. The Dental cosmos. be carriedto the usual height, that is, as high asit can be borne with comfort, and withoutabrading the cheek. Opposite the secondbicuspids and molars the flange shoulddescend from the top margin at an in-clination of between 20 and 30 degreesto the vertical, sloping outward. Thisabrupt slope enables the plate to escapethe downward displacing action of thebuccinator. Then, at a short distanceabove the necks of the teeth, the flangetakes an inward turn which reaches thenecks of the teeth in a curve. The flangethus produced is intended to lie over thebulge of the muscle, and
. The Dental cosmos. be carriedto the usual height, that is, as high asit can be borne with comfort, and withoutabrading the cheek. Opposite the secondbicuspids and molars the flange shoulddescend from the top margin at an in-clination of between 20 and 30 degreesto the vertical, sloping outward. Thisabrupt slope enables the plate to escapethe downward displacing action of thebuccinator. Then, at a short distanceabove the necks of the teeth, the flangetakes an inward turn which reaches thenecks of the teeth in a curve. The flangethus produced is intended to lie over thebulge of the muscle, and so catch itsretention. The original contour of the natural upper alveolar margin is thus ap-proximately restored, while no attempt ismade to locate the teeth themselves other-wise than in the usual artificial denture;that is to say, they will be placed insidethe line of the natural teeth. Generally the alveolar ridge is of sucha shape that the plate naturally lies overthe buccinator bulge, and all we have to Fig. Sectional diagram in molar region, showingcheek overlying the flanges. do is to insure that this tendency is ac-centuated in shaping the plate. Mis-management may result in the buccinatordisplacing the denture instead of sup-porting it. OVERCOMING DISPLACING ACTION OFCHEEK MUSCLES. Much has been written of this dis-placing action of the cheek muscles, but itis only necessary so to arrange the flangethat it receives support from the muscle,while the teeth themselves are protectedfrom the too strong pressure which wouldhave a displacing effect. This may beeffected in various ways. The flange maybe made extra prominent, or the teethmay be set a little farther in, or again, theteeth may be shortened and the flangebrought farther down. But in whateverway it is managed, the pressure under HILLYER.—rROSTHETIC DENTISTRY AND THE CASTING PROCESS. 879 the flange must be greater than the pres-sure on the teeth, or above the flange. COMPENSATING FOR THE SETTLING OFDENTURES I
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectdentist, bookyear1912
