Cranial plate

In the 1950s, surgeons discovered that titanium metal was not rejected by the body and so was ideal for mending broken bones. It has been used in operations for hip and knee replacements, inserting cranial plates for skull fractures, and even for attaching teeth, some of... 

The cytotoxic, mutagenic, and sensitizing potential of the cranial plate was evaluated in a series of in-vitro and in-vivo studies. The poly(L-lactide) rivet/pins were not evaluated for biocompatibility because PLA containing devices have been shown to be biocompatible when implanted in animals and because of the long clinical history of safe use of various of PLA devices including bone screws and suture anchors. 

A 3 cm long mid-sagital incision was made through the skin and galea. The periosteum was elevated and an 8-mm diameter trephine craniotomy was made inunediately proximal to the coronal suture in the parietal bone, without dural involvement. The circular cranial plates were secured to the skull and the soft tissues were closed with 4-0 Vicryl suture using simple interrupted stitches. The skin wound was closed in a standard manner with staples. 

A rapidly growing use in the medical field is for surgical implants as either bone plates and screws, joint replacements, or for the repair of cranial injuries. Here, titanium and its alloys have the advantages of complete compatibility with body fluids, low density, and low modulus. Applications also exist in dentistry. 

The central nervous system arises from a thickened area of the ectoderm called the neural plate on day 19 in the human embryo. This process is referred to as induction. The neural plate then differentiates into the neural tube (providing the origins for the brain and spinal cord) and the neural crest (forming the basis of the peripheral nervous system). The process by which the neural tube arises from the neural plate is referred to as neurulation. To form the neural tube, the neural plate changes shape and forms a pronounced groove, closing from the cranial end to the caudal end. The neural tube has openings on both ends that close on about day 25 and day 27, respectively. 

Small cell neuroendocrine carcinomas similar to those seen in the lung are exceptionally rare in the nasal cavity and paranasal sinuses. They affect both sexes equally and occur over a broad age range (38 to 68 years in one studyThey may arise either in the nasal cavity or in the paranasal sinuses, especially the ethmoid and maxilla. Though some tumors will remain localized to the site of origin, higher grade tumors are likely to invade into adjacent structures such as the orbit, cribriform plate, or cranial cavity. 

The neural plate is a pseudostratified epithelivun. Between its caudal tip and the prospective infundibulum, its midline overlies the notochord, which induces the overlying neuroepithelial cells to become the floor plate. Anterior to the infundibulum the neural plate overlies prechordal mesoderm. Lateral to the midline, the neural plate overlies paraxial mesoderm the segmented somitic mesoderm posteriorly (behind the prospective otocyst) and unsegmented cranial paraxial mesoderm anteriorly. 

Fig. 6. Stage 5 (HH), the head process has reached its most cranial position and laid down the prospective head territory. The cells of the epiblast overlying the head process form a pseudostratified epithelium, the medullary plate, and the presumptive neural plate. Hensen s node is clearly asymmetrical. The bilateral heart primodia lie lateral and anterior to the node. (See Color Plate)...

An 8-mm circular trephine defect, centered on the sagital suture line, was made in the calvarium of 42 skeletally mature male New Zealand white rabbits. A cranial fixation burr hole cover plate was attached over the defect site. The absorbable plating and rivet/pin devices were composed of the polymers described above. The metal burr hole cover plate and screws are made of titanium (Bioplate ). 

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