|Year : 2014 | Volume
| Issue : 2 | Page : 133-135
Rare gingival odontoma: Report of a case and review of literature
Anila Koneru1, M Vanishree2, R Surekha3, A Hamsini4, Santosh Hunasgi5
1 Senior Lecturer, Department of Oral and Maxillofacial Pathology, Navodaya Dental College, Raichur, Karnataka, India
2 Professor and HOD, Department of Oral and Maxillofacial Pathology, Navodaya Dental College, Raichur, Karnataka, India
3 Reader, Department of Oral and Maxillofacial Pathology, Navodaya Dental College, Raichur, Karnataka, India
4 Professor, Department of Oral and Maxillofacial Pathology, Navodaya Dental College, Raichur, Karnataka, India
5 Practitioner, Raichur, Karnataka, India
|Date of Web Publication||20-Jun-2014|
Department of Oral and Maxillofacial Pathology, Navodaya Dental College, Raichur - 584 103, Karnataka
Source of Support: None, Conflict of Interest: None
Peripheral odontogenic tumors are rare with mostly single case reports or a small series of case reports. Odontoma is the most common central odontogenic tumor, but odontomas arising in the extra-osseous soft-tissue, also known as peripheral odontoma (PO), are extremely uncommon. To the best of our knowledge, very few cases of POs have been previously reported. Here, we report an additional case of PO occurring in the gingiva with review of literature on clinical features. A 15-year-old male patient complained of two tiny, asymptomatic, white masses in the left upper labial gingiva. On gross examination, specimens were oval in shape, measuring 0.3 cm, white in color and hard to firm in consistency with a smooth surface. Hematoxylin and eosin stained decalcified sections revealed enamel matrix and dentinal tubules in cross-section with entrapped core of pulpal tissue. All tissues were arranged in a disorganized pattern. A final diagnosis of peripheral complex odontoma of gingiva was given. Clinical features of previously reported cases, together with the current case were reviewed. Features of this interesting odontogenic entity add to our knowledge and are of special relevance to pediatric health-care providers, since PO of gingival origin usually occurs in young children.
Keywords: Gingiva, odontoma, peripheral, review
|How to cite this article:|
Koneru A, Vanishree M, Surekha R, Hamsini A, Hunasgi S. Rare gingival odontoma: Report of a case and review of literature. J NTR Univ Health Sci 2014;3:133-5
|How to cite this URL:|
Koneru A, Vanishree M, Surekha R, Hamsini A, Hunasgi S. Rare gingival odontoma: Report of a case and review of literature. J NTR Univ Health Sci [serial online] 2014 [cited 2020 Apr 6];3:133-5. Available from: http://www.jdrntruhs.org/text.asp?2014/3/2/133/134889
| Introduction|| |
Odontogenic lesions show a wide variety of conditions such as cysts, hamartomas and tumors. These lesions can affect the jaws as intra-osseous or extra-osseous entities. Peripheral odontogenic tumors are also referred to as extra-osseous or soft-tissue odontogenic tumors arising specially in gingival tooth bearing areas and manifest the histopathologic characteristics of their central or intra-osseous counter parts. ,
Peripheral odontogenic tumors are rare with mostly single case reports or a small series of cases reports. Odontogenic tumors that can originate in the gingiva include ameloblastoma, calcifying epithelial odontogenic tumor, calcifying cystic odontogenic tumor, adenomatoid odontogenic tumor, ameloblastic fibroma, odontoma and odontogenic fibroma, some of which are exceedingly rare. 
Odontoma is the most common central odontogenic tumor and considered as a hamartoma, formed from the growth of completely differentiated epithelial and mesenchymal cells like ameloblast and odontoblast. However, odontoma arising in the extra-osseous soft tissue, also known as peripheral odontoma (PO), is extremely uncommon. PO shows the histological characteristics similar to an intra-osseous counterpart. 
To the best of our knowledge, very few cases of PO have been previously reported. Here, we report an additional case of PO occurring in the gingiva with review of literature on clinical features.
| Case report|| |
A 15-year-old male patient complained of two tiny, asymptomatic, white masses in the left upper labial gingiva. The mass had been slowly enlarging for about 3 months and was not associated with any obvious trauma. Patient was otherwise in good health and his medical and family history was non-contributory.
Intraoral examination revealed two tiny white nodular masses, measuring 0.3 cm, located on the left upper labial gingiva between central and lateral incisors [Figure 1]. Upon palpation, the lesion was found to be firm and non-tender. Periapical radiography of upper anterior area revealed no underlying bone resorption and no evidence of involvement of intra osseous lesion [Figure 1].
|Figure 1: (a) Clinical photograph showing two white nodular masses in upper left labial gingiva between central and lateral incisors, (b) periapical radiography of left upper anterior area revealed no underlying bone resorption and (c) an excised gross specimen|
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The clinical impression was of a benign tumor of soft-tissue origin and the entire mass was subsequently excised. On gross examination, specimens were oval in shape, measuring 0.3 cm, white in color, hard in consistency with a smooth surface [Figure 1]. The specimen was decalcified using 4% of HNO 3 for 2 days, processed and embedded in paraffin wax.
Hematoxylin and eosin stained decalcified sections revealed hematoxophilic areas resembling enamel matrix and eosinophilic areas showing dentinal tubules in cross section with entrapped core of pulpal tissue [Figure 2]. All the tissues were arranged in a disorganized pattern. Ultimately the histological diagnosis was peripheral complex odontoma of gingiva. The excised area healed completely and a follow-up of 2 years showed no signs of recurrence [Figure 3].
|Figure 2: (a) H and E stained decalcified section showing haematoxophilic areas resembling enamel matrix (×100), (b) eosinophilic areas with dentinal tubules resembling dentin (×200) and (c) dentin with entrapped core of pulpal tissue (×100)|
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| Discussion|| |
Peripheral odontogenic tumors, as a group, are considered rare, with only 0.05% of all biopsy specimens. Of all the peripheral odontogenic tumors, 51% were peripheral odontogenic fibroma, 29% were peripheral ameloblastomas, 13% were peripheral calcifying cystic odontogenic tumor and PO was only about 2%. 
PO are usually asymptomatic, exophytic masses occurring in gingiva but may also be found in palate, buccal mucosa, nasopharynx, middle ear and opercula of unerupted teeth. POs are reported in 3-44 years of age, but second decade is very common.  Similarly, our case was also seen in 15-year-old male patient.
Peripheral odontomes may be radiopaque or have no radiographic features other than saucerization of underling bone.  The present case also showed no significant radiographic features. Most odontomes previously reported were relatively small not exceeding 1 cm, the present case also showed two tiny structures, measuring 3 mm in diameter. The clinical differential diagnosis for such soft tissue odontomas are foreign body, soft-tissue osteoma, superimposition of a calcified mass of the adjacent soft-tissue, or retained root tip. 
A review of the English-language literature revealed that only seven POs of gingiva have been previously reported with detailed histopathological confirmation. The clinical features of these previously reported cases, together with the current case, are summarized in [Table 1]. ,,,,,
|Table 1: A review of clinical features of peripheral odontomas in gingiva that were previously Reported, together with the present case|
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PO is thought to arise from the remnants of dental lamina entrapped within the gingiva (rests of serres) or from the basal layer of the oral mucosa, which retain the ability to follow necessary epithelial mesenchymal interactions leading to an odontoma formation.  Etiological factors were unknown, but proposed being local trauma, infection, hereditary and genetic mutation. However, evidence suggests that odontomes are inherited from a mutant gene or interference during tooth development. Thus mutation in the epithelial cells of the tooth germ may change an inherent capacity of odontogenic epithelium to go through the bud, cap and bell stages of tooth development and retain its ability to stimulate the mesenchymal differentiation leading to odontoma formation. ,
According to the histopathological perspective, odontomas either central or peripheral can be grouped as: (a) Complex odontomas, in which the dental tissues are well-formed, but exhibit a more or less disorderly arrangement; and (b) composite odontomas, in which the dental tissues are normal, but their size and conformation are altered giving rise to multiple small tooth-like structures. 
PO usually contain dentin, cementum and pulp-like material but little odontogenic epithelium or enamel matrix.  Majority of previously reported PO are of compound type but based on clinical and histopathological findings, the present case was diagnosed as peripheral complex odontoma of gingival origin.
Odontomas are generally considered as hamartoma with a very limited growth potential and thus surgical removal should be conservative with no real expectation of recurrence.  None of the previously reported PO showed recurrence. Therefore, present case also showed no signs of recurrence in a follow-up of 2 years.
| Conclusion|| |
Occurrence of odontoma in gingiva is uncommon. Hence, the present case may be considered as one of the rare cases of PO of gingival origin. Features of this interesting odontogenic entity add to our knowledge and are of special relevance to pediatric health-care providers, since peripheral odontoma of gingival origin usually occurs in young children.
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[Figure 1], [Figure 2], [Figure 3]