Case Report: Interdisciplinary management of a complex odontoma with a periapical involvement of superior anterior teeth

Case presentation and patient information

A Brazilian white 27-year-old female presented for routine examination with a slight dental mobility in teeth 11 and 12 with no history of trauma or previous treatments. Patient clinical history did not present relevant findings.

Patient assessment

The patient had no symptoms and no history of trauma or previous treatments in this region. Teeth 13 to 23 was tested by pulp vitality test (cold test) carried out by refrigerant gas (Endo Ice, Maquira Dental products industry LTDA–Brazil) and relative isolation using cotton rolls and a dental saliva ejector. The apical region was also tested by digital palpation and perpendicular percussion and was asymptomatic, with no fistula. The depth of its gingival pocket varied between 1–3 mm with various exploring locations and grade I mobility. Panoramic radiographic examination revealed a radiopaque bone-like structure but with a greater density than bone, circumscribed by a thin radiolucent margin in the apical region of teeth 11 and 12 presenting features of complex odontoma (Figure 1). Cone beam computed tomography (CBCT) was indicated to obtain an accurate diagnosis of the lesion and its relationship with the adjacent teeth. CBCT was fundamental in the surgery planning and management in choosing the most appropriate access, which was palatal access in this case.

Figure 1. The radiographical diagnosis of complex odontoma.

A) and B) panoramic and periapical radiography showing radiopaque lesion in the upper right incisors region; C) tomographic image of the sagittal section showing the relation of the lesion with the apex of the upper right central and lateral incisors; D) axial reconstruction of odontoma.

Therapeutic interventions

Firstly, teeth 11 and 12 underwent endodontic treatment due to the negative response to the pulp vitality test, utilizing a Reciproc system R50/0.05 file (VDW, Munich, Germany) and chlorohexidine gluconate gel 2% (Endogel Essential Pharma, Itapetininga, Brazil) as a lubricator and antimicrobial agent during the preparation of the root canals, and then obturating with gutta-percha and Ah Plus sealer (Dentsply, DeTrey GmbH, Konstanz, Germany). No medication was prescribed before or during the treatment. The patient was advised to take acetaminophen (500 mg, maximum four times a day) in case of pain.

A week later, after tomographic planning, surgical excision of the lesion was carried out under local anesthesia using one anesthetic tube (4% articaine with epinephrine 1: 100,000), with intra-oral access to the mass achieved via intra-sulcular incision of the palatal region from tooth 14 to 24. After detachment of the flap, osteotomy was performed using a surgical carbide drill nº 06 (Angelus Prima Dental Ltda. Londrina / PR, Brazil) under intense irrigation with saline solution.

The enucleated lesion presented as a hyperdense mass located palatal to the roots of teeth 11 and 12, with clinical features of complex odontoma that involved the apical third of the tooth 11. A bone regularization procedure was carried out, followed by cleaning of the surgical cavity by irrigation with saline solution (Figure 2).

Figure 2. Surgical approach for total excision of the complex odontoma.

A) Osteotomy; B) total excision of the odontoma; C) repositioning of flap and intra-sulcular suture; D) enucleated complex odontoma.

Afterwards, the hard-dental surfaces were polished with McCall periodontal curette (Fava Metalúrgica São Paulo, SP). Tooth 12 demonstrated external apical resorption; thus, an apicectomy was performed, which was then retro-filled with 5MO (SHAM Dentico, Oman) (Figure 3). No bone graft was indicated. The flap was repositioned, followed by intra-sulcular suturing with 3-0 silk thread (Procare Xuyi Webest Medical Products Co, Jiangsu China). The suture was removed after seven days and the patient progressed well postoperatively without intercurrences.

Figure 3. Clinical approach to retro-obturation with five mineral oxides (5MO).

A) Image of the surgical access after washing and polishing the rigid structures with curette; B) creation of a niche in the apical third for des-obturation; C) placement of 5MO cement in the retro-obturation.

Histopathological assessment

Immediately after sample excision, the mass was immersed in 10% formalin for 48 hours in order to obtain tissue fixation and was sent for histopathological examination under a microscope for differential diagnosis. Routine histological techniques were performed for soft tissues embedding in paraffin. Hard tissues fragments were demineralized in Ethylenediaminetetraacetic acid (EDTA) (TiTriplex® Merk Darmstadt, Germany) for two months, before embedding. The paraffin blocks were cut into sections and slides were subjected to hematoxylin and eosin (HE) staining and observed using an optical microscope. All slides images were obtained using a Pannoramic Scan (3DHISTECH, Budapest, Hungary).

Follow-up and outcomes

After seven days, no postoperative intercurrences were reported by the patient. Through intra oral evaluation, no hematoma or edema was noticed except for the first two days as the patient mentioned. No exudate was noticed.

Soft tissue sections (correspondent to tumor surrounding tissue) demonstrated fragments of connective tissue composed of dense collagen fibers randomly arranged, with fibroblasts and hyalinization areas. Immersed in bundles of collagen fibers, many basophilic round calcification areas were observed. Inflammatory cells were not present. Odontogenic islands were observed.

Histologically, the tumor mass was composed of tooth-like structures exhibiting an irregular arrangement. Hard tissue sections presented fragments of a mixture of material composed mainly of immature dentin, enamel matrix, cementum, and pulp tissue. Dentin immature matrix presented irregular tubules; enamel matrix demonstrated a basophilic pattern and barely prismatic spaces from hydroxyapatite loss during the demineralization process; cementum areas were superimposed to dentin, differing from dentin because of its basophilic irregular lines and the presence of cells inside the matrix (cellular cementum); finally, pulp tissue was observed surrounded by dentin matrix, composed of delicate collagen fibers and fibroblasts. In some places, the dentin matrix surface presented columnar cells similar to odontoblasts. Histopathological examination confirmed the diagnosis of complex odontoma (Figure 4).

Figure 4. Histopathological analysis of the odontoma.

A) Connective tissue around the tumor showing bundles of collagen representing mineralized areas (green arrows) and an island of odontogenic epithelium (blue arrow); B) pulpal tissue-like area, demonstrating delicate collagen fibers, a columnar layer of odontoblasts (blue arrows) related to the pre-dentin (yellow arrow) and the dentin matrix showing dentinal tubules (green arrow); C) enamel matrix; D) mineralized tissue similar to cement, presenting basophilic reverse lines (green arrows).

Three follow-up sessions were performed after 30 days, four months and 12 months. In these sessions, clinical intra oral examination was carried out as well as radiographic examination. Bone neoformation was observed by periapical radiograph in the lesion region at the second follow-up session (after four months) compared to the initial one. The periapical radiograph was taken using a radiographic positioner (Figure 5).

Figure 5. Radiographic preservation.

A) Periapical radiography of the endodontic treatment before surgery; B) radiographic examination after excision of the odontoma and performing the apical retro-obturation of tooth 12; C) 30 days after surgery; D) and E) 12 months after removal of the odontoma.

Consent

Written informed consent for publication of their clinical details and clinical images was obtained from the patient.