|Year : 2011 | Volume
| Issue : 1 | Page : 50-52
Bilateral fusion in primary mandibular teeth: A report of two cases
N Tewari, RK Pandey
Department of Pedodontics with Preventive Dentistry, Faculty of Dental Sciences, CSM Medical University, Lucknow, Uttar Pradesh, India
|Date of Web Publication||23-Apr-2011|
3/82-83,Vrindavan Scheme-2, Raebareily Road, Lucknow, Uttar Pradesh - 226 025
Source of Support: None, Conflict of Interest: None
| Abstract|| |
The rare anomaly of fusion in primary dentition has very little documentation in Indian population. Two rare cases of bilateral fusion between primary mandibular lateral incisors and canines and primary mandibular central incisors and lateral incisors have been presented in this report. A minimal intervention approach, preventive procedures, and a long-term follow-up have been discussed.
Keywords: Fusion, gemination, minimal intervention technique, tooth germ
|How to cite this article:|
Tewari N, Pandey R K. Bilateral fusion in primary mandibular teeth: A report of two cases. J Indian Soc Pedod Prev Dent 2011;29:50-2
|How to cite this URL:|
Tewari N, Pandey R K. Bilateral fusion in primary mandibular teeth: A report of two cases. J Indian Soc Pedod Prev Dent [serial online] 2011 [cited 2020 Jul 11];29:50-2. Available from: http://www.jisppd.com/text.asp?2011/29/1/50/79936
| Introduction|| |
Fusion presents as one of the most unusual and rarest anomaly of shape of the tooth.  Fusion arises through the union of two normally separated tooth germs, whereas gemination arises from an attempt at division of a single tooth germ. The phenomenon of fusion has often been confused with gemination, especially if it involves a supernumerary tooth. ,,
The clinical presentation often ranges from two separate crowns to a crown of double the size of normal.  Radiographically, the presentation may range from separate pulp chambers and root canals to a common pulp chamber and root canal system.  The presence of deep fissure in fused teeth predisposes them to dental caries and makes them unaesthetic. Different treatment modalities can be implied according to the requirements of the situation.
This report describes two rare cases of bilateral fusion between the primary mandibular incisors and canine, accompanied by missing permanent incisors.
| Case Reports|| |
A 42-month-old boy presented with bilateral anomalous primary mandibular lateral incisors and canines. Medical history appeared noncontributory. There was no family history of dental anomalies and no consanguinity was reported in the parents.
Intraoral examination revealed that <72-73> and <82-83> were fused together. The fused teeth <72-73> had deep grooves on labial and lingual surfaces. The fused teeth <82-83> had a smooth surface carious lesion on the gingival third of the labial surface, though it did not exhibit deep groove on labial or lingual surface. An incisal ditch was present in both <72-73> and <82-83> [[Figure 1]a].
|Figure 1: (a) Fusion of clinical crown of <72-73> and <82-83>. (b) <72- 73> and <82-83> treated through minimal intervention technique. (c) Radiograph showing type-I morphology and complete fusion of <72-73> and <82-83>|
Click here to view
The periapical radiographs exhibited that the crowns and the roots of <72-73> and <82-83> were fused with complete union of their pulp chambers and root canals. The morphology of both <72-73> and <82-83> seemed to be type I: Bifid pulp chamber and normal sized root canal with slight widening in cervical portion [[Figure 1]c].  The orthopantomograph [Figure 2] revealed the bilateral absence of 32 and 42.
The treatment plan comprised of removal of caries on the gingival third of the labial surface of the <82-83> and restoration of the prepared site and the incisal ditch of the <82-83> and the deep grooves of the <72-73> using flowable composite [[Figure 1]b]. The patient was put on 3-month recall program.
A 36-month-old girl reported with bilateral anomalous primary mandibular central and lateral incisors. Medical history appeared noncontributory. There was no family history of dental anomalies and no consanguinity was reported in the parents.
Intraoral examination revealed that <71-72> and <81-82> were fused together. The fused teeth <71-72> had smooth labial and lingual surfaces. The fused <81-82> had an incisal ditch with a labial groove. Both the fused teeth were also caries free [[Figure 3]a].
|Figure 3: (a) Fusion of clinical crown of <71-72> and <81-82>. (b) Radiograph showing type-II morphology in <71-72> and type-III in <81-82>|
Click here to view
The periapical radiograph exhibited that the crowns and the roots of <71-72> were fused with complete union of their pulp chambers and root canals. The fusion in <81-82> seemed to be incomplete: common pulp chamber and separate root canals. The morphology of <71-72> was type II with a single shared pulp chamber and one shared large root canal. The <81-82> had the type III morphology: Sharing of some portion of pulp chambers with separate root canals [[Figure 3]b].  The succedaneous teeth 31 and 41 seemed to be missing in the periapical radiograph.
Since there were no carious lesions present, a preventive approach was planned. It consisted of topical fluoride application, dietary changes, and periodic follow-ups. The patient was put on a 3-month recall and parents informed about the possible missing succedaneous teeth: Permanent mandibular central incisors in this case.
| Discussion|| |
Two rare cases of bilateral fusion of primary mandibular anterior teeth were presented. The specificity of the cases can be realized by the statistical data of bilateral fusion given by Tomizawa et al.  for Caucasians (0.02%) and Japanese (0.32%). The data for bilateral fusion in Indian population are not available; the previous survey for unilateral fusion of primary teeth revealed 0.14%, as confirmed by Reddy and Munshi. 
The morphology exhibited by both <72-73> and <82-83> was type I, which is rare and contrary to the finding of Aguilo et al.  who stated the type-I morphology to be seen only in maxilla. The morphology of <71-72> was type-II and that of <81-82> was type-III which was in concurrence to his findings.
Yuen et al. have revealed that the fusion of primary teeth is associated mostly with hypodontia in succedaneous dentition.  The present cases have shown concurrence with the study, exhibiting bilaterally missing permanent mandibular lateral incisors and central incisors.
The fusion of primary teeth exhibits the problems of aesthetics and early pulp exposure due to deep grooves. , The minimal intervention technique and preventive approach for the management of the fused teeth has been advocated, if the pulp exposure can be ruled out. Management of fusion warrants regular and long-term follow-ups.
| References|| |
|1.||Duncun WK, Helpin ML. Bilateral fusion and gemination: A literature analysis and case report. Oral Surg Oral Med Oral Pathol 1987;I:82-7. |
|2.||Tomizawa M, Shimizu A, Hayashi S, Noda T. Bilateral maxillary fused primary incisors accompanied by succedaneous supernumerary teeth: Report of a case. Int J Paediatr Dent 2002;12:223-7. |
|3.||Aguilo L, Gandia JL, Cibrian R, Catala M. Primary double teeth. A retrospective clinical study of their morphological characteristics and associated anomalies. Int J Paediatr Dent 1999;9:175-83. |
|4.||Reddy NN, Munshi AK. Fusion of primary incisors-a report of six cases. J Indian Soc Pedod Prev Dent 1999;17:55-60. |
|5.||Yuen SW, Chan JC, Wei SH. Double Primary Teeth and Their Relationship with the Permanent Successors: A Radiographic Study of Three Hundred Seventy-six Cases. Pediatr Dent 1987;9:42-8. |
[Figure 1], [Figure 2], [Figure 3]