Cementum

“ We are taught that a cement filling is not a permanent one, and especially should not be used below the gum border; but we are advised to use open-face crowns and to set them on with cement. If cement will not last when put into a cavity of a tooth at the gum line, we should hardly imagine that it would last very long when only protected by a thin gold band placed below the gum line, where secretions have continual play at it. ”

“ In the Museum of the Royal College of Surgeons in London there is an intestinal concretion weighing 470 grains, which was passed by a woman of seventy who had suffered from constipation for many years. Sixteen years before the concretion was passed she was known to have swallowed a tooth. At one side of the concretion a piece had been broken off exposing an incisor tooth which represented the nucleus of the formation. Manasse recently reported the case of a man of forty-four whose stomach contained a stone weighing 75 grams. ”

“ Such cysts are generally of small size, and pyriform shape; externally they are smooth, membranous, and of rather a delicate texture; internally, they are lined by lymph of soft consistence, and contain purulent matter. In fact, they are purulent depôts, which form in consequence of inflammation around the fangs of the teeth, and from which the matter is occasionally discharged through a small aperture at the upper part of the cyst, and by the side of the affected tooth. They sometimes attain a very considerable size. ”

“ Six months later the patient had recurrence of pain in the same tooth of two months’ duration; it was extracted and pus continued to exude from the socket. A probe, passed 21⁄2 centimeters to the floor of the nose and septum, showed a cavity covered with membrane in the anterior parts of upper jaw, which was a cyst at the root of the tooth. The anterior cyst walls were removed with bone forceps, and the remainder scraped. The cavity gradually healed.
The cyst probably broke through under the septal mucous membrane. ”

“ The shading of the thin walls by the amalgam is absolutely prevented by the cement. I have in my own mouth a molar in which the filling was loosened by mastication five times on account of the cavity being one of the kind where reliable anchorage could not be obtained. The pulp finally became exposed from frequent cutting away of tooth structure, and the sixth filling was anchored by taking advantage of the pulp chamber, or a portion of it. To use cement as anchorage for amalgam, this is the process: Mix the amalgam according to your custom ”

“ The so-called enamel layer is a simple product of the thickening and calcification of the basement membrane, and since this membrane is derived from the mucous layer of the epidermis, the enamel is clearly to be viewed as an epidermic product. There is no indication of a gradual conversion of the bases of the columnar cells forming the mucous layer of the epidermis into enamel prisms, as is frequently stated to occur in the formation of the enamel of the teeth in higher Vertebrates. ”

“ Turn the great omentum up on the chest wall, exposing the underlying intestines. This manipulation, as already stated, will cause the omentum to carry the transverse colon with it, on account of the adhesion, in the adult, of the gut to the dorsal layer of the omentum. Hence the cephalic or upper layer of the transverse mesocolon will not be seen at this stage because the omental adhesion just referred to prevents us from passing between the greater curvature of the stomach and the transverse colon without tearing peritoneal layers. ”

“ In the brachyodont or low-crowned tooth, such as a human molar, the cement merely forms a sheath over the roots and does not appear upon the crown, but in many hypsodont teeth, those of horses and elephants, for example, the cement completely encases the entire tooth in a thick layer, filling up all the depressions and irregularities of the enamel surface and making a freshly erupted and unworn tooth look like a shapeless lump. ”

“ In order to incise the peritoneum without damaging the tumour, cyst, or intestine, a fold of the membrane is picked up with forceps and cautiously pricked with the point of a scalpel; air rushes in, destroys the vacuum, and generally produces a space between the cyst (or intestines) and the belly-wall; the surgeon then introduces his finger, and divides the peritoneum to an extent equal to the incision in the skin.
It is important to remember that the bladder is sometimes pushed upward by tumours, and lies in the subperitoneal tissue above the pubes; it is then liable to be cut. ”

“ It is doubtful if anything but sound tissue could have withstood the strain that was put upon this man's diseased cecum from gas distention. The infection-laden gas could find a way anywhere in diseased tissue and broken continuity. Why should the pus break through the adhesions and find its way into the peritoneum after they had been able to make an effectual resistance till the bulk of it had forced a passage into the bowel? Why should the adhesions have less power to resist when there is less strain upon them and also a patent outlet for the pus? ”

“ The foreign body is easily removed; an incision is made through the membrane of the mouth, and the concretion dislodged by forceps, a scoop, or the fingers. The saliva regains its course, and irritation subsides. Sometimes the foreign body is exposed by ulceration, and might ultimately escape from its bed spontaneously.
A figure of a salivary calculus of considerable size is here given. When the concretion is small, its extraction is not so easily accomplished as might be supposed. ”

“ As the individuals grow and increase in size, so do the glands and cement-ducts; but it seems often to happen, that when a specimen is immovably attached, the cementing apparatus ceases to act, and the cellular contents of the duct become converted into a thread of transparent tough cement; the investing membrane, also, of the ducts, in Conchoderma sometimes becomes hard and mamillated. I have already alluded to the case of a Pollicipes, in which both glands and ducts, and even a small portion of the two adjoining ovarian tubes, had become thus filled up. ”

“ I have given a figure (Pl. 28, fig. 3) of three of the cement-glands, removed from the basal membrane, together with their ducts. The cement-trunk (f f) seemed to be a little enlarged, and to be crossed by septa, as it entered the glands (h) , but I could not make out this structure clearly enough to be represented. Whilst young, the cement-glands stand some little way apart from each other; and in the figure given of some of the last-formed glands, they are hardly separate enough. ”

“ Protection of the Intestines and Omentum.—During all manipulations within the abdomen the peritoneum, intestines, and omentum should be handled most gently. Injury of the peritoneum increases the danger of shock, sepsis, and intestinal adhesions. The intestines should never be allowed to protrude through the abdominal incision unless it is necessary for the performance of the operation. Such a necessity rarely, if ever, arises in gynecological operations. All the intestines may be removed from the field of operation—the pelvis—by placing the woman in the Trendelenburg position. ”

“ Magnesia, insoluble pills, and other medicines sometimes form concretions in the bowel. Enteroliths and accidental concretions form in the intestinal canal and are sources of obstruction. Any foreign body is a nucleus around which concentric layers of phosphate of lime are deposited, and thus a hard calculus is formed. Gall-stones may pass into the canal and there accumulate in such numbers as to interfere with the passage of the fecal matter. ”

“ In hernia with a very small orifice the omentum alone may pass through, even the small intestine proving too large for admission. In such cases it is usual to find the band of omentum adherent to the callus formed by the repair of a fractured rib. 366When the orifice is somewhat larger a portion of small intestine or of the double colon or cæcum may be engaged, while with a still larger opening the stomach, spleen, or liver may form the hernia. In cattle the reticulum is most likely to be the hernial mass, as noted in an article below. ”

“ The constant dilating of the cecum from gas accumulations and the forced dilations from diarrheas made either from drugs or irritating foods, must not only damage the cecum but the appendix as well; for the appendix opens into this part of the intestine and it is reasonable to believe that it suffers distention from gas and that toxic secretions are driven into it. When its function is not interfered with by an unusual pressure as from constipation, no doubt it can empty itself and does do so. ”

“ I have not followed the centrosome through its migrations. In fig. 2 one of the two bodies is the centrosome, but I did not trace its changes farther.
5.—Cell Body.
The cells, up to the stage of figs. 13 or 14, have been scattered promiscuously through the cyst; but as the cell begins to elongate, the one end becomes the anterior-nuclear end, and it shifts to the periphery of the cyst. The central part of the cyst now shows the so-called central lumen. As the lengthening goes on the heads of the forming spermatozoa are all turned toward the distal end of the cyst. ”

“ The incision, about an inch in length, was closed with a single stitch of silk thread, and after thorough cleansing the whole mass was returned to the abdominal cavity. In this hernial protrusion were recognized four or five feet of the ileum, the cecum with its appendix, part of the ascending colon with corresponding portions of the mesentery; the distribution of the superior mesentery, made more apparent by its living pulsation, was more beautifully displayed in its succession of arches than in any dissection that Doughty had ever witnessed. ”

“ Their true significance and their influence on the adult anatomical arrangement of the abdomen is, however, only appreciated when the changes in the arrangement of the peritoneal membrane which they involve, are taken into account.
The dorsal mesogastrium changes more than any other portion of the peritoneum in the course of development. It not only becomes displaced and altered in direction by the rotation of the stomach, but in addition it grows so extensively that it finally hangs down like an apron over the entire mass of small intestines, forming the great omentum. ”

“ All the coats are affected, but particularly the muscular; the surface becomes fasciculated; the fibres grow fleshy and strong, and are collected in large bundles. Cysts form, often of a large size; some are caused by interlacement of the enlarged muscular fibres, others are produced by outward protrusion of the mucous coat. This membrane being, by excessive muscular action in the viscus, pushed between the enlarged fasciculi, dilates into a bag, and forms a cyst of greater or less size, communicating with the cavity of the bladder, generally by a narrow neck ”

“ The oral or buccal cavity into which the mouth leads is a stomodaeum, and is lined by inpushed epidermis, while the hinder portion of the cloaca and the anus are lined by a somewhat similar inpushing of the epidermis which forms the proctodaeum. The rest of the alimentary canal, consisting in succession of a pharynx, an oesophagus, a stomach, and an intestine, constitutes the mesenteron, and is lined by endoderm. Teeth are developed from the walls of the stomodaeum, and glands for the secretion of digestive fluids from the endoderm of the mesenteron. ”

“ In medicine, a hard concretion formed within the animal body by the deposition of matters which usually remain in solution. The concretions most commonly found are those formed in the kidneys or bladder, and termed urinary calculi, and those formed in the gall-bladder or biliary ducts, which are called biliary calculi. Urinary calculi are in most cases composed of substances which are constituents of healthy urine, such as uric acid, urate of ammonia, and the phosphates of lime and magnesia ”

“ The lymphnodes may be opened by longitudinal or transverse incisions.
The left adrenal and kidney are now examined. If the pancreas and stomach have not been removed from the body they are turned over toward the thoracic cavity, so as to expose completely the left adrenal. The movability of the kidney is then tested. [Pg 146] Beginning above the adrenal an incision is made through the peritoneum and underlying tissue, curving outward around the kidney and downward to its lower pole, taking care not to bring the incision too far around the lower pole of the organ for fear of cutting the ureter. ”

“ The fluid is generally glairy, sometimes thick and gelatinous, often turbid and dark coloured. Not unfrequently the main cyst is subdivided, either by membranous septa, or by an aggregation of smaller cysts of the nature of hydatids. The swelling is at first on one side, and gradually rises out of the pelvis; often it remains long moveable; it increases, becomes more fixed, and ultimately fills the abdomen, displacing the viscera, and giving rise to feelings of much uneasiness, deformity, and loss of health. ”

“ Encystment, or at least a resting stage at full growth, is very characteristic, and frequently an excretion of granules takes place into the first-formed cyst, whereupon a second inner cyst is formed which may be followed by a third. These brood-cysts, in which multiple fission takes place, may be of two kinds, ordinary and resting, the latter being distinguished by a firm, and usually ornamented and cuticularized cell-wall, and only producing its zoo spores after an interval. ”