In obstetrics, the term flexion point refers to a spot on the fetal head on which the cup of a ventouse should to be placed for extraction of the child to be most effective.
When the cup of the ventouse is applied on the flexion point, the fetal head will remain flexed under traction, hence the name flexion point.
The flexion point is located on the sagittal suture, 3 cm (about 1 inch) forward of the posterior fontanelle. [1]
A fontanelle is an anatomical feature of the infant human skull comprising any of the soft membranous gaps (sutures) between the cranial bones that make up the calvaria of a fetus or an infant. Fontanelles allow for rapid stretching and deformation of the neurocranium as the brain expands faster than the surrounding bone can grow. Premature complete ossification of the sutures is called craniosynostosis.
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 skull in the occipital bone, there is a large oval opening called the foramen magnum, which allows the passage of the spinal cord.
The parietal bones are two bones in the skull which, when joined together at a fibrous joint, form the sides and roof of the cranium. In humans, each bone is roughly quadrilateral in form, and has two surfaces, four borders, and four angles. It is named from the Latin paries (-ietis), wall.
Vacuum extraction (VE), also known as ventouse, is a method to assist delivery of a baby using a vacuum device. It is used in the second stage of labor if it has not progressed adequately. It may be an alternative to a forceps delivery and caesarean section. It cannot be used when the baby is in the breech position or for premature births. The use of VE is generally safe, but it can occasionally have negative effects on either the mother or the child. The term comes from the French word for "suction cup".
Craniosynostosis is a condition in which one or more of the fibrous sutures in an infant 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.
A sagittal plane, or longitudinal plane, is an anatomical plane which divides the body into right and left parts. The plane may be in the center of the body and split it into two halves (mid-sagittal) or away from the midline and split it into unequal parts (para-sagittal).The anatomical term sagittal was coined by Gerard of Cremona.
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.
The sagittal suture 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. The derivation of this term may be demonstrated by observing how the sagittal suture is notched posteriorly, like an arrow, by the lambdoid suture. The sagittal suture is also known as the interparietal suture, the sutura interparietalis.
The coronal suture is a dense, fibrous connective tissue joint that separates the two parietal bones from the frontal bone of the skull.
The superior sagittal sinus, within the human head, is an unpaired area along the attached margin of the falx cerebri. It allows blood to drain from the lateral aspects of anterior cerebral hemispheres to the confluence of sinuses. Cerebrospinal fluid drains through arachnoid granulations into the superior sagittal sinus and is returned to venous circulation.
The bregma is the anatomical point on the skull at which the coronal suture is intersected perpendicularly by the sagittal suture.
The posterior fontanelle is a gap between bones in the human skull, triangular in form and situated at the junction of the sagittal suture and lambdoidal suture. It generally closes in 6–8 weeks from birth. The cranial point in adults corresponding the fontanelle is called 'lambda' A delay in closure is associated with congenital hypothyroidism.
The anterior fontanelle is the largest fontanelle, and is placed at the junction of the sagittal suture, coronal suture, and frontal suture; it is lozenge-shaped, and measures about 4 cm in its antero-posterior and 2.5 cm in its transverse diameter. The fontanelle allows the skull to deform during birth to ease its passage through the birth canal and for expansion of the brain after birth.
Cruciate ligaments are pairs of ligaments arranged like a letter X. They occur in several joints of the body, such as the knee joint and the atlanto-axial joint. In a fashion similar to the cords in a toy Jacob's ladder, the crossed ligaments stabilize the joint while allowing a very large range of motion.
Fibrous joints are connected by dense connective 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.
The calvaria or skullcap is the top part of the skull. It is the upper part of the neurocranium and covers the cranial cavity containing the brain. It forms the main component of the skull roof.
Obstetrical forceps are an instrument that can be used to assist in the delivery of a baby as an alternative to the ventouse method.
The occipital angle is rounded and corresponds with the point of meeting of the sagittal and the lambdoid suture—a point which is termed the lambda ; in the fetus this part of the skull is membranous, and is called the posterior fontanelle.
A cephalic presentation or head presentation or head-first presentation is a situation at childbirth where the fetus is in a longitudinal lie and the head enters the pelvis first; the most common form of cephalic presentation is the vertex presentation where the occiput is the leading part. All other presentations are abnormal (malpresentations) which are either more difficult to deliver or not deliverable by natural means.
The fetal head, from an obstetrical viewpoint, and in particular its size, is important because an essential feature of labor is the adaptation between the fetal head and the maternal bony pelvis. Only a comparatively small part of the head at term is represented by the face. The rest of the head is composed of the firm skull, which is made up of two frontal, two parietal, and two temporal bones, along with the upper portion of the occipital bone and the wings of the sphenoid.