with improved obstetric management from 1 per 1000 births before 2000, to 0.5 per 1000 births after 2000. Supraclavicular traction or stretching of the brachial plexus during delivery can injure nerve fibers; hence this injury is sometimes termed obstetric palsy . Historically risk factors have included shoulder dystocia, fetal macrosomia, labor abnormalities, forceps or vacuum delivery,…

Genesis Prolonged compression or stretching of a peripheral nerve may lead to compression palsy, apparently on the basis of neural ischemia. The frequency of congenital facial palsy is 0.71 to 1.4 per 1000. The mechanism of injury is usually either direct trauma from delivery or compression of the side of the face and nerve against the sacral promontory, with the side of the injured facial nerve…

Genesis Dislocation of the radial head is the most common congenital anomaly of the elbow, but it is relatively rare, accounting for 0.15% to 0.2% of outpatient orthopedic visits. It can occur as an isolated abnormality or as part of a number of different syndromes. The presence of associated anomalies and bilateral involvement suggests a congenital joint dislocation syndrome. Some authors believe that many unilateral cases…