Introduction
Odontomas are the most common benign odontogenic tumors, characterized by their slower growth and non-aggressive 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 well-formed 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 ill-defined 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.
Figure 5
Multiple impacted tooth like denticles/malformed/irregular opacities noted w.r.t impacted teeth 21,22.
Figure 7
Scanner view: The dentin matrix is eosinophilic and contains tubules, arrangement of these tissues is disordered
Figure 9
High power view showing: dentin, enamel spaces, enamel matrix appears as hematoxphillic fibrillar material
Figure 10
No radio-opaque denticles are seen in the 21, 22 region. Erupting permanent incisors are visible much below the basal maxilla compared to pre-operative view
Trapezoidal incision was made and a full thickness mucoperiosteal flap was raised showing bony prominence w.r.t labial cortical plate. Well encapsulated multiple tooth like denticles along with thin labial cortical plate were removed. Simple interrupted sutures were placed. The excised tooth like denticles were received by Department of Oral and maxillofacial Pathology for histopathological examination.
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.(Figure 7, Figure 8, Figure 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.(Figure 7, Figure 8, Figure 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.
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