| Abstract|| |
Radicular cysts arising from deciduous teeth are rare. This article presents a case report of a radicular cyst associated with a mandibular deciduous second molar and with unusual radiographic findings. The second premolar was displaced to the lower border of the mandible, below the first premolar. The management comprised enucleation of the cystic sac under local anesthesia.
Keywords: Bilocular, primary molar, radicular cyst
|How to cite this article:|
Narsapur SA, Chinnanavar SN, Choudhari SA. Radicular cyst associated with deciduous molar: A report of a case with an unusual radiographic presentation. Indian J Dent Res 2012;23:550-3
Radicular cysts are by far the most common of the cystic lesions that occur in the jaw. They are considered to be rare in primary dentition, comprising only 0.5%-3.3% of the total number of radicular cysts in both primary and permanent dentition. , Radicular cysts originate from epithelial remnants of the periodontal ligament as a result of inflammation that is generally a consequence of pulp necrosis. The resulting cysts commonly involve the apex affected tooth. Caries is the most frequent etiological factor, along with traumatic injuries to the primary teeth.  Assuming that the development mechanisms of radicular cysts are identical in the primary and permanent dentitions, the low frequency in the former is yet to be explained. 
|How to cite this URL:|
Narsapur SA, Chinnanavar SN, Choudhari SA. Radicular cyst associated with deciduous molar: A report of a case with an unusual radiographic presentation. Indian J Dent Res [serial online] 2012 [cited 2019 May 27];23:550-3. Available from: http://www.ijdr.in/text.asp?2012/23/4/550/104970
This paper reports the case of a radicular cyst associated with a carious primary molar and with an unusual and rare radiographic presentation.
| Case Report|| |
A 9-year-old male patient reported to the outpatient department with the complaint of a painless swelling in the left lower back region of the jaw since 4-5 months. Initially the patient had episodes of toothache in the same region; this was followed by the swelling, which gradually increased to its present size. There was no history of any previous dental treatment involving carious tooth 75.
Extraoral examination [Figure 1] revealed a painless bony-hard swelling in the lower left side of the mandible. Intraoral examination [Figure 2] revealed carious tooth 75 with obliteration of buccal sulcus, indicating expansion of the buccal cortical plate. Slight lingual cortical plate expansion was also noted. The swelling was nontender. Teeth 75 and 36 were found to be nonvital with the electric pulp test
|Figure 1: Extraoral photograph of the patient showing slight swelling on the left lower side of the face.|
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|Figure 2: Intraoral photograph showing slight obliteration of the buccal sulcus.|
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Periapical radiograph [Figure 3] revealed a well-defined radiolucency involving the interdental area and extending beyond the confines of the roots of tooth 75. An occlusal radiograph [Figure 4] revealed an unusual, well-defined bilocular radiolucency, with buccal cortical plate as well as slight lingual cortical plate expansion, indicating a thin reactive cortex. Orthopanto mogram (OPG) [Figure 5] revealed a radiolucency of 3.5 × 5 cm size, approximately at the apex of 75 and extending from 74 to the distal aspect of 36. Slight blunting of the apices of tooth 36, along with loss of lamina dura with the same was noted. The radiolucency was less intense along the distoinferior and inferior aspect of the lesion. The second premolar was displaced to the lower border of the mandible on the mesial aspect, away from the normal path of eruption, with loss of its follicular space.
|Figure 4: Occlusal radiograph showing bilocular radiolucency with lingual and buccal cortical plate expansion.|
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A light-yellow blood-mixed liquid was collected on aspiration, and its result was compatible with a cystic lesion, with the differential diagnosis being radicular or dentigerous cyst
From the history and the clinical and radiographic presentation, we arrived at a provisional diagnosis of radicular cyst.
The cyst was exposed under local anesthesia. There was a very thin, incomplete, bony wall present in the upper part of the single cavity, which broke off while the lining was being scraped; this was probably due to incomplete bone resorbtion. The cyst was enucleated, with extraction of tooth 75 as well as the second premolar, as the latter was distracted from the normal path of eruption. The specimen was sent for histopathological examination.
Histopathological features revealed [Figure 6] a cystic lumen lined by stratified squamous epithelium that was 4-5 cells thick. The cyst was covered by a fibrous connective tissue wall with spindle-shaped cells which confirmed the diagnosis of radicular cyst. Postsurgical healing was uneventful.
| Discussion|| |
Radicular cysts originating from primary teeth are very rare and only a few cases have been published.  A radicular cyst is one which arises from epithelial residues in the periodontal ligament as a result of inflammation. The inflammation usually follows the death of dental pulp. Cysts arising in this way are found most commonly at the apices of the involved tooth.  The cause for its rarity in primary dentition may be due to various reasons; for example:
This case was diagnosed as radicular cyst for the following reasons:
- Periapical lesions resolve after removal of the tooth.
- They remain untreated because of relatively less severe symptoms.
- Due to diagnostic errors and nonreferral for pathologic examination.
- Due to regression of the lesion after endodontic treatment. 
Grundy, Adkins, and Savage reported a series of radicular cysts associated with deciduous teeth that were treated endodontically with material containing formocresol which, in combination with tissue protein, is antigenic and has been shown to elicit a humoral and cell-mediated immune response. ,
- Presence of a large and painless radiolucent lesion in relation to the roots of a nonvital primary tooth
- Predominant mandibular buccal cortical plate expansion
- Thin reactive cortex Displacement of succedaneous tooth and surgical confirmation that the lesion was not associated with the successive permanent tooth
- Histological confirmation of cystic epithelial lining
The present case reports a radicular cyst associated with primary molar which was non-endodontically treated. Usually radicular cysts are unilocular  but in the present case there was an unusual bilocular radiographic appearance along with expansion of lingual cortex. The bilocular radiographic feature may have been due to the presence of a thin incomplete bony wall in the upper part of the cavity. The findings in the present case were similar to that in the two cases of multilocular radicular cysts reported by Lustmann and Shear. 
Radicular cysts arising from deciduous teeth may mimic dentigerous cyst radiographically, especially when they are multilocular as in the present case.  That possibility was ruled out in the present case as the lesion was associated with a grossly decayed nonvital primary molar. An intraoperative finding of cyst separated from the tooth germ was precedent in diagnosing of this uncommonly expressed cyst and definite diagnosis was made on the basis of the histopathological picture.
Since, in the present case, the second premolar was displaced to the base of the mandible away from its normal path of eruption, with loss of its follicular space, it had high chance of being impacted; therefore, it was extracted as was done by Bhatt in a similar case.  However, Chiu et al. in 2008 have reported cases of normal alignment of the permanent teeth occurring spontaneously even though the initial positions were highly unfavorable. 
In this patient apicectomy with 36 was not performed preoperatively to avoid multiple surgical procedures and complications of anesthesia in the child. Postsurgical routine endodontic therapy with inverted gutta percha cones was planned as there were no blunderbuss canals with 36.
Radicular cyst in deciduous dentition affects the mandibular teeth (as in this patient) because they are the ones most frequently affected by caries; in contrast, there is maxillary predominance in permanent dentition. 
Most authors agree that the treatment of choice is enucleation of the cyst. Marsuplization is a more conservative intervention and is indicated when there is no likelihood of damaging anatomic structures. The major disadvantage of the marsupialization technique is that pathologic tissue is left in situ without thorough histologic examination  and multiple visits are required for regular washing of the cavity and follow-up. In the present case enucleation was preferred, because the pathologic cavity was small and because we wanted to get histopathological confirmation of the diagnosis.
In children healing of postsurgical osseous defects is always good as they have high propensity for bone regeneration.  In present case we could not appreciate this as the child was unable to visit hospital for follow-up.
In conclusion, the cystic potential of a radicular lesion in primary dentition should be carefully considered even in non-endodontically-treated primary carious teeth with unusual radiographic presentation.
| References|| |
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Sulabha A Narsapur
Department of Oral Medicine & Radiology, Al-Ameen Dental College & Hospital, Bijapur, Karnataka
Source of Support: None, Conflict of Interest: None
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]