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Bilateral fusion of the maxillary central incisors to supernumerary teeth: report of case
CLINICAL
tion p referab le. C orticosteroids m ay be ad m in istered intravenously o r in tra m u s cularly to aid in th e prevention o f edem a by p rev en tin g capillary dilation. T h ey also aid in d e c r e a s in g in f la m m a tio n a n d ed em a th a t occur as a result o f the release o f b rad y k in in s, substance P, an d o th e r am ino acids. C orticosteroids have a slow onset, how ever, an d are o f little im m ediate value.8
Summary A re p o rt o f an anaphylactic reaction to oral penicillin is p rese n ted ; th e relative pharm acologic reactions are review ed; the initial signs an d sym ptom s are analyzed; a n d a successful tre a tm e n t m ethod is d e scribed. -----------------------JW O A --------------------------
Dr. Kloberdanz was resident, and Dr. Bennett is professor and chairman, departm ent o f anesthesia, and Dr. McDonald is assistant professor, departm ent o f oral surgery, University o f Pittsburgh School of Dental Medicine, C-130 Salk Hall, Pittsburgh, 15261. A ddress requests for reprints to Dr. Bennett. 1. Malamed, S.F. Medical emergencies in the dental office. St. Louis, C. V. Mosby Co, 1982, pp 286-308. 2. Roberts, J; Bianco, M.M.; and Fine, J. Fatal anaphylactic reaction to oral penicillin: report o f a case.JAD A 110(4):505-506, 1985. 3. Bennett, O.R., ed. M onheim’s local anesthesia and pain control in dental practice. St. Louis, C. V. Mosby Co, 1984, pp 225-235. 4. Beall, G.N. Allergy and clinical immunology. New York, John Wiley & Sons, Inc, 1983. 5. Isselbacher, K.J., and others. H arrison’s princi ples o f internal medicine, ed 9. New York, McGrawHill Book Co, 1980, pp 242-244. 6. Bach, M.K. Im mediate hypersensitivity. M odern concepts and developments. New York, Marcel Dekker, Inc, 1978, pp 598-602. 7. Gill, C., and Michaelides, P.L. Dental drugs and anaphylactic reactions: rep o rt o f case. O ral Surg
REPORTS
50(l):30-32, 1980. 8. Goodman, L.S., and Gilman, A.G. T he p h ar macological basis o f therapeutics, ed 5. New York, Macmillan Publishing Co, 1975, pp 589-623. 9. E rffm eyer, J. Adverse reactions to penicillin. Ann Allergy 47:288-297, 1981. 10. Batson, J.M . Anaphylactic reactions to oral ad ministration o f penicillin. N Engl J Med 262:590-595, 1960. 11. K ropin, P. Anaphylaxis with orally adm inis tered penicillin. N Engl J Med 267:820-821, 1962. 12. Geym an, J.P . Anaphylactic reaction to oral penicillin. Calif Med (114):87-89, 1971. 13. Levine, M.I.; Perri, J.; and Anthony, J.J. A fatal anaphylactic reaction to oral penicillin. J Allergy 31:487-491, 1960. 14. S p ark , R.P. Fatal anaphylaxis d u e to oral penicillin. Am J Clin Pathol 56:407-411, 1971. 15. Sullivan, T.J. Cardiac disorders in penicillin-in duced anaphylaxis: association with in trav en o u s therapy. JA M A 248(17):2161-2162, 1982. 16. H erm an, J.E ., and Fleischman, P. Unusual evi dence of myocardial involvement during hypersensiti vity r e a c tio n to o ra l p e n ic illin . I s r J M ed Sci 14(8):848-851, 1978.
Bilateral fusion of the maxillary central incisors to supernumerary teeth: report of case K e ith D . S tillw e ll, D D S J o h n M . C o k e, D D S
A rare occurrence o f bilateral dental fusion is reported. An alternative to conventional treatm ent is described in which the super numerary teeth are separated and m ain tained as p a rt o f the anterior complement o f teeth.
n th e past, m isshapen accessory te e th o r fu sed incisors in th e p e rm a n e n t d e n titio n w ere e x tracted an d replaced with a prosthesis. A few case rep o rts, how ever, detailed co n servative, m ultidisciplinary ap p ro a ch es to m a n a g e a n d re s to re th e fu n c tio n an d esthetic a p p e a ra n c e o f teeth affected by a n te rio r d en tal fu sio n .1'6 T h is article re ce n tral incisors fuse to su p e rn u m e ra ry p o rts a ra re o ccurrence o f bilateral dental te eth . A fte r a p re o p e ra tiv e ev alu atio n , fusion in w hich th e m axillary p e rm a n e n t w hich includ ed consultations with peri-
I
62 ■ JAD A, V ol. 112, January 1986
F ig 1 ■ S h o w n is a la b ia l v ie w o f th e in d e p e n d e n t m a x illa r y p erm a n en t righ t and left central incisors bilat erally fu sed to supernum er ary teeth (late m ixed denti tion).
F ig 2 ■ A n o c c lu s a l v ie w show s norm al arch form with m a x illa r y p erm a n en t righ t and le ft lateral in c is o r s in palatoversion to on e another. Enam el projection s are ap parent on the lin gual surface o f the fused pair o f m axillary p e r m a n e n t le ft c en tra l in cisors (mirror image).
o d o n tis ts, e n d o d o n tis ts , a n d o ra l a n d m axillofacial su rg eo n s, th e fused pairs o f te e th w ere tr e a te d by s e p a r a tin g a n d
CLINICAL
REPORTS
F ig 4 ■ T h e p e r ia p ic a l r a F ig 3 ■ T h e p e r ia p ic a l r a d io g ra p h sh o w s w e ll-fo rm e d b u t s e p a ra te ro o ts a n d p u lp c h a m b e r o f th e m a x illa ry p e r m a n e n t r ig h t c e n tra l in c is o r . T h e la te r a l in c is o r is s u p e rim p o s e d .
d io g ra p h sh o w s s im ila r ro o t a n d p u lp m o rp h o lo g ic s tru c tu re o f th e m a x illa ry p e rm a n e n t le ft c e n tra l in c is o r. T h e l a t e r a l i n c i s o r is s u p e r i m p o se d . A n e n a m e l p ro je c tio n is sh o w n , a n d a p u lp a l c o n n e c tio n is su sp e c te d .
m ain tain in g th e su p e rn u m e ra ry te e th as p a rt of the a n te rio r co m p le m e n to f teeth.
Review of literature D ental fusion is a developm ental abnorm ality in which th ere is a den tin al union o f two o r m ore indep en d en tly developed, adjacent te e th .1,7'9 A lthough d e n ta l fusion can affect any tooth, teeth in the a n te rio r region o f the prim ary d e n tition are affected m ost freq u en tly .7,9 S uper n u m era ry tee th a re any teeth in excess o f the norm al n u m b e r o f teeth. In contrast to fusion, su p e rn u m era ry tee th rarely are fo und in the p rim a ry d e n titio n .10 S u p e rn u m e ra ry te e th pred o m in an tly occur in the a n te rio r sextant o f the p e rm a n e n t d entition. S u p e rn u m era ry teeth have a statistical p red ilectio n o f 2 to 1 for m ales.11,12 M any clinical problem s may arise as a result o f one o r the o th e r o f these two anom alies, including a ltered tim es o f prim ary tee th e x f o lia tin g , a lte r e d r e q u ir e m e n t s f o r a rc h len g th ,12 a m idline diastem a, re ta rd ed tooth e ru p tio n , d e n ta l im paction, displacem ent o f p e rm a n en t incisors,13 a n d periodontal com pli cations.9 Also, fused o r su p e rn u m era ry teeth often affect adversely the esthetic a p p earan ce o f a patien t’s face.
Report of case A w hite m ale aged 11 years 3 m onths cam e to th e u n iv e rs ity ’s d e n ta l c linic. T h e p a tie n t seem ed to be a healthy child in no a p p are n t discom fort. T h e patient's m o th er stated th at the son’s p rim ary incisors were retained until the son was 8 years old. As the patien t’s p e rm a n e n t incisors began to e ru p t, the m o th e r noticed th at the teeth w ere d e fo rm e d , a p p ea rin g as one tooth instead o f as sep arate teeth. T h e d e fo r m ity was o f c oncern to both the patien t a n d the p a ren ts, as th e p a tie n t said he was ridiculed by schoolm ates a n d siblings because o f his a p p e a r ance. R esults o f th e patien t’s and fam ily’s m edical and social histories a n d physical exam ination w ere n o n c o n trib u to ry . A n oral exam ination disclosed th a t th e patient had a late m ixed d e n tition. T h e re was evidence that the patient had n o rm al d e n to sk eleta l grow th, w ith bilateral Class I m olar relationships and no a p p a re n t discrepancies in arch lengths. T h e p a tie n t’s m idlines w ere in ag ree m e n t with the 40% over bite and 1.5 m m overjet. T h e crow n o f the m axillary rig h t central incisor was fused to a su p e rn u m era ry tooth with a total m esiodistal d iam e te r o f 16 m m. T h e crow n o f the m axillary left central incisor also was fused to a su p e r
n u m era ry tooth with a total m esiodistal diam e te r o f 15.5 m m . An enam el projection th a t re sem bled a talon cusp was associated w ith the lingual su rface o f the left p a ir o f fused teeth. T h is p ro jec tio n was fo u n d to be in h y p e r occlusion. T h e m axillary right a n d left lateral incisors w ere e ru p te d 8 m m in palatoversion to o n e a n o th e r b u t w ere well fo rm ed (Fig 1, 2). R ad io g ra p h s disclosed th a t all o f th e p a tie n t’s p e rm a n e n t teeth w ere p re sen t a n d developing norm ally except in the m axillary a n te rio r sex tan t. Superim position o f th e lateral incisors’ roots com plicated the d elineation o f the lines o f fusion. It a p p ea red th a t the m axillary rig h t cen tral incisor was fused by enam el and d e n tin from its incisal edge to the alveolar crest. Sepa ra te roots a n d p u lp c ham bers w ere well form ed. T h e line o f fusion fo r the tooth fused w ith the m axillary left central incisor seem ed sym m etri cal, with sim ilar p ulp and root separation and m atu ratio n . H ow ever, it was suspected th a t the associated enam el projection was co nnected to th e u n d e rly in g root canal systems o f b oth teeth (Fig 3, 4). It was d ecid ed to a tte m p t to se p a ra te each p air o f fused incisors a n d to re co n to u r each to m ake them a p p e a r as no rm al m axillary cen tral a n d lateral incisors. T h e palatally positioned lateral incisors w ere left in place until a p ro g nosis could be established a fte r surgery. A fter a local infiltration anesthetic was adm inistered, the p ro c e d u re began. A buccal subm arginal in cision was m ade in a scalloped fashion from the m axillary rig h t prim ary canine to the m axillary left p rim a ry canine. T h e buccal incision th en was elevated as a full-thickness, m ucoperiosteal en v elo p e fla p , a n d b o th m axillary p rim a ry canines w ere extracted. T h e fused cen tral in cisors w ere se p a ra ted fro m th e ir respective s u p e r n u m e ra ry tee th w ith a th in , ta p e re d , high-speed d iam o n d b u r with th e use o f copi ous am o u n ts o f w ater. T h e w id th o f th e s u p e rn u m e ra ry crow ns w ere increased at the expense o f the crow ns o f th e cen tral incisors to create th e im pression o f no rm al m esiodistal dim ensions. Each sep a ra tion was m ade to approxim ately 2 to 3 mm below the bony alveolar crest to e n su re com-
Stillw ell-C oke : FUSIO N OF M AXILLARY CENTRAL INCISORS ■ 63
CLINICAL REPORTS
plete separation. A flame-shaped finishing bur then was applied to recontour the interproximal and incisal enamel surfaces and effect a simulation o f a normal crown’s m orphologic structure. Minor osteoplasty was perform ed along the cem entoenam el junction, and interproximal sluiceways were provided to promote the formation o f normal gingival architecture. N o pulp exposure was detected clinically after separating the tooth fused with the maxillary righ t cen tral incisor. H ow ever, w h en the enamel projection was removed from the lin gual surface o f the left pair, pulpal exposures occurred in both teeth along the lines o f separa tion, interproximally 1 mm coronal to the alveo lar crest. Partial pulpectomies were perform ed immediately on exposed pulps, using a calcium hydroxide-zinc phosphate base, followed by acid-etched composite restorations. T h e entire surgical site was closed with no. 4 (0) black silk, continuous-locking sutures. T h e patient’s recovery after surgery was un complicated. By the 30-day recall appointment, normal gingival architecture was seen inter proxim ally and buccolingually between the separated teeth. T h e sulcus depth circumferentially did not exceed 3 mm. T he patient’s four incisors showed signs o f pulpal sensitivity. T h e palatally erupted lateral incisors were extracted, with the patient under local anes thesia, without complication. Forty-five days after the initial surgery, the patient’s maxillary incisors showed significant percussion sensitiv ity and increasing mobility. Thermal and elec tric pulp testing confirmed a tentative diagnosis o f irreversible pulpitis. Conventional endodon tic therapy was used to treat each newly sepa rated in cisor. A fter d eb rid em en t and in strumentation were done, a laterally condensed gutta-percha technique was used to obturate the root canals. At the 60-day evaluation after surgery, all symptoms associated with the in cisors had ceased. The gingival tissues were o f normal color and consistency. T he mobility o f teeth decreased greatly, and the surgical site continued to be free o f sulcular bleeding or excessive pocket depth. Light-cured, acidetched composite veneers were applied to each incisor to enhance further the esthetic appear ance (Fig 5). T he continued stability o f the in cisors was m onitored for 18 m onths after surgery.
Discussion T he incidence o f dental fusion is .42% to .50% , an d th e in c id e n c e o f s u p e r numerary teeth is .46% to 2.0%.14-19 Thus, an occurrence o f bilateral dental fusion to supernumerary teeth, such as the one in this case, is rare. Bilateral dental fusion may have occurred in this case after both maxillary central incisors com pleted a nearly perfect mitotic division, form ing, in effect, a pair o f supernumerary maxillary central incisors. This would explain how both halves o f the fused structures almost 64 ■ JADA, Vol. 112, Janu ary 1986
were identical in shape and width. Then, as crowding o f the tooth buds occurred in the developing premaxilla, the paired enamel projections may have been forced together, resulting in the fusion o f the maturing crowns o f the incisors. T he clinical management o f this case was approached unconventionally and, o f necessity, included consideration o f the patient’s cooperative ability, em otional stability, and the family’s financial limita tions. Had orthodontic treatment been within the family’s financial means, an or thodontic appliance w ould have been placed after the surgical removal o f the fused structures which would have in creased greatly the length o f treatment. T he extractions o f the involved maxillary central incisors would have created a re sidual edentulous area after surgery that would have required a costly replacement o f a prosthesis in the future. If both pairs o f fused incisors had been extracted with out orthodontic correction o f the palatally positioned lateral incisors, an even larger e d e n tu lo u s sp a ce w o u ld h a v e b een created. This space would have required placement o f a transitional partial denture for an extended period. Occasionally, the wearing o f a partial denture for long periods can promote the loss o f alveolar b one in the anterior maxilla. This could have resulted in a ridge d efect, which w ould have com prom ised the ultimate placem ent o f a fixed partial denture. By separating and maintaining the fused teeth, alveolar bone support was preserved, and the concerns o f esthetic appearance were met without delay or added expense.
Conclusion A rare case o f bilateral dental fusion in which the maxillary permanent central in cisors fused to supernumerary teeth is presented. T he treatment, consisting o f a surgical separation o f the fused pairs o f maxillary permanent central incisors, was an attem pt to incorporate the super numerary teeth as part o f the anterior complement o f maxillary incisors. T he ra tionale for surgical intervention was based on several objectives: to improve the esthe tic appearance o f the patient’s mouth; to separate and maintain the fused incisors and avoid extended and costly orthodon tic intervention; and, by not extracting the affected teeth, to preserve the alveolar bone support and avoid a ridge deficiency. An acceptable esthetic appearance re sulted from the procedure, which did not rely on complex prosthetic rehabilitation;
potentially dam aging occlusal interfer ences were removed; and the gingival ar chitecture and periodontal prognosis o the involved incisors were improved sig nificantly. T he separation technique described ir this paper and in earlier papers provide: another alternative for the managemeni o f patients who have bilateral dental fu sion. T h e separation and incorporation oi similarly fused teeth can be considered vi able treatment.
------------------JWOA-------------------D r. Stillwell is in g ro u p practice, M anhattan, KS. D r C oke is clinical associate p rofessor, U niversity o f Col o ra d o School o f D entistry, D enver, a n d d ire c to r, d e n tal e d u ca tio n , St. Jo se p h H ospital, 1835 F ran k lin St D enver, 80218. A ddress requests fo r re p rin ts to D r Coke. 1. Itkin, A.B., a n d B a rr, G.S. C om prehensive m an ag em en t o f the dou b le tooth: re p o rt o f case. JA D ^ 90(6):1269-1272, 1975. 2. E idelm an, E. Fusion o f m axillary prim ary c e n tra a nd lateral incisors bilaterally. P e d ia tr D ent 3(4):346 347, 1981. 3. Lowell, R.J., a n d Solom on, L. Fused teeth . JA D ^ 68(5):762, 1964. 4. C lem , W .H ., a n d N atkin, E. T re a tm e n t o f the fused tooth: re p o rt o f case. O ral S u rg 21:365-370 1966. 5. M arechaux, S.C. T h e tre a tm e n t o f fusion o f a m axillary c en tra l incisor an d a s u p e rn u m erary : report o f a case. ASDC J D en t C hild 51(3): 196-199, 1984. 6. S hapira, J ., a n d others. A tw o-step separation technique fo r fused teeth : clinical re p o rt. P e d ia tr Deni 5(4):270-272, 1983. 7. B ier, S.J. Fusion. NY State D e n t J 24:246-247 1958. 8. Levitas, T .C . G em ination, fusion, tw inning, and concrescence. ASDC J D ent C hild 32:93-100, 1965. 9. M ader, C.L. Fusion o f te e th . JA D A 98( l):62-64, 1979. 10. S h afer, R.E.; H ine, M .K.; a n d Levy, B.M. A textbook o f oral pathology, ed 3. P hiladelphia, W. B S aunders C o, 1974, p 43. 11. L u ten , J.R . T h e prevalence o f s u p ern u m erary te e th in p rim ary a n d m ixed d e n titions. ASDC J D eni C hild 34:346-353, 1967. 12. T a y , F.; Pang, A.; an d Y uen, S. U n e ru p te d m axillary a n te rio r s u p e rn u m e ra ry teeth : re p o rt o f 204 cases. ASDC J D ent C hild 51(4):289-294, 1984. 13. W eber, F.N . S u p e rn u m e ra ry teeth . D ent Clin N o rth A m July:509-517, 1964. 14. B y rd , E.D. Incidence o f su p e rn u m e ra ry and congenitally m issing teeth. ASDC J D ent C hild 10:8486, 1943. 15. C layton, J.M . C ongenital d e n ta l anom alies oc c u rrin g in 3552 children. ASDC J D en t C hild 23:206208, 1956. 16. G ra h n e n , H ., and G ra h n a th , L.E. N um erical variations in the prim ary de n titio n an d th e ir c o rre la tio n w ith th e p e rm a n e n t d e n titio n . O d o n to l Revy 12:348-357, 1961. 17. M enczer, L.F. A nom alies o f th e p rim ary d e n ti tion. ASDC J D ent C hild 22:57-62, 1955. 18. B u e n v ia je , T .M ., a n d R a p p , R. D e n ta l anom alies in children: a clinical a n d ra d io g ra p h ic su r vey. ASDC J D ent C hild 51:42-46, 1984. 19. M c K ib b e n , D .R ., a n d B r e a r le y , L .J . R a d io g ra p h ic d e te r m in a tio n o f th e p re v a le n c e of selected d e n ta l anom alies in ch ild ren . ASDC J D ent C hild 38:390-398, 1971.
tion p referab le. C orticosteroids m ay be ad m in istered intravenously o r in tra m u s cularly to aid in th e prevention o f edem a by p rev en tin g capillary dilation. T h ey also aid in d e c r e a s in g in f la m m a tio n a n d ed em a th a t occur as a result o f the release o f b rad y k in in s, substance P, an d o th e r am ino acids. C orticosteroids have a slow onset, how ever, an d are o f little im m ediate value.8
Summary A re p o rt o f an anaphylactic reaction to oral penicillin is p rese n ted ; th e relative pharm acologic reactions are review ed; the initial signs an d sym ptom s are analyzed; a n d a successful tre a tm e n t m ethod is d e scribed. -----------------------JW O A --------------------------
Dr. Kloberdanz was resident, and Dr. Bennett is professor and chairman, departm ent o f anesthesia, and Dr. McDonald is assistant professor, departm ent o f oral surgery, University o f Pittsburgh School of Dental Medicine, C-130 Salk Hall, Pittsburgh, 15261. A ddress requests for reprints to Dr. Bennett. 1. Malamed, S.F. Medical emergencies in the dental office. St. Louis, C. V. Mosby Co, 1982, pp 286-308. 2. Roberts, J; Bianco, M.M.; and Fine, J. Fatal anaphylactic reaction to oral penicillin: report o f a case.JAD A 110(4):505-506, 1985. 3. Bennett, O.R., ed. M onheim’s local anesthesia and pain control in dental practice. St. Louis, C. V. Mosby Co, 1984, pp 225-235. 4. Beall, G.N. Allergy and clinical immunology. New York, John Wiley & Sons, Inc, 1983. 5. Isselbacher, K.J., and others. H arrison’s princi ples o f internal medicine, ed 9. New York, McGrawHill Book Co, 1980, pp 242-244. 6. Bach, M.K. Im mediate hypersensitivity. M odern concepts and developments. New York, Marcel Dekker, Inc, 1978, pp 598-602. 7. Gill, C., and Michaelides, P.L. Dental drugs and anaphylactic reactions: rep o rt o f case. O ral Surg
REPORTS
50(l):30-32, 1980. 8. Goodman, L.S., and Gilman, A.G. T he p h ar macological basis o f therapeutics, ed 5. New York, Macmillan Publishing Co, 1975, pp 589-623. 9. E rffm eyer, J. Adverse reactions to penicillin. Ann Allergy 47:288-297, 1981. 10. Batson, J.M . Anaphylactic reactions to oral ad ministration o f penicillin. N Engl J Med 262:590-595, 1960. 11. K ropin, P. Anaphylaxis with orally adm inis tered penicillin. N Engl J Med 267:820-821, 1962. 12. Geym an, J.P . Anaphylactic reaction to oral penicillin. Calif Med (114):87-89, 1971. 13. Levine, M.I.; Perri, J.; and Anthony, J.J. A fatal anaphylactic reaction to oral penicillin. J Allergy 31:487-491, 1960. 14. S p ark , R.P. Fatal anaphylaxis d u e to oral penicillin. Am J Clin Pathol 56:407-411, 1971. 15. Sullivan, T.J. Cardiac disorders in penicillin-in duced anaphylaxis: association with in trav en o u s therapy. JA M A 248(17):2161-2162, 1982. 16. H erm an, J.E ., and Fleischman, P. Unusual evi dence of myocardial involvement during hypersensiti vity r e a c tio n to o ra l p e n ic illin . I s r J M ed Sci 14(8):848-851, 1978.
Bilateral fusion of the maxillary central incisors to supernumerary teeth: report of case K e ith D . S tillw e ll, D D S J o h n M . C o k e, D D S
A rare occurrence o f bilateral dental fusion is reported. An alternative to conventional treatm ent is described in which the super numerary teeth are separated and m ain tained as p a rt o f the anterior complement o f teeth.
n th e past, m isshapen accessory te e th o r fu sed incisors in th e p e rm a n e n t d e n titio n w ere e x tracted an d replaced with a prosthesis. A few case rep o rts, how ever, detailed co n servative, m ultidisciplinary ap p ro a ch es to m a n a g e a n d re s to re th e fu n c tio n an d esthetic a p p e a ra n c e o f teeth affected by a n te rio r d en tal fu sio n .1'6 T h is article re ce n tral incisors fuse to su p e rn u m e ra ry p o rts a ra re o ccurrence o f bilateral dental te eth . A fte r a p re o p e ra tiv e ev alu atio n , fusion in w hich th e m axillary p e rm a n e n t w hich includ ed consultations with peri-
I
62 ■ JAD A, V ol. 112, January 1986
F ig 1 ■ S h o w n is a la b ia l v ie w o f th e in d e p e n d e n t m a x illa r y p erm a n en t righ t and left central incisors bilat erally fu sed to supernum er ary teeth (late m ixed denti tion).
F ig 2 ■ A n o c c lu s a l v ie w show s norm al arch form with m a x illa r y p erm a n en t righ t and le ft lateral in c is o r s in palatoversion to on e another. Enam el projection s are ap parent on the lin gual surface o f the fused pair o f m axillary p e r m a n e n t le ft c en tra l in cisors (mirror image).
o d o n tis ts, e n d o d o n tis ts , a n d o ra l a n d m axillofacial su rg eo n s, th e fused pairs o f te e th w ere tr e a te d by s e p a r a tin g a n d
CLINICAL
REPORTS
F ig 4 ■ T h e p e r ia p ic a l r a F ig 3 ■ T h e p e r ia p ic a l r a d io g ra p h sh o w s w e ll-fo rm e d b u t s e p a ra te ro o ts a n d p u lp c h a m b e r o f th e m a x illa ry p e r m a n e n t r ig h t c e n tra l in c is o r . T h e la te r a l in c is o r is s u p e rim p o s e d .
d io g ra p h sh o w s s im ila r ro o t a n d p u lp m o rp h o lo g ic s tru c tu re o f th e m a x illa ry p e rm a n e n t le ft c e n tra l in c is o r. T h e l a t e r a l i n c i s o r is s u p e r i m p o se d . A n e n a m e l p ro je c tio n is sh o w n , a n d a p u lp a l c o n n e c tio n is su sp e c te d .
m ain tain in g th e su p e rn u m e ra ry te e th as p a rt of the a n te rio r co m p le m e n to f teeth.
Review of literature D ental fusion is a developm ental abnorm ality in which th ere is a den tin al union o f two o r m ore indep en d en tly developed, adjacent te e th .1,7'9 A lthough d e n ta l fusion can affect any tooth, teeth in the a n te rio r region o f the prim ary d e n tition are affected m ost freq u en tly .7,9 S uper n u m era ry tee th a re any teeth in excess o f the norm al n u m b e r o f teeth. In contrast to fusion, su p e rn u m era ry tee th rarely are fo und in the p rim a ry d e n titio n .10 S u p e rn u m e ra ry te e th pred o m in an tly occur in the a n te rio r sextant o f the p e rm a n e n t d entition. S u p e rn u m era ry teeth have a statistical p red ilectio n o f 2 to 1 for m ales.11,12 M any clinical problem s may arise as a result o f one o r the o th e r o f these two anom alies, including a ltered tim es o f prim ary tee th e x f o lia tin g , a lte r e d r e q u ir e m e n t s f o r a rc h len g th ,12 a m idline diastem a, re ta rd ed tooth e ru p tio n , d e n ta l im paction, displacem ent o f p e rm a n en t incisors,13 a n d periodontal com pli cations.9 Also, fused o r su p e rn u m era ry teeth often affect adversely the esthetic a p p earan ce o f a patien t’s face.
Report of case A w hite m ale aged 11 years 3 m onths cam e to th e u n iv e rs ity ’s d e n ta l c linic. T h e p a tie n t seem ed to be a healthy child in no a p p are n t discom fort. T h e patient's m o th er stated th at the son’s p rim ary incisors were retained until the son was 8 years old. As the patien t’s p e rm a n e n t incisors began to e ru p t, the m o th e r noticed th at the teeth w ere d e fo rm e d , a p p ea rin g as one tooth instead o f as sep arate teeth. T h e d e fo r m ity was o f c oncern to both the patien t a n d the p a ren ts, as th e p a tie n t said he was ridiculed by schoolm ates a n d siblings because o f his a p p e a r ance. R esults o f th e patien t’s and fam ily’s m edical and social histories a n d physical exam ination w ere n o n c o n trib u to ry . A n oral exam ination disclosed th a t th e patient had a late m ixed d e n tition. T h e re was evidence that the patient had n o rm al d e n to sk eleta l grow th, w ith bilateral Class I m olar relationships and no a p p a re n t discrepancies in arch lengths. T h e p a tie n t’s m idlines w ere in ag ree m e n t with the 40% over bite and 1.5 m m overjet. T h e crow n o f the m axillary rig h t central incisor was fused to a su p e rn u m era ry tooth with a total m esiodistal d iam e te r o f 16 m m. T h e crow n o f the m axillary left central incisor also was fused to a su p e r
n u m era ry tooth with a total m esiodistal diam e te r o f 15.5 m m . An enam el projection th a t re sem bled a talon cusp was associated w ith the lingual su rface o f the left p a ir o f fused teeth. T h is p ro jec tio n was fo u n d to be in h y p e r occlusion. T h e m axillary right a n d left lateral incisors w ere e ru p te d 8 m m in palatoversion to o n e a n o th e r b u t w ere well fo rm ed (Fig 1, 2). R ad io g ra p h s disclosed th a t all o f th e p a tie n t’s p e rm a n e n t teeth w ere p re sen t a n d developing norm ally except in the m axillary a n te rio r sex tan t. Superim position o f th e lateral incisors’ roots com plicated the d elineation o f the lines o f fusion. It a p p ea red th a t the m axillary rig h t cen tral incisor was fused by enam el and d e n tin from its incisal edge to the alveolar crest. Sepa ra te roots a n d p u lp c ham bers w ere well form ed. T h e line o f fusion fo r the tooth fused w ith the m axillary left central incisor seem ed sym m etri cal, with sim ilar p ulp and root separation and m atu ratio n . H ow ever, it was suspected th a t the associated enam el projection was co nnected to th e u n d e rly in g root canal systems o f b oth teeth (Fig 3, 4). It was d ecid ed to a tte m p t to se p a ra te each p air o f fused incisors a n d to re co n to u r each to m ake them a p p e a r as no rm al m axillary cen tral a n d lateral incisors. T h e palatally positioned lateral incisors w ere left in place until a p ro g nosis could be established a fte r surgery. A fter a local infiltration anesthetic was adm inistered, the p ro c e d u re began. A buccal subm arginal in cision was m ade in a scalloped fashion from the m axillary rig h t prim ary canine to the m axillary left p rim a ry canine. T h e buccal incision th en was elevated as a full-thickness, m ucoperiosteal en v elo p e fla p , a n d b o th m axillary p rim a ry canines w ere extracted. T h e fused cen tral in cisors w ere se p a ra ted fro m th e ir respective s u p e r n u m e ra ry tee th w ith a th in , ta p e re d , high-speed d iam o n d b u r with th e use o f copi ous am o u n ts o f w ater. T h e w id th o f th e s u p e rn u m e ra ry crow ns w ere increased at the expense o f the crow ns o f th e cen tral incisors to create th e im pression o f no rm al m esiodistal dim ensions. Each sep a ra tion was m ade to approxim ately 2 to 3 mm below the bony alveolar crest to e n su re com-
Stillw ell-C oke : FUSIO N OF M AXILLARY CENTRAL INCISORS ■ 63
CLINICAL REPORTS
plete separation. A flame-shaped finishing bur then was applied to recontour the interproximal and incisal enamel surfaces and effect a simulation o f a normal crown’s m orphologic structure. Minor osteoplasty was perform ed along the cem entoenam el junction, and interproximal sluiceways were provided to promote the formation o f normal gingival architecture. N o pulp exposure was detected clinically after separating the tooth fused with the maxillary righ t cen tral incisor. H ow ever, w h en the enamel projection was removed from the lin gual surface o f the left pair, pulpal exposures occurred in both teeth along the lines o f separa tion, interproximally 1 mm coronal to the alveo lar crest. Partial pulpectomies were perform ed immediately on exposed pulps, using a calcium hydroxide-zinc phosphate base, followed by acid-etched composite restorations. T h e entire surgical site was closed with no. 4 (0) black silk, continuous-locking sutures. T h e patient’s recovery after surgery was un complicated. By the 30-day recall appointment, normal gingival architecture was seen inter proxim ally and buccolingually between the separated teeth. T h e sulcus depth circumferentially did not exceed 3 mm. T he patient’s four incisors showed signs o f pulpal sensitivity. T h e palatally erupted lateral incisors were extracted, with the patient under local anes thesia, without complication. Forty-five days after the initial surgery, the patient’s maxillary incisors showed significant percussion sensitiv ity and increasing mobility. Thermal and elec tric pulp testing confirmed a tentative diagnosis o f irreversible pulpitis. Conventional endodon tic therapy was used to treat each newly sepa rated in cisor. A fter d eb rid em en t and in strumentation were done, a laterally condensed gutta-percha technique was used to obturate the root canals. At the 60-day evaluation after surgery, all symptoms associated with the in cisors had ceased. The gingival tissues were o f normal color and consistency. T he mobility o f teeth decreased greatly, and the surgical site continued to be free o f sulcular bleeding or excessive pocket depth. Light-cured, acidetched composite veneers were applied to each incisor to enhance further the esthetic appear ance (Fig 5). T he continued stability o f the in cisors was m onitored for 18 m onths after surgery.
Discussion T he incidence o f dental fusion is .42% to .50% , an d th e in c id e n c e o f s u p e r numerary teeth is .46% to 2.0%.14-19 Thus, an occurrence o f bilateral dental fusion to supernumerary teeth, such as the one in this case, is rare. Bilateral dental fusion may have occurred in this case after both maxillary central incisors com pleted a nearly perfect mitotic division, form ing, in effect, a pair o f supernumerary maxillary central incisors. This would explain how both halves o f the fused structures almost 64 ■ JADA, Vol. 112, Janu ary 1986
were identical in shape and width. Then, as crowding o f the tooth buds occurred in the developing premaxilla, the paired enamel projections may have been forced together, resulting in the fusion o f the maturing crowns o f the incisors. T he clinical management o f this case was approached unconventionally and, o f necessity, included consideration o f the patient’s cooperative ability, em otional stability, and the family’s financial limita tions. Had orthodontic treatment been within the family’s financial means, an or thodontic appliance w ould have been placed after the surgical removal o f the fused structures which would have in creased greatly the length o f treatment. T he extractions o f the involved maxillary central incisors would have created a re sidual edentulous area after surgery that would have required a costly replacement o f a prosthesis in the future. If both pairs o f fused incisors had been extracted with out orthodontic correction o f the palatally positioned lateral incisors, an even larger e d e n tu lo u s sp a ce w o u ld h a v e b een created. This space would have required placement o f a transitional partial denture for an extended period. Occasionally, the wearing o f a partial denture for long periods can promote the loss o f alveolar b one in the anterior maxilla. This could have resulted in a ridge d efect, which w ould have com prom ised the ultimate placem ent o f a fixed partial denture. By separating and maintaining the fused teeth, alveolar bone support was preserved, and the concerns o f esthetic appearance were met without delay or added expense.
Conclusion A rare case o f bilateral dental fusion in which the maxillary permanent central in cisors fused to supernumerary teeth is presented. T he treatment, consisting o f a surgical separation o f the fused pairs o f maxillary permanent central incisors, was an attem pt to incorporate the super numerary teeth as part o f the anterior complement o f maxillary incisors. T he ra tionale for surgical intervention was based on several objectives: to improve the esthe tic appearance o f the patient’s mouth; to separate and maintain the fused incisors and avoid extended and costly orthodon tic intervention; and, by not extracting the affected teeth, to preserve the alveolar bone support and avoid a ridge deficiency. An acceptable esthetic appearance re sulted from the procedure, which did not rely on complex prosthetic rehabilitation;
potentially dam aging occlusal interfer ences were removed; and the gingival ar chitecture and periodontal prognosis o the involved incisors were improved sig nificantly. T he separation technique described ir this paper and in earlier papers provide: another alternative for the managemeni o f patients who have bilateral dental fu sion. T h e separation and incorporation oi similarly fused teeth can be considered vi able treatment.
------------------JWOA-------------------D r. Stillwell is in g ro u p practice, M anhattan, KS. D r C oke is clinical associate p rofessor, U niversity o f Col o ra d o School o f D entistry, D enver, a n d d ire c to r, d e n tal e d u ca tio n , St. Jo se p h H ospital, 1835 F ran k lin St D enver, 80218. A ddress requests fo r re p rin ts to D r Coke. 1. Itkin, A.B., a n d B a rr, G.S. C om prehensive m an ag em en t o f the dou b le tooth: re p o rt o f case. JA D ^ 90(6):1269-1272, 1975. 2. E idelm an, E. Fusion o f m axillary prim ary c e n tra a nd lateral incisors bilaterally. P e d ia tr D ent 3(4):346 347, 1981. 3. Lowell, R.J., a n d Solom on, L. Fused teeth . JA D ^ 68(5):762, 1964. 4. C lem , W .H ., a n d N atkin, E. T re a tm e n t o f the fused tooth: re p o rt o f case. O ral S u rg 21:365-370 1966. 5. M arechaux, S.C. T h e tre a tm e n t o f fusion o f a m axillary c en tra l incisor an d a s u p e rn u m erary : report o f a case. ASDC J D en t C hild 51(3): 196-199, 1984. 6. S hapira, J ., a n d others. A tw o-step separation technique fo r fused teeth : clinical re p o rt. P e d ia tr Deni 5(4):270-272, 1983. 7. B ier, S.J. Fusion. NY State D e n t J 24:246-247 1958. 8. Levitas, T .C . G em ination, fusion, tw inning, and concrescence. ASDC J D ent C hild 32:93-100, 1965. 9. M ader, C.L. Fusion o f te e th . JA D A 98( l):62-64, 1979. 10. S h afer, R.E.; H ine, M .K.; a n d Levy, B.M. A textbook o f oral pathology, ed 3. P hiladelphia, W. B S aunders C o, 1974, p 43. 11. L u ten , J.R . T h e prevalence o f s u p ern u m erary te e th in p rim ary a n d m ixed d e n titions. ASDC J D eni C hild 34:346-353, 1967. 12. T a y , F.; Pang, A.; an d Y uen, S. U n e ru p te d m axillary a n te rio r s u p e rn u m e ra ry teeth : re p o rt o f 204 cases. ASDC J D ent C hild 51(4):289-294, 1984. 13. W eber, F.N . S u p e rn u m e ra ry teeth . D ent Clin N o rth A m July:509-517, 1964. 14. B y rd , E.D. Incidence o f su p e rn u m e ra ry and congenitally m issing teeth. ASDC J D ent C hild 10:8486, 1943. 15. C layton, J.M . C ongenital d e n ta l anom alies oc c u rrin g in 3552 children. ASDC J D en t C hild 23:206208, 1956. 16. G ra h n e n , H ., and G ra h n a th , L.E. N um erical variations in the prim ary de n titio n an d th e ir c o rre la tio n w ith th e p e rm a n e n t d e n titio n . O d o n to l Revy 12:348-357, 1961. 17. M enczer, L.F. A nom alies o f th e p rim ary d e n ti tion. ASDC J D ent C hild 22:57-62, 1955. 18. B u e n v ia je , T .M ., a n d R a p p , R. D e n ta l anom alies in children: a clinical a n d ra d io g ra p h ic su r vey. ASDC J D ent C hild 51:42-46, 1984. 19. M c K ib b e n , D .R ., a n d B r e a r le y , L .J . R a d io g ra p h ic d e te r m in a tio n o f th e p re v a le n c e of selected d e n ta l anom alies in ch ild ren . ASDC J D ent C hild 38:390-398, 1971.