The Dental cosmos . which the patient was capablewas registered at four pounds and two ounces. The involuntary orhabitual tendency of the jaw to drop equaled an average force of alittle less than one pound. An examination of all the accessible text-books disclosed no meas-urements of the dynamic powers of this group of muscles under likecircumstances, and hence I infer the novelty of both theory and prac-tice in the course and constructions adopted in this case. The first procedure was to fit and adjust upper and lower electro- DENTAL DEVICES FOR CORRECTING DEFORMITY, ETC. 733 metallic plates
The Dental cosmos . which the patient was capablewas registered at four pounds and two ounces. The involuntary orhabitual tendency of the jaw to drop equaled an average force of alittle less than one pound. An examination of all the accessible text-books disclosed no meas-urements of the dynamic powers of this group of muscles under likecircumstances, and hence I infer the novelty of both theory and prac-tice in the course and constructions adopted in this case. The first procedure was to fit and adjust upper and lower electro- DENTAL DEVICES FOR CORRECTING DEFORMITY, ETC. 733 metallic plates provided with retracting spiral springs of gold wire,but this contrivance was abandoned as being too bulky and lackingsufficient tensile strength in the springs to draw the jaw into position andretain it during the process of mastication. Several devices were thentried in various ways, including an inclined plane of steel. The final planwas to make for the superior left molars two gold cap-crowns, which were Fig. soldered together, and at their buccal junction there was soldered astiff and knobbed gold wire projecting downward at an angle of aboutforty-five degrees. A gold cap-crown was also made for the inferiorleft cuspid, and to the labial surface of the crown was soldered anothershort knobbed gold wire extending in the direction of normal occlu-sion. A steel spring similar to that used in the flexible connection ofthe dental engine with the hand-piece was repeatedly cut off and tested. 734 THE DENTAL COSMOS. until the required resilient power was found in a length of thirty-twocoils. This spring was electro-plated, and the looped ends slippedover the knobs on the crowns, which had been previously cementedonto the molars and cuspid respectively. The action of the device wasvery gratifying, for when the patient closed her mouth the remainingteeth were brought into normal apposition, as represented in Fig. 4,and were so retained by the action of the spring. The great menta
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Keywords: ., bookauthor, bookcentury1800, bookdecade1890, booksubjectdentistry
