Fusion of complex odontome with permanent mandibular molar.

Odontomas are malformation of the dental tissue, arising during normal tooth development. They are usually asymptomatic, but often associated with tooth eruption disturbance. This article reports a case of complex odontome in a 23-year-male, which hampered the eruption of mandibular right second molar as well devitalization of first molar.

Odontomas are the most common odontogenic tumors representing 22% of the tumors of the jaws.[12] They often interfere with eruption of deciduous and permanent teeth, associated with abnormalities such as malpositioning, diastema, aplasia, malformation, devitalization of adjacent teeth, paresthesia of lower lip, headache in frontal area of skull, swelling of affected area, pain, and development of cystic lesions such as dentigerous cyst.[34] We present a case of complex odontome fused with first molar, which interfered with the eruption of right mandibular second molar.

Case Report

A 23-year-old male reported to the Department of Oral Medicine and Radiology, JKKN Dental College and Hospital, with the complaint of pain in the right lower back tooth for past 1 month which was mild, intermittent, dull aching, that aggravated during mastication. There was no history of trauma or swelling or inability in opening the mouth. Medical, family, and personal history were noncontributory. Intraoral examination revealed partially erupted 47 [Figure 1] with asymptomatic pericoronal flap and enamel caries in 46 with tenderness on vertical and horizontal percussion. Provisional diagnosis of localized periodontitis in relation to 46 and impacted 47 was made. Intraoral periapical radiograph [Figure 2] revealed dense, oval-shaped, nonhomogenous radiopaque mass of 1.5×1 cm, overlying distal root of 46 and coronal portion of 47, interrupting with its eruption. Mesially, the radiopaque mass was surrounded by diffuse radiolucent image extending to furcation area and periapical region of distal root of 46. Orthopantamograph [Figure 3] revealed similar radiographic appearance. Radiographic diagnosis of complex odontome was made. Differential diagnosis included cementoblastoma, osteoid osteoma, cement-ossifying fibroma, and focal sclerosing osteomyelitis.

Figure 1

Intraoral photograph showing partially erupted 47

Figure 2

Intraoral periapical radiograph showing dense radiopaque mass associated with impacted 47

Figure 3

Orthopantamograph showing radiopaque mass associated with 46 and 47

Surgical removal [Figure 4] of calcified mass and 46 was done under local anesthesia to facilitate the eruption of 47. Surgical mass revealed calcified mass fused with the distal root of 46. Histopathologic examination of the excised mass [Figure 5] revealed encapsulated lesion with irregularly arranged dental hard tissue with areas of cell rich pulpal tissue. The adjacent tissue showed chronic inflammatory cell infiltrate, suggestive of the lesion being secondarily infected.

Figure 4

Surgical removal of the lesion

Figure 5

Excised odontome

Discussion

The term odontome, first described by Paul Broca in 1867, was originally used as a general descriptive term for any tumor of odontogenic origin.[4] However, owing to their complication, slow-growing, and non-aggressive behavior, they are referred to as hamartoma (not a true tumor).[45] Etiology of odontomas is unknown; suggested theories include either inherited or local trauma during primary dentition, a positive family history, genetic mutation, and hereditary anomalies such as Gardner syndrome, Hermann's syndrome, odontoblastic hyperactivity, and alterations of genetic components responsible for controlling tooth development.[4-6]

They are classified as complex, when the calcified tissue presents simply as an irregular mass composed mainly of mature tubular dentin, or compound, if there is superficial anatomic similarity to even rudimentary teeth. Occurrence of complex odontome to compound variety is 1:2.[4] Complex odontomes are less common in men. They are found in the mandibular first and second molar area (70%).[2] They occur more frequently on right side of the jaw (68%).[6] They are usually small and produce few clinical signs and symptoms which include retention of deciduous or permanent teeth that accounts for 10–44% of complex odontomes, pain, expansion of cortical bone, tooth displacement, and paresthesia in the lower lip.[47] In the present case, pain in 46 was the only symptom, probably due to secondary infection.

Complex odontomas present as solid radiopaque masses surrounded by radiolucent borders corresponding to connective tissue capsule.[68] The increase in the size of odontome over time produces a force sufficient to cause bone resorption.[9] In our case, we found periapical radiolucency in relation to distal root and furcation bone loss in 46.

Odontomas exhibit considerable growth, cyst formation, and bone destruction due to odontogenic nature.[10] Surgical treatment consists of complete enucleation with curettage of the lesion and surrounding area. Recurrence is occasional but uncommon.[7] In our case, 46 was extracted as it was secondarily infected with bone resorption.

Conclusion

The most significant characteristic of odontome comprises alteration in tooth eruption. Most often, they are associated with impacted maxillary central incisor, maxillary canine, followed by mandibular canine and maxillary third molar. Here, we report a rare case of complex odontome fused with permanent mandibular first molar, causing impaction of permanent mandibular second molar and diagnosis was established while investigating for its delayed eruption. Occasionally, in the presence of odontome, missing tooth from the arch has been reported; however, in our case, it was not associated with missing tooth but as a rare variant found fused with the permanent tooth.