Genesis In face and brow presentations, the face is the compressed presenting part, usually with extension of the head ( Fig. 44-1 ). Face presentation occurs in 1 to 2 per 1250 deliveries, and persistent brow presentation is less common.…
Genesis Transverse lie is the second most common non-vertex presentation and occurs in 12 per 1000 deliveries. It is associated with multiparity (90%), prematurity (13%), placenta previa (11%), polyhydramnios (8%), uterine anomalies (8%), and uterine myomas (3%), especially when myomas…
Genesis The frequency of singleton breech presentation at term is 3.1% and rises to 6.2% when multiple births are included. Breech presentation is an important cause of deformation, and fully one third of all deformations occur in babies who have…
Genesis Wormian bones are accessory bones that occur within cranial suture lines, and, although they do not cause any impairment themselves, their significance is variable. The prevalence varies by size and quantity. Individuals with few and small (less than 4 mm)…
Genesis Cephalohematoma is a common problem occurring in about 2.5% of newborns. It is a subperiosteal extracranial hemorrhage that may enlarge after delivery, sometimes taking weeks to resolve. This condition contrasts with the scalp edema of caput succedaneum, which reaches…
Genesis Aplasia cutis congenita (ACC) is a congenital, localized absence of skin that most commonly affects the scalp. The frequency is 1 per 3000 live births and this condition can occur in isolation or as part of a heterogeneous group…
Genesis Parietal foramina are a rare calvarial defect estimated to be less than 1 in 25,000 births. They present as symmetric oval defects situated on either side of the sagittal suture near the parietal eminences and separated from each other…
Genesis On very rare occasions, the anterior fontanel will ossify into a bony plate that may be slightly elevated in relation to the rest of the cranium. This may occur because of decreased growth-stretch tensile forces across the anterior fontanel…
Genesis Prolonged forceful pressure on the presenting part, usually at the vertex affecting the superior portions of the parietal bones, may result in diminished mineralization within the compressed region. The calvarium is generated from the underlying dura mater, and persistent…
Genesis Vertex birth molding describes the mechanical changes in fetal head shape caused by external compression on the cranium from bony adjustments within the cranial vault that occur as the neonate in vertex presentation passes through the birth canal. Additional…