A practical treatise on the technics and principles of dental orthopedia and prosthetic correction of cleft palate . t be accomplished by grinding grooves in themarginal ridges. In fact, it would be better to leave the imder surface of the barrotmded and sufficiently free from the enamel to allow the removal of accumula-tions, with dental floss, etc. In fitting the bar on the model, place it at one side ofthe projecting posts, either occlusally or gingivally as seems best to meet the re-quirements and avoid occlusal contact, or separate bars may be fitted between theposts. By making a labio-li
A practical treatise on the technics and principles of dental orthopedia and prosthetic correction of cleft palate . t be accomplished by grinding grooves in themarginal ridges. In fact, it would be better to leave the imder surface of the barrotmded and sufficiently free from the enamel to allow the removal of accumula-tions, with dental floss, etc. In fitting the bar on the model, place it at one side ofthe projecting posts, either occlusally or gingivally as seems best to meet the re-quirements and avoid occlusal contact, or separate bars may be fitted between theposts. By making a labio-lingual section of a central incisor, as shown in Fig. 315,it will be found that the thickness and shape of the linguo-cervical wall will safely 404 PART VIII. RETENTION IN DENTAL ORTHOPEDIA permit the boring of a hole of sufficient size and depth, if started in a Hne with themiddle of the wall and carried parallel to the central axis of the tooth. The location and direction of the proposed hole can easily be determined bythe eye. In gazing root-wise at a labial tooth, take such a position as will bring Fig. the cutting edge exactly in the center between the gingivo-labial and gingivo-lingual borders of the crown, and you will be looking directly along the line of thecentral axis of the tooth. Use a No. 19 drill and start the hole in the lingual fossa at a point whose lineof direction, parallel to the central axis, will leave sufficient body on the lingualside of the pit, and then bore to the depth of about three millimeters. In a typi-cally formed central incisor of ordinary size, the thickness of the linguo-gingivalwall is about three millimeters to the depth of at least six millimeters. The diam-eter of a No. 19 drill is about .035 of an inch. One millimeter is over .039 of aninch. Consequently, if the proper course is pursued, you are safely one millimeterfrom either wall. The holes should be perfectly parallel with each other as beforestated, with margins very slightly
Size: 2847px × 878px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, bookidpracticaltre, bookyear1921
