. The Dental cosmos. of the triangle, the central string D re-mains stable at 90 degrees, while the twoother strings E and F can be adjusted at anydesired angle. The cast is placed under the REVIEW OF CURRENT DENTAL LITERATURE. 491 triangle, so that the perpendicular string Dcomes to lie between the central incisors, andthe plate B is lowered so that the stringscome in contact with the teeth. The stringsE and F are then adjusted at equal angles,and by observing whether or not they inter-sect homologous points of homologous teeth,it is at once ascertained whether the teeth onboth sides are situ
. The Dental cosmos. of the triangle, the central string D re-mains stable at 90 degrees, while the twoother strings E and F can be adjusted at anydesired angle. The cast is placed under the REVIEW OF CURRENT DENTAL LITERATURE. 491 triangle, so that the perpendicular string Dcomes to lie between the central incisors, andthe plate B is lowered so that the stringscome in contact with the teeth. The stringsE and F are then adjusted at equal angles,and by observing whether or not they inter-sect homologous points of homologous teeth,it is at once ascertained whether the teeth onboth sides are situated at the same angle, 01 A valuable supplement to this apparatuswas contrived in the form of a transparentmeasuring plate, with triangular graduation,based on the same principle as the symmet-roscope. The author finds this contrivanceto be valuable in studying the illustrationsof cases of malocclusion as published in text-books and journals, showing the conditionsbefore and after regulative treatment, also Fig. whether any of them have deviated linguallyor buccally. The horizontal string H ismoved backward or forward over the graduated lines. If it intersects homologous pointsin every portion of the cast, then the arch issymmetrical. Any irregularities present willbecome evident at a glance at these threeguide strings, and it can be determined ac-curately whether a deviation mesially, dist-al ly, buccally, or lingually has taken the purpose of diagnosis and control ofthe advance made in treatment and of thesuccess obtained in retention, this apparatusseems most practical and accurate. for determining the center of the bar arch,for bending it and examining its symmetricalor asymmetrical position, by simply layingthe celluloid measuring plate on the studymodel. Absolutely accurate results such asare obtained by the symmetroscope cannot,however, be expected from this purely acces-sory measuring plate. [Lancet, London, January 27, 1912.]ALCOHOL INJECTION OF THE GASS
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectdentist, bookyear1912
