Technique for Surgical Removal of Multirooted Teeth
If the decision is made to perform an open extraction of a multi rooted tooth, such as a mandibular or maxilIary molar, the same surgical, technique used for the single rooted tooth is generally used. The major difference is that the tooth may be divided with a bur to convert a multi rooted tooth into several single-rooted teeth. If the crown of the tooth remains intact, the crown portion is sectioned in such a way as to facilitate removal of roots. However, if the crown portion of the tooth is missing and only the roots remain, the goal is to separate the roots to make them easier to remove with elevators.
Removal of. the lower first molar with an intact crown is usually done by sectioning, the tooth buccolingually and thereby dividing the tooth into a mesial half (with mesial root and half of the crown) and a distal half. An envelope incision is also made, and a small amount of crestal bone is removed. Once the tooth is sectioned, it is luxated with straight elevators to begin the mobilization process. The sectioned tooth is treated as a lower premolar tooth and is removed with a.lower universal forceps (Fig. 8-41). The flap is re-positioned and sutured.
The surgical technique begins with the reflection of an adequate flap (Fig. 8-42, A and B). The surgeon selects either an envelope or three cornered flap as the requirement for access and personal preference dictate. valuation of the need for sectioning roots and removing bone is made at this, stage, as it was with the single-rooted tooth. Occasionally, forceps, elevators or both are positioned with direct visualization to achieve better mechanical advantage and to remove the tooth without removing the bone.
However, in most situations a small’ amount of crestal bone-should be removed, and the tooth should be divided. Tooth sectioning is usually accomplished with a straight hand piece with a straight bur, such as the no. 8 round bur, or with a fissure bur, such as the no. 557 or no. 703 bur (Fig. 8-42, C).
Once the tooth is sectioned, the small straight elevator is used to luxate and mobilize the sectioned roots (Fig. 8-42, D). The straight elevator may be used to deliver the mobilized sectioned tooth (Fig. 8-42, E). If the crown of the tooth is sectioned, upper or lower universal forceps is used to remove the individual portions of the sectioned tooth (Fig. 8-42, F). If the crown is missing, then straight and triangular elevators are used to elevate the tooth roots from the sockets.
Sometimes, a remaining root may be difficult to remove and additional bone removal (as is described for a single rooted tooth) may be necessary. Occasionally, it is necessary to prepare a purchase point with the bur and to use an elevator, such as the Crane pick to elevate the remaining root.
After the tooth and all the root fragments have been removed, the flap is repositioned and the surgical area palpated for sharp bony edges. If any are present, they are smoothed with a bone file. The wound is thoroughly irrigated and debrided of loose fragments of tooth, bone, calculus, and other debris. The flap is repositioned again and sutured in the usual fashion (Fig. 8-42, G).
An alternative method for removing the lower first molar is to·reflect the soft tissue flap and remove sufficient buccal bone to expose the bifurcation. Then the bur is used to section the mesial root from the tooth and convert the molar into a single-rooted tooth (Fig. 8-43). The crown with the mesial root intact is extracted with no. 17 lower molar forceps. The remaining mesial root is elevated from the socket with a Cryer elevator. The elevatar is inserted into the empty tooth socket and rotated, using the wheeland axle principle. The sharp tip of the elevator engages the cementum of the remaining root, which is elevated occlusally from the socket. If the interradicular bone is heavy, the first rotation or two of the Cryer elevator removes the bone, which allows the elevator to engage the cementum of the tooth on the second or third rotation.
procedure again begins with the reflection of an envelope flap and removal of a small amount of crestal bone. The bur is used to section the two roots into mesial and distal components (Fig. 8-H, A). The small straight elevator is used to mobilize and luxate the mesial root, which is delivered from its socket by insertion of the Cryer elevator into the slot prepared by the dental bur (Fig. 8-4-1, ll). The Cryer elevator is rotated in the wheel and axle manner, and the mesial root is delivered occlusally from the tooth socket. The opposite member of the paired Cryer instruments is inserted into the empty root socket and rotated through the interridicular bone to engage and deliver the remaining root (Fig, R-4-1, C).
Extraction of maxillary molars with widely divergent buccal and palatal roots that require excessive force to extract can be removed more prudently by dividing the root into several sections. This three-rooted tooth must be divided in a pattern different from that of the two rooted mandibular molar. If the crown of the tooth is intact, the two buccal roots are sectioned from the tooth and the crown is removed along with the palatal root.
The standard envelope flap is reflected, and a small portion of crestal bone is removed to expose the trifurcation area. The bur is used to section off the mesiobuccal and distobuccal roots (Fig. 8-45, A). With gentle but firm bucca-occlusal pressure, the upper molar forceps delivers the crown and palatal root along the long axis of the root (Fig. 8-45, B). No palatal force should be delivered with the forceps to the ‘crown portion, because thi~ results in fracture of the palatal root. The entire delivery force should be in the buccal direction. A small straight elevator is then used to luxate the buccal roots (Fig. 8-45, C), Which can then be delivered either with a Cryer elevator used in the usual fashion (Fig. 8-45, D) or with a straight elevator. If straight elevators are used, the surgeon should remember that the maxillary sinus might be very close to these roots, so apically directed forces must be kept to a minimum and carefully controlled. The entire force of the straight elevator should be in a mesiodistal direction,and slight pressure should be applied apically.
If the crown of the maxillary molar is missing or fractured,the roots should be divided into two buccal roots and a palatal root. The same general approach as before is used. An envelope flap is reflected and retracted with a periosteal elevator. A moderate amount of buccal bone is removed to expose the tooth for sectioning (Fig. 8-46, rI). The roots are sectioned into the two buccal roots and a single palatal root. Next the roots are luxated with a straight elevator and delivered with Cryer elevators,according to the preference of the surgeon (Fig. 8-40. H , and C). Occasionally, enough access to the roots exists so that a maxillary root forceps or upper universal forceps can be used to deliver the roots independently (fig-46. lJ). Finally, the palatal root is delivered after the two buccal roots. have been removed. Often much of the interradicular bone is lost by this time; therefore the small
straight elevator can be used efficiently. The elevator is forced down the periodontal ligament space on the palatal aspect with gentle, controlled wiggling motions, which causes displacement of the tooth in the buccoocclusal direction (Fig. H-46, E).