Discussion:
Odontomas represent an important entity among maxillary benign odontogenic tumors [3]. Patients often have no pain, and odontoma is accidentally diagnosed during routine checks or during a delayed eruption permanent teeth or, more rarely, of milk teeth [6]. Odontogenic tumors may occur at any period of life from epithelial tissue, ectomesenchyme or both with or without hard tissue formation [7]. The etiology of odontomas is uncertain. There are several hypotheses: local trauma during primary dentition, infection, family history, hereditary abnormality, odontoblastic hyperactivity or spontaneous genetic mutation [8]. Compound odontoma as well as complex odontoma are benign, slow-growing pathological entities and self-limiting [9]. Despite the high incidence of this tumor, compound-complex type which shows both radiologic and histologic characteristics of compound and complex types is not common in the literature.
A bibliographic research on pubMed platform was performed. The articles included were written in English language and published until 2021. Only five publications (5 case reports and 1 retrospective study) report cases of compound-complex odontomas [5, 10, 11]. Therefore, it shows that our case report is uncommon.
There are different clinical aspects of odontoma. It can be either intra-osseous, extra-osseous or erupted [5]. Most cases are intra osseous as seen in our case. Although the anterior region of the maxilla (67%) is the most prevalent location [12], our case was reported on the posterior region of the mandible. Radiological appearance may vary depending on the stage of development and degree of mineralization of the tumor. Odontomas may be seen as radio transparent in the beginning. Increasing mineralization leads to a corresponding increase in calcifications, with constant decrease in radiotransparence. Mature complex odontomas appear under form of round or ovoid radioopacities with well-defined edges. The compound odontoma consists as a number of radioopacities of different sizes, which resemble small dental structures [13]. On histopathological examination, these two forms of odontomas consist of all hard dental tissues –enamel, dentin and cementum– as well as pulp tissue. These different tissues are mixed anarchically in complex odontoma, whereas in the compound odontoma, they organize themselves like a natural tooth, which are clearly recognizable. Both types of lesions are surrounded by a fine conjunctive capsule [5].
The treatment consists in a surgical removal of the lesion with curettage. Their enucleation is simple as they are capsulated tumors [2]. The recurrence is not common [12]. But an early discovery and management allows us to be more conservative during the surgery, to avoid degeneration of the lesion and retain the vitality and the placement of adjacent tooth and eventually ensure a good prognosis.