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Operative surgery . of the a trephine of moderatecaliber—say one half to threequarters of an inch—pushdown the pin for about aneighth of an inch below theteeth of the instrument; fas-ten the pin firmly in position,and place the point on solidbone (a) as near to the lineof depression as is wise (see , Important Considerations), and at the point best calculated to facilitateelevation (Fig. 267), provided it be not located above an important vessel. Bear firmly on thetrephine to intro-duce the point intothe bone; turn theinstrument quicklyand lightly fromright to left, andthe
Operative surgery . of the a trephine of moderatecaliber—say one half to threequarters of an inch—pushdown the pin for about aneighth of an inch below theteeth of the instrument; fas-ten the pin firmly in position,and place the point on solidbone (a) as near to the lineof depression as is wise (see , Important Considerations), and at the point best calculated to facilitateelevation (Fig. 267), provided it be not located above an important vessel. Bear firmly on thetrephine to intro-duce the point intothe bone; turn theinstrument quicklyand lightly fromright to left, andthe reverse until agroove is made in/ ^--^^_JiPC ^ ^X^~- ^ )_^j^ I the bone of suffi- cient depth to re-tain the instrumentin place during fur-ther action. Dur-ing this step of theoperation it is wiseto hold the head of the trephine in place with the thumb and index fingerof the disengaged hand, or by the index finger of the other extended alongthe trephine down to the skull. When a suitable track is made withdraw. Fig. 266.—Circular craniotomy (trephining).
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Keywords: ., bookauthorbryantjosephdjosephde, bookcentury1900, bookdecade1900