(1) Profesor Titular Vinculado. Universidad de Oviedo. Hospital Central de Asturias
(2) Licenciado en Odontología. Práctica Privada, Valencia
(3) Profesora Asociada Integrada de Adultos. Universidad de Oviedo. Clínica Odontológica
(4) Médico-Adjunto Cirugía Oral y Maxilofacial. Hospital Central de Asturias

Address:
Luis Junquera.
Universidad de Oviedo. Escuela de Estomatología
Catedrático José Serrano s/n. 33009. Oviedo. España
E-mail: Junquera@sci.cpd.uniovi.es

Received: 10-01-2004  Accepted: 16-07-2004

Odontomas are defined as hamartomas of odontogenic origin. They are composed of all the structures that form dental tissues. Histologically, two types of odontomas are recognized: complex and compound lesions (1). The compound type is composed of tooth-like structures that can be seen radiographically as opacities. The complex type comprises a mixture of odontogenic tissues without dental organization (2). Clinically, three types of odontomas are recognized in the literature: central (intraosseous) odontoma, peripheral (extraosseous or soft tissue) odontoma, and erupted odontoma.

Intraosseous (central) odontomas are the odontogenic tumors of greatest incidence. According to Daley et al. (3), they represent 51% of all odontogenic tumors. Central odontomas occur predominantly in the anterior maxilla (the usual location of compound lesions) and mandibular molar regions (the most common location of complex lesions) (4). Peripheral or extraosseous odontomas are defined as tumors with the histological characteristics of intraosseous odontoma but occurring only in the soft tissue covering the tooth-bearing portion of the mandible and maxilla. Only 6 cases of peripheral odontoma have been reported to date (5,6). All lesions were microscopically diagnosed as compound odontomas.

Rarely, intraosseous odontomas located coronally to an erupting or impacted tooth or superficially in bone may facilitate their eruption into the oral cavity. These lesions have traditionally been referred to as erupted odontomas. To our knowledge, only 11 acceptable cases have been reported to date (7-15). We report an erupted odontoma arising in the posterior maxilla, and discuss its relation and possible differences with peripheral odontoma.

CASE REPORT

A 23-year-old Caucasian male was referred to our Service with a hard mass on the posterior left region of the maxilla. The patient history was unremarkable. The patient claimed to have noticed the mass 13 months before receiving routine dental care. The lesion was painless, though the mass was noticed to grow towards the oral cavity. Intraoral examination revealed the presence of a whitish-yellow mass of solid and firm consistency, occupying the distal zone of the erupted 26 to the maxillary tuberosity. The mass had erupted into the oral cavity and was covered by attached gingiva (Fig. 1); it occupied the space of teeth 27 and 28. Orthopantomography showed the existence of a radiopaque mass 30 mm in diameter. In the apical portion of the lesion we noted the inclusion of a molar (Fig. 2). Under general anesthesia and with a preoperative diagnosis of odontoma, ameloblastic fibro-odontoma, or peripheral osteoma, the lesion was excised and curettage was practiced after extraction of the included molar (Fig. 3). The histopathological study of the surgical piece confirmed the diagnosis of complex odontoma. Two years after surgery, the patient was free of symptoms and no complications were recorded.

DISCUSSION

The definition of peripheral or soft tissue odontomas excludes those lesions developing in bone and which ultimately erupt. Peripheral odontomas closely resemble intraosseous odontomas, though the absence of bony erosion beneath the tumor supports the notion that they developed from gingiva (6). To our knowledge, only 6 cases of peripheral odontoma have been described to date (5,6), including Swan’s case report (5), which is considered by others as an erupted odontoma. The mean patient age was 15.5 years (range 3-39). Two cases were located on the upper vestibular gum and one on the palatal upper gum. The three reported cases located in the lower jaw arose in the lingual gum. All were compound odontomas.

Erupted odontomas are initially intraosseous or central odontomas that posteriorly become extraosseous or erupted. To date, all but one of the reported cases are related with non-erupted teeth, mainly second molars; it may therefore be postulated that the eruptive force of these teeth plays an important role in odontoma eruption. In the case reported by Ragalli et al. (14), there was no synchronous impacted tooth. However, this patient was 59 years old and showed severe bone resorption at the site of odontoma eruption. The reported mean age was 20.3 years (range 9-59), i.e., slightly greater than in the case of peripheral odontoma. Nine cases affected women and were preferentially located in the posterior maxillary segments. Histologically, they were regarded as complex odontomas (7-10,13-15).

In summary, our report constitutes one of the very few cases reported in the literature where intraosseous odontomas erupt into the oral cavity and can be examined visually and manually. Although this pathology is very infrequent, erupted odontomas – unlike peripheral odontomas – appear to show the following main differential characteristics: a histological picture of complex odontoma, older patient age at diagnosis, and frequent association to non-erupted second molars.

BIBLIOGRAFÍA        [ Links ]

2. Philipsen HP, Reichart PA, Praetorius F. Mixed odontogenic tumours and odontomas. Considerations on interrelationship. Review of the literature and presentation of 134 new cases of odontomas. Oral Oncol 1997;33:86-99.         [ Links ]

3. Daley TD, Wysoki GP, Pringle GA. Relative incidence of odontogenic tumors and oral jaw cyst in a canadian population. Oral Surg Oral Med Oral Pathol 1994;77:276-80.         [ Links ]

4. Hisatomi M, Asaumi JI, Konouchi H, Honda Y, Wakasa T, Kishi K. A case of complex odontoma associated with an impacted lower deciduous second molar and analysis of the 107 odontomas. Oral Dis 2002;8:100-5.         [ Links ]

5. Swan RH. Odontomas. A review, case presentation and periodontal considerations in treatment. J Periodontol 1987;58:856-60.         [ Links ]

6. Ide F, Shimoyama T, Horie N. Gingival peripheral odontoma in an adult: case report. J Periodontol 2000;71:830-2.         [ Links ]

7. Rumel A, de Freitas A, Birman EG, Tannous LA, Chacon PT, Borkas S. Erupted complex odontoma. Report of a case. Dentomaxillofac Radiol 1980; 9:5-9.         [ Links ]

8. Al-Sahhar WF, Putrus ST. Erupted odontoma. Oral Surg Oral Med Oral Pathol 1985;59:225-6.         [ Links ]

9. Serio FG, Levy BA. Erupted compound odontoma. Review and report of case. Ann Dent 1987;46:41-2.         [ Links ]

10. Gomel M, Seçkin T. An erupted odontoma: case report. J Oral Maxillofac Surg 1989;47:999-1000.         [ Links ]

11. López-Areal L, Silvestre Donat F, Gil Lozano J. Compound odontoma erupting in the mouth: 4-year follow-up of a clinical case. J Oral Pathol Med 1992;21:285-8.         [ Links ]

12. Kaneko M, Fukuda M, Sano T, Ohnishi T, Hosokawa Y. Microradiographic and microscopic investigation of a rare case of complex odontoma. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1998;85:131-4.         [ Links ]

13. Ferrer MJ, Silvestre FJ, Estrelles E, Grau D, López R. Recurrent infection of a complex odontoma following eruption in the mouth. Med Oral 2001;6: 269-5.         [ Links ]

14. Ragalli CC, Ferreria JL, Blasco L. Large erupting complex odontoma. Int J Oral Maxillofac Surg 2000;29:373-4.         [ Links ]

15. Amado S, Gargallo J, Berini L, Gay C. Revisión de 61 casos de odontoma. Presentación de un odontoma complejo erupcionado. Med Oral 2003;8:366-73.        [ Links ]