After having spoken of the incisors and the canines, he says that the ten upper molars generally have three roots, and very often four, whilst the ten lower ones have only three; this is because the lower jaw is harder than the upper, and also because the lower molars, _estant assises sur la racine, et non suspendues, comme celles de la mandibule d’en haut, n’avoient besoin de tant de racines pour leur stabilité asseurance_.[300] Ambroise Paré, too, admits that the teeth grow throughout the whole lifetime, and that the wearing away consequent on reciprocal friction and mastication is compensated in this way. Galen had already affirmed, and Ambroise Paré also held erroneously, that the exquisite sensibility of the teeth aids the sense of taste. In speaking of the development of the teeth, Ambroise Paré says only that they are already solid and osseous before birth, he himself having observed this in dissecting the jaws of a child who had died immediately after birth. In Chapter VII, Book XIII,[301] Paré treats of fracture of the lower jaw. The method of cure he proposes is altogether identical with that of Celsus. With regard to the teeth, he says that “_si elles sont divisées, ebranlées, ou separées hors de leurs alvéoles ou petites cavités, elles doivent estre reduites en leurs places et seront liées et attachées contre celles qui sont fermes, avecques un fil d’or ou d’argent, ou de lin. Et les y faut tenir jusques à ce qu’elles soient bien affermies, et le callus soient refait et rendu solide._”[302] Toothache, says Paré,[303] is, of all others, the most atrocious pain that can torment a man without being followed by death. It depends, in many cases, on a humorous fluxion of a hot or cold nature which flows into the alveolus, forcing the tooth outward, loosening it, and causing the patient so much pain on the slightest pressure being exercised on it, that he cannot dare to bite with it in the least. If, however, the tooth is corroded, hollowed out, or pierced to the root, the pain is so strong, when the patient drinks—particularly if the liquid is cold—that he seems to have had a stab with a stiletto inside the tooth. If the pain is acute and pungent, like that produced by needles being thrust into the diseased tooth; if the patient complains of a strong pulsation at the root of the tooth, and in the temples; if the application of cold remedies calms the pain, all these signs indicate that the cause of the evil is heat. Instead, the cause of the pain may be held to be cold when the patient complains of a great heaviness in the head, emits a quantity of saliva, and finds relief in the application of hot remedies. In the treatment of toothache one must fulfil the following three indications: 1. Regulate fittingly the mode of living.