Journal of Dentistry

Dilated Odontoma of the Mandible: A Rare Case Report with Discussion about the Differential Diagnosis

Document Type : Case Report

Authors

Saede Atarbashi-Moghadam 1
Ali Lotfi 1
Nazanin Foroozandehfar 2
Parsa Eftekhari Moghadam 2

1 Dept. of Oral and Maxillofacial Pathology, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

2 Student of Research Committee, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

https://doi.org/10.30476/dentjods.2025.106990.2707
Abstract
Dilated odontoma is a rare developmental anomaly considered the most severe form of dens invaginatus (dense in dente). It results from a deep enamel-lined invagination into the dental papilla before mineralization, forming a ring-shaped radiopaque mass with a radiolucent center. Anterior mandibular involvement is uncommon. Familiarity with the radiographic features of this lesion is crucial for dental practitioners to make an accurate diagnosis. We report a case of a 12-year-old girl with a painless bony hard swelling in the anterior mandible. Panoramic radiograph revealed a well-defined, doughnut-like radiopaque lesion along with an unerupted permanent canine. The provisional diagnosis was dilated odontoma and ameloblastic fibro-odontoma. The treatment plan consisted of surgical removal of the lesion, followed by histopathologic study to confirm the initial diagnosis. Dilated odontoma may lead to permanent tooth impaction, particularly in atypical locations such as the mandible. It is recommended that the order of tooth eruption in the mixed dentition age group be carefully evaluated. 

Keywords

Dense in dente
Dens invaginatus
Mandible
Impacted tooth
  • Zara F, D'Angeli G, Corsi A, Polimeni A, Sfasciotti GL. Dilated odontoma arising in the mandibular third molar germ: Report of a case of an unusual lesion in an uncommon site. Diagnostics (Basel). 2021; 11: 2256.
  • Sebastian AA, Ahsan A, George AJ, Aby J. An unusual triad: Bilateral dilated odontoma, hypodontia and peg laterals. Dent Res J (Isfahan). 2013; 10: 674-677.
  • Jayachandran S, Kayal L, Sharma A, Priyanka K. Dilated odontoma: A report of two cases from a radiological perspective. Contemp Clin Dent. 2016; 7: 107-110.
  • Sharma G, Nagra A, Singh G, Nagpal A, Soin A, Bhardwaj V. An erupted dilated odontoma: A rare presentation. Case Rep Dent. 2016; 2016: 9750947.
  • Meneses RKL, Rocha TB, Santos CMB, Barros EF, Cunha JLS, Nonaka CFW, et al. Dilated odontoma: A series of three cases with an emphasis on imaging findings. Oral Surg, Oral Med, Oral Pathol and Oral Radiol. 2024; 137: e264.e265.
  • Mahmoodi A, Shahidi S, Houshyar M, Houshyar M. Bilateral cystic lesions associated to maxillary erupted dilated odontomas: a case report. J Dent (Shiraz). 2012; 13: 85-89.
  • Matsusue Y, Yamamoto K, Inagake K, Kirita T. A dilated odontoma in the second molar region of the mandible. Open Dent J. 2011; 5: 150-153.
  • Santos MF, Baroni EJ, Maragno AC, Stürmer MB. Dilated odontoma in the mandibular third molar region: a case report. RGO Rev Gaúch Odontol. 2023; 71: e20230043.
  • Muczkowska N, Czochrowska E, Masłowska K, Wojtowicz A, Popowski W. Combined surgical and orthodontic treatment of complex odontoma in growing patients: Presentation of two cases. Dent J (Basel). 2025; 13: 82.
  • Galvez P, Garot E, Bres A, Crelier A, Castain C, Catros S, et al. Dilated odontoma: An unusual case report and literature review. J Oral Med and Oral Surg. 2021; 27: 24.
  • Soluk-Tekkesin M, Vered M. Ameloblastic fibro-odontoma: At the crossroad between "developing odontoma" and true odontogenic tumor. Head Neck Pathol. 2021; 15: 1202-1211.
  • Oghli AA, Scuto I, Ziegler C, Flechtenmacher C, Hofele C. A large ameloblastic fibro-odontoma of the right mandible. Med Oral Patol Oral Cir Bucal. 2007; 12: E34-37.
  • Matsumoto T, Seto K. Histopathological studies of four cases of dilated odontoma. Oral Med Pathol. 1996; 1: 56-59.
  • Syed AZ, Venkata AP, Mendes RA. Dilated odontoma: an incidental finding. BMJ Case Rep. 2015; 2015: bcr2015212594.
  • Almeida B, Silva A, Pereira M, Silva M, Nunes S. Case report of a dilated odontome in the posterior mandible. Int J Surg Case Rep. 2016; 20: 14-16.
  • Cuković-Bagić I, Macan D, Dumancić J, Manojlović S, Hat J. Dilated odontome in the mandibular third molar region. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2010; 109: e109-e113.
Journal of Dentistry
Volume 27, Issue 2
Spring 2026
Pages 176-180

  • Receive Date 21 May 2025
  • Revise Date 22 July 2025
  • Accept Date 10 October 2025
  • First Publish Date 14 October 2025
  • Publish Date 01 June 2026

Home

Guide for Authors

Submit Manuscript

Guide for Reviewers

Contact Us