322
Australian Dental Journal. August. I 9 7 8
Volume 23. No. 4
-
Furcation involvement a suggested rationale for treatment Robert C. Bower AND
Patrick J. Henry
ABSTRACT-Furcation involvement is classified and methods of treatment discussed. Evidence is presented to indicate t h a t altered plaque elimination techniques are essential in the furcation region.
(Recei,*ed for pithlicatiori Sepiern her. 1977)
Introduction
Periodontal pocket formation in the region of root division of a multirooted tooth creates problems of plaque control which affect the prognosis of the tooth. The elimination of these pockets is not straightforward and before undertaking such ii procedure it is essential to recognize those factors which influence the likely success of the operation and also to be aware o! the modalities o f therapy likely to give the desired result. It is the purpose of this communication to discuss the detection of furcation involvement. its simple classification based on the type of surgical management required. anatomical considerations likely to affect the success of treatment and some techniques of management. Detection of furcation involvement
The use of a periodontal probe to detect and measure periodontal pockets forms an essential part of any complete dental examination. Most periodontal probes are straight and therefore not itlrul for the examination of multirooted teeth where pocketin2 may involve the root division
(furcation). The exploration of this region may be facilitated by the use of a periodontal curette (Fig 1 ) . ;is the curved configuration of the instrument allows easier and less painful probingl. In the case of mandibular molar teeth the bifurcation should be investigated from both the buccal and lingual sides. Maxillary molar teeth must be examined for trifurcation involvement from buccal, mesio-palatal and disto-palatal aspects. The maxillary first premolar tooth with buccal and lingual roots rnay also show furcation involvement. This is particularly likely to occur where angular defects have occurred on the mesial aspect and a deep groove frequently runs into the furcation on this surface. On rare occasions, the maxillary first premolar rnay have three roots, in which casc examination procedure is as for the molar. Failure to recognize this variation may rcsult in faulty diagnosis and inadequate treatment planning of the maxillary posterior teeth (Fig. 2). Kadiolucency in the interradicular region of a multirooted tooth is indication of bone destruction
Australian Dental Journal, August. 1978
Fig. 2.-Trifurcated maxillary premolar root clearly shown on endodontic X-ray film.
Classification of furcation involvement
Fig. 1.-The use of a periodontal curette to explore the furcation area in multi-rooted teeth. a, Buccal view; b. sectional view through furcation; c. periodontal ciirette at bifurcation.
The treatment of pockets involving the furcation will be partly influenced by the degree of destruction of the interradicular tissues and a number of classifications based on the amount of destruction and of varying complexity have been suggested2.3.4. The following classification of furcation involvement is simple and related only to the need for simple or more complex treatment. The exact type of treatment is not determined by the degree of tissue destruction alone. Factors such as root anatomy. tooth support and adjacent anatomic structures must be considered with plaque control facility in choosing the surgical procedure for pocket elimination (Fig. 4).
Fig. 3.-The effect of altered axial beam of X-ray source on radiographs of the mandibular molar teeth. a, Beam directed \tr:iipht through furcation; b. beam directed oblique to furcation rewlting in overlapping of root images.
and is likely to be the result of periodontal breakdown in the region. The importance of the angulation of the axial beam of the X-ray source relative to the furcation should be recognized as small variation in the angulation may alter the radiographic image (Fig. 3). Optimum results are obtained using a film the use Of holder and i n particular One long cone “right angle” techniques of intraoral radiography such as the R i m XCP kit*.
*
R i n n Corporation, Elgin. 111.. U.S.A.
Tibbets, L. s.-use of diagnostic probe5 for detection of periodontal disease. J.A.D.A., 78:3. 549.555 (Mar.) 1969. 5 Glickman. I.-Clinical Periodontology. Philadelphia, W. B. Saunders Company, 4th ed., 1972 (pp. 695-700). :, H~~~ s, E, N~~~~ s,, and ~ , - p ~ ~ , ~ d ~ ~ ~ ~ trdtment ’of multirooted teeth (Risults after five years), J , Clin, periodontal. 2;3, 126-135 (1975). I Staffileno, H. J.-Surgical manHgement of the furca invasion, Dental Clin. Nth. America, I 3 : l . 103-119 (Jan.) 1969. I
Australian Dental .lourn;il. August. I Y 7 X
3 24 I
The latter group includes all lesions from those with slightly more than one-third of the interradicular tissue destroyed to the so called “through and through” lesion with no remaining tissue at the level of furcation. If there is radiographic evidence of furcation involvement it is probably no longer initial.
1
Other factors influencing treatment of furcation involvement b
Fig. 4.-lnitial and advanced furcation involvement. Initial involvement with destruction of less than one-third of the interradicular tissue at the level of the furcation: b, advanced involvement with destruction of more than one-third of the interradicular tissue ;it the level of the furcation: c, roots of lower first molar sectioned to show morphology at bifurcation. d. e, furcations seen after sectioning of the roots at ii level approximately 2 mm apical to the furcation: d. mandibular first molar: e. maxillary first molar. C . Concavity of furcal aspect: D. distal root: M, mesial root: Db, disto-buccal root; Mb. mesio-buccal root; P. palatal root.
:I,
Classification of initial involvement is made where less than one-third of the interradicular tissue at the level of furcation has been destroyed from any aspect. Advanced involvement is considered where more than one-third of the interradicular tissue at the level of furcation has been destroyed.
Other factors which influence whether treatment of furcation involvement is advisable and the surgical technique of choice are related to access (both in surgery and plaque control) and the strategic value of the tooth. Access for both plaque control and surgery is limited in the following situations which should be considered as contraindications to periodontal pocket eliminatio’n in the furcation area. Where the furcation level is in the apical half of the root and where little root divergence is present. Where adjacent anatomic structures such as the maxillary sinus or external oblique ridge limit access. The strategic value of the tooth. or individual roots of it, must be high to justify the endodontic and surgical treatment necessary to retain it. This is particularly true where the retained tooth will require splinting and adjacent teeth must therefore be reduced for retainer placement. In this situation careful consideration must be given to bridge placement as pontics fail less frequently than endodontically treated teeth with periodontal breakdown. Plaque removal capacity in the furcation region is also partly determined by the molar root anatomy. Neglect of this consideration will frequently lead to dental caries in the furcation requiring extraction of the tooth. Examination of the furcal surfaces of extracted mandibular molar teeth reveals concavity in 100 per cent of mesial roots and 99 per cent of distal roots. This means that plaque control will be ineffective in the furcation when rigid wood points or floss, which will not reach the concavity, are used. A similar problem exists in maxillary first molars as the roots diverge into the furcation in 96 per cent of cases5 (Fig. 4c, d). The presence of concavities dictates that a compressible cleaning device such as an interproximal brush (Fig. 5 ) or pipe cleaner must he used to achieve adequate plaque control. Root divergence into the furcation means that to be effective any cleaning device must be directed into the furcation from the lateral extremes of the interradicular area. Bower, R . C.-Unpublirhed
data in preparation.
325
Australian Dental Journal. August, I978
vectomy to eliminate the defect i j the treatment of choice. I f however, osteoplasty or apical positioning of the mucogingival complex is required, a full thickness flap procedure is advisable. In situations where a sharp concavity exists in the root division and plaque control will consequently be difficult, the tooth should be reshaped to produce a more gentle concavity. (Fig. 6.) Treatment of advanced furcation involvement
Fig. 5.-Interproximal hrush suitable for cleaning concavities in the furcation. (Crescent Dental Mfp. Co., Lyons, 111.. U.S.A.)
Fig
6.-Initial
Where more than one-third of the interradicular tissue at the level of furcation has been destroyed, the area must be opened to allow plaque control. This may be achieved by amputating one or more roots of the tooth, or by opening the furcation completely for cleaning.
furcation involvement. a, Before treatment; b after treatment by dpical repositioning of the gingival complex and both osteopla;ty and odontoplaqty.
of roots in treatment of advanced Fig. 7.-Division furcation involvement mandibular first molar tooth restored with individual cast post core crowns.
Treatment of initial furcation involvement
The aim o f treatment is to create a situation which can be maintained plaque free to avoid further breakdown. Where pocketing is present and adequate attached gingiva remains with no adverse bonc contour suspected, a simple gingi-
Techniques o f root resection are not new and were suggested as early as 1915 by Blacks. However the recent development of more predictable endodontic and periodontal procedures makes these old techniques more applicable to modern dental practice. A. Mandibular molar furcations 1 . Where both roots have good bone support and are amenable to endodontic therapy, the endodontically treated roots should be divided by a vertical bur cut passing into the furcation and extending from buccal to lingual. Each root is then restored to premolar form using a cast post core system7 (Fig. 7). It must be remembered that concavities still exist on th.e furcal aspects of mesial and most distal roots and that a compressible cleaning agent must be used in plaque removal.
6 7
Black, G . V.-Special Dental Pathology. Chicago, MedicoDental Publishing Company, 1st ed., 1915. Henry, P . J., and Bower, R . C.-Post core systems in crown and bridgework. Austral. D . J,, 22:l. 46-52 (Feb.) 1977.
3 26
Australian Dental Journal, August, 1978
Fig. 8.-Root amputation of mandibular molar tooth with advanced furcation involvement and subsequent treatment. a. Endodontics comuleted: b. root amuutation: c, temporary restoration- using amalgam alloy: d. amputation of distal root in treatment of advanced furcation involvement mandihular first molar tooth.
2. Where one root is poorly supported or not amenable to endodontic therapy that root should be removed. This may be achieved either by root amputation (Fig. 8) or hemisection (Fig. 9). Root amputation is best considered as a temporary measure f o r space maintenance while periodontal healing takes place prior to completion of the hemisection and placement of a bridge.
Fig. 9.-Hemisection of mandibular first molar tooth with advanced furcation involvement and subsequent treatment. a, Endodontics completed; b, hemisection and extraction of the weakest root: c. restoration using a post core abutment in the remaining root and full crown on second bicuspid; d, hemisection of mandibuIar first molar tooth with extraction of the mesial half and bridge placement.
B. Maxillary molar furcation Management of advanced trifurcation involveOf teeth is no longer regarded as heroic although the prognosis remains less favourable than for other furcation involvements. Treatment relies on alteration of the fur-
327
Australian Dental Journal, August, I978
Fig.
Il).--Koot
:imputation of’ maxillary first tooth.
molar
cation architecture to makc it cleanable. In most instances the root with the poorest individual prognosis is amputated leaving a “bifurcation”
‘ tlelf‘er. A . R.. Melnick, S.. and Schilder, H.-
!’
Determination of the moisture content of vital pulpless teeth. Oral Surg., 34:4. 661-670 (Oct.) 1972. Smukler, H.. a n d Tagger, M.-Vital root amputation (a clinical and histological study). J. Periodontol., 47:6, 324-330 (June) 1976.
which is amenable to therapy. Any one o f the three roots may be amputated (Fig. 10). In any of the mentioned procedures the cut surface remaining after amputation o r root division must be smoothed and conform with the remaining tooth anatomy. After recontouring is complete topical fluoride should be applied to render the tooth less susceptible t o dental caries. Wherever possible endodontic therapy should be completed prior to root - o r tooth - sectioning. This allows assessment o f endodontic results and eliminates the possibility o f acute pulpal problems developing before the pulp canals can be obturated. I f root amputation milst be carried out unexpectedly at the time of pocket elimination. little post operative pulpal pain results a s long a s endodontics can be completed within two weeks of root amputationy. A dressing is placed over the vital pulp stump after amputation. Conclusion Furcation involvement n o longer carries a mandatory hopeless prognosis provided that adequate plaque control is possible after treatment. This may involve root resection techniques a n d the method of plaque control must take into account the detail of the furcation. 39 Colin Street, West Perth, W.A., 6005.
Australian Dental Journal. August. I 9 7 8
Volume 23. No. 4
-
Furcation involvement a suggested rationale for treatment Robert C. Bower AND
Patrick J. Henry
ABSTRACT-Furcation involvement is classified and methods of treatment discussed. Evidence is presented to indicate t h a t altered plaque elimination techniques are essential in the furcation region.
(Recei,*ed for pithlicatiori Sepiern her. 1977)
Introduction
Periodontal pocket formation in the region of root division of a multirooted tooth creates problems of plaque control which affect the prognosis of the tooth. The elimination of these pockets is not straightforward and before undertaking such ii procedure it is essential to recognize those factors which influence the likely success of the operation and also to be aware o! the modalities o f therapy likely to give the desired result. It is the purpose of this communication to discuss the detection of furcation involvement. its simple classification based on the type of surgical management required. anatomical considerations likely to affect the success of treatment and some techniques of management. Detection of furcation involvement
The use of a periodontal probe to detect and measure periodontal pockets forms an essential part of any complete dental examination. Most periodontal probes are straight and therefore not itlrul for the examination of multirooted teeth where pocketin2 may involve the root division
(furcation). The exploration of this region may be facilitated by the use of a periodontal curette (Fig 1 ) . ;is the curved configuration of the instrument allows easier and less painful probingl. In the case of mandibular molar teeth the bifurcation should be investigated from both the buccal and lingual sides. Maxillary molar teeth must be examined for trifurcation involvement from buccal, mesio-palatal and disto-palatal aspects. The maxillary first premolar tooth with buccal and lingual roots rnay also show furcation involvement. This is particularly likely to occur where angular defects have occurred on the mesial aspect and a deep groove frequently runs into the furcation on this surface. On rare occasions, the maxillary first premolar rnay have three roots, in which casc examination procedure is as for the molar. Failure to recognize this variation may rcsult in faulty diagnosis and inadequate treatment planning of the maxillary posterior teeth (Fig. 2). Kadiolucency in the interradicular region of a multirooted tooth is indication of bone destruction
Australian Dental Journal, August. 1978
Fig. 2.-Trifurcated maxillary premolar root clearly shown on endodontic X-ray film.
Classification of furcation involvement
Fig. 1.-The use of a periodontal curette to explore the furcation area in multi-rooted teeth. a, Buccal view; b. sectional view through furcation; c. periodontal ciirette at bifurcation.
The treatment of pockets involving the furcation will be partly influenced by the degree of destruction of the interradicular tissues and a number of classifications based on the amount of destruction and of varying complexity have been suggested2.3.4. The following classification of furcation involvement is simple and related only to the need for simple or more complex treatment. The exact type of treatment is not determined by the degree of tissue destruction alone. Factors such as root anatomy. tooth support and adjacent anatomic structures must be considered with plaque control facility in choosing the surgical procedure for pocket elimination (Fig. 4).
Fig. 3.-The effect of altered axial beam of X-ray source on radiographs of the mandibular molar teeth. a, Beam directed \tr:iipht through furcation; b. beam directed oblique to furcation rewlting in overlapping of root images.
and is likely to be the result of periodontal breakdown in the region. The importance of the angulation of the axial beam of the X-ray source relative to the furcation should be recognized as small variation in the angulation may alter the radiographic image (Fig. 3). Optimum results are obtained using a film the use Of holder and i n particular One long cone “right angle” techniques of intraoral radiography such as the R i m XCP kit*.
*
R i n n Corporation, Elgin. 111.. U.S.A.
Tibbets, L. s.-use of diagnostic probe5 for detection of periodontal disease. J.A.D.A., 78:3. 549.555 (Mar.) 1969. 5 Glickman. I.-Clinical Periodontology. Philadelphia, W. B. Saunders Company, 4th ed., 1972 (pp. 695-700). :, H~~~ s, E, N~~~~ s,, and ~ , - p ~ ~ , ~ d ~ ~ ~ ~ trdtment ’of multirooted teeth (Risults after five years), J , Clin, periodontal. 2;3, 126-135 (1975). I Staffileno, H. J.-Surgical manHgement of the furca invasion, Dental Clin. Nth. America, I 3 : l . 103-119 (Jan.) 1969. I
Australian Dental .lourn;il. August. I Y 7 X
3 24 I
The latter group includes all lesions from those with slightly more than one-third of the interradicular tissue destroyed to the so called “through and through” lesion with no remaining tissue at the level of furcation. If there is radiographic evidence of furcation involvement it is probably no longer initial.
1
Other factors influencing treatment of furcation involvement b
Fig. 4.-lnitial and advanced furcation involvement. Initial involvement with destruction of less than one-third of the interradicular tissue at the level of the furcation: b, advanced involvement with destruction of more than one-third of the interradicular tissue ;it the level of the furcation: c, roots of lower first molar sectioned to show morphology at bifurcation. d. e, furcations seen after sectioning of the roots at ii level approximately 2 mm apical to the furcation: d. mandibular first molar: e. maxillary first molar. C . Concavity of furcal aspect: D. distal root: M, mesial root: Db, disto-buccal root; Mb. mesio-buccal root; P. palatal root.
:I,
Classification of initial involvement is made where less than one-third of the interradicular tissue at the level of furcation has been destroyed from any aspect. Advanced involvement is considered where more than one-third of the interradicular tissue at the level of furcation has been destroyed.
Other factors which influence whether treatment of furcation involvement is advisable and the surgical technique of choice are related to access (both in surgery and plaque control) and the strategic value of the tooth. Access for both plaque control and surgery is limited in the following situations which should be considered as contraindications to periodontal pocket eliminatio’n in the furcation area. Where the furcation level is in the apical half of the root and where little root divergence is present. Where adjacent anatomic structures such as the maxillary sinus or external oblique ridge limit access. The strategic value of the tooth. or individual roots of it, must be high to justify the endodontic and surgical treatment necessary to retain it. This is particularly true where the retained tooth will require splinting and adjacent teeth must therefore be reduced for retainer placement. In this situation careful consideration must be given to bridge placement as pontics fail less frequently than endodontically treated teeth with periodontal breakdown. Plaque removal capacity in the furcation region is also partly determined by the molar root anatomy. Neglect of this consideration will frequently lead to dental caries in the furcation requiring extraction of the tooth. Examination of the furcal surfaces of extracted mandibular molar teeth reveals concavity in 100 per cent of mesial roots and 99 per cent of distal roots. This means that plaque control will be ineffective in the furcation when rigid wood points or floss, which will not reach the concavity, are used. A similar problem exists in maxillary first molars as the roots diverge into the furcation in 96 per cent of cases5 (Fig. 4c, d). The presence of concavities dictates that a compressible cleaning device such as an interproximal brush (Fig. 5 ) or pipe cleaner must he used to achieve adequate plaque control. Root divergence into the furcation means that to be effective any cleaning device must be directed into the furcation from the lateral extremes of the interradicular area. Bower, R . C.-Unpublirhed
data in preparation.
325
Australian Dental Journal. August, I978
vectomy to eliminate the defect i j the treatment of choice. I f however, osteoplasty or apical positioning of the mucogingival complex is required, a full thickness flap procedure is advisable. In situations where a sharp concavity exists in the root division and plaque control will consequently be difficult, the tooth should be reshaped to produce a more gentle concavity. (Fig. 6.) Treatment of advanced furcation involvement
Fig. 5.-Interproximal hrush suitable for cleaning concavities in the furcation. (Crescent Dental Mfp. Co., Lyons, 111.. U.S.A.)
Fig
6.-Initial
Where more than one-third of the interradicular tissue at the level of furcation has been destroyed, the area must be opened to allow plaque control. This may be achieved by amputating one or more roots of the tooth, or by opening the furcation completely for cleaning.
furcation involvement. a, Before treatment; b after treatment by dpical repositioning of the gingival complex and both osteopla;ty and odontoplaqty.
of roots in treatment of advanced Fig. 7.-Division furcation involvement mandibular first molar tooth restored with individual cast post core crowns.
Treatment of initial furcation involvement
The aim o f treatment is to create a situation which can be maintained plaque free to avoid further breakdown. Where pocketing is present and adequate attached gingiva remains with no adverse bonc contour suspected, a simple gingi-
Techniques o f root resection are not new and were suggested as early as 1915 by Blacks. However the recent development of more predictable endodontic and periodontal procedures makes these old techniques more applicable to modern dental practice. A. Mandibular molar furcations 1 . Where both roots have good bone support and are amenable to endodontic therapy, the endodontically treated roots should be divided by a vertical bur cut passing into the furcation and extending from buccal to lingual. Each root is then restored to premolar form using a cast post core system7 (Fig. 7). It must be remembered that concavities still exist on th.e furcal aspects of mesial and most distal roots and that a compressible cleaning agent must be used in plaque removal.
6 7
Black, G . V.-Special Dental Pathology. Chicago, MedicoDental Publishing Company, 1st ed., 1915. Henry, P . J., and Bower, R . C.-Post core systems in crown and bridgework. Austral. D . J,, 22:l. 46-52 (Feb.) 1977.
3 26
Australian Dental Journal, August, 1978
Fig. 8.-Root amputation of mandibular molar tooth with advanced furcation involvement and subsequent treatment. a. Endodontics comuleted: b. root amuutation: c, temporary restoration- using amalgam alloy: d. amputation of distal root in treatment of advanced furcation involvement mandihular first molar tooth.
2. Where one root is poorly supported or not amenable to endodontic therapy that root should be removed. This may be achieved either by root amputation (Fig. 8) or hemisection (Fig. 9). Root amputation is best considered as a temporary measure f o r space maintenance while periodontal healing takes place prior to completion of the hemisection and placement of a bridge.
Fig. 9.-Hemisection of mandibular first molar tooth with advanced furcation involvement and subsequent treatment. a, Endodontics completed; b, hemisection and extraction of the weakest root: c. restoration using a post core abutment in the remaining root and full crown on second bicuspid; d, hemisection of mandibuIar first molar tooth with extraction of the mesial half and bridge placement.
B. Maxillary molar furcation Management of advanced trifurcation involveOf teeth is no longer regarded as heroic although the prognosis remains less favourable than for other furcation involvements. Treatment relies on alteration of the fur-
327
Australian Dental Journal, August, I978
Fig.
Il).--Koot
:imputation of’ maxillary first tooth.
molar
cation architecture to makc it cleanable. In most instances the root with the poorest individual prognosis is amputated leaving a “bifurcation”
‘ tlelf‘er. A . R.. Melnick, S.. and Schilder, H.-
!’
Determination of the moisture content of vital pulpless teeth. Oral Surg., 34:4. 661-670 (Oct.) 1972. Smukler, H.. a n d Tagger, M.-Vital root amputation (a clinical and histological study). J. Periodontol., 47:6, 324-330 (June) 1976.
which is amenable to therapy. Any one o f the three roots may be amputated (Fig. 10). In any of the mentioned procedures the cut surface remaining after amputation o r root division must be smoothed and conform with the remaining tooth anatomy. After recontouring is complete topical fluoride should be applied to render the tooth less susceptible t o dental caries. Wherever possible endodontic therapy should be completed prior to root - o r tooth - sectioning. This allows assessment o f endodontic results and eliminates the possibility o f acute pulpal problems developing before the pulp canals can be obturated. I f root amputation milst be carried out unexpectedly at the time of pocket elimination. little post operative pulpal pain results a s long a s endodontics can be completed within two weeks of root amputationy. A dressing is placed over the vital pulp stump after amputation. Conclusion Furcation involvement n o longer carries a mandatory hopeless prognosis provided that adequate plaque control is possible after treatment. This may involve root resection techniques a n d the method of plaque control must take into account the detail of the furcation. 39 Colin Street, West Perth, W.A., 6005.
