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There are many recognized dental anomalies, among the least common being the “triple tooth”, with a prevalence of 0.02% in the primary dentition. However, such malformation can more easily lead not only to carious pathology, due to dental dysmorphisms, and pulpal lesions, but also to rhizalysis and agenesis of the permanent elements, causing eruption alterations and malocclusions. Therefore, techniques such as CBCT and 3D anatomical replicas have been proposed to be able to study complex clinical situations such as the triple tooth in its entirety, in order to analyze anatomical structures and identify the best treatment plan. In this paper we propose a clinical case of a triple tooth in a 6-year-old child in the left mandible with fusion of incisor with a supernumerary tooth associated with the lateral incisor fusion.
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G. Eramo
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Annali di stomatologia
3D printing
Cone beam CT and stereolithographic model in primary dentition
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Case Report
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G. Eramo
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Ordinary Professor, Department of Medicine and Surgery, University of Perugia, Perugia, Italy
1971-1441
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3D printing
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Cone beam CT and stereolithographic model in primary dentition
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                                                                                                            Case report


Cone beam CT and stereolithographic
model in primary dentition

Giancarlo Barraco1                                              pathogenesis of triple tooth can be traced to fusion, gemi-
Stefano Pagano                                                  nation or concrescence5. Bennett described the first case
Stefano Eramo1                                                  in the late 1880s6 and only five cases were reported until
Stefano Eramo                                                   1984 when Knapp and McMahon reported one case and
                                                                reviewed the topic2-5 and coined the term describing this
                                                                anomaly in children. Shilpa and Nuvvula8 proposed the
1
    Ordinary Professor, Department of Medicine and Sur-         first classification9-11 recognized by the international sci-
    gery, University of Perugia, Perugia, Italy                 entific community:
                                                                • Type I: three pulpal chambers and three root canals
                                                                     due to fusion:
Corresponding author:                                                - Type Ia: fusion of two normal teeth with one super-
Prof Stefano Eramo                                                       numerary tooth;
Ordinary Professor, Department of Medicine and Sur-                  - Type Ib: fusion of three normal teeth.
gery, University of Perugia, Perugia, Italy                     • Type II: two pulpal chambers and two root canals:
                                                                     - Type IIa: a combination of a twin tooth (double
                                                                         tooth) and a supernumerary tooth;
Abstract                                                             - Type IIb: one twinned tooth (double tooth) and one
                                                                         normal tooth.
There are many recognized dental anomalies, among
                                                                In order to study complex dental situations, 3D printed ana-
the least common being the “triple tooth”, with a preva-
                                                                tomical replicas, already widely used in other medical fields
lence of 0.02% in the primary dentition. However, such
                                                                (such as orthopedics, cardiac and oncologic surgery, neu-
malformation can more easily lead not only to carious
                                                                rosurgery and transplants), have been proposed. Thanks
pathology, due to dental dysmorphisms, and pulpal
                                                                to stereolithography (SLA), an additive manufacturing
lesions, but also to rhizalysis and agenesis of the per-
                                                                technology12 anatomical structures visible in radiological
manent elements, causing eruption alterations and
                                                                images can be reproduced13. The latest technologies can
malocclusions. Therefore, techniques such as CBCT
                                                                be useful to study complex preoperative treatment plans,
and 3D anatomical replicas have been proposed to be
                                                                reducing surgery duration with fewer complications using
able to study complex clinical situations such as the
                                                                intra-operative surgical guides, improving doctor-patient
triple tooth in its entirety, in order to analyze anatom-
                                                                communication and reducing medical-legal conflicts14.
ical structures and identify the best treatment plan. In
                                                                SLA would also find a wide horizon in the medical train-
this paper we propose a clinical case of a triple tooth
                                                                ing for simulation techniques. Bioprinting15 represents the
in a 6-year-old child in the left mandible with fusion of
                                                                desirable advancement of such technology, with no longer
incisor with a supernumerary tooth associated with the
                                                                anatomical replicas in resin but in tissues and/or organs
lateral incisor fusion.
                                                                created “ad personam,” starting from the same cells as the
                                                                recipient individual.
                                                                This paper aims to make an accurate grading of the triple
Keywords: Cone Beam; Stereolithography; Ortho-                  tooth anomaly and obtain a complete anatomical and mor-
dontics; 3D printing.                                           phological evaluation for a correct prognosis and a suita-
                                                                ble treatment plan minimizing iatrogenic risks. The clinical
Introduction                                                    oral examination alone is not adequate for a correct and
                                                                complete treatment program, while CBTC radiodiagnostic
Teeth malformations can be classified in size abnormal-
                                                                techniques,
ities (microdontics and macrodontics), shape (such as
dens in dente, dens invaginatus, fusion or gemination),
number (such as agenesis, oligodontia, hypodontia or hy-
                                                                Methods
perodontia), position (ectopia, heterotopia or transposition)
or structure (dysplasia and hypoplasia). Primary dentition      We report a case of “triple tooth” of a 6-year-old child
abnormalities are frequently pathogenetic of cosmetic and       in the left mandible (fusion of incisors with supernumer-
functional, transient or permanent problems such as ab-         ary tooth) associated with the lateral incisor succedant
normal eruption or development of the permanent teeth           fusion. The patient was evaluated in the Department of
either in the chronology or site of eruption.                   Surgical and Biomedical Sciences, Section of Orthodon-
“Double teeth”, resulting from fusion or gemination, are        tics and Reconstructive Dentistry. History of trauma or
relatively frequent with an incidence between 0.1% and          special pathology and family history were not relevant.
1.55%1, while the union of the three teeth, or “triple tooth”   Examination showed irregular tooth morphology in the
is rarely reported in the primary dentition2-7. The etio-       patient’s anterior region, and there was fusion of the left

Annali di Stomatologia 2021; XII (4): 22-25                                                                                     22
     Cone beam CT and stereolithographic model in primary dentition

     maxillary central incisor with a supernumerary tooth and       Results
     of this with the lateral incisor (Figure 1). The fused teeth
     were caries-free, the succedant tooth 3.1 was partially        CT scan enabled a 3D reconstruction that highlights var-
     erupted but placed in a lingualized location. Based on         ious anatomical structures, such as the course of the in-
     the clinical and radiological features, we can describe        ferior alveolar nerve and the site of the chin foramen and
     our present case as Type IIa according to the classifi-        the realization of the stereolithographic replica (Figure 3).
     cation of Shilpa and Nuvvula8, a case of fusion of two         The parents were informed about the abnormality of the
     normally developed teeth with a supernumerary tooth            triple tooth and reassured that element 3.1 was erupting
     and an endodontic anatomy characterized by two pulpal          and already visible in the arch, even if lingualized, and the
     chambers and two root canals. The remaining primary            germ of lateral incisor 3.2 was developing normally. Con-
     teeth in both arches were normal. Periapical radiography       sidering the clinical examination and the CT findings, the
     revealed fusion of the central and supernumerary tooth         triple tooth was extracted. Parents were also made aware
     with the deciduous lateral incisor without a clear distinc-    of the concomitant problems and advised to perform reg-
     tion of the root canal in the supernumerary tooth with the     ular follow up, consult an orthodontist for potential erup-
     central canal. A cone beam CT scan was performed to            tion alterations. The dysmorphism of the tooth can make
     make a prognostic assessment of the subsequent clin-           it more subjected to carious lesions, with possible pul-
     ical picture and to evaluate the correct presence of the       popathy-related problems that may interfere with permu-
     permanent elements, their morphological structure, and         tation, inducing malocclusion or agenesis of the perma-
     the relationships between the triple tooth roots and the       nent succedant as reported in the literature 5,6,10,11,16.
     permanent tooth buds in relation to the planning of the        The examinations showed a physiological rhizalysis, the
     triple tooth extraction (Figure 2).                            presence of permanent tooth 3.2, and sufficient distance




                                                                           Figure 1. Triple tooth in the left mandible with a fu-
                                                                           sion of incisor and a supernumerary tooth associated
                                                                           with the lateral incisor succedant fusion.




     Figure 2. Cone beam CT scan of the triple tooth.

23                                                                                     Annali di Stomatologia 2021; XII (1-4): 22-25
G. Barraco et al.




Figure 3. Anatomic replica of the 6-years-old child mandible situation.



between the roots of the triple tooth and the underlying           but progressively fused endodontic units at the apex19.
permanent teeth; this allowed us to confidently schedule           Iis clear that the presence of an apical lesion makes en-
the extraction of the pathological element without any             dodontic therapy very hostile, considering endodontic
complications. At the follow-up visit one month after the          variability and dysmorphisms, orienting therapy toward
extraction, the soft tissues were in good trophic condition        extraction20. It should be noted that the literature con-
and 3.1 had spontaneously repositioned in the arch.                cordantly reported a high prevalence of agenesis of re-
                                                                   placement permanents8,9,19,21, this leads to the fact
Discussion                                                         that it is essential to perform a CBTC examination in or-
                                                                   der to make a correct prognostic and identify a suitable
The few cases reported does not allow a meaningful                 treatment plan.
assessment, but it can be stated that the prevalence of            Currently, there is no agreement among researchers on
triple teeth in the primary dentition is rare (0.02%)2 and         the mechanism by which triple dentition develops. Some
more frequent in the male sex and Asian populations as             believed that it is the derivation of three dental buds of
reported by M. Lagarde et al.17 stating how “triple tooth”         the primary dental lamina fused together6,8, however,
is more frequent in males than females (2:1), and that             most cases described a union between a supernumerary
the age of affected children ranged from 1 year and 11             tooth and the central or lateral incisor. Additional hypoth-
months to 10 years (mean age 4.9 years). Regarding the             eses are related to gemination events associated with
site, maxillary triple teeth are more common than man-             fusion of primary and secondary lamina and the high
dibular ones18. There is a preponderance in the left side          prevalence of permanent tooth agenesis5,8,19,22.
compared to the right side (4:3), while Shultz-Weidner             Performing a CBTC is essential for a 3D and/or stereo-
also reported the presence of a bilateral maxillary triple         lithographic reconstruction of the loco-regional situation
tooth11. Few cases in the literature evaluated the anat-           in order to assess not only the size of the roots and the
omy of chamber and root endodontium, however Knapp                 resulting anatomical relationships with the bud of the
and McMahon described how each tooth element of the                underlying permanent, but also potential agenesis and
triple tooth possessed its own root canal but converged            rhizalysis23. With these information an intervention can
into a shared chamber4. Deepti et al.16 presented a case           be planned, which may include an immediate extraction
in which the pulpal canals of 6.2 and a supernumerary              or a period of observation using preventive techniques,
tooth are largely fused with an hourglass figure, the canal        fluoroprophylaxis and topical fluoride therapy of dysmor-
of 6.1 is deformed and a communication or otherwise dys-           phic grooves9,24,25. However, triple-tooth cases require
plasia of dentin between 6.1 and the supernumerary can             collaboration between conservative dentist, orthodontist
be glimpsed. Aguilo L. et al.10 in a CT histology and mor-         and oral surgeon to achieve a complete resolution and
phology study of a triple tooth highlighted an endodontic          avoid cosmetic and functional complications26,27.
anatomy showing three autonomous pulpal chambers
whose canals however merge into a single canal within
                                                                   Conflict of Interest Statement
the three fused roots. Other Authors have described cas-
es of fused crowns and roots presenting three separate             None Declared.

Annali di Stomatologia 2021; XII (4): 22-25                                                                                       24
     Cone beam CT and stereolithographic model in primary dentition

     References                                                             16. Deepti T, Jatinder KD, Mridula G. Images in Medicine: Trip-
                                                                                licated Primary Anterior Teeth - A Report of Two Cases.
     1.    Kramer PF, Feldens CA, Ferreira SH, Spiguel MH, Feldens              JCDR. 2016;10:ZJ03-ZJ04
           EG. Dental anomalies and associated factors in 2- to 5-year-     17. Lagarde M et al. Simultaneous occurrence of triple teeth
           old Brazilian children. Int J Paediatr Dent. 2008;18:434–40.         and double teeth in primary dentition: A rare case report and
     2.    Ravn JJ. Aplasia, supernumerary teeth and fused teeth in             review of the literature. Clinical Case Reports. 2020
           the primary dentition. An epidemiologic study. Scand J Dent      18. Gellin ME. The distribution of anomalies of primary anterior
           Res. 1971;79:1–6.                                                    teeth and their effect on the permanent successors. Dent
     3.    Brook AH, Winter GB. Double teeth. A retrospective study             Clin North Am. 1984;28:69‐ 80.
           of ‘geminated’ and ‘fused’ teeth in children. Br Dent J.         19. Mohapatra A, Prabhakar AR, Raju OS. An unusual triplica-
           1970;129:123–30.                                                     tion of primary teeth-A rare case report. Quintessence Int.
     4.    Knapp JF, McMahon JI. Treatment of triple tooth: Report of           2010;41:815–20.
           case. J Am Dent Assoc. 1984;109:725–7.                           20. Giuca MR, Carli E, Lardani L, Pasini M, Miceli M, Fambrini
     5.    Dhooria HS, Badhe AG. An unusual fusion of three teeth. A            E. Pediatric Obstructive Sleep Apnea Syndrome: Emerging
           case report. J Indian Dent Assoc. 1983;55:327–8.                     Evidence and Treatment Approach. Scientific World Jour-
     6.    Long O. Gemination of three deciduous lower incisors. Br             nal. 2021;2021:5591251.
           Dent J. 1951;91:324.                                             21. Giuca MR, Pasini M, Drago S, et al. Influence of Vertical
     7.    Burley MA, Reynolds CA. Germination of three anterior                Facial Growth Pattern on Herbst Appliance Effects in Pre-
           teeth. Br Dent J. 1965;118:169–70.                                   pubertal Patients: A Retrospective Controlled Study. Int J
     8.    Shilpa G, Nuvvula S. Triple tooth in primary dentition: A pro-       Dent. 2020;2020:1018793.
           posed classification. Contemp Clin Dent. 2013;4:263–267.         22. Wu CW, Lin YT, Lin YT. Double primary teeth in children
     9.    Rao A. Synodontia of deciduous maxillary central and later-          under 17 years old and their correlation with permanent
           al incisors with a supernumerary tooth. J Indian Soc Pedo
                                                                                successors. Chang Gung Med J. 2010;33:188‐ 193.
           Prev Dent. 2000;18:71–5.
                                                                            23. Gultekin IM, Uysal S, Turgut MD, Dural S, Tekcicek M. A
     10.   Aguilo L, Catala M, Peydro A. Primary triple teeth: Histolog-
                                                                                rare triple tooth in primary dentition: CT findings. Pediatr
           ical and CT morphological study of two case reports. J Clin
                                                                                Dent J. 2017;27:157‐161.
           Pediatr Dent. 2001;26:87–9
                                                                            24. Bagattoni S, Lardani L, D’Alessandro G, Piana G. Oral
     11.   Schultz-Weidner N, Ansari F, Mueller-Lessmann V, Wetzel
           WE. Bilateral triplicated primary central incisors: Clinical         health status of Italian children with Autism Spectrum Disor-
           course and therapy. Quintessence Int. 2007;38:395–9.                 der. Eur J Paediatr Dent. 2021;22(3):243-247.
     12.   Prince JD. 3D printing: An industrial revolution. J Electron     25. Graziani F, Izzetti R, Lardani L, Totaro M, Baggiani A. Ex-
           Resour Med Libr. 2014;11:39‑45.                                      perimental Evaluation of Aerosol Production after Dental
     13.   Mitsouras D, et al. Medical 3D Printing for the Radiologist.         Ultrasonic Instrumentation: An Analysis on Fine Particu-
           Radiographics. 2015;35:1965–88.                                      late Matter Perturbation. Int. J. Environ. Res. Public Health
     14.   Pagano S, Lombardo G, Coniglio M, et al. Autism spec-                2021;18:3357.
           trum disorder and paediatric dentistry: A narrative overview     26. Juneja S, Verma KG, Singh N, Sidhu GK, Kaur N. Clinical
           of intervention strategy and introduction of an innovative           course and treatment of a triplication defect: a case report.
           technological intervention method. Eur J Paediatr Dent.              J Dent. 2015;12:385‐388.
           2022;23:54-60. doi:10.23804/ejpd.2022.23.01.10                   27. Colombo S, Gallus S, Beretta M, et al. Prevalence and de-
     15.   Chia HN, Wu BM. Recent advances in 3D printing of bio-               terminants of early childhood caries in Italy. Eur J Paediatr
           materials. Journal of biological engineering, 2015;9(1),4.           Dent. 2019;20(4):267-273.




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