Surgical treatment of cementoblastoma: case report

Cementoblastoma is a benign, slow-growing, and unlimited mesenchymal dental tumor. Due to its rarity, we aimed to report the case of a 24-year-old female patient who presented pain complaints and increased volume in the left mandibular region. Imaging tests showed a hyperdense lesion with hypodense halo, associated with the roots of elements 35, 36, and 37. Histopathology revealed diagnosis of cementoblastoma. The proposed treatment consisted of the enucleation of the tumor mass together with the exodontia of the teeth involved and osteotomy of the bone remnant. The patient has been under follow-up for one year with no signs of recurrence.

Radiographically, cementoblastoma is presented as a welldefined radiopaque image, or of mixed density, with a radiolucent halo associated with the tooth root (3,5,7) .
In histopathology, we observed a circumscribed tumor composed of cement-like tissue, with cementoblasts dispersed in a mineralized matrix, with the presence of a variable number of basophilic reversal lines and fibrovascularized stroma (2,3,(5)(6)(7) .
The treatment of choice consists of complete surgical excision associated with the removal of the teeth involved (2)(3)(4)(5)7) . However, treatments such as enucleation together with the preservation of the affected tooth (7) , endodontic therapy and (2) have also been reported. The cementoblastoma recurrence is considered rare, occurring only in cases where the lesion is not completely removed (2,3,5,7) .
As this is an unusual finding, this report aims to provide information that allows healthcare professionals to refine the diagnosis and treatment of cementoblastoma, debating issues about therapy, proservation and the clinical, radiographic and histopathological aspects from a clinical case of that lesion.

case report
Female patient, 24 years old, brown, sought care in a private dental clinic with pain complaints and increased volume in the left mandibular region for about one year. The medical history was not contributory. In addition, changes in the extraoral examination were not found. The intraoral examination showed a single, circumscribed volume in the mandibular region, color similar to the adjacent normal mucosa, involving the second premolar and the first and second lower molars, with expansion of the buccal and lingual cortical plates. The related teeth showed vitality ( Figure 1).
Computed tomography (CT) was performed preoperatively; the following aspects were evidenced: hyperdense lesion with a well-defined and rounded hypodense halo, associated with the distal root of the lower second premolar, the roots of the lower first molar, and the mesial root of the lower second molar, without affecting the mandibular canal ( Figure 2).
After performing the incisional biopsy, specimen fragments of brownish tissues were obtained, measuring together, 0.5 × 0.5 cm; then, they were submitted to hematoxylin and eosin (HE) staining to histopathological analysis. This, in turn, revealed fragments of benign odontogenic tumor consisting of cementoid and osteoid particles, with sheets and trabeculae of mineralized material, containing cells scattered over the gaps and basophilic reversal e2262020  By correlating clinical, radiographic, and histopathological findings, the diagnosis of cementoblastoma was confirmed. After signing the informed consent form, the proposed treatment consisted of enucleation of the tumor mass together with the extraction of the teeth involved and osteotomy of the bone remnant, in order to completely remove the lesion and maintain bone vitality for better healing, besides preventing recurrence ( Figure 4).
Thirty days after surgery, the affected region presented satisfactory clinical healing. Panoramic control radiography was performed and showed initial signs of bone neoformation.
The patient continued to be followed up, undergoing tests to control her clinical condition. One year after the established treatment, no clinical signs of recurrence were observed ( Figure 5).
Panoramic radiography showed local bone repair. Due to tooth and bone loss in the affected area, the patient was referred for oral rehabilitation treatment ( Figure 6).

discussion
Benign cementoblastoma was first described by Dewey, in 1927, and by Noberg, in 1930, as a true cementoma (3,6,9,10,12) . The 2005 classification of the World Health Organization (WHO) updated the terminology for cementoblastoma (1,12) . The term benign was removed from the classification because it is an odontogenic tumor that has no malignant counterpart (1,12) .
The tumor does not show a significant gender predilection (5,6,8,10,12) , although some studies show a higher prevalence in males (3,5,13) , which differs from the case reported here because it affects a female patient. Chrcanovic et al. (2017) (8) performed an analysis of 258 clinical cases and concluded that cementoblastoma occurs more frequently in young patients, as verified in this report -mean age 20.7 years (1,3) , with occurrence ranging between 6 and 72 years (2,6) . It commonly affects the mandible (1,2,6,7,9,10) , in the region of molars and premolars. In general, the teeth are vital (1,6,12) , and the lower first molar is the most affected (6,8,(10)(11)(12) . The radiographic appearance of cementoblastoma may vary (1,5,7,8,10,12) ; in its mature phase, a radiopaque mass is observed, surrounded by a thin peripheral sclerotic halo (1, 5-8, 10, 12) . The contour of the roots that are in close contact with the tumor is poorly defined due to the resorption of the root and the fusion of the mass to the tooth (1,(6)(7)(8)(9)(10) . CT can be used to define the size, location of the tumor and its relationship with the mental foramen, as well as to assess the degree of root resorption and assist in surgical planning (2,7) . The CT features contributed to the diagnosis and planning of the reported case.
Microscopic findings demonstrate a neoplasm composed of a calcified mass of cementum-like tissue (1,7,9,12) with basophilic tumor cells, which may exhibit pleomorphism (7) and a large number of reversal lines. The periphery of the tumor is generally not mineralized and presents active soft tissue cementoblasts in a fibrovascularized stroma (1,7,9,10,12) . Mitotic figures are uncommon (1,7) . Such characteristics are compatible with the lesion presented in this report.
The treatment of choice for cementoblastoma adopted in the present case was surgical excision of the tumor mass associated with the extraction of the teeth involved (2)(3)(4)(5)7) , since the tissue remaining after surgery may lead to tumor recurrence (2,3,5,7) . conclusion Cementoblastoma is a rare neoplasm; therefore, it is important to consider similar clinical, radiographic, and microscopic entities as a differential diagnosis. Recurrences are associated with inadequate treatments, in which the tumor mass is not completely removed. Surgical enucleation of the lesion was the treatment proposed for this case along with the extraction of the teeth involved, a data consistent with the literature. Currently, the patient is undergoing clinical and radiographic monitoring, with no signs of recurrence. e2262020