Vesalius, for the first time, dared to unveil and clearly put in evidence the errors of Galen; but this made him many enemies among the blind followers and worshippers of that demigod of medicine. Europe resounded with the invectives that were bestowed upon Vesalius. Among others, there rose against him Eustachio at Rome, Dryander at Marburg, Sylvius at Paris, and this last did not spare any calumny that might degrade his old pupil, who had become so celebrated. In spite of this, the fame of Vesalius kept on growing more and more, so much so that Charles V called him to Madrid, to the post of chief physician of his Court, a place which he kept under Philip II, also after the abdication of Charles V. The good fortune of Vesalius, unhappily, was not to be of long duration. In 1564 a Spanish gentleman died, in spite of the care bestowed upon him by Vesalius, and the illustrious scientist requested from the family, and with difficulty obtained, the permission to dissect the body. At the moment in which the thoracic cavity was opened the heart was seen, or thought to be seen, beating. The matter reached the ears of the relations of the deceased, and they accused Vesalius, before the Inquisition, of murder and sacrilege; and he certainly would not have escaped death except by the intervention of Philip II, who, to save him, desired that he should go on a pilgrimage to the Holy Land, as an expiation. On his return, the ship which carried Vesalius was wrecked, and he was cast on a desert beach of the Isle of Zante, where, according to the testimony of a Venetian traveller, he died of hunger, October 15, 1564.
Vesalius left to the world an immortal monument, his splendid treatise on Anatomy,[282] published by him when only twenty-eight years of age, and of which, from 1543 to 1725, not less than fifteen editions were issued. The appearance of this work marked the commencement of a new era. The struggle between the supporters of Galen and those of Vesalius rendered necessary, on both sides, active research concerning the structure of the human body, so that anatomy, the principal basis of scientific medicine, gradually became more and more perfect, and, as a consequence of this, as well as of the importance which the direct observation of facts acquired over the authority of the ancients, there began in all branches of medicine a continual, ever-increasing progress, which gave and still gives splendid results, such as would have been impossible under the dominion of Galenic dogmatism.
In the great work of Vesalius the anatomy of the teeth is unfortunately treated with much less accuracy than that of the other parts of the body. However, his description of the dental apparatus[283] is far more exact than that of Galen, and represents real progress. The number of the roots of the molar teeth (large and small) is indicated by Galen in a very vague and inexact manner, since he says that the ten upper molars have generally three, sometimes four roots, and that the lower ones have generally two, and rarely three. Vesalius, having examined the teeth and the number of their roots in a great number of skulls, was able to be much more precise. In regard to roots, he makes, for the first time, a very clear distinction between the premolars next to the canine (small molars) and the other three, and says that the former in the upper jaw usually have two roots, and in the lower, one only, whilst the last three upper molars usually have three roots and the lower ones two. As everyone sees, these indications are, in the main, exact.
Other important facts established by Vesalius are as follows:
The canines are, of all the teeth, those which have the longest roots. The middle upper incisors are larger and broader than the lateral ones, and their roots are longer. The roots of the last molars are smaller than those of the two preceding molars. In the penultimate and antepenultimate molars, more often than in the other teeth, it sometimes happens that a greater number of roots than usual are found, it being not very rare to meet with upper molars with four roots, and lower ones with three. The molars are not always five in each half jaw; sometimes there are only four, either on each side, or on one side only, in only one jaw or in both. Such differences generally depend on the last molar, which does not always appear externally, remaining sometimes completely hidden in the maxillary bone, or only just piercing with some of its cusps the thin plate of bone which covers it; a thing which Vesalius could observe in many skulls in the cemeteries.
In regard to the last molar, the author speaks of its tardy eruption and of the violent pains which not unfrequently accompany it. The doctors, he adds, not recognizing the cause of the pain, to make it cease have recourse to the extraction of teeth, or else, attributing it to some defects of the humors, overwhelm the sufferer with pills and other internal remedies, whereas the best remedy would have been the scarification of the gums in the region of the last molar and sometimes the piercing of the osseous plate which covers it.
This curative method, of which no one can fail to recognize the importance, was experimented by Vesalius on himself, in his twenty-sixth year, precisely at the time that he had just begun to write his great treatise on anatomy.
The existence of the central chamber of the teeth appears to have been unknown to Galen, as he does not allude to it in the least. Vesalius was the first to put this most important anatomical fact in evidence. He expresses an opinion that the central cavity facilitates the nutrition of the tooth. He says, besides, that when a hole is produced in a tooth by reason of acrid corrosive humors, the corrosion, when once the internal cavity is reached, spreads rapidly and deeply in the tooth, owing to the existence of the said cavity, and sometimes reaches even the end of the root.
In the chapter in which Vesalius treats of the anatomy of the teeth (Chapter XI, p. 40), two very well-drawn figures are found, one of which represents a section of a lower molar, showing the pulp cavity and its prolongation into the two root canals. The other represents the upper and lower teeth of the right side, in their reciprocal positions, and shows very clearly their general shape, the length of their roots, and the number of these.