PEDIATRIC DENTISTRY[Copyright © 1986 byThe American Academy of Pediatric Dentistry

Volume 8 Number 4

Gemination of a maxillary permanent central incisortreated by autogenous transplantation of asupernumerary incisor: case report

Richard L. Spuller, DDS Matthew Harrington, DDS

AbstractThis report describes the extraction of a geminated maxillary

right permanent central incisor in an 8-year-old white femalefollowed by the autogenous transplantation of a maxillary leftsupernumerary incisor. A 2-year clinical and radiographic follow-up revealed no pathologic findings and confirmed continued rootdevelopment and pulp vitality in the transplanted tooth. Thisreport documents the usefulness of autogenous transplantation asa viable treatment option in selected cases.

Autogenous transplantation of teeth has been

utilized successfully for many years primarily for re-placing grossly carious permanent molars with un-erupted permanent third molars.1-3 The autogenoustransplantation of permanent anterior teeth is lesscommon because of a lack of appropriate donor teethsuitable for transplantation. 4 Supernumerary teethmay be ideal for replacing missing or develop-mentally malformed permanent incisors.5

Gemination and fusion are 2 developmentalanomalies affecting the permanent and primary den-titions. Gemination, the attempt by a single toothbud to divide, is detected clinically by crown en-largement and incisal notching.6 In contrast, fusionis defined as a union between the dentin and/orenamel of 2 or more developing teeth. 6 The inci-dence of gemination and fusion is less than 1% andis more common in the primary dentition.7

Radiographically, a fused tooth will have 2 rootcanals and pulp chambers. Geminated teeth have asingle pulp chamber and a single root canal. Whenfusion occurs, the total number of teeth in the dentalarch will be reduced unless a supernumerary toothis involved, s Gemination of teeth by definition willnot reduce the number of teeth present. Clinically,the 2 anomalies may be difficult to differentiate.Orthodontic, periodontic, endodontic, surgical, pros-

thetic, and multidisciplinary approaches have beenused in the management of fused and geminatedteeth.9-11 This report describes the autogenous trans-plantation of a supernumerary incisor to replace ageminated maxillary permanent central incisor.

Case Report

A 7-year-old Caucasian female was brought toColumbus Children’s Hospital dental clinic by hermother with a chief complaint that "a large tooth wasgrowing into her daughter’s mouth." Medical anddental histories were noncontributory. The motherreported that the primary dentition had appearednormal and there was no history of traumatic injury.Physical examination showed a normally developed7-year-old white female in excellent health. Oral ex-amination revealed a Class II mixed dentition withseveral carious teeth present.

The maxillary right permanent central incisorwas erupting and appeared enlarged mesiodistally,measuring 13 mm (Fig 1). The enamel on this toothwas normal in color and texture. A labial depressionor "coronal groove" extending cervically was pres-ent, but there was no detectable defect in the enamelcovering the groove. All other teeth appeared to bedeveloped normally and appropriate for the patient’schronological age. Initial clinical impression waseither gemination or fusion of the maxillary rightpermanent central incisor.

Radiographic examination was utilized to estab-lish the diagnosis and evaluate the unerupted devel-oping dentition. Occlusal, periapical, and panoramicradiographs showed a maxillary right permanentcentral incisor with root canal and pulp chambermorphology consistent with gemination. A super-numerary incisor also was present between the un-erupted maxillary left permanent central and lateralincisors (Fig 2).

PEDIATRIC DENTISTRY: December 1986/Vol. 8 No. 4 299

FIG 1. Geminated maxillary right permanent central in-cisor.

Following consideration of alternative treatmentoptions, it was decided that autogenous transplan-tation of the unerupted supernumerary incisor fol-lowing extraction of the geminated maxillary rightpermanent central incisor would provide the great-est benefit to the patient. Routine restorative dentaltreatment was performed and the patient was placedon 6-month recall to allow more root developmenton the unerupted supernumerary incisor.

The patient returned to the dental clinic 6months following examination. Intraoral radio-graphs demonstrated that root development on thesupernumerary incisor was between l/3 and ]/2 totalroot length. Using local anesthesia, a mucoperiostealflap was elevated on the left anterior maxilla. Thesupernumerary incisor was exposed and found to beacceptable morphologically for transplantation. Thegeminated maxillary right central incisor was ex-

FIG 3. Intraoral radiograph of transplanted supernumer-ary incisor.

tracted and the supernumerary incisor placed im-mediately into the extraction site and stabilized with3-0 silk sutures criss-crossing the incisal edge fromthe labial to the lingual gingivae (Fig 3). The muco-periosteal flap was repositioned and sutured. The pa-tient was advised not to bite on the front teeth andno rinsing of the area was allowed for 24 hr. After24 hr, the patient was instructed to begin rinsing theoral cavity several times a day and to begin gentlebrushing of the teeth.

The patient returned 1 week posttransplantationwithout complaints of discomfort. Excellent tissuehealing was observed and the sutures were removed.Subsequent examinations on a monthly basis dem-onstrated normal healing, decreased mobility, andno signs or symptoms of dental infection. Radio-graphic examinations revealed no signs of root re-sorption or periapical pathology. Negative responses

FIG 2. Intraoral radiograph revealing pulp chamber androot canal morphology of the geminated incisor and pres-ence of unerupted supernumerary incisor.

FIG 4. Photograph 2 years posttransplantation. Note thatthe patient appears to have 2 maxillary left central incisors.

300 TRANSPLANTATION OF A SUPERNUMERARY INCISOR: Spuller and Harrington

FIG 5. Intraoral radiograph 2 years posttransplantationdemonstrating continued root development and absence ofperiapical pathology.

were recorded to standard hot, cold, and electricalpulp tests. At 3 months posttransplantation, the pa-tient could not be contacted. Two years posttrans-plantation, the mother again contacted the dentalclinic and reported that she had returned to the localarea and requested a dental examination for herdaughter. Examination 2 years posttransplantationdemonstrated normal periodontal tissue status, con-tinued root development, and positive vitality teststo both ice and electrical stimulation (Figs 4, 5).

DiscussionThe presence of a geminated permanent tooth

in a developing dentition is a particularly difficultproblem to manage. The mesiodistal dimension ofthe tooth and the arch perimeter occupied makesnormal tooth alignment impossible. Reduction in thewidth of the tooth is the main treatment objective.When fusion is present, sectioning and reimplanta-tion may be considered because 2 distinct pulp cham-bers and root canals exist.12 When gemination occurs,pulp chamber morphology prohibits sectioning be-cause of periodontal and endodontic problems sec-ondary to the management of the pulp chamber androot canal perforations. In the case reported, auto-genous transplantation was possible because an ac-ceptable donor tooth was present.

The success of autogenous transplantation ofteeth is related to several factors. Plainfield has re-ported a success rate of 95% and has defined severalprecautions that will help insure successful trans-plantation.2 One of the first requirements is that thepatient should be healthy with an acceptable levelof oral hygiene. The parent and child must be in-structed in the proper postoperative care of the trans-planted tooth including keeping the operative site

clean and protecting the transplant from undue trau-ma until reattachment is complete. A soft diet with-out pulpy foods which might pack into the crevicularspace during the initial stages of healing is impor-tant.

Maintenance of pulpal viability is the most im-portant objective following the autogenous trans-plantation. Viability of the pulpal tissue is extremelyimportant for continued root development. Theamount of root development is directly related to theability of the transplanted tooth to revascularize. An-dreasen and Hjorting-Hansen have demonstrated thatteeth with incomplete root development nearly al-ways reestablish vascularization when reimplantedwithin 90 min.13 Studies by Skoglund and Tronstadhave confirmed these findings in autotransplantedteeth in dogs.14 Plainfield states that root develop-ment of the donor tooth should be between Vs andVi of the total root length.2 This recommendation in-creases transplant stability and ensures revasculari-zation.

Continued root development with apical clo-sure, as demonstrated in the present case, indicatesthat revascularization occurred following the trans-plantation of the donor supernumerary tooth al-though pulp tests were initially negative. The lackof patient response to thermal and electrical pulpstimulation at 3 months posttransplantation is notunusual. Plainfield states that it is common for trans-planted teeth to test nonvital for 6 months to 1 yearafter transplantation.2 Johnson et al. described 2 caseswhere immature permanent central incisors werereimplanted following trauma and did not respondto electrical or thermal testing for over 1 year.15 Inthe present case, a positive response to ice and elec-trical stimulation was recorded at the 2-year exami-nation. This finding indicates that sometime be-tween 3 months and 2 years, patient response topulpal stimulation returned. It is important to rec-ognize that the lack of pulpal response to thermaland electrical stimulation must not be interpreted asan indication of pulp tissue necrosis or transplantfailure.

Another important precaution is avoiding un-due trauma to Hertwig's epithelial root sheath or theroot surface of the donor tooth during transplanta-tion. Extraction of the donor tooth should be asatraumatic as possible. Damage to the cementum andloss in viability of the periodontal ligament are as-sociated with replacement resorption.16 The root sur-face of the donor tooth should not be scraped ortouched and transplantation should be completed asquickly as possible.

Splinting of the transplanted tooth is controver-sial with recommendations ranging from 1 to 6weeks.!-2'4 Andreasen has reported that splinting does

PEDIATRIC DENTISTRY: December 1986/Vol. 8 No. 4 301

not improve periodontal ligament healing and thatreplacement resorption was less in nonsplinted teethwhen compared to splinted teeth. Iz The main objec-tive in splinting the transplanted tooth is to insureinitial reattachment. Stabilization of the tooth mustnot inhibit normal physiologic functions of the tooth.Sutures in the present case were allowed to remain1 week. This allowed some movement of the trans-planted incisor which may reduce the incidence ofreplacement resorption and encourage periodontalligament viability.

Postoperative problems reported secondary toautogenous transplantation include pulpal necrosis,root resorption, ankylosis, arrest of root develop-ment, and root canal calcification2 -3 These compli-cations were not observed in the present case andshould not be expected if biologic principles are sat-isfied by appropriate transplantation techniques.

SummaryThe g~minated maxillary permanent incisor is a

particularly difficult problem to manage in a devel-oping dentition. A clinical report has been presenteddocumenting the successful transplantation of a su-pernumerary incisor to replace a geminated incisor.Pulpal viability and continued root development areto be expected in autotransplanted teeth if close at-tention is given to defined biologic principles andcareful case selection.

Dr. Spuller is an assistant professor, pediatric dentistry, The OhioState University and clinical director of the pediatric dental resi-dency program at Columbus Children’s Hospital; Dr. Harringtonis in the private practice of pediatric dentistry in North Olmsted,Ohio. Reprint requests should be sent to: Dr. Richard L. Spuller,Dept. of Pediatric Dentistry, The Ohio State University, Collegeof Dentistry, Postle Hall, 305 W. 12th Ave., Columbus, OH 43210-1241.

1. Apfel H: Transplantation of the unerupted third molar tooth.Oral Surg 9:96-98, 1956.

2. Plainfield S: A viable alternative: tooth transplantation. JProsthet Dent 50:667-71, 1983.

3. Bolton R: Autogenous transplantation and reimplantation ofteeth: report on 60 treated patients. Br J Oral Surg 12:147-65,1974.

4. Myers DR: Autogenous transplantation of an unerupted max-illary central incisor. J Pedod. 5:245-48, 1981.

5. Shulman LB: Impacted and unerupted teeth: donors for trans-planted tooth replacement. Dent Clin North Am 23:369-83,1979.

6. Pindborg JJ: Pathology of the Dental Hard Tissues. Philadel-phia; WB Saunders Co, 1970 pp 51-52.

7. Davis JM, Law DB, Lewis TM: An Atlas of Pedodontics, 2nded. Philadelphia; WB Saunders Co, 1981 pp 57-58.

8. Good DL, Berson RB: A supernumerary tooth fused to a max-illary permanent central incisor. Pediatr Dent 2:294-96, 1980.

9. Delaney GM, Goldblatt LI: Fused teeth: a multidisciplinaryapproach to treatment. J Am Dent Assoc 103:732-34, 1981.

10. Weiss JK: The double tooth. J Clin Orthod 14:780-87, 1980.11. Mehlman E: Management of a totally fused central and lateral

incisor with internal resorption perforating the labial aspectof the root. J Endod 4:189-91, 1978.

12. Blank B, Ogg RR, Levy AR: A fused central incisor. Periodon-tal considerations in comprehensive treatment. J Periodontol56:21-24, 1985.

13. Andreasen JO, Hjorting-Hansen E: Replantation of teeth. I.Radiographic and clinical study of 110 human teeth replantedafter accidental loss. Acta Odontol Scand 24:263-86, 1966.

14. Skoglund A, Tronstad L, Wallenius K: A microangiographicstudy of vascular changes in replanted and autotransplantedteeth in young dogs. Oral Surg 45:17-28, 1978.

15. Johnson WT, Goodrich JL, Garth JA: Replantation of avulsedteeth with immature root development. Oral Surg 60:420-27,1985.

16. Morris M, Moreinis A, Patel R, Prestup A: Factors affectinghealing after experimentally delayed tooth transplantation. JEndod 7:80-84, 1981.

17. Andreasen JO: The effect of splinting upon periodontal heal-ing after replantation of permanent incisors in monkeys. ActaOdontol Scand 33:313-23, 1975.

Quotable Quote: did you know that...

¯.. the government predicts there will be 20% more dentists in the United States by the end of thecentury? That forecast is included in the Health and Human Services annual report on healthmanpower. The report to Congress anticipates that 16% of the nation’s dentists will be female at theend of the century, compared to 5% today.

¯.. smoking rates among male dentists declined over the past decade? The American Cancer Societyreports that only 16% of male dentists aged 30-39 now smoke, whereas 25% of men smoke overall.This statistic was reported in Ca--A Cancer Journal for Clinicians.

302 TRANSPLANTATION OF A SUPERNUMERARY INCISOR: Spu|ler and Harrington