. The science and practice of dental surgery. that is commencing to thicken to form thecingulum. Variation in the amount of thisoverlap may occur in either direction, and thequestion at once arises, whether the abnormalityexists m that part of the arch where it is mostapparent, namely, the anterior portion, or whe-ther the posterior region is also mvolved. It is probable that in a few cases the defectoccurs in connection with, and is reaUy limited to,the incLsor region only; but undoubtedly in mostcases the bony development of the ascendmgranius or angle of the mandible or posterior por-tion o
. The science and practice of dental surgery. that is commencing to thicken to form thecingulum. Variation in the amount of thisoverlap may occur in either direction, and thequestion at once arises, whether the abnormalityexists m that part of the arch where it is mostapparent, namely, the anterior portion, or whe-ther the posterior region is also mvolved. It is probable that in a few cases the defectoccurs in connection with, and is reaUy limited to,the incLsor region only; but undoubtedly in mostcases the bony development of the ascendmgranius or angle of the mandible or posterior por-tion of the maxilla is at fault, and the anteriordefect is a necessary consequence. Li some ofthe latter it is clear that secondary changesoccur later in the development of the incisorregion, and produce conditions that simulatecases of malformation due to difierent causes. («) Open Bite.—The extent to which the teethfail to occlude may vary between a small lOS separation of the incLsors and awhich only the second molars condition inocclude. In. Fig. 180.—Open bite. Tlie only teath that occlude are the second left the right side the second molars have moved forward, especially tlieupper. For the interesting result of treatment of this case, and figures,seep. 244; Figs. 371, 372, 373. (Norman G. Bennett.) a typical case abnormal development of themandible is very apparent; the ascendingramus is short and the angle unduly is easy to understand that if the depth of themandible and height of the molar teeth in bothjaws are normal, the effect of a short ascendingramus nuist be to produce an open conditionanteriorly, and the obliquity of the angle is anecessary concomitant. Curiously enough theanterior portion of the mandible presents indifferent cases exactly opposite there is deficient development, andsometimes excessive growth of chin togetherwith an apparent bending at the anterior borderof the insertion of the masseter muscle ^ (see Figs.
Size: 1539px × 1623px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectdentistry, bookyear19
