|Year : 2016 | Volume
| Issue : 2 | Page : 119-123
A rare case report of orthokeratinized odontogenic keratocyst associated erupting complex odontome with impacted mandibular molar
Kshitij O Bang, Ramakrishna S Shenoi, Rahul N Dahake, Nilima J Budhraja
Department of Oral and Maxillofacial Surgery, VSPM Dental College, Nagpur, Maharashtra, India
|Date of Web Publication||6-Jan-2017|
Rahul N Dahake
Department of Oral and Maxillofacial Surgery, VSPM Dental College, Digdoh Hills, Hingna Road, Nagpur - 440 019, Maharashtra
Source of Support: None, Conflict of Interest: None
Odontogenic keratocyst is a cyst of dental origin with an aggressive clinical behavior, having high recurrence rate. Odontomas are hamartomatous lesions composed of mature enamel, dentin, and pulp and may be compound or complex depending on the extent of morphodifferentiation or on their resemblance to normal teeth. They are the most common benign odontogenic tumors, constituting 22% of all odontogenic tumors of the jaw. We present a case report of a 19-year-old female with infected odontogenic keratocyst associated with the impacted mandibular second molar with the odontome and a submandibular space infection. However, there are very few case reports in the literature of the simultaneous occurrence of these two lesions, and hence this case is very rare. It is unclear whether the two lesions were just coincidental or were actually related to each other.
Keywords: Odontogenic keratocyst; odontome; orthokeratinized
|How to cite this article:|
Bang KO, Shenoi RS, Dahake RN, Budhraja NJ. A rare case report of orthokeratinized odontogenic keratocyst associated erupting complex odontome with impacted mandibular molar. Indian J Multidiscip Dent 2016;6:119-23
|How to cite this URL:|
Bang KO, Shenoi RS, Dahake RN, Budhraja NJ. A rare case report of orthokeratinized odontogenic keratocyst associated erupting complex odontome with impacted mandibular molar. Indian J Multidiscip Dent [serial online] 2016 [cited 2019 Sep 22];6:119-23. Available from: http://www.ijmdent.com/text.asp?2016/6/2/119/197775
| Introduction|| |
The odontogenic keratocyst (OKC) was first described in 1876, named by Phillipsen in 1956 and has been associated with a tendency to recur.  According to the new histological classification of the World Health Organization (WHO), OKC is considered an odontogenic tumor.  OKC represent a more aggressive form of odontogenic cyst. Out of the two variants, the parakeratinized variant is thought to have a high recurrence rate than the orthokeratinized. Because of these features, a more aggressive treatment than simple enucleation has been advised. 
The term odontoma firstly described by Paul Broca in 1867 was originally used as a general descriptive for any tumor of odontogenic origin.  Odontomas are the most common benign odontogenic tumors of epithelial and mesenchymal origin. The WHO defines odontomas as two types: Complex odontomas, a malformation in which all dental tissues are present but arranged in a more or less disorderly pattern and compound odontomas, a malformation in which all of the dental tissues are represented in a pattern that is more orderly than that of the complex type.  In the reported case, there was simultaneous occurrence of orthokeratinized OKC and odontome.
| Case Report|| |
A female patient aged 19 years reported to the Department of Oral and Maxillofacial Surgery, with a complaint of swelling in the lower right side of her face [Figure 1]. The patient was febrile; past medical, dental, and family histories were not significant. There was no history of trauma on the maxillofacial region. Patient gives history which revealed the presence of swelling which had gradually increased in size over the past 1 month. On extra oral examination, there was a diffused swelling over right submandibular region suggestive of diffused space infection. Intraoral examination revealed the pericoronal flap with the erupting odontome distal to the permanent mandibular right first molar (46) with the apparent absence of the right mandibular second (47) and third molar (48). An inflamed mass of the gingiva distal to 46 was found on palpation with no pus discharge. Panoramic radiograph showed a predominantly radiopaque mass located distal to 46 similar in density to calcified dental tissues, with small radiolucencies within, and coronal to impacted and displaced 47 suggestive of complex odontome [Figure 2]. Radiograph also revealed completely formed roots of 47, the apex of roots are 2-3 mm away from the inferior border of mandible. Radiolucency of approximately 1.5 cm × 1.5 cm was seen distal to the impacted 47 suggestive of some pathologic lesion. The tooth bud of 48 was also missing. On the basis of the radiological features, a differential diagnosis of calcifying epithelial odontogenic cyst, dentigerous cyst, primordial cyst, cement-ossifying fibroma, and complex odontoma was made. Aspiration cytology was done suggestive of the presence of keratin and cholesterol crystals in the lumen. A provisional diagnosis of OKC was made. Taking into account the clinical and radiological presentations, a provisional diagnosis of infected OKC associated with erupting complex odontome was determined, and the case was planned for surgical excision under general anesthesia. The patient was prepared for the surgery, and extraoral drainage of submandibular space infection was done. A crevicular incision was given from 45 extending up to retromolar region. The mucoperiosteal flap was raised to expose the very superficially located calcified mass that was removed and submitted for histopathological examination. The tooth beneath was exposed and extracted. The access for the cystic cavity was made a cheesy straw-colored fluid was present inside the lumen. Enucleation was done followed by chemical curettage with Carnoy's solution [Figure 3].
|Figure 2: Orthopantomogram showing vertically impacted second molar on the right side associated with unilocular radiolucency on its distal side and pericoronal odontome|
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|Figure 3: Clinical image showing intraoperative view after extraction of molar and odontome|
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The histopathologic section shows cystic lumen lined by orthokeratinized stratified squamous epithelium. Stratum granulosum is prominent. There is a tendency toward the intraepithelial keratin pearl formation. The cystic lumen is filled with the keratin. The underlined connective tissue capsule is fibrocellular with moderately dense chronic inflammatory cell infiltrate. Histopathological examination of the cystic lining reveals the presence of orthokeratinized OKC [Figure 4]. Histopathological examination of the excised mass showed irregularly arranged dental hard tissues with areas of cell-rich pulpal tissue. Clear spaces and clefts representing the mature enamel that is lost in the process of decalcification are often seen confirming the diagnosis of a complex odontome [Figure 5].Post operative (OPG) showing the unilocular radiolucency on the distal aspect of the first molar after enucleation of the cystuc lesion [Figure 6].
|Figure 4: Histopathological image showing cystic lumen lined by orthokeratinized stratified squamous epithelium|
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|Figure 5: Histopathological image showing clear spaces and clefts representing the mature enamel in complex odontoma|
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|Figure 6: Orthopantomogram showing unilocular radiolucency on its distal side after extraction of tooth and odontome|
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| Discussion|| |
The orthokeratinized odontogenic cyst was recognized as a variant of OKC based on the presence of abundant orthokeratin in the cystic lining. The suggestive etiology for OKC is either from epithelial remnants of tooth germ in the mandible and maxilla or the basal cell layer of the overlying surface epithelium. , Although it can occur in any part of mandible and maxilla, in 70% of the cases arise in the posterior body and 6.9% at the symphyseal region of the mandible. ,
The mandible is the more favored site than the maxilla, 78 versus 22%.  Ramus and the molar area are the most favored sites. On histopathological examination, an OKC has a fibrous wall lined by epithelium with a thin layer of stratified squamous epithelium. This epithelium has a basal cell layer of six to eight cells thick and a lining of flattened keratotic epithelial cells.  The formed keratin lines the luminal surface of the epithelial cells in a slightly wavy of corrugated pattern.  The different consistencies of the luminal content which was commonly observed are "straw-colored fluid," "thick pus-like" material or a caseous, thick, cheesy, milk white mass.  These various densities of keratinaceous debris are responsible for varying consistencies. Histologically, OKCs have been classified into parakeratotic and orthokeratotic subtypes.  These types refer to the histological characteristics of the lining and the type of keratin produced. The parakeratotic type is the most frequent (80%) and has a more aggressive clinical presentation than the orthokeratinized variant.  In the presented case, the orthokeratinized variant was observed which is rare in occurrence.
In our case, the OKC was associated with the odontome which was diagnosed on the radiographic examination. On the panoramic radiograph, the radiolucent lesion was present with an extensive well-defined area of bone destruction and sclerotic borders. Computed tomography images were suggestive of lingual bone destruction which is a characteristic feature of OKC. It is very difficult to differentiate between the OKC, dentigerous cysts, and unicystic ameloblastomas by clinical and radiographic examination. OKC do not expand the bone to the same degree as dentigerous cysts and are less likely to produce teeth resorption. OKC is more likely to have scalloped periphery, but dentigerous cysts have smooth periphery.
Controversy exists regarding the management of the OKC. The most important feature of OKC is its high recurrence rate ranging from 5% to 62.5%. There are various recommended treatments for the OKC: curettage with peripheral ostectomy, curettage plus application of Carnoy's solution, localized en bloc resection, and occasionally, mandibular segmental resection. In our case, the cystic enucleation was done followed by chemical curettage with the Carnoy's solution. Carnoy's solution is a tissue fixative. The purpose of using Carnoy's solution is to kill epithelial remnants and dental lamina in the osseous margins. It penetrates bone to a depth of 1.54 mm and decreases the risk of recurrence, by killing the epithelial remnant or satellite cysts. 
Odontomas are inherited from a mutant gene or interference, most possibly with the genetic control of tooth development postnatally.  According to the literature, available difference in the prevalence of odontomes exists, but the most common site is the posterior regions of the mandible. , With a slight female predilection, the relative frequency of occurrence varies between 5% and 30%.  They may be discovered at any age, while the majority of the cases (84%) occur before the third decade of life. Usually, they are not diagnosed until the routine radiographic examination as they are asymptomatic. Clinically, the absence or unerupted permanent teeth, retention of deciduous teeth, or the expansion of cortical bone may be suggestive of the presence of odontome.  Radiographically, the odontome can be diagnosed at different stages, on the basis of the stage of development and degree of mineralization and in first stage radiolucency appears due to lack of calcification. Partial calcification is observed in the intermediate stage, while in the third stage, the lesion usually appears radiopaque with amorphous masses of dental hard tissue surrounded by a thin radiolucent zone corresponding to the connective capsule histologically. ,
In the presented case, the odontome is found distal to 46 and overlying the crown of an impacted 47 and missing 48 associated with cystic pathology related distally to 47. Odontome associated with the absence of one or more teeth and with infected cystic pathology seems to be rare. The present case is exceptional not only because of the orthokeratinized OKC but also associated with odontome and its apparent eruption at the site of 47. Radiographically, the predominant radiopaque mass was seen which is similar in density to calcified dental tissues, with small radiolucencies within suggestive of features of complex odontome. The eruption of the odontome in oral cavity is unusual, and the mechanism is also unknown. In case of odontome, there is the absence of periodontal ligament as well as no root formation; probably the increasing size may be responsible for bone resorption and occlusal movement.  In our case, the erupting force from the 47 may be responsible for the eruption of the odontome.
The pericoronal level with radiopaque mass with radiolucency in between is present in our case, so it should be differentiated form ameloblastic fibrodentinoma, adenomatoid odontogenic tumors, calcifying epithelial odontogenic tumors, or odontoameloblastoma.  Histologically, the presence of dental tissue which is disorderly arranged confirmed the diagnosis of the complex odontome. The fate of the impacted tooth will be decided on the condition of the roots and associated infection. As in our case, the odontome was excised along with the impacted tooth 47. The roots of impacted 47 was completely formed, but it was associated with the cystic pathology also the path of eruption was not favorable. That's why the decision of extraction was taken.
| Conclusion|| |
In the reported case, we present a rare case of orthokeratinized odontogenic keratocyst associated with erupting complex odontome and impacted second molar and a missing third molar. The condition was also associated with submandibular space infection. OKCs and the odontome are frequent benign jaw tumor, but orthokeratinized OKC associated with complex odontome is relatively rare. Furthermore, the size and location of the erupting odontome in oral cavity were rare. The early diagnosis of such cases can be done during the routine radiographic examination.
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.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]