Journal of Indian Academy of Oral Medicine and Radiology

: 2014  |  Volume : 26  |  Issue : 1  |  Page : 119--123

Orthokeratinized odontogenic cyst: A rare presentation

Neha Bhasin1, Sreedevi1, Sanyog Pathak2, Vinuth Dhundanahalli Puttalingaiah3,  
1 Departments of Oral Medicine and Radiology, Hitkarini Dental College and Hospital, Jabalpur, Madhya Pradesh, India
2 Department of Oral Surgery, Hitkarini Dental College and Hospital, Jabalpur, Madhya Pradesh, India
3 Department of Oral Pathology, Hitkarini Dental College and Hospital, Jabalpur, Madhya Pradesh, India

Correspondence Address:
Neha Bhasin
House No-2934/A, Vidya Villa, Opposite Narmada Nagar, Adjacent Sukh Sagar Motors, Gwarighat Road, Jabalpur - 482 008, Madhya Pradesh


Orthokeratinized Odontogenic Cyst (OOC) is a developmental cyst of odontogenic origin and was initially defined as the uncommon orthokeratinized variant of the Odontogenic Keratocyst (OKC), until the World Health Organization«SQ»s (WHO«SQ»s) classification in 2005, where it was separated from the Keratocystic Odontogenic Tumor (KCOT). It is a relatively uncommon developmental cyst comprising of only 0.4% of all odontogenic cysts. It is rather mystifying that its radiographic features are similar to the dentigerous cyst and histological characteristics are similar to the odontogenic keratocyst; and it has inconsistent cytokeratin expression profiles overlapping with both the dentigerous cyst and odontogenic keratocyst as well as with the epidermis. It has a predilection for the posterior mandibular region. This is a report of a rare case of OOC in an unusual maxillary anterior region, with emphasis on its biological characteristics.

How to cite this article:
Bhasin N, Sreedevi, Pathak S, Puttalingaiah VD. Orthokeratinized odontogenic cyst: A rare presentation .J Indian Acad Oral Med Radiol 2014;26:119-123

How to cite this URL:
Bhasin N, Sreedevi, Pathak S, Puttalingaiah VD. Orthokeratinized odontogenic cyst: A rare presentation . J Indian Acad Oral Med Radiol [serial online] 2014 [cited 2020 Feb 22 ];26:119-123
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Orthokeratinized Odontogenic Cyst (OOC) is a relatively uncommon developmental cyst. [1] Schultz (1927) first described it as a dermoid cyst. In 1945, Philipsen considered this entity as a variant of the Odontogenic Keratocyst (OKC). [2] OOC gained individuality in 1981, after Wright suggested it to be an 'orthokeratinized variant of OKC'. [1],[3] Li et al. suggested the term 'orthokeratinized odontogenic cyst'. [1]

The WHO, 2005 edition, reclassified the parakeratotic type of OKC as a Keratocystic Odontogenic Tumor (KCOT), in view of its intrinsic growth potential and propensity to recur, and it stated that, 'cystic jaw lesions that are lined by orthokeratinizing epithelium do not form part of the spectrum of KCOT'. [4] OOCs involvement of the mandible to maxilla is 9.17:1, with a predilection for the posterior region. [1] Maxillary involvement is rare. The purpose of the article is to present a unique case of OOC arising in the anterior maxilla, an unusual site for the lesion, and to highlight the importance of distinguishing it from the more common KCOT.

 Case Report

A 36-year-old male patient presented with a swelling in the maxillary anterior region, of one-month duration. The history revealed that the swelling grew progressively in size, with no significant aggravating or relieving factors, and with no history of pain, discomfort or any extraction procedure. There was a history of trauma to the same region two years back, following which the patient had received restorative treatment. His past medical history was of no relevance and his general physical status was good, with no skin lesions, as in the basal cell nevus syndrome. The intraoral examination revealed root stumps in relation to 53 and 63, missing 13 and 23, restored 11 and 21, with secondary caries, and moderate distoproximal caries in 14. There was diffuse swelling in the right side of the anterior two-third of the palate, extending anteroposteriorly, 1 cm from the gingival margin of 11 and 12, up to the valley of rugae, and mediolaterally from the midpalatal raphe to 0.5 cm from the gingival margin of 14 and 15, roughly oval in shape, and measuring approximately 1 × 1.5 cm in size [Figure 1]. The overlying mucosa appeared relatively normal. On palpation it was firm and tender. A provisional diagnosis of a dentigerous cyst was made. The maxillary occlusal and intraoral periapical radiographs revealed impacted 13 and 23, and unilocular pericoronal radiolucency associated with 13, surrounded by a sclerotic border, attached to the cementoenamel junction (CEJ), with the cystic space appearing completely radiolucent [Figure 2] and [Figure 3]. On the basis of the clinical and radiographic findings a diagnosis of dentigerous cyst and a differential diagnosis of adenomatoid odontogenic tumor and OKC were made. Disimpaction of 13 and 23 was done. A palatal crevicular incision was given from 16 up to the central incisor and continued till 26, and the flap was raised [Figure 4]. The cyst was exposed, enucleated [Figure 5], and sent for histopathological examination. Sutures were placed and an impression was taken for fabrication of a stent. Histopathology revealed a uniform orthokeratinized stratified squamous epithelium of varying thickness, lining a thin fibrous wall [Figure 6]. The flattened basal cell layer lacked the palisading, and the prominent granular cell layer was apparent [Figure 7]. A final diagnosis of OOC was given. A follow-up after four weeks showed uneventful healing [Figure 8] and [Figure 9].{Figure 1}{Figure 2}{Figure 3}{Figure 4}{Figure 5}{Figure 6}{Figure 7}{Figure 8}{Figure 9}


Until recently, OOC has been considered to be a type of OKC. Its incidence varies, ranging from 5.2-16.8% [1] or 3.3-12.2% [5] of the cases previously classified as OKC to only 0.4% of all odontogenic cysts. OOC has been reported to occur in the third and fourth decades, [3] with an average age of 38.9 years. [1] Some authors have advocated its occurrence in the fourth and fifth decades. [6] It has a male to female ratio of 2.59:1. [2] Dong et al. have suggested a female predominance. [7] The mandible - maxilla ratio is 9.17:1, with a predilection for the mandibular molar and ramus region. [1] Hence, involvement of an unusual location, like the maxillary anterior region, makes the present case a unique one. Clinically, OOC usually presents as a slowly growing, asymptomatic jaw swelling with or without pain, with size varying from less than 1 cm to 7 cm, [8] which goes with the clinical presentation of this case. It may be associated with a calcifying odontogenic cyst, ameloblastoma, heterotopic cartilage or even squamous cell carcinoma. [9]

Radiographically, OOCs present as unilocular (87.0%) [2] or multilocular [10] radiolucencies. Often associated with impacted teeth (60.8%), [2] their diameters commonly range from 2 to 7 cm. [3] OOCs are almost absent from cases of the nevoid basal cell carcinoma syndrome (NBCCS). About two-thirds of the OOCs are encountered in a lesion that appears clinically and radiographically like a dentigerous cyst, [7] as observed in the present case. The differential diagnosis of OOC includes dentigerous cyst, paradental cyst, ameloblastoma, and KCOT. An OOC does not cause root resorption, which is a frequent characteristic of ameloblastomas and KCOT. [10]

Vuhahule et al. suggested that OOCs could be dentigerous cysts with orthokeratinization [7] or could even represent a central dermoid or epidermoid cyst. Zhu suggested that while a KCOT may arise from the dental lamina, in the presence of the dental papilla, OOC may arise from the oral epithelium under the influence of dental papilla or only from the oral epithelium. [5]

Histologically OOC is characterized by a thin, uniform epithelial lining, four to eight cell layers thick and is composed of an orthokeratinized stratified squamous epithelium with a prominent granular cell layer, [2] as seen in the present case. The basal cells are usually cuboidal or flattened and do not exhibit any palisading or polarization. Immunoprofiling reveals that the OOC is a well-formed and more organized cyst when compared to the KCOT. [5] Decreased expression of Ki-67 and p63 in OOCs as compared to KCOTs indicates their low proliferative activity. [1] OOC and OKC differ greatly in various aspects [Table 1].{Table 1}

Aggressive treatment for KCOT includes peripheral ostectomy, chemical curettage or enbloc resection. [7] Enucleation with curettage is the usual treatment for OOCs. [10] Recurrence has rarely been noted (2.2%); unlike KCOT (42.6%). [2]


The present case reconfirmed the importance of precise clinicopathological observation. As in the present case, the size and location of the lesion did not corroborate with the usual clinical findings of an OOC. The OOC should be considered in the differential diagnosis of jaw lesions associated with an impacted tooth, particularly those cases simulating a dentigerous cyst. Diagnosis of OOC is important, as the pathological behavior, clinical outcome, and surgical management of the OOC is disparate.


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