An eight-year-old boy with large complex odontoma in maxillary anterior area associated with unerupted tooth

Odontomas are the most common odontogenic benign tumors composed of dental tissue. The term odontoma was first coined by Broca (1866); he defined odontoma as a tumor formed by an overgrowth of complete dental tissues. They can be thought of as “tooth hamartomas” with the lesion consisting of various tooth components. Histologically Odontomas are divided into complex and compound odontomas. In this paper we are describing the case of a complex odontoma in an eight -year-old boy diagnosed due to the retention of the permanent left maxillary central and lateral incisor. A surgical excision was performed without distressing the unerupted central and lateral incisor. The results obtained indicate that early diagnosis of odontomas enables adoption of less complex treatment, a better prognosis, and displacement or devitalisation of adjacent tooth. © This is an open access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/) which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Introduction
Odontomas are the most common benign odontogenic tumors, characterized by their slower growth and nonaggressive behaviour. 1 In 1866 the term odontoma was first coined by Paul Brocain, who defined it as a tumour of overgrowth of complete dental tissue. 2 These Odontomas are considered to be developmental anomalies resulting from the growth of completely differentiated epithelial and mesenchymal cells that give rise to ameloblasts and odontoblasts. These odontogenic tumours are mostly formed of enamel and dentin however can also contain variable amounts of cementum and pulp tissue. 3,4 These tumours are thought to be hamartomas and not true neoplasms because the epithelial and mesenchymal cells and tissues of an odontoma can appear normal but are deficient in structural arrangement. 5 Although etiology of odontoma is still unknown however it has been suggested local traumas or infections may cause odontomas. 6 On radiographic examination, odontomas appear as dense radiopaque lesions with prominent external margins surrounded by a thin radiolucent zone. 7,8 In 2005 the World Health Organization (WHO) has classified odontomas on the basis of the histopathological findings: complex odontomas, and compound odontomas. Complex odontomas are the ones in which dental tissues are wellformed but unstructured and these tissues are haphazardly arranged, on the contrary in compound odontomas, the dental tissues are normal, arranged in an orderly pattern, but their size and anatomy are altered, giving rise to numerous small teeth like elements called odontoids or denticles. 9 It has been reported that majority of odontomas which are located in the anterior region of the maxilla are compound, while the great majority of odontomas located in the posterior areas, especially in the mandible, are of the complex types. 1 Excision of odontoma is advised in the absence of any contraindication. Prognosis after treatment is very favourable, with scant relapse. 10,11

Case Report
An Eight-year-old boy, came to the Department of Oral and Maxillofacial Pathology with a chief complaint of missing left upper front teeth since birth. (Figure 1) Patient's medical and family history were indecisive. Intraoral examination revealed the presence of class IV caries w.r.t 53 and 63.
Area of chief complaint: Site: Left maxillary anterior region of the jaw. Extending from maxillary labial frenum to the canine prominence. (Figure 2) Labial vestibule was obliterated with no palatal extension, ovoid in shape, with smooth overlying surface epithelium. Overlying and surrounding mucosa were normal. Measuring about 2 x1cm in size. (Figure 3) Consistancy was bony hard texture was smooth and it was non tender. All the findings were confirmed on palpation.
The radiographic examination revealed the irregular illdefined calcified masses in the upper Anterior region. Multiple impacted tooth like denticles/malformed/irregular opacities were noted w.r.t impacted teeth 21,22. (Figure 4) An OPG revealed the same finding as seen in intraoral periapical radiograph. (Figure 5) On the basis of clinical and radiographic examination, a provisional diagnosis of complex odontome was made.         On gross examination the specimen received were calcified masses and were irregular in shape. (Figure 6) The specimen was decalcified and processed in the conventional manner. On histopathological examination the specimen revealed the dentin matrix which was eosinophilic and contains tubules. The arrangement of these tissues was disordered dentin, enamel spaces, enamel matrix appeared as hematoxphillic fibrillar material. (Figures 7, 8 and 9) On the basis of clinical, radiographical and histopathological invastigations a diagnosis of complex odontoma was given other provisional diagnosis are compound odontome, Adenomatoid odontogenic tumor and Dentigerous cyst.
Three months postoperatively, OPG was advised to check for the eruption of permanent incisors ( Figure 10) and revealed a continuous eruption of the tooth into the oral cavity.

Discussion
Complex odontoma is a common odontogenic tumor, and it is usually a hard painless mass, which rarely exceeds diameter of the tooth. Odontomas are mostly discovered accidentally on radiographics. Symptoms of complex odontomas include impacted permanent teeth and swelling. Budnick in 1976 concluded that 61% of cases are associated with impacted teeth. 12 As seen in our case report permanent central and lateral incisors were impacted. The origin of complex odontoma is still unclear; some studies suggest trauma or infection to be the cause. In a study conducted by Lopez-Areal et al, they evaluated that a 10 months year old child developed multiple odontomas after experiencing trauma with intrusion of incisor teeth. 13 A study conducted by Hitchin, reported that odontomas are inherited or developed as a result of genetic mutation. 14 The individuals having Gardner's syndrome which is a heritable syndrome an increased number of odontomas were seen. 15 Recurrence of complex odontomas is exceptional. On radiographic examinations, complex odontoma appears as a radiopaque mass which does not resemble tooth structure. Microscopically the complex odontoma is characterized by sheets of immature tubular dentin with encased hallow tooth like structures. (Figures 7, 8 and 9 ) Conservative surgical excision of the lesion is the treatment of choice.

Conclusion
In general odontomas are common odontogenic tumours, however when compared to other odontomas, complex odontomas are very unusual. Complex odontomas should be surgically excised because they are characterized by expansion of cortical plates and if left untreated can cause pathological fracture of the bone.

Source of Funding
None.

Conflict of Interest
The authors declare that there is no conflict of interest.