Fibroma ameloblástico asociado a un odontoma compuesto. La importancia del estudio histopatológico / Ameloblastic fibroma associated with a compound odontoma. Importance of the histopathological study

El fibroma ameloblástico es un tumor odontogénico mixto benigno de rara aparición, que constituye el 2% de todos los tumores odontogénicos, es de crecimiento lento, más común en niños y adultos jóvenes, compuesto por tejido conjuntivo fibroso embrionario y epitelio odontogénico primitivo, se caracteriza por la proliferación de tejido epitelial y mesenquimático. Aparece con más frecuencia en la mandíbula en zona de molares y premolares de pacientes jóvenes sin predilección de sexo, asociándose a veces a un diente incluido. El presente artículo tiene como objetivo describir un caso clínico de un paciente en la segunda década de vida, con aparente anodoncia en el maxilar superior, que se encontraba asintomático y en el cual fue diagnosticado fibroma ameloblástico en maxilar superior, zona de incisivos anteriores, lado izquierdo, se realiza una breve revisión de la literatura y diagnósticos diferenciales, se analizan sus características clínicas e histológicas y la actitud terapéutica a tomar. El tratamiento quirúrgico conservador con extirpación seguida de curetaje parece ser la opción terapéutica más adecuada, y teniendo presente que el porcentaje de recidiva es del 18,3% principalmente debido a escisión incompleta de la lesión, se deben realizar controles radiográficos postoperatorios 6 meses después y cada año por los siguientes 5 años (AU)

The ameloblastic fibroma is a benign mixed, rare odontogenic tumour, which accounts for 2% of all odontogenic tumours. It is slow growing, and more common in children and young adults. It is composed of embryonic fibrous connective tissue and early odontogenic epithelium, and characterised by the proliferation of epithelial and mesenchymal tissue. It appears most frequently in the jaw area of molars and premolars of young patients with no sex predilection, and is sometimes associated with an impacted tooth. This article aims to describe a clinical case of a child in the second decade of life, with apparent anodontia in the maxilla, which was asymptomatic and later diagnosed as an ameloblastic fibroma in the left side maxilla incisors area. A brief review of the literature and differential diagnoses was carried out, including an analysis of its clinical and histological features, and the therapeutic approach to take. Conservative surgical excision followed by curettage seems to be the most appropriate treatment option. It should be noted that the recurrence rate is 18.3%, mainly due to incomplete excision of the lesion. Radiographic controls should be performed six months postoperatively, and every year for the following five years (AU)

Fibro-odontoma ameloblástico de la mandíbula / Ameloblastic fibro-odontoma of the jaw

El fibro-odontoma ameloblástico (FOA) es un tumor odontogénico poco frecuente que afecta a personas jóvenes, sin predilección por género y usualmente se localiza en la zona posterior de la mandíbula. Clínicamente el paciente puede presentar retraso en la erupción dentaria acompañado de aumento de volumen indoloro. Radiográficamente es una lesión radiolúcida uni o multilocular de tamaño variable con áreas radiopacas. El tratamiento varía de acuerdo a su tamaño y se debe tener especial cuidado en la decisión de conservar o no los dientes adyacentes, ya que existe la posibilidad de recurrencia de la lesión. Presentamos un caso de FOA de gran tamaño en un paciente de 4 años. Se describen las características específicas, histológicas y clínicas. Se discute en la conducta terapéutica conservadora y la necesidad de control postoperatorio prolongado en el tiempo(AU)

Ameloblastic fibro-odontoma (AFO) is an infrequent odontogenic tumor that affects young people of either sex and is usually located in the posterior mandibular zone. Clinically, the patient might present a delay in dental eruption with a painless increase in volume. Radiographically, it is a uni- or multilocular radiolucent lesion of variable size with radiopaque areas. Treatment varies with tumor size and the decision to conserve the adjacent teeth must be weighed carefully due to the possibility of recurrence. The case of a large AFO in a 4-year-old patient is reported. The specific histological and clinical characteristics are described and the conservative therapy and need for long-term postoperative follow-up are discussed(AU)

Differentiation and regenerative capacities of human odontoma-derived mesenchymal cells.

Regenerating human tooth ex vivo and biological repair of dental caries are hampered by non-viable odontogenic stem cells that can regenerate different tooth components. Odontoma is a developmental dental anomaly that may contain putative post-natal stem cells with the ability to differentiate and regenerate in vivo new dental structures that may include enamel, dentin, cementum and pulp tissues. We evaluated odontoma tissues from 14 patients and further isolated and characterized human odontoma-derived mesenchymal cells (HODCs) with neural stem cell and hard tissue regenerative properties from a group of complex odontoma tissues from 1 of 14 patients. Complex odontoma was more common (9 of 14) than compound type and females (9 of 14) were more affected than males in our set of patients. HODCs were highly proliferative like dental pulp stem cells (DPSCs) but demonstrated stronger neural immunophenotype than both DPSCs and mandible bone marrow stromal cells (BMSCs) by expressing higher levels of nestin, Sox 2 and betaIII-tubulin. When transplanted with hydroxyapatite/tricalcium phosphate into immunocompromised mice, HODCs differentiated and regenerated calcified hard tissues in vivo that were morphologically and quantitatively comparable to those generated by DPSCs and BMSCs. When transplanted with polycaprolactone (biodegradable carrier), HODCs differentiated to form new predentin on the surface of a dentin platform. Newly formed predentin contained numerous distinct dentinal tubules and an apparent dentin-pulp arrangement. HODCs represent unique odontogenic progenitors that readily commit to formation of dental hard tissues.

Odontoma compuesto: diagnóstico radiográfico y tratamiento quirúrgico de un caso clínico / Compound odontoma: radiographic diagnosis and surgical management of a clinical case

Se presenta un caso clínico de odontoma compuesto asociado a un diente supernumerario y un canino retenido superior derecho. El paciente de 16 años de edad es de sexo masculino. Se realizan diversos estudios radiográficos para su diagnóstico, que consisten en técnica panorámica y técnicas intraorales. Posteriormente se realizó la intervención quirúrgica para extirpar la lesión y las estructuras dentarias asociadas a ella. El estudio histopatológico confirmó el diagnóstico presuntivo. Basado en lo expuesto se analiza al odontoma compuesto según localización, sexo y edad habiendo realizado una revisión del tema según diversos autores (AU)

A clinical case of a compound odontoma associated with a supernumerary tooth and an upper right impacted canine in a 16-year-old male, is reported. To perform the diagnosis, several radiographic studies were made, mainly consisting of panoramic and intraoral techniques. Then, a surgical procedure was carried out to remove both the lesion and the surrounding tooth structures. The histo-pathological examination confirmed our presumptive diagnosis. Therefore, based on these findings, the compound odontoma is analyzed according toits location, sex and age of patients as well, after reviewing other authors´ opinions in the current literatura (AU)

Midkine expression correlating with growth activity and tooth morphogenesis in odontogenic tumors.

Midkine (MK; a low molecular weight heparin-binding growth factor) is a multifunctional cytokine. MK plays a role in morphogenesis of many organs including teeth through epithelial-mesenchymal interactions. We immunohistochemically examined MK expression in various human odontogenic tumors. There was no difference in positive rate and intensity of MK between benign odontogenic tumors and their malignant counterparts. Ameloblastoma showed MK localization in the peripheral columnar cells in budding processes from the parenchyma, which frequently expressed proliferating cell nuclear antigen. MK was also preferentially expressed in keratinized cells in acanthomatous ameloblastoma and keratocystic odontogenic tumor. In odontogenic mixed tumors except for odontoma, intense immunoreactivity to MK was found in epithelial follicles, the surrounding odontogenic ectomesenchymal tissue, and the basement membrane between them. Intensity in the odontogenic ectomesenchyme decreased in relation to distance from the epithelial follicles. No expression was found in tumor cells associated with production of dental hard tissues in odontogenic mixed tumors including odontoma. These findings suggested that MK is involved in the reciprocal interaction between odontogenic epithelium and odontogenic ectomesenchymal tissue in areas without dental hard tissue formation in odontogenic mixed tumors. Coexpression of MK and proliferating cell nuclear antigen was also observed in epithelial follicles and highly cellular nodules in the ectomesenchyme of odontogenic mixed tumors. MK is considered to mediate growth activity of odontogenic tumors and cell differentiation of odontogenic mixed tumors through molecular mechanisms similar to those involved in morphogenesis of the tooth.

Clinical observations of odontomas in Japanese children: 39 cases including one recurrent case.

Retrospective investigations of odontomas in Japanese children and one recurrent case were carried out. Thirty-nine cases of odontoma in 38 children were treated in the Paediatric Dentistry Clinic of Niigata University Dental Hospital between September 1979 and December 2002. The patients consisted of 23 males and 15 females and their ages ranged from 1 year 2 months to 14 years old. The chief complaints were delayed tooth eruption in 19 cases (five: primary teeth, 14: permanent teeth), retention of primary teeth in 11, incidentally found on the radiographic examination in eight cases, and swelling of the jaw in one case. Thirty-four cases (87%) were associated with tooth eruption disturbances. The most frequently affected region was the maxillary anterior region. Treatment consisted of surgical removal of odontomas in all cases, after which if the impacted teeth did not erupt, exposure of the crown and/or orthodontic traction was performed. Pathological diagnoses were compound odontoma in 30 cases, complex odontoma (n = 7), and compound and complex odontoma (n = 2). A retrospective study of the radiographs revealed the developing process of odontomas in four cases and odontoma disturbed tooth eruption since the early uncalcified developing stage. A recurrent case was a boy aged 6 years 5 months in whom the first surgical removal of odontoma was performed at the age of 1 year 8 months. Recurrence of an odontoma is very rare, but in very young children odontomas are in the early developing stages, containing uncalcified portions, so it is important to perform periodical observations until the succedaneous teeth erupt.

[Clinical studies on 16 cases of odontoma in children].

16 cases of odontoma (male: 12, female: 4) in young patients from 1 year 2 months to 14 years of age at the Pedodontic Clinic of Niigata University Dental Hospital in a recent 9 year period were investigated clinically. As for the pathologic histology, 12 cases were of the compound type, 2 were of the complex type, 1 was of the intermediate type between compound and complex, and 1 was of ameloblastic fibro-odontoma type. 9 cases occurred in the maxilla, 7 cases occurred in the mandible. Most of the compound type were observed in the area of the maxillary incisors and cuspids, and the complex type cases were noted in the anterior part of the maxilla. In many cases, there were clinical symptoms such as retarded eruption. Some cases of odontoma in children were small in scale and showed a low degree of calcification. Therefore they showed a tendency not to be found out at radiography, and it is difficult to diagnose them as odontoma. By finding odontoma prematurely and removing it in time, the retarded eruption teeth were able to erupt spontaneously or to be guided to a normal position.