Remnants Of Odontogenic Epithelium Research Articles

ACANTHOMATOUS AMELOBLASTOMA IN ANTERIOR MANDIBULAR REGION: A RARE CASE REPORT

After odontoma, ameloblastoma is the second most common odontogenic tumor. Ameloblastoma is locally aggressive and exhibit high tendency of recurrence. It arises from the remnants of odontogenic epithelium, odontogenic cystic lining and the basal layer of the oral mucosa. Ameloblastoma accounts for 1% of all odontogenic cyst and tumors, and 9-11% of various odontogenic tumors of the jaw. There is no sex predilection, it affects both the genders equally, and male to female ratio is 1:1. Clinically it present as painless, slow-growing odontogenic tumor, usually involves mandibular posterior region. There are several histological varieties of ameloblastoma but the acanthomatous variety being one of the rarest. We present a case of acanthomatous ameloblastoma involving mandibular anterior region.

Primary Intraosseous Carcinoma of the Mandible: A Case Report

Primary intraosseous carcinoma (PIOC) is a rare tumor that has been infrequently reported. Carcinoma arising primarily from the jaw is a locally aggressive lesion with poor prognosis. Primary intraosseous carcinoma (PIOC) lesion develops either de novo remnants of odontogenic epithelium, odontogenic cyst/tumor, epithelium remnants, or/and salivary gland residues. This article describe a case of primary intraosseous carcinoma of mandible.

Sequential treatment from mandibulectomy to reconstruction on mandibular oral cancer - Case review I: mandibular ramus and angle lesion of primary intraosseous squamous cell carcinoma.

Primary intraosseous squamous cell carcinoma (PIOSCC) is very rare type of squamous cell carcinoma (SCC) that occurs within the jaw and arises from remnants of odontogenic epithelium with no connection to the oral mucosa. This study reports two cases of PIOSCC of the mandible. Reported in this article are two cases of PIOSCC of the mandible that were treated with resection and reconstruction using a fibular free flap. The first case was a 36-year-old male patient who complained of right mandibular pain. Computed tomography (CT) and panoramic radiograph revealed a large radiolucency in the mandibular ramus area. At first, an odontogenic keratocyst was tentatively diagnosed, and an excision procedure was carried out at another clinic. A final biopsy after cyst enucleation revealed well-differentiated SCC, so we proceeded with segmental mandibulectomy and reconstruction using a fibular free flap. The second case was a 48-year-old male patient with left mandibular pain. CT and panoramic radiograph revealed irregular radiolucency in the mandibular angle area near tooth #38. At first, osteomyelitis was tentatively diagnosed, and a curettage was carried out. A later biopsy revealed well-differentiated SCC, so segmental mandibulectomy and reconstruction with a fibular free flap were secondarily performed. Our two cases have had no recurrence. The facial appearance of both patients is satisfactory, and the neo-mandibular body created using a fibular bone transfer displays adequate bony volume.

Acanthomatous ameloblastoma – A case report

Ameloblastomas are locally aggressive jaw tumors with a high propensity for recurrence that are believed to arise from remnants of odontogenic epithelium, lining of odontogenic cysts and basal layer of overlying oral mucosa. They can occur in either the maxilla or mandible at nearly any age but most frequently are discovered as a painless expansion in the mandible of patients in their 20s-40s. Histopathologically, the follicular and plexiform patterns are the most common. When extensive squamous metaplasia, often associated with keratin formation occurs in central portions of the epithelial islands of follicular ameloblastoma, the term acanthomatous is sometimes applied. Here we present a case of acanthomatous ameloblastoma in a 20 year old patient. Key words:Ameloblastoma, Aacanthomatous, Mandibular Tumors. How to cite this article: Geeta Singh, Rashmi Agarwal, Vimlesh Kumar, Deepak Passi. Acanthomatous Ameloblastoma- A Case Report. J Int Oral Health 2013; 5(2):60-64..

Activation of mesenchymal stem cells promotes new bone formation within dentigerous cyst

BackgroundDentigerous cyst (DC) is a bone destructive disease and remains a challenge for clinicians. Marsupialization enables the bone to regenerate with capsule maintaining, making it a preferred therapeutic means for DC adjacent to vital anatomical structures. Given that capsules of DC are derived from odontogenic epithelium remnants at the embryonic stage, we investigated whether there were mesenchymal stem cells (MSCs) located in DC capsules and the role that they played in the bone regeneration after marsupialization.MethodsSamples obtained before and after marsupialization were used for histological detection and cell culture. The stemness of cells isolated from fresh tissues was analyzed by morphology, surface marker, and multi-differentiation assays. Comparison of proliferation ability between MSCs isolated from DC capsules before (Bm-DCSCs) and after (Am-DCSCs) marsupialization was evaluated by Cell Counting Kit-8 (CCK-8), fibroblast colony-forming units (CFU-F), and 5′-ethynyl-2′-deoxyuridine (EdU) assay. Their osteogenic capacity in vitro was detected by alkaline phosphatase (ALP) and Alizarin Red staining (ARS), combined with real-time polymerase chain reaction (RT-PCR) and immunofluorescence (IF) staining. Subcutaneous ectopic osteogenesis as well as cranial bone defect model in nude mice was performed to detect their bone regeneration and bone defect repairability.ResultsBone tissue and strong ALP activity were detected in the capsule of DC after marsupialization. Two types of MSCs were isolated from fibrous capsules of DC both before (Bm-DCSCs) and after (Am-DCSCs) marsupialization. These fibroblast-like, colony-forming cells expressed MSC markers (CD44+, CD90+, CD31−, CD34−, CD45−), and they could differentiate into osteoblast-, adipocyte-, and chondrocyte-like cells under induction. Notably, Am-DCSCs performed better in cell proliferation and self-renewal. Moreover, Am-DCSCs showed a greater osteogenic capacity both in vitro and in vivo compared with Bm-DCSCs.ConclusionsThere are MSCs residing in capsules of DC, and the cell viability as well as the osteogenic capacity of them is largely enhanced after marsupialization. Our findings suggested that MSCs might play a crucial role in the healing process of DC after marsupialization, thus providing new insight into the treatment for DC by promoting the osteogenic differentiation of MSCs inside capsules.

ASSESSING PATHOGENIC MUTATIONS IN DENTAL FOLLICLES

Objective: While ameloblastomas show BRAF P.V600 E mutations, adenomatoid odontogenic tumors harbor KRAS P.G12 R/V. Considering the fact that ameloblastoma and adenomatoid odontogenic tumors can originate from dental follicles, we hypothesized that the BRAF and KRAS variations might be early events in odontogenic tumor tumorigenesis. We aimed to assess BRAF and KRAS mutations in dental follicles associated with asymptomatic impacted teeth. Study Design: Forty-eight dental follicles containing odontogenic epithelial remnants were included in the study. As ameloblastomas most often occur in the posterior mandible and adenomatoid odontogenic tumors have a predilection for the anterior jaws, we assessed by allele-specific quantitative polymerase chain reaction (qPCR) the presence of BRAF P.V600 E in 32 dental follicles associated with impacted mandibular third molar teeth and KRAS P.G12 V and KRAS P.G12 R mutations in 16 dental follicle specimens obtained from around impacted anterior teeth. Sanger sequencing was used as an additional method. Results: None of the dental follicle cases tested positive for the mutations. Conclusion: In conclusion, we tried to detect the early genetic events associated with odontogenic tumor development in dental follicles, but we were unable to showcase that BRAF P.V600 E and KRAS P.G12 R or P.G12 V mutations are the early genetic events associated with odontogenic tumor development. Supported by CAPES/CNPq_Brazil Objective: While ameloblastomas show BRAF P.V600 E mutations, adenomatoid odontogenic tumors harbor KRAS P.G12 R/V. Considering the fact that ameloblastoma and adenomatoid odontogenic tumors can originate from dental follicles, we hypothesized that the BRAF and KRAS variations might be early events in odontogenic tumor tumorigenesis. We aimed to assess BRAF and KRAS mutations in dental follicles associated with asymptomatic impacted teeth. Study Design: Forty-eight dental follicles containing odontogenic epithelial remnants were included in the study. As ameloblastomas most often occur in the posterior mandible and adenomatoid odontogenic tumors have a predilection for the anterior jaws, we assessed by allele-specific quantitative polymerase chain reaction (qPCR) the presence of BRAF P.V600 E in 32 dental follicles associated with impacted mandibular third molar teeth and KRAS P.G12 V and KRAS P.G12 R mutations in 16 dental follicle specimens obtained from around impacted anterior teeth. Sanger sequencing was used as an additional method. Results: None of the dental follicle cases tested positive for the mutations. Conclusion: In conclusion, we tried to detect the early genetic events associated with odontogenic tumor development in dental follicles, but we were unable to showcase that BRAF P.V600 E and KRAS P.G12 R or P.G12 V mutations are the early genetic events associated with odontogenic tumor development. Supported by CAPES/CNPq_Brazil

Pericoronal follicles revealing unsuspected odontogenic cysts and inflammatory lesions: A retrospective microscopy study.

This study aimed to analyze the prevalence of diseases related to pericoronal follicles, and assess the rate of concordance between clinical and histopathological diagnoses. Histologically, we analyzed 1,298 tissue samples surrounding the crowns of teeth that were diagnosed clinically as pericoronal follicles. In addition, we determined associations among histopathological diagnosis, patients' age and sex, tissue site, presence of nests of odontogenic epithelium, presence of reduced enamel epithelium, and presence of diffuse inflammation. Odontogenic pathologies were present in 35% of the samples, and rate of concordance between clinical and histopathological diagnoses was 0.54. Probability of developing odontogenic pathologies was high in the mandibular molars (odds ratio: 2.13) and in the tissues with odontogenic epithelial remnants (odds ratio: 1.2), reduced enamel epithelium (odds ratio: 1.3), and diffuse inflammation. (odds ratio: 10.5). The findings of this study highlight the clinical relevance of histopathological examination of the pericoronal tissue in unerupted and partially erupted teeth for early diagnosis of pathologies because this study demonstrated the odontogenic cysts and inflammatory lesions in tissues clinically diagnosed as pericoronal follicles.

A LATE DIAGNOSIS OF A PRIMARY INTEROSSEOUS SQUAMOUS CELL CARCINOMA: A CASE REPORT

<h3>Background</h3> Primary intraosseous squamous cell carcinoma is a rare malignant central jaw tumor derived from odontogenic epithelial remnants. It predominantly affects the mandible, although both jawbones may be involved. <h3>Objective(s)</h3> The purpose of this article was to represent the clinical, radiologic, and microscopic characteristics of a late diagnosed primary interosseous squamous cell carcinoma (PIOSCC). This case adds to the very few cases of PIOSCC in the literature. <h3>Study Design</h3> This case report describes a 60-year-old man who was initially misdiagnosed with a periapical infection related to the right lower wisdom tooth, that is, an infected odontogenic cyst of the mandible. After 4 months, the patient presented to a private dental clinic with a large swelling at the right side of the mandible. <h3>Results</h3> Extraoral examination revealed a swelling with paresthesia in the right mandibular angle. A panoramic radiograph was requested and revealed a complete erosion of the right ramus with an extension of the lesion to the body of the mandible. Advanced imaging revealed a large, ill-defined, right facial soft tissue mass lesion measuring 8.8 × 4.5 × 5 cm. The microscopic examination revealed fibrofatty tissue infiltrated by a tumor mass formed of solid groups of large pleomorphic atypical squamous cells with high nuclear-to-cytoplasmic ratio and focal intracytoplasmic keratin formation. The diagnosis was PIOSCC. <h3>Discussion/Conclusions</h3> Radiologic and clinical characteristics of PIOSCCs are similar to those of benign odontogenic cysts and tumors. In certain cases, early-stage PIOSCC may mimic routine dental disorders, such as periapical and periodontal disease, which may lead to misdiagnosis or delayed diagnosis. Clinicians must be aware that PIOSCC may initially present as a routine dental disorder, and that unsuccessful treatment may be a sign of underlying malignancy.

Assessing pathogenic mutations in dental follicles as an attempt to identify early events in odontogenic tumours tumourigenesis

ObjectiveDriver oncogenic mutations have been reported in several benign neoplasms. While ameloblastomas show BRAF p.V600E mutations, adenomatoid odontogenic tumours harbour either KRAS p.G12R or p.G12 V. The lack of understanding of the core molecular changes involved in tumour initiation and progression represents a critical barrier to developing new strategies for cancer detection and prevention. Considering the fact that ameloblastoma and adenomatoid odontogenic tumours can originate from dental follicles, we hypothesized that the BRAF and KRAS mutations might be early events in odontogenic tumours tumourigenesis. We aimed to assess BRAF and KRAS mutations in dental follicles associated with asymptomatic impacted teeth. DesignForty-eight dental follicles containing odontogenic epithelial remnants were included in the study. As ameloblastomas most often occur in the posterior mandible and adenomatoid odontogenic tumours have a predilection for the anterior jaws, we assessed by allele-specific qPCR the presence of BRAF p.V600E in 32 dental follicles associated with impacted 3rd mandibular molar teeth and KRAS p.G12 V and KRAS p.G12R mutations in 16 dental follicle specimens obtained from around impacted anterior teeth. Sanger sequencing was used as an additional method. ResultsNone of the dental follicle cases tested positive for the mutations. ConclusionIn conclusion, we tried to detect the early genetic events associated with odontogenic tumours development in dental follicles, but we were unable to showcase that BRAF p.V600E and KRAS p.G12R or p.G12 V mutations are the early genetic events associated with odontogenic tumours development.

Cyst volume changes measured with a 3D reconstruction after decompression of a mandibular dentigerous cyst with an impacted third molar.

The aim of this article is to describe a large mandibular cyst treated with decompression followed by surgical enucleation. Furthermore, we described the utility of cyst volume measurements by using a 3D reconstruction on Cone Beam Computed Tomography (CBCT). The dentigerous cyst is the most common cyst type of epithelial origin, arising from remnants of odontogenic epithelium, asymptomatic and associated with the crown of an unerupted or partially or completely impacted tooth. However, after a long duration and extension of the cyst volume it may provoke significant bone resorption, cortical expansion, tooth displacement and the vitality of neighboring teeth may be affected. The regular treatment of this lesion is enucleation and extraction of the involved tooth. Marsupialization and decompression are proposed when the volume of the cyst is well developed to release the cystic pressure and allow the bone cavity to progressively decrease in volume with the gradual apposition of bone. This report presents a large dentigerous cyst related to impacted mandibular third molar of a 21-year-old male patient. The cyst was treated successfully by decompression and later by surgical enucleation with surgical extraction of the related molar. In conclusion, the combination of decompression and surgical approach showed on the three-dimensional CBCT investigation a significant correlation between the treatment and volume reduction of the cyst. The clinical case described allows us to observe bone formation after decompression and surgical enucleation was performed with less risk on vital anatomic elements.

Clinicopathological Study of Primary Intraosseous Squamous Cell Carcinoma of the Jaw and a Review of the Literature

Primary intraosseous squamous cell carcinoma (PIOSCC) is a rare malignant odontogenic tumor that originates from odontogenic epithelial remnants. It is often difficult to diagnose PIOSCC definitively; hence, extraction or surgical treatment is performed before the initial diagnosis in most cases. The present study examined new insights into and prognostic factors of patients with PIOSCC admitted to the authors' department. An extensive record review was conducted of patients who underwent radical surgery for PIOSCC from January 2001 through December2014. Of all cases of OSCC, the frequency of PIOSCC was 1.45%. The 2-year relapse-free survival (RFS) and overall survival (OS) rates were 50.0 and 41.6% in all cases, respectively. Three patients underwent surgery or tooth extraction before the initial diagnosis; in fact, intervention before initial diagnosis was found to be an important poor prognostic factor for RFS and OS. In contrast, patients who were not treated before the initial diagnosis was made did not exhibit any locoregional recurrence. The treatment of PIOSCC should be similar to that for oral cancer with at least clinical stage T3N0 in the National Comprehensive Cancer Network clinical practice guidelines. In addition, cases of PIOSCC that are not treated before the initial diagnosis are more likely to obtain a good prognosis.

Primary intraosseous squamous cell carcinoma derived from a maxillary cyst: A case report and literature review

Primary intraosseous squamous cell carcinoma (PIOSCC) is a rare malignant central jaw tumor derived from odontogenic epithelial remnants. PIOSCC predominantly affects the mandible, although both jawbones may be involved. This case report describes a PIOSCC type 2 of the maxilla in a 37-year-old man, treated by partial maxillectomy. Histopathologically, the tumor was diagnosed as PIOSCC derived from an odontogenic cyst. Postoperatively, the patient has been followed up for 53 months, with no recurrence of the disease. We herein describe the clinical details, treatment results and histopathological characteristics of a rare case of PIOSCC derived from a maxillary odontogenic cyst with reference to the relevant literature.

Immunohistochemical Evaluation of Calretinin and Cytokeratin-19 in Odontogenic Keratocyst and Ameloblastoma: A Retrospective Study

ABSTRACTThe odontogenic epithelial remnants, i.e. cell rests of Serre and Malassez, are formed from dental lamina and Hertwig's epithelial root sheath respectively, may proliferate and have role in pathogenesis of odontogenic cysts and tumors. Odontogenic keratocyst (OKC) is the most common and aggressive cyst of the dental lamina origin. Ameloblastoma, the second most common odontogenic tumor (OT), is a clinically benign and locally invasive polymorphic neoplasia. Differentiation of OKC from ameloblastoma sometimes poses a diagnostic dilemma, thus necessitating the need to differentiate between the two (especially unicystic ameloblastoma and OKC). Calretinin, a calcium binding protein, functions as a calcium buffer and a regulator of apoptosis. Some studies have shown its expression in parakeratinized OKC, unicystic and solid ameloblastoma, but not in other OTs. Calretinin may thus provide a better understanding of the biological behavior and tumorogenesis of ameloblastoma. cytokeratin (CK)-19 is a type I cytokeratin, has been found to be a reliable marker of epithelial differentiation. The intense expression of CK-19 is useful for identification of odontogenic epithelial components, thus suggesting their potential for proliferation to form epithelial odontogenic cysts and tumors. The aim of this study is to evaluate calretinin and Ck-19 in OKC and ameloblastoma. For this retrospective study, 20 formalin fixed paraffin embedded tissue samples of histopathologically proven OKC and ameloblastoma each, retrieved from the department of oral pathology was used. The results will be evaluated by using immunohistochemical analysis.How to cite this articlePawar VM, Patel S, Pathak J, Swain N, Hosalkar R, Iyer J. Immunohistochemical Evaluation of Calretinin and Cytokeratin-19 in Odontogenic Keratocyst and Ameloblastoma: A Retrospective Study. J Contemp Dent 2015;5(2):98-103.

Extraosseous odontoma in the mouth floor: report of a case and literature review

Introduction: Odontoma growing in the extraosseous soft tissue is very rare. Only seven cases of peripheral odontoma have been published to date. Observation: A case of peripheral odontoma arising in the mouth floor of a 1 yearold girl is reported. On the basis of the clinical appearance and localization the first suggested diagnosis was lipoma After surgical excision the diagnosis of peripheral odontoma was proposed and confirmed by scanning electron microscopy. Discussion: Extraosseous odontoma are rarely observed. The suspected mechanism is that remnants of odontogenic epithelium entrapped in the oral soft tissues may be a potent source for peripheral odontogenic tumor differentiation. Conclusion: This case of peripheral odontoma occurring in the mouth floor is the first reported in the literature to our knowledge. Possible explanations regarding its origin lie in embryological assumptions

Hemimandibulectomy For Unicystic Ameloblastoma Plus Manual TMJ Implant of Methylmethacrylate: Case Report

Ameloblastoma is the most clinically significant odontogenic tumor originating from the remnants of odontogenic epithelium. This benign tumor is locally invasive and grows slowly but is aggressive. It is more prevalent in posterior areas of the mandibular body and ramus. The three clinical and radiographic manifestations are conventional solid or multicystic, cystic, and peripheral or extraosseous. Woman, 29, sought care from the Service Oral and Maxillofacial Surgery of Roraima State for a second time.

A confocal view of the calcifying odontogenic cyst: Report of two cases

The calcifying odontogenic cyst (COC) is a rare odontogenic lesion representing about 1% of all jaw cysts. There is a wide age range from 1 to 82 years with a first peak in the second decade and the second in the sixth/seventh decade. This lesion is characterized by the presence of ghost cells. The pathogenesis of the lesion is from the reduced enamel epithelium or the remnants of odontogenic epithelium. Here, we report two cases, both in 18-year-old male patients; previously diagnosed as dentigerous cyst and residual cyst respectively. But histologically, both the cases turned out to be COCs. Confocal laser scanning microscopy (CLSM) has become an invaluable tool for a wide range of investigations in the medical sciences for imaging thin optical sections of tissues. The COCs were evaluated using CLSM to analyze the properties of the cystic lining and the ghost cells.

Solid-type primary intraosseous squamous cell carcinoma of the mandible: a case report with histopathological and imaging features

Primary intraosseous squamous cell carcinoma (PIOSCC) is a rare malignant odontogenic tumor arising from odontogenic epithelial remnants within the jawbones. PIOSCC is histopathologically divided into 3 types: solid-type carcinoma, carcinoma derived from a keratocystic odontogenic tumor, and carcinoma derived from an odontogenic cyst. In this article, we report a case of solid-type PIOSCC involving reactive bone formation in the mandible in a 60-year-old female patient together with its histopathological and imaging findings.

Is podoplanin expression associated with the proliferative activity of ameloblastomas?

The aim of this study was to investigate the relationship between podoplanin expression and proliferative activity of ameloblastomas and remnants of the odontogenic epithelium from dental follicles (DF) of unerupted teeth. Thirty-three paraffin-embedded ameloblastomas and thirty-two DF obtained of unerupted teeth were analyzed by immunohistochemistry using anti-human podoplanin and anti-Ki-67 antibodies. Podoplanin expression in odontogenic epithelial cells was evaluated using a scoring method, and the Ki-67 labeling index was determined by the percentage of positive odontogenic cells. All ameloblastomas displayed podoplanin expression in ameloblast-like cells of the epithelial islands. Membranous expression of podoplanin in ameloblastomas was stronger than in the remnants of odontogenic epithelium (P = 0.001). Statistically significant difference was observed between the cytoplasmic and membranous expression of podoplanin in the remnants of odontogenic epithelium (P = 0.001). The index of epithelial odontogenic proliferative activity, verified by Ki-67 expression, was higher in ameloblastomas vs remnants of odontogenic epithelium (P < 0.001). No statistically significant correlation was identified between podoplanin and the cellular odontogenic proliferative activity in meloblastomas and DF (P > 0.05). These results provide evidence that there is no connection between podoplanin immunostaining and odontogenic cellular proliferative activity and suggest a role for membranous podoplanin expression in the local invasion of ameloblastomas.

Plexiform ameloblastoma of the maxilla with extension to sinonasal cavity: Presenting with loosening of teeth

Ameloblastomas are locally aggressive jaw tumors with a high propensity for recurrence that are believed to arise from remnants of odontogenic epithelium, lining of odontogenic cysts, and the basal layer of the overlying oral mucosa. The unusual presenting symptoms, as well as the highly destructive nature of these lesions when arising in the maxilla, make them worthy of consideration in the differential diagnosis of nasal and maxillary masses. We present a rare case of right maxillary ameloblastoma in a 48 year old male patient who presented with the main complaint of loosening of molar teeth. History also revealed unilateral nasal obstruction of long duration about which the patient was least concerned. The computed tomography scan revealed a soft tissue polypoidal mass in the right maxillary sinus involving alveolar arch of the maxilla, with expansion of sinus and erosion of posterolateral wall. Initial biopsy confirmed ameloblastoma, which was followed by excision of the tumor by radical surgery. The case represents an unusual presentation of a rare odontogenic tumor.

Histopathological Features of Keratocystic Odontogenic Tumor

The aim of this study was to describe the clinicopathologic features of 177 keratocystic odontogenic tumors (KCOTs) diagnosed in a Brazilian population. A total of 177 KCOTs were reviewed and affected 158 patients with ages ranging from 5 to 79 years (mean age = 32 years) with a slight female predominance. Mandible was the most common affected site (69.3%), and a unilocular radiolucency was the most common radiographic image. Microscopically, all cases showed at least focal areas of classic KCOT, but several histological aspects were also observed, including diffuse and focal epithelial lining hyperplasia (48.6%), epithelial budding (12.4%), reactive cytological alterations (11.3%), dystrophic calcification (7.9%), daughter cysts (7.8%), odontogenic epithelial remnants (4.5%), focal areas of orthokeratinization (2.8%), and ameloblastomatous epithelium (1.7%). These variations may make KCOT diagnosis challenging in some cases, so careful full-sample analysis and knowledge of these uncommon histological features associated with KCOT are essential for correct diagnosis.