Fracture of the maxilla tuberosity may occur during the removal of the third upper molar, and Mr. Nicol[7] records such an accident during the removal of the second upper permanent molar. In a case recorded by Mr. L. Matheson[8] a transverse fracture of the maxilla occurred in a line between the first and second permanent molars during the removal of the first-named tooth. Direct transverse fracture of the horizontal ramus of the mandible due to extraction of the teeth has also been recorded. _Treatment._--In fracture of small portions of the alveolar process, no special treatment is called for except that all loose fragments should be removed. When the fracture is of a more extensive character, the fragments must be retained in position by a suitable form of splint, a description of which will be found in most works on dental surgery. (_b_) =Necrosis= of the alveolus may result from extraction and is generally the result of undue violence or of some septic process occurring in the wound. The _treatment_ to be followed consists of the use of antiseptic and deodorant mouth washes; the necrosed bone when quite separated from the living tissue should be removed with a pair of suitable forceps. (_c_) =Dislocation of the mandible.=--The use of too much force in extracting a lower tooth and not at the same time counteracting the force by supporting the chin, may lead to unilateral or bilateral dislocation of the mandible. This accident may also be brought about by forcing the mouth open too much with a Mason’s gag during the administration of an anæsthetic. It may likewise occur without the employment of undue force in those who have previously met with or are liable to dislocation. _Reduction_ may be brought about by placing the thumbs, carefully wrapped in a napkin, on the molar teeth and the palmar surfaces of the fingers below the chin. If downward pressure is then made with the thumbs, and upward pressure with the fingers, the condyles of the mandible will generally pass back easily into the glenoid cavity. In cases where more difficulty than this is experienced, the patient should be placed in a recumbent position, and corks should be inserted between the back teeth. Upward pressure should then be applied on the under surface of the chin. It is advisable, after reduction, for the patient to wear a four-tailed bandage for about a week. (_d_) =Forcing a root into the antrum.=--This accident occurs mostly in connection with the extraction of the second upper bicuspid root and buccal roots of the first upper permanent molar. If a root has been so dislocated into the antral cavity as to still partly remain in its socket, the best course to pursue is to leave it alone and not to attempt removal as the attempt might only result in complete dislocation of the root into the antrum. The socket should be kept quite clean by the continual use of antiseptic washes. As a rule the root gives rise to no subsequent trouble.