Root Amputation, Hemisection, and Radectomy

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Objective
To remove one or more diseased, fractured, or nontreatable roots of an otherwise retainable and restorable multirooted tooth.
Note
Endodontics must first be satisfactorily completed on the retainable root(s) before others are removed. The need to reflect a flap is determined on a case-by-case basis and is predicated on furca anatomy, location, degree of caries, fracture depth, and amount of access needed.
ndications for the need for root amputation include the following:
• Periodontal, through and through, nontreatable furcas
• Severe pocket depth involving only one of the roots
• Extensive root caries, creating a nonrestorabie condition
• irreparable perforation or resorption in one of the roots
• Vertical fracture of one of the roots
• Mesiodistal fracture of maxillary molar
• Buccolingual fracture of a molar
• One root that is not amenable to conventional or surgical endodontic treatment
Contraindications for root amputation include:
• Systemic risks
• Extensive bone loss of all the roots
• Pronounced mobility of the tooth
• A furca that is so far apical, access would leave little bone support
• Inseparable, fused roots
• No roots amenable to conventional or surgical endodontics
• A crown-root ratio of the retained root that offers insufficient bone support
• No benefit to the treatment plan
Instruments*
#23/UNC15 Expro explorer #1 DE Explorer
»701 Long-shank carbide bur for a high-speed surgical 45° handpiece (Brassier)
#149 Periosteal elevator
#2/4 Molt DE curette
#2, #3 Root elevators or root picks
FX#74 Forceps, 150,151
#83, #84 Lucas DE curettes
Techniques
Root amputation of mandibular molars
1. This compromising technique involves the removal of a root without disturbing the crown (Figs 1-1 a and 1-1 b). An intrasulcular flap is usually neces­sary and, to provide a path for the extraction, an extensive amount of buccal bone must be removed to uncover the root

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Fig 1-1 a


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Fig 1-1 b


Figs 1-1 a and 1-1 b Although re noving one root from a multirooted tooth while retaining the crown solves the imme­diate problem, it condemns the p atient to possible peri­odontal problems in the future.


2. Once the flap is elevated and retracted, the coro­nal half of the buccal aspect of the root to be sacri­ficed is denuded of bone with a round bur in a high-speed handpiece. A tapered fissure bur rotat-ng at high speed enters the now-exposed root at or slightly below/above the proximal cementoe-namel junction, it continues to cut horizontally and lingually, penetrating the root until separation is complete at the furcal junction. Periodic radi­ographs should be taken to monitor the level and progress of the cut. 3. Using appropriately sized root picks, hemostats, and small forceps, the disconnected root is ele­vated and lifted from its socket in a buccal direc­tion. If considerable resistance is met when applying the extracting force, increased extraction space may be developed by removing additional buccal and interseptal bone, and/or shortening the length of the root by reducing the coronally exposed segment with the fissure bur.
Problems. Even when the furca is supracrestal and a minimal amount of bone has been removed, the healing area following root amputation presents an abnormal architecture. Food trapping soon becomes unmanageable, and even patients with superb oral hygiene habits have difficulty keeping a clean mouth. The long-term prognosis of this service should be considered poor, and this fact must be conveyed to the patient.

Hemisection of mandibular molars
l Because conventional endodontic procedures to gain access to the canal normally precede the election to hemisect a mandibular molar, the inter­nal chamber of the crown has generally been gut­ted. To minimize the potential for fracturing the weakened crown structure during the extraction process, the overall crown height is reduced 2 to 4 mm, and the segment over the condemned half is further reduced to within 2 mm of the gingival crest (Figs 1-2a and 1-2b). The buccal and lingual grooves, when present, act as guides for this crown division. All crown and root division can be accomplished with a carbide bur in a high-speed handpiece. A copious water spray and high-volume aspiration should accompany all cutting proce­dures. At this time, a radiograph is taken to orient the vertical step to the furca.


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Fig1-2a                                                       Fig 1-2b


Figs 1-2a to 1-2g This sequence of steps will simplify the re moval of a single root from most mandibular and max­illary mult pie-rooted teeth:

if the crown in severely weakened, rec jce the occlu­sion, particularly over the target root 21 Use the buccal grooves to orient the initial cut to the furca.
Continue the vertical cut to the furca. Separate the root from the tooth ixxfyj Verify the separation radiographically Extract the root.
Verify the cleanliness of the socket raadiographically.
2. Once adjusted to the furca, a single, vertical, buc-cal-to-lingual cut, no wider than the bur, is made 2 to 4 mm deep or until it reaches the gingival crest. A second radiograph is taken to determine whether the vertical cut is perpendicular to the furca. Direction adjustments are made if necessary, and the vertical cut is continued until separation is complete. The more apical the furca, the more often radiographs and directional adjustments must be made (Figs 1-2c to 1-2e).
3. Root separation may be determined visually, by feel (bone offers less cutting resistance than root structure), by radiograph, or by test elevat­ing the root for movement (Fig 1-2f). However, no instrument is ever used to wedge roots apart. When separation is confirmed, the buccal, ngual, and proximal walls of the root are ele­vated until a Class ill mobility is realized, and the root is free in its socket. The beaks of appropriately sized forceps are positioned on the root body and, with minimal compressive forces, the root is lifted from its socket. A final radiograph is taken to confirm the absence of root segments and foreign bodies {Fig 1-2g



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Fig 1-2e                                                    Fig 1-2f


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Fig 1-2g


Problems.
1- Unlike in a root amputation, a flap should only be necessary with a mandibular hemisection
when the target root has fractured or decayed subcrestally, refuses to lift from the socket, or breaks during the hemisecting procedure. If such a situation should arise, the technique described for root amputation is followed.
2. Deep apical furca junctions demand flap eleva­tion and considerable bone removal to locate the junction and protect the retained root from inadvertent bur damage.
3. Root spurs or ledges left on the retained root create an uncleansable pocket and lead to peri­odontal breakdown. The furcal junction must be made smooth with a safe end tapered bur or diamond (Figs 1-3a to 1-30).
4. Excessive mobility of the retained root may require provisional splinting until bone in the extraction site has had an opportunity to regen­erate.
5. For its protection and for the health of the sur­rounding tissues, the crown segment of the retained root(s) should be reduced and a well-fit­ting, temporary, nonoccluding crown placed.


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Fig 1-3a                                             Fig 1-3D



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Fig 1-3C                                          Fig 1-3d

Radectomy
Buccal root(s) of maxillary molars. When consid­ering the removal of one or more of the roots of a maxillary molar, the most desirable technique calls for the removal of the overlying segment of the crown prior to an attempt to remove the root. However, because maxillary teeth have a greater root base, the restorative options are also greater. For this reason, the amputation procedure described in this lesson for mandibular teeth may sometimes be applied to maxillary molars.
To provide sufficient access and increased visi­bility and to prevent damage to the remaining roots, the ideal resection of the maxillary root(s) requires a full mucoperiosteal flap. The following example describes the procedure for the removal of the mesiobuccal root of the maxillary first molar. The steps should be interpreted and adjusted to meet the demands of other maxillary roots.
1. The occlusion is reduced by 2 to 4 mm, and the section over the offending root is reduced to the gingival crest. The mucosa is incised, ele­vated, and reflected, and the cortical bone is removed from the coronal aspect of the buccal surface of the target root with a large round #4 bur in a slow-speed handpiece.
2. A tapered fissure bur in a high-speed, 45-degree surgical handpiece is used to initiate the cut at the mesioproximai cementoenamel junction. The bur cuts on a hohzontal plane, but in a slightly apical direction as it proceeds toward the furca
Fig 1-4a). To prevent nicking the adjacent buc­cal or lingual roots as the furca is approached, caution becomes most important. Whenever there is doubt regarding location or direction of the furca, a radiograph should be taken.
3. The success of the cut is determined by prob-ing, curetting, or elevating the root to ascertain mobility. At no time is a wedge placed in the separating cut. When the root moves freely, the thin layer of remaining crown structure over the freed root is removed, and the root is lifted from ts socket. To enhance the patient's oral hygiene, the sharp edges of bone and remaining roots are filed smooth. The crown is recon-toured and a well-fitting temporary crown is fab­ricated and seated. The flap is repositioned, and a final radiograph is taken to ensure that all root structure and debris have been eliminated. After assessment of the radiograph, the flap is sutured in place (Fig 1-4b).



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Fig 1-4a                                                       Fig 1-4b

Figs 1-4a and 1-4b The serial removal of the distal buc­cal root of a maxillary molar.
Lingual root of maxillary molar

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A palatal flap is reflected and bone is removed until the lingual root is exposed and identified. The coronal half of the root is denuded of lx»ne with a round #4 bur. A long-shank carbide fissure bur, at high or slow speed, initiates a horizontal cut a few millimeters apical to the mesio-proxlmal cementoenamel junction. The bur is moved inward buccally/distally and slightly apically (to com­pensate for the root's lingual inclination) until separa­tion is complete. This allows the root to be extracted i n accordance with its vertical lingual line axis. Once the root is elevated and lifted from its socket, the lx»ne and crown are recontoured, and the flap is repo­sitioned. A final radiograph is taken to ensure that all root structure and debris has been removed. After assessment of the radiograph, the flap is reapproximated and sutured in place (Figs 1-5a and 1-5b).


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Fig 1-5a                                                Fig 1-5b


Problems.
1. Most often the angle of the palatal root Is diver­gent, and consequently its buccal path of removal is generally obstructed by the crown. To solve this problem, the occlusal/Ungual aspect of the crown must be grossly reduced. A less favorable option is to remove additional palatal bone and drastically change the shape of the ridge.
2. To avoid periodontal food packing, the crown should be fabricated with a reduced buccollngual table.
 




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