Indian Journal of Dental Research

: 2015  |  Volume : 26  |  Issue : 6  |  Page : 641--643

Extragnathic and gnathic odontome

Muthu Sekhar, Loganathan Selvaraj 
 Department of Oral and Maxillofacial Surgery, Saveetha Dental College, Chennai, India

Correspondence Address:
Dr.? Loganathan Selvaraj
Department of Oral and Maxillofacial Surgery, Saveetha Dental College, Chennai


This is a very rare case report of a multiple odontome involving the upper jaws, lower jaws and an extragnathic site. A thirty seven year-old male complained of missing teeth in his left upper and lower jaw since childhood. Radiographic examination revealed multiple calcified teeth like structures in the left side of the patient«SQ»s maxilla, mandible and mastoid region of skull base. We arrived at the diagnosis of compound odontome. Patient was otherwise systemically normal and with good health. He underwent surgical enucleation of the jaw odontome while the extragnathic odontome was left under observation. This rare case report proves that the embryonic dental cells might migrate to the primordium of the Rathke«SQ»s pouch and further might be carried towards the site of the developing cranial base region.

How to cite this article:
Sekhar M, Selvaraj L. Extragnathic and gnathic odontome.Indian J Dent Res 2015;26:641-643

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Sekhar M, Selvaraj L. Extragnathic and gnathic odontome. Indian J Dent Res [serial online] 2015 [cited 2022 Dec 7 ];26:641-643
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Odontomes occurring in sites other than the jaws are extremely rare. Odontomas of unknown etiology, referred to as hamartomas represent about 22% of the odontogenic tumors. [1],[2],[3],[4] Existing literature reveals few cases of extragnathic odontomes involving intracranial regions, middle ear, and nasopharynx. This report discusses a rare case of compound odontome involving the mastoid region of skull base, along with its presence in the common sites of maxillae and mandible. This report substantiates the postulation of embryological development of extragnathic odontomes.

 Case Report

In October 2011, a 37-year-old Asian male patient presented with missing teeth in his left side of the upper and lower jaws since his childhood. Patient was asymptomatic and presented with good health. Intraoral examination revealed missing teeth 18, 27, 28, 35, 36, 37, 38, and 48. Orthophantomogram also revealed missing teeth 18, 27, 28, 35, 36, 37, 38, and 48, and multiple calcified teeth-like structures in the left side of the patient's maxilla and mandible [Figure 1]. Computerized Tomography (CT) revealed multiple calcified teeth-like structures in the maxilla and mandible with impacted teeth 27, 28, 35, 36, 37, and 38, and ill-defined calcified structures near the cranial base at the mastoid region [Figure 2].{Figure 1}{Figure 2}

The patient was medically fit on physical examination. Endocrine evaluation, blood analysis, and neuroimaging reports were normal. Neurosurgeon confirmed the diagnosis on the basis of CT, neuroimaging, and endocrine analysis. Further, he ruled out neural involvement. Under general anesthesia, the lesions in the left side of maxilla and mandible were enucleated, with no surgical intervention done on the lesion near the cranial base.

The gross specimen consisted of 11 and 13 tooth-like structures with thin capsule in the maxilla and mandible, respectively [Figure 3] and [Figure 4]. Histopathologic examination showed the tooth structures as enamel, dentin, pulp, and cementum, which further confirmed the lesion to be a compound odontome. Postoperative healing was uneventful. Meanwhile, the patient has been provided with a temporary prosthesis. The patient is under regular follow-up.{Figure 3}{Figure 4}


Odontomes are the most common benign tumors accounting for 22% of all odontogenic tumors of the jaws. [3],[4],[5] In 1946, McClure first reported an extragnathic odontome. Since then, only few cases of extragnathic odontomes have been reported in the literature, involving middle ear, intracranial sites, and tympanum.

The true etiology behind the occurrence of odontomes is unknown. However, it has been suggested that infection, trauma, hereditary anomalies like Herman's syndrome, Gardner's syndrome, or mutations in the genetic control of the tooth development could be the probable etiologies. [6],[7],[8],[9] The persistence of portions of lamina might also be an etiological factor. [6],[10] Sun et al. (2004) have stated that disordered odontogenesis could lead to odontome formation.

In 1975, Bellucci et al. postulated the hypothesis of migration of the embryonic dental cells to the primordium of the Rathke's pouch, and then further toward the developing region of the hypophysis around the third week of gestation, as an etiology of the sellar odontomes. This hypothesis further explained the formation of craniopharyngioma which has also been supported by Garnett et al. in 2007, Zimmerman and Halac in 2005, and Prabu and Brown in 2005. The above references support the possibility of similar origin in the extragnathic odontomes in relation to cranial base.

In this case report, the jaw odontomes were diagnosed based on imaging which showed dense radiopaque foci in the posterior region of left maxilla and mandible with radiolucent halo and a sclerotic margin. [6] Most of the odontomes are usually associated with impacted teeth and malformed adjunct teeth like aplasia. [11] In this case report, the odontomes were associated with impacted teeth 18, 27, 28, 35, 36, 37, 38, and 48. Histopathologic data showed enamel, dentin, cementum, and pulp chamber in order, which in turn confirmed the diagnosis as compound odontome. The extragnathic odontomes were not removed to avoid unnecessary complications and the patient was instructed to have regular follow-up visits in the future.

The extragnathic odontome was diagnosed based on the CT report which showed a well-defined radiopaque lesion with the resemblance of teeth at the nasomaxillary region and the base of petrous bone region. Neuroimaging, blood analysis, and endocrine assessment were normal. Further, the histological proof of absence of ameloblastic-like cells ruled out the diagnosis of ameloblastic fibro-odontoma. Ghost cells, cyst follicles, and amyloid cells, which are usually more diagnostic of craniopharyngiomas, were absent, and this helped us to narrow down to the diagnosis of multiple odontome. [12]

To our knowledge, this is the first case report of odontome involving mastoid region of the skull base, along with the occurrence in the common sites of maxillae and mandible. Our case supports the embryological aspects of development of extragnathic odontomes.


1Gnepp D. Diagnostic Surgical pathology of the head and neck. Philadelphia: Saunders WB; 2001.
2Marx RE, Stern D. Odontogenic tumors (14); Oral and maxillofacial pathology. Quintessence; 2003. p. 678-9.
3Amado CS, Gargallo AJ, Berini AL, Gay EC. Review of 61 cases of odontoma: Presentation of an erupted complex odontoma. Med Oral 2003;8:366-73.
4Bhasker SN. Odontogenic tumors of jaws in synopsis of oral pathology. 7 th ed. Mosby; 1986. p. 292-303.
5Bordini J Jr, Contar CM, Sarot JR, Fernandes A, Machado MA. Multiple compound odontomas in the jaw: Case report and analysis of the literature. J Oral Maxillofac Surg 2008;66:2617-20.
6Vengal M, Arora H, Ghosh S, Pai KM. Large erupting complex odontoma: A case report. J Can Dent Assoc 2007;73:169-72.
7Das UM, Nagarathna, Arathi. Unerupted maxillary primary canine associated with compound composite odontoma: A case report. J Indian Soc Pedod Prev Dent 2002;20:98-101.
8Singh S, Singh M, Singh I, Khandelwal D. Compound composite odontome associated with an unerupted deciduous incisor-A rarity. J Indian Soc Pedod Prev Dent 2005;23:146-50.
9Wg Cdr P Jeyraj, Air Cmde S. Murali Mohan. Medical journal armed forces India 2008;64:382-3.
10Ide F, Obara K, Mishima K, Saito I, Horie N, Shimoyama T, et al. Peripheralodontogenic tumor: A clinicopathologic study of 30 cases: General features and haemartomatous lesions. J Oral Pathol Med 2005;34:552-7.
11Kaneko M, Fukuda M, Sano T, Ohnishi T, Hosokawa Y. Microradiographicand microscopic investigation of a rare case of complex odontoma. Oral SurgMed Oral Pathol Oral Radiol Endod 1998;85:131-4.
12Harris BT, Horoupian DS, Tse V, Herrick MK. Melanotic craniopharyngioma: A report of two cases. Acta Neuropathol 1999;98:433-6.