Archives of Medicine and Health Sciences

: 2021  |  Volume : 9  |  Issue : 1  |  Page : 113--116

Odontogenic keratocyst with horizontal impaction of third molar

Hannah Maryam1, Harshita Bejai Ratnakar1, P Rithul1, Bhargabi Paul Majumder1, Anita M Varghese1, Preethi A Poonja1, Prasanna Kumar Rao1, Raghavendra Kini1, Nithin Gonsalves2,  
1 Department of Oral Medicine and Radiology, A J Institute of Dental Sciences, Mangaluru, Karnataka, India
2 Department of Oral Pathology, A J Institute of Dental Sciences, Mangaluru, Karnataka, India

Correspondence Address:
Dr. Preethi A Poonja
Department of Oral Medicine and Radiology, A J Institute of Dental Sciences, NH 66, Kuntikana, Mangaluru - 575 004, Karnataka


Odontogenic keratocyst (OKC), previously known as keratocystic odontogenic tumor, are benign cystic lesions involving the mandible or maxilla and are believed to arise from dental lamina. What makes this cyst special is its aggressive behavior and high recurrence rate. This cyst is predominantly seen in younger patients (2nd–3rd decade) and may be seen in either the body or ramus of the mandible or maxilla. The distribution between sexes varies from equality to a male-to-female ratio of 1.6:1, except in children. There may be male predilection. Radiographically, it appears as unilocular or multilocular lesions with scalloped contour. This cyst is commonly detected incidentally. When symptomatic, jaw swelling and pain are common symptoms associated with this tumor. Less commonly, trismus and paresthesia may occur. Here, we present a case of OKC in a young male patient associated with an impacted right mandibular third molar.

How to cite this article:
Maryam H, Ratnakar HB, Rithul P, Majumder BP, Varghese AM, Poonja PA, Rao PK, Kini R, Gonsalves N. Odontogenic keratocyst with horizontal impaction of third molar.Arch Med Health Sci 2021;9:113-116

How to cite this URL:
Maryam H, Ratnakar HB, Rithul P, Majumder BP, Varghese AM, Poonja PA, Rao PK, Kini R, Gonsalves N. Odontogenic keratocyst with horizontal impaction of third molar. Arch Med Health Sci [serial online] 2021 [cited 2022 Jan 29 ];9:113-116
Available from:

Full Text


Odontogenic keratocyst (OKC) is defined as a developmental odontogenic cyst of the jaw that exhibits aggressive clinical behavior, characterized by a uni- or multi-cystic intraosseous tumor with a distinct lining of parakeratinized stratified squamous epithelium. This represents 4%–12% of all odontogenic cysts.[1]

The term OKC was first used by Philipsen in 1956. Pindborg and Hansen in 1963 described the essential features of this type of cyst. The initial terminology of OKC was primordial cyst as the origin of the lesion was thought to be the tooth primordium.

The World Health Organization histological typing of odontogenic tumors listed OKC as the preferred terminology for such cyst with keratinized lining in 1992.[2] Here has been a controversy in recent years over whether this lesion should be classified as a cyst or a tumor. Both terms are currently being used although the most recent World Health Organization classification system supports designation as OKC.[3]

In comparison to the other cysts of jaws, OKC is unique because of its distinguishing clinical features, including potentially aggressive behavior, high recurrence rate, and an association with the nevoid basal cell carcinoma syndrome. Most of the times, OKCs may be asymptomatic and found incidentally on dental radiographs. Rarely, if symptoms can arise, they are due to infection or expansion of the bone.[4] The neoplasm being locally aggressive, marsupialization/enucleation/excision ± aggressive curettage is advised.[5] Here, we present a case of OKC in a 22-year-old male patient associated with an impacted third molar.

 Case Report

A 22-year-old, healthy, male patient reported to the department of oral radiology in February 2020, with the complaint of pain in the right lower back tooth region for 1 week. Pain was gradual in onset, continuous, and insidious in nature. Initially, the pain was dull aching which was later sharp and aching in nature. There were no aggravating and relieving factors. The patient gives a history of taking medications (analgesics) for relieving the pain, but it made no difference. The patient gives a history of smoking 4 times a day for the past 2 years.

On extraoral examination, facial asymmetry with diffuse swelling on the right side of the face involving the angle of the mandible was present [Figure 1]. The submandibular lymph node was single, mobile, and firm in consistency and was tender on palpation.{Figure 1}

On intraoral examination, there was reduced mouth opening with the third molars missing from all four quadrants. On inspection, inflamed, pericoronal flap was present with buccal and lingual vestibules enlarged with no mucosal discoloration; there was a diffuse swelling present involving the area of 48 extending from 46 to the retromolar area, which was firm and tender on palpation. On palpation, the vestibule was tender and obliterated.

A panoramic radiograph revealed a normal condylar and coronoid process with maxillary and mandibular dentition. A unilocular, well-defined radiolucency with fully formed, ectopic impacted third molar in the right ramus region was seen [Figure 2]. The cyst lining was extending from the middle of the ramus to distal of 46 with the involvement of the mandibular canal. In cone beam computed tomography view, coronal section reveals well-defined radiolucency surrounding tooth 48. Axial view reveals horizontally placed 48 surrounded by well-defined radiolucency. Sagittal section reveals thinning buccal and lingual cortical plates and perforation of lingual cortical plate seen posterior to 47 [Figure 3].{Figure 2}{Figure 3}

Following this, the patient was advised for a biopsy. The histopathological examination stained with H and E revealed cystic lining and contents: stratified squamous epithelium, parakeratinized epithelium, and the thickness varying from 5 to 10 layers. Basal layers were tall, columnar. The lumen of the lesion comprises keratin material. Underlying connective tissue composed of collagen fibers was arranged parallel to the epithelium [Figure 4]. Dense amounts of inflammatory cells and cholesterol clefts were evident. Areas of hemorrhage were seen. the section of lymph node showed lymphocytes, germinal center, and a capsule. The architecture of the lymph node was not disturbed.{Figure 4}

Thus, correlating the clinical, radiographic, and histopathological features, a diagnosis of follicular keratocyst was made.

The patient was referred to the oral surgery department for surgical enucleation followed by peripheral ostectomy and reconstruction using reconstruction plates. The patient came for follow-up after 3 months [Figure 5].{Figure 5}


OKC is an aggressive odontogenic cyst that is derived from the rests of dental lamina. The lesion is named keratocyst because the lining epithelium produces so much keratin that almost fills the cyst lumen.[2]

This diverse group of lesions exhibits varying presentations ranging from a small innocuous lesion, which may be detected accidentally or may be presented as a highly aggressive and destructive lesion that may even transform into a malignancy.[6]

Because of this aggressive nature, the World Health Organization used the term “keratocystic odontogenic tumor (KCOT) “to describe the cyst.

The cyst occurs in any age group but most commonly seen in the second and third decades of life, with male predilection. In our presented case, the patient was a 21-year-old male. OKCs are found in the mandible in approximately 2:1 ratio. In the mandible, the posterior portion of the body and the region of ramus are most commonly affected. Moreover, in the maxilla, the third molar area is most commonly affected.[7] This relates to the presented case were the cyst was developed in the lower right third molar area. There are no characteristic clinical manifestations. The more common features are pain, soft tissue swelling, expansion of bone, drainage, and paresthesia of the lip or teeth.[2] Drainage and paresthesia were absent in the previously mentioned case whereas pain was present.

Radiographically, OKCs appear as a well-defined unilocular or multilocular radiolucency bounded by corticated margins. Unilocular lesions are predominant, whereas the multilocular variant is observed in approximately 30% of cases representing a central cavity having satellite cysts. In panoramic radiography, mandibular unilocular OKCs may show few and incomplete septa within the lesions; this finding is more common in larger than in smaller OKCs.[8] In addition to well-defined unilocular radiolucency, thinning of buccal and lingual cortical plates were also noted in case presented.

If associated with the crown of an unerupted/impacted tooth, they can mimic dentigerous cyst. If associated with roots of a nonvital tooth, they can mimic radicular cyst. When it is multilocular and especially if located in the third mandibular molar area, it may be confused radiographically with an ameloblastoma.[9] The cyst was associated with impacted third molar in our presented case.

Histopathologically, KCOT exhibits distinctive features which may be altered by inflammation. The epithelial lining is uniformly thin, usually 6–8 cells thick which does not demonstrate rete ridges and may result in the epithelium lifting from the underlying fibrous connective tissue. Diagnostic features include a uniform cyst lining, hyperchromatic and palisaded basal cells, wavy parakeratin production, and a flat interference between the epithelium and connective tissue wall.[10] The cystic neoplasm shows a distinct lack of rete ridges, resulting in a characteristic separation of the epithelial lining from the underlying fibrous connective tissue. The lumen contains varying amounts of keratinaceous material. Epithelial hyaline bodies (Rushton bodies) can be seen.[11] One of the most peculiar characteristic features of OKC is the appearance of satellite cysts and islands of odontogenic epithelium. High recurrence rate can be attributed to the satellite cysts that are retained during enucleation; thin, fragile cystic walls can be left intact.

The case we presented showed 5–10 cells layered stratified squamous parakeratinized epithelium with tall, columnar basal cells. The lumen showed keratin material and the underlying connective tissue composed of collagen fibers arranged parallel to the epithelium. Areas of hemorrhage were also seen. There were no satellite cells seen.


OKCs should be the taken into consideration too in cases of younger patients when associated with an impacted third molar as this could also be related to a dentigerous cyst. The treatment of the cyst should involve complete eradiation of the pathological lesion, reduction potential for recurrence, and preservation of surrounding structures. Due to relatively high recurrence rate, long-term follow-ups are essential with periodic radiographic examination following the surgical treatment.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


1Nelson B. Head and Neck Pathology. 3rd ed., Ch. 18. Hybrid (Transformative Journal); 2006;1: p. 459-91.
2Sivapathasundharam B, editor. Shafer's Textbook of Oral Pathology. 8th ed. India: Elsevier; 2016.
3Brad W. Neville in Colour Atlas of Oral and Maxillofacial Diseases. 1st ed.Edinburgh, Elsevier. 2018.
4Hadziabdic N, Dzinovic E, Kozaric AK, Udovicic Gagula D Sulejmanagic N, Osmanovic A, et al. Nonsyndromic examples of odontogenic keratocyst; presentation of interesting cases with a literature review. Case Rep Dent 2019:9498202; 1-12.
5Sandhu KR, Bibra A, Bibra G. Enucleation and chemical cauterization of odontogenic keratocyst followed by prosthetic rehabilitation with dental implants; 2 year follow up. Int J Curr Res 2017;9:47508-15.
6Nayak MT, Anjali Singh A, Rohit Sharma R. Odontogenic keratocyst: What is in the name? J Nat Sc Biol Med 2013;4:282-5.
7Regezi J, Sciubba J, Jordan R. Cysts of Jaws and Neck in Oral Pathology: Clinical Pathology and Correlations. 6th ed. Saunders, Philadelphia; 2012.
8Borghesi A, Nardi C, Giannitto C, Tironi A, Maroldi R, Di Bartolomeo F, et al. Odontogenic keratocyst: Imaging features of a benign lesion with an aggressive behaviour. Insights Imaging 2018;9:883-97.
9Barnes L, Eveson JW, Reichart P, Sidransky D, editors. World Health Organization Classification of Tumours: Pathology and Genetics of Head and Neck Tumours. World Health Organization Classification of Tumours. Lyon, France: IARC Press; 2005.
10Lester Thompson Justin Bishop. Head and Neck Pathology. 3rd Edition. Elsevier, Edinburgh. 2017. p. 351 79.
11Shekar MC, Thabusum DA, Shalini M. A review of odontogenic keratocyst and report of a case. J Adv Med Med Res 2013;13:43-50.