. The science and practice of dental surgery. Fig. lill. pletely unopposed, there are developedabnormally long slidmg contacts betweenthem and partially opposing teetli. Thismeans that the lateral stress is here in-creased in the range of its action; andabnormal wearmg or loosening results. Fig. 611 shows a case where the frontteeth developed an abnormally long over-bite, owing to loss of opposition betweenupper and lower back teeth. As the over-bite in front became deeper and deeper,tlie lateral stresses, outwards m the upperand inwards in the lower, came to actover a greater and greater rang
. The science and practice of dental surgery. Fig. lill. pletely unopposed, there are developedabnormally long slidmg contacts betweenthem and partially opposing teetli. Thismeans that the lateral stress is here in-creased in the range of its action; andabnormal wearmg or loosening results. Fig. 611 shows a case where the frontteeth developed an abnormally long over-bite, owing to loss of opposition betweenupper and lower back teeth. As the over-bite in front became deeper and deeper,tlie lateral stresses, outwards m the upperand inwards in the lower, came to actover a greater and greater range of slidingcontact; as well as bemg absolutely in-creased on these teeth, owing to thediminished number of teeth result is seen in the unnatural spacingof Fig. 612 shows tlie lower arch of the samecase. Here the lateral stress that forced for-. FiG. Cil2. This difference in the effect of the same forceacting on upper and lower incisors is frequentlyseen, since, as already pointed out, it is mucheasier to force the units of an arch out bypressure from withui, than to force them in bypressure from w ithout. So, in the latter case, tlieforce rather exhausts itself in wearing the teeth. Fig. 613 shows undue approximation of thejaws owing to loss of opposition between backteeth. This has developed increased stressesin the incisor and canine region, resulting inforward movement and spacing of the upperfront teeth. It also shows that as the bitehas closed, an abnormally long slidmg contacthas_been developed between the distal surfaceof 5 j and the medial surface of 5 I partlyarticulating with it. The displacement back-
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectdentistry, bookyear19
