An Aggressive Anterior Mandibular Adenomatoid Odontogenic Tumor: A Case Report

Special Article - Oral Squamous Cell Carcinoma

J Dent & Oral Disord. 2016; 2(5): 1025.

An Aggressive Anterior Mandibular Adenomatoid Odontogenic Tumor: A Case Report

Gill DG¹* and Schlieve TS²

¹Department of Oral and Maxillofacial Surgery, Meharry Medical College, USA

²Department of Oral and Maxillofacial Surgery, University of Texas Southwestern Medical Center, USA

*Corresponding author: Danielle G Gill, Department of Oral and Maxillofacial Surgery, Meharry Medical College, USA

Received: June 13, 2016; Accepted: July 07, 2016; Published: July 08, 2016


The Adenomatoid Odontogenic Tumor (AOT) is a rare benign complex odontogenic tumor, representing about 3% of all odontogenic tumors. The literature describes the AOT as both a true benign, non-aggressive, non-invasive neoplasm versus a developmental hamartomatous odontogenic growth. The tumor is characterized by its overwhelming female predilection, presence in the second decade of life, anterior position in the maxilla, association with impacted teeth, and appearance of scattered opacities within the tumor. Treatment is typically standard enucleation. Here, we report a case of extrafollicular-type adenomatoid odontogenic tumor in a 14-year-old African American female in the anterior mandible crossing the midline as well as the clinical, radiological, histological features of the tumor.

Keywords: Adenomatoid odontogenic tumor; Extrafollicular; Mandible; Perforation


AOT: Adenomatoid Odontogenic Tumor; BMI: Body Mass Index; CBCT: Cone Beam Computed Tomography; WHO: World Health Organization


The AOT is a benign complex tumor representing 3% [1,2] of odontogenic tumors, and ranked fourth most diagnosed [2-4]. The reported frequency of the AOT differs amongst various publications with most reporting 2.2-7.1% [1,2], but others have documented ranges from 0.6-38.5% [2,5]. The AOT was first documented in 1903 as a cystis chenepithelialen Geschwülste by Dr. Nakayama, a Japanese general surgeon [6]. Since then, authors all over the globe have described characteristics of what is now called the AOT, which was officially adopted in 1971 by the World Health Organization.

Descriptions of what they the actual AOT entity may be are controversial, with some defining the lesion as a true benign, nonaggressive, non-invasive neoplasm and others adapting the lesion as a developmental hamartomatous odontogenic growth [2,4,7]. Marx and Stern argue that the AOT is a true cyst, a not a neoplasm at all, but a true cyst with a lumen, lining and connective tissue [8,9].

Due to its classic and consistent clinical and radiographic characteristics, the AOT has earned the nickname “tumor of twothirds” [8-10]. Two-thirds of diagnosed AOTs occur in females of the second decade in the anterior maxilla. Two-thirds will also be superimposed on dentigerous cysts, associated with an impacted tooth, usually a canine and have scattered opacities throughout the lesion [10].

Age of diagnosis varies from three to 82 years, but most occur in the second decade of life [1]. The AOT has a female predilection, with a ratio of 2:1 compared to males, [1,10] is more likely to present on the left side of jaws, 50.7% versus 38.8% on the right, [11] and has a maxilla-to-mandible ratio of 1.7:1 [7]. Average reported size of the AOT is 1-3 cm, [12] ranging from 0.4-12 cm [7].

There are three known subtypes of the AOT, the follicular, extrafollicular, and peripheral types [3]. The follicular or pericoronal type makes up the majority of AOTs at 70.8%. The extrafollicular or extracoronal type and the rare peripheral or extraosseous/ gingival type make up 26.9% and 2.3%, respectively.

There are numerous radiological features that are associated with the AOT. It is mostly described as a unilocular radiolucency with welldefined borders [5,7]. They are usually associated with an impacted teeth, most often a permanent canine [7,11,13]. The presence of calcifications is a common finding appearing in 78% of AOTs [13]. Periapical radiographs are the gold standard when confirming appearance of calcified deposits [7,14]. These calcifications can present as a single radiopacityor numerous radiopaque foci [12].

Surgical management of the AOT is most often enucleation and curettage with predictable results [15]. The associated impacted tooth may or may not be extracted during enucleation. Marsupialization or decompressions are also treatment options with favorable outcomes [6]. Partial resection has been indicated with larger tumors or patients who are at risk for pathologic fracture [10]. The AOT has a recurrence rate of 0.2% and is not locally invasive [10].

In this case report, we present an extrafollicular type AOT of substantial size causing discernable facial asymmetry in the lower facial one-third. Uncommon clinical, radiographic, and histologic features are discussed and compared to the classic presentation of the AOT.

Case Report

A 14-year-old African-American female presented to the University of Illinois at Chicago Oral and Maxillofacial Surgery Clinic with swelling of the anterior mandible. The swelling started two years prior and had been slowly increasing in size, with intermittent of sharp pain. No history of trauma was reported. She was a febrile and denied paresthesia, dysguesia, dysphagia, dyspnea, chills, nausea and vomiting. Medical history included asthma, seasonal allergies, and morbid obesity (BMI34). The patient was prescribed a decongestant for seasonal allergies, albuterol as needed for asthma, and over the counter pain relievers for pain relief. Previous surgical history, social history or family history was non-contributory.

Head and neck examination revealed moderate to severe asymmetry of the lower one-third of the face. The area was firm and tender when manipulated. There was no appreciable erythema or purulence, nor was there any associated lymphadenopathy, trismus, nasal deviations, or temporomandibular joint pathology. Two-point discrepancy and brush stroke testing were normal on the tongue, lower lip and chin indicating no neurological deficits. Intraorally, anterior mandibular labial and lingual expansion was appreciated, extending from teeth #22-27. There was visible splaying of mandibular anterior teeth as well as mobility of teeth #23-27. Vitality results of teeth #22- 27 were normal during examination. Maximum incisor opening was over forty millimeters. Oropharynx was clear. Uvula was midline, and no palatal draping was noted. Floor of the mouth was soft, nontender and non-extended.

CBCT revealed a 3.3 x 2.7 cm diameter, well-defined, unilocular, radiolucency mesial to tooth #22 crossing the midline to the mesial of tooth #28 (Figure 1). Resorption of the root apices on teeth #24- 27 (Figure 1) was displayed. Centered within the radiolucency was a single 2x2 mm radiopacity (Figures 2 & 3) and both labial and lingual cortices of the anterior mandible were perforated (Figure 4).