Surgical management of dentigerous cyst arises from ectopic tooth: A report of three consecutive cases and literature review

BACKGROUND

Dentigerous cysts are slow-growing, asymptomatic lesions that typically form around the crowns of impacted teeth. They are not detected until they start to harm the tissues around the teeth.

AIM

The present study aimed to describe surgical techniques for treating dentigerous cysts associated with ectopic teeth.

CASES

Three patients with dentigerous cysts associated with ectopic teeth, their surgical approaches, and the supporting literature are presented herein. In two cases, the surgical technique used was intra-oral, and in one case was extra-oral. Under general anesthesia, dentigerous cyst enucleation and ectopic tooth removal were carried out.

DISCUSSION

In the present study, the ectopic tooth cases were all linked to dentigerous cysts. Enucleation or marsupialization treatments could be used to treat dentigerous cysts. Enucleation with the removal of the impacted tooth is the preferred treatment for dentigerous cysts.

CONCLUSION

To perform minimally invasive surgery, the position of the ectopic teeth, the accessibility of the surgical site, the degree of bone reduction, and the simplicity of instrumentation should all be considered.

Diagnosis of common intraosseous lesions of the dentomaxillofacial region by chemometry-assisted FT-IR spectroscopy in dental tissue samples

PURPOSES

This study aimed to determine the differential diagnosis of three intraosseous lesions (odontogenic keratocyst (OKC), central giant cell granuloma (CGCG), and dentigerous cyst (DC)) of the dentomaxillofacial region with very similar radiological and clinical features by using chemometrics assisted FT-IR (Fourier transform infrared) spectroscopy in tissue samples.

METHODS

Tissue samples (exposed to formaldehyde for a similar time) of 20-micron thickness belonging to 19 intraosseous lesions diagnosed histopathologically were obtained from the pathology laboratory. The samples were analyzed by FT-IR spectroscopic method using the 400-4000 cm-1 wavenumber range, and the obtained spectra of the samples were evaluated using the orthogonal partial least squares discriminant analysis (OPLS-DA) algorithm.

RESULTS

The intraosseous lesions with different histopathological diagnoses were accurately and precisely clustered with different FT-IR bands corresponding to the main molecular vibrations, especially the phosphodiester region, of the tissue components using the proposed model with 3 latent variables.

CONCLUSIONS

The model showed high sensitivity and specificity. The present study is the first to report the elucidation of clear spectral differences between similar lesions in the maxillofacial region. In the future, the FT-IR method may be used in the non-destructive classification of similar lesions in the maxillofacial region as an alternative to histopathological evaluation.

Dentigerous cysts suspected the other odontogenic lesions on panoramic radiography and CT

Dentigerous cysts are known as the second most common type of cyst in the jaws. The cyst is one of the lesions occurred frequently in the posterior body of the mandible and is often related to the unerupted third molar and forms around the crown of the unerupted tooth attaching at the cementoenamel junction. Such characteristic appearances are the diagnostic points differentiating from ameloblastoma or odontogenic keratocyst. However, it would be hard for us to diagnose it as a dentigerous cyst if the lesion does not show its typical appearance. We experienced two cases of dentigerous cysts which did not form around the crown of the unerupted tooth on radiologically. Both cysts were relatively large and resorbed adjacent teeth roots. Therefore, an ameloblastoma or an odontogenic keratocyst was suspected rather than a dentigerous cyst as the imaging diagnosis. The biopsy revealed that the lesion was a "dentigerous cyst" in one of the cases and "developmental cyst with inflammation" in another case. After the excision, the histopathological diagnosis was a dentigerous cyst with inflammation in both cases. This report shows the two cases of dentigerous cysts focusing on panoramic radiography and CT images. Also, we discuss the differential diagnosis by reconsidering those diagnostic points.

Assessment of MUC5AC and MUC2 Immunoexpression in Glandular Odontogenic Cysts, Dentigerous Cysts, and Mucoepidermoid Carcinomas

Glandular odontogenic cysts (GOCs) and dentigerous cysts may show mucous metaplasia. Central mucoepidermoid carcinoma is very rare and mostly associated with dental cysts. It is hypothesized that odontogenic cysts showing mucus differentiation in their lining, have a propensity to transform into MEC. The present study is the first attempt to explore the relationship between odontogenic cysts [GOCs and dentigerous cysts with mucus metaplasia (DCMM)] and MEC by evaluating immunoexpression of MUC5AC and MUC2. Immunoexpression of MUC5AC and MUC2 was evaluated semiquantitatively in GOCs (20 cases), DCMMs (20 cases), and MECs (20 cases). The percentage of positive cells, intensity, and localization of immunoexpression were assessed for each marker in all cases. Of GOCs, DCMMs, and MECs cases, 85%, 70%, and 80%, respectively, were immunopositive for MUC5AC. Strong cytoplasmic immunoreactivity for MUC5AC was noted, particularly in mucous cells present diffusely within MECs. However, the immunoreactivity was limited to the epithelial lining of GOCs and DCMMs. Most of the MECs (60%) showed more than 25% positivity for MUC5AC, followed by GOCs, and the least in DMMCs. Mild cytoplasmic and nuclear positivity of MUC2 was noted only in epithelial lining cells of 70% GOCs and 45% DCMMs. Whereas, 55% of MECs displayed moderate to strong cytoplasmic and membranous immunopositivity for MUC2 exclusively within mucous cells. As MECs showed strong MUC5AC immunoreactivity in mucous cells, immunoexpression of MUC5AC in odontogenic cysts with mucus cells can possibly explain the pathogenesis of MEC from cysts. However, the variable expression of MUC2 did not give any strong evidence regarding its role as a marker.

The IL-1β-p65 axis stimulates quiescent odontogenic epithelial cell rests via TGF-β signalling to promote cell proliferation of the lining epithelia in radicular cysts: A laboratory investigation

AIM

Cyst formation of the jaws is frequently accompanied by the proliferation of odontogenic epithelial cells located in the periodontal ligament (PDL), which consists of heterozygous cells and includes the most fibroblasts. The lining epithelium of radicular cyst, an odontogenic cyst of inflammatory origin, is derived from the proliferation of the remnants of the Hertwig epithelial root sheath (odontogenic epithelial cell rests of Malassez; ERMs) in the PDL. ERMs are maintained at a lower proliferative state under physiological conditions, but the regulatory mechanisms underlying the inflammation-dependent enhanced-proliferative capabilities of ERMs are not fully understood. The aim of this study was to evaluate the effects of cytokine pathway association between TGF-β signalling and IL-1β signalling on the regulation of odontogenic epithelial cell proliferation using radicular cyst pathological specimens and odontogenic epithelial cell lines.

METHODOLOGY

Immunofluorescence analyses were performed to clarify the expression levels of Smad2/3 and Ki-67 in ERMs of 8-week-old mouse molar specimens. In radicular cyst (n = 52) and dentigerous cysts (n = 6) specimens from human patients, the expression of p65 (a main subunit of NF-κB), Smad2/3 and Ki-67 were investigated using immunohistochemical analyses. Odontogenic epithelial cells and PDL fibroblastic cells were co-cultured with or without an inhibitor or siRNAs. Odontogenic epithelial cells were cultured with or without TGF-β1 and IL-1β. The proliferative capabilities and Smad2 phosphorylation levels of odontogenic epithelial cells were examined.

RESULTS

Immunohistochemically, Smad2/3-positivity was increased, and p65-positivity and Ki-67-positivity were decreased both in ERMs and in the epithelial cells in dentigerous cysts, a non-inflammatory developmental cyst. In contrast, p65-positive cells, along with the expression of Ki-67, were increased and Smad2/3-positive cells were decreased in the lining epithelia of radicular cysts. Co-culture experiments with odontogenic epithelial cells and PDL fibroblastic cells revealed that PDL cells-derived TGF-β1/2 and their downstream signalling suppressed odontogenic epithelial cell proliferation. Moreover, TGF-β1 stimulation induced Smad2 phosphorylation and suppressed odontogenic epithelial cell proliferation, while IL-1β stimulation reversed these phenotypes through p65 transactivation.

CONCLUSIONS

These results suggest that IL-1β-p65 signalling promotes odontogenic epithelial cell proliferation through suppressing TGF-β-Smad2 signalling, which would be involved in the pathogenesis of radicular cysts.

Identification of ferroptosis-related proteins in ameloblastoma based on proteomics analysis

PURPOSE

We used proteomic sequencing and experimental verification to identify the potential ferroptosis-related proteins in ameloblastoma.

METHODS

Samples of ameloblastoma (n = 14) and normal gingival tissues (n = 5) were collected for proteomic sequencing to identify differentially expressed proteins (DEPs) in ameloblastoma. Ferroptosis-related genes were downloaded from FerrDb V2, which were then compared with DEPs to obtain ferroptosis-related DEPs (FR-DEPs). A functional enrichment analysis was performed, and a protein-protein interaction network was built. The hub proteins were screened using the Cytoscape software, and potential drugs targeting them were retrieved from the DrugBank database. A hub protein was selected for immunohistochemical validation, and its expression was assessed in ameloblastomas, odontogenic keratocysts, dentigerous cysts, and normal gingival tissues. The primary ameloblastoma cells were cultured to explore the effect of the protein on the migratory properties of the tumour cells.

RESULTS

A total of 58 FR-DEPs were screened, and six hub proteins were identified: mTOR, NFE2L2, PRKCA, STAT3, EGFR, and CDH1. Immunohistochemical analysis showed that mTOR expression was upregulated in ameloblastomas compared with that in odontogenic keratocysts, dentigerous cysts, and normal gingival tissues. p-mTOR was highly expressed in ameloblastomas, with a positivity rate of 83.3%. In addition, rapamycin, an inhibitor of mTOR, can inhibit the migratory capacity of primary cultured ameloblastoma cells.

CONCLUSION

Our results revealed the ferroptosis-related proteins in ameloblastomas and their underlying biological processes. Additionally, mTOR was overexpressed and was found to be associated with the aggressiveness of ameloblastomas, which may be a potential target for future treatments.

Pediatric Oral Pathology: Odontogenic Cysts

Cysts encountered in the head and neck typically arise from epithelium that would normally be programmed to form teeth or tooth-supporting structures (odontogenic epithelium). These cysts come with a confusing array of similar-sounding names and histopathologic features that are sometimes shared between conditions. Here we describe and contrast the relatively-common lesions: hyperplastic dental follicle, dentigerous cyst, radicular cyst, buccal bifurcation cyst, odontogenic keratocyst, glandular odontogenic cyst, and the less-common gingival cyst of the new-born and thyroglossal duct cyst. The goal of this review is to help clarify and simplify these lesions for the general pathologist, pediatric pathologist, and surgeon.

Differential expression of PEA3 in odontogenic cysts and tumors

BACKGROUND

PEA3 transcription factor has been identified as a downstream target of the MAPK and PI3K pathways, and PEA3 overexpression has been observed in a variety of tumor types. We aimed to evaluate PEA3 expression in odontogenic cysts and tumors and compare the expression among odontogenic lesions. In addition, the correlations between PEA3 expression and clinicopathological characteristics of conventional ameloblastoma and unicystic ameloblastoma were investigated.

METHODS

This study was performed on 165 samples of odontogenic cysts and tumors including 20 dentigerous cysts, 20 odontogenic keratocysts, 16 adenomatoid odontogenic tumors, 5 ameloblastic fibromas, 45 unicystic ameloblastomas, and 59 conventional ameloblastomas. The sections were immunohistochemically stained with mouse monoclonal anti-PEA3 antibody and PEA3 expression was evaluated as the immunoreactive score.

RESULTS

PEA3 expression was absent in all dentigerous cysts (DCs) and odontogenic keratocysts, while all adenomatoid odontogenic tumors showed either no (75%) or low (25%) expression of PEA3. Most of the ameloblastic fibromas (60%) displayed no PEA3 expression. A high expression of PEA3 was observed in a substantial number of unicystic ameloblastomas (48.9%) and conventional ameloblastomas (49.2%) in our study. PEA3 expression in DCs, odontogenic keratocysts and adenomatoid odontogenic tumors were significantly different from that in conventional ameloblastomas and that in unicystic ameloblastomas (p < 0.05). The expression of PEA3 was significantly different in the age groups of unicystic ameloblastomas and histological subtypes of conventional ameloblastomas (p < 0.05).

CONCLUSION

PEA3 overexpression is predominant in unicystic ameloblastomas and conventional ameloblastomas compared to other odontogenic lesions, indicating a pivotal role of PEA3 as a downstream effector of MAPK pathway in these two odontogenic lesions.

Comprehensive cornified envelope protein profile of odontogenic keratocysts clarifies the characteristics of non-keratinized oral epithelium

BACKGROUND

Odontogenic keratocysts constitute 10%-20% of odontogenic cysts and exhibit a distinctive corrugated parakeratinized lining epithelium. Considering that cornified envelope formation is an important phenomenon during keratinocyte differentiation, this study aimed to clarify the characteristics of cornified envelope formation in odontogenic keratocysts.

METHODS

We investigated the cellular distribution of cornified envelope-related proteins (transglutaminases and their substrates), as well as the upstream regulatory protein c-Fos, by immunohistochemical analysis of the lining epithelium of 20 odontogenic keratocysts. We examined the corresponding mRNA levels by quantitative polymerase chain reaction. Ten dentigerous cysts served as control non-keratinized cysts.

RESULTS

The distributions of transglutaminase and their substrates except loricrin and small protein-rich protein 1a significantly differed between odontogenic keratocysts and dentigerous cysts. There was no significant difference in c-Fos expression between odontogenic keratocysts and dentigerous cysts. The mRNA levels of transglutaminases and their substrates were significantly higher in odontogenic keratocysts than in dentigerous cysts. However, c-Fos mRNA levels did not significantly differ between groups.

CONCLUSION

Surprisingly, the overall appearance of cornified envelope-related proteins of odontogenic keratocysts was consistent with the characteristics of non-keratinized oral mucosa identified in previous studies. These findings indicate that the contribution of cornified envelope-related molecules in odontogenic keratocysts is similar to that in non-keratinized oral epithelium, rather than keratinized oral epithelium, suggesting that odontogenic keratocysts are not genuine keratinized cysts. The upregulation of cornified envelope-related genes in odontogenic epithelium could be an important pathognomonic event during odontogenic keratocyst development.

Immunoexpression of CXCL12 and CXCR4 in Radicular Cysts, Dentigerous Cysts, and Odontogenic Keratocysts

The aim of this study was to evaluate the immunoexpression of chemokine CXCL12 and its receptor CXCR4 in radicular cysts (RCs), dentigerous cysts (DCs), and odontogenic keratocysts (OKCs), and to correlate the findings with morphologic parameters of RCs (inflammatory infiltrate and cystic epithelium). Twenty RCs, 20 DCs, and 20 OKCs were submitted to immunohistochemistry. The percentages of cytoplasmic (CXCL12 and CXCR4) and nuclear (CXCR4) staining in epithelial and fibrous capsule cells were determined. RCs and DCs exhibited higher epithelial expression of CXCL12 than OKCs ( P <0.05). The expression of CXCL12 in the fibrous capsule was higher in DCs than in RCs and OKCs ( P <0.05). Higher cytoplasmic expression of CXCR4 was observed in the epithelial lining and fibrous capsule of RCs and DCs compared with OKCs ( P <0.05). In the fibrous capsule, DCs exhibited higher nuclear expression of CXCR4 than OKCs ( P <0.05). No significant differences in the immunoexpression of CXCL12 or CXCR4 were observed according to the morphologic parameters of RCs ( P >0.05). Strong positive correlations were found between cytoplasmic and nuclear expression of CXCR4 in the epithelial lining of RCs and DCs and in the fibrous capsule of all groups ( P <0.05). The results suggest the participation of CXCL12 and CXCR4 in the pathogenesis of RCs, DCs, and OKCs. These proteins may be particularly relevant for the development of odontogenic cysts with less aggressive biological behavior, irrespective of their nature (inflammatory or developmental). In RCs, the expression of CXCL12 and CXCR4 may not be related to the intensity of the inflammatory infiltrate or the status of cystic epithelium.

Giant follicular cyst with maxillary sinus and pterygomaxillary space extension

BACKGROUND

Dentigerous, follicular, cysts are developmental odontogenic cysts of reduced adamantine epithelium origin, associated with an impacted tooth. They are the second most frequent cystic pathology after inflammatory cysts. Although the frequency of dentigerous cysts associated with upper third molars is far lower than the mandibular ones, their complications are nothing but ordinary. Most of the times asymptomatic, being discovered during routine x-ray examinations, maxillary follicular cysts can grow to important size, altering the position of adjacent teeth, producing osteolysis of the nearby bone structures, as well as infectious complications, antral and orbital pathology.

CASE REPORT

The present manuscript describes the clinical, radiological, pathological and therapeutical aspects of a giant follicular cyst with antral and pterygomaxillary extension, associated with an impacted upper third molar.

CONCLUSION

The most efficient treatment of maxillary follicular cysts consists in the surgical removal of the lesion along with the involved tooth. Complete excision is mandatory to prevent recurrence. Extension into adjacent structures might complicate the surgery Preoperative evaluation and rigorous planning are essential, especially in large-sized lesions. Pathological examination is outmost importance in order to exclude aggressive transformations.

KEY WORDS

Dentigerous follicular cyst, Maxillary sinus extension, Pterygomaxillary space.

Transmigrated and Impacted Upper 2nd Premolar Associated with Dentigerous Cyst

A male patient about 45 years old came to my private clinic "The Dental Aid", Dhanmondi, Dhaka, Bangladesh last year (February 2016) with the complaint of pain at right palatal premolar region. On clinical examination we found the absence of upper left 2nd premolar from the series of dentition but on the right side premolars are present. The oral mucosa was intact and normal in color. There was no caries, dental pocket or any other pathology in the teeth of both jaws. On palpation we found soft area on the right palatal side at the premolar area. We took intraoral peri-apical radiograph and found impacted left 2nd premolar whose crown was encircled by radiolucent area at the palatal side. Here, we present a rare case of transmigrated and impacted left 2nd maxillary premolar associated with dentigerous cyst. The cyst was successfully treated under general anaesthesia by enucleation along with extraction of the involved maxillary transposed and impacted left second premolar.

A Bag of Marbles: A Fascinating Compound Odontoma of the Maxilla

Odontomas are the most common odontogenic tumors, typically diagnosed during the first two decades of life. 1 The purpose of this paper was to report an interesting case of an eight-year-old Caucasian boy who presented with an asymptomatic, progressive, firm swelling of the right maxilla with no eruption of the permanent maxillary right lateral incisor. Radiographic investigation revealed a mixed radiolucent and radiopaque lesion measuring 28 by 24 by 17 mm with a corticated border causing expansion and thinning of the buccal cortical plate. This large bag-of-marbles-like appearance representing odontoids was impeding his adult teeth from erupting; hence, complete surgical removal under general anesthesia was the treatment of choice. Removal of the lesion resulted in an unexpected loss of the embedded permanent maxillary right lateral incisor. Histopathological investigations gave a diagnosis of compound odontoma; due to their low growth potential, recurrence after removal is not expected.

Metachronous ameloblastic fibro-odontoma and dentigerous cyst in the posterior mandible

An ameloblastic fibro-odontoma (AFO) is a rare mixed odontogenic tumor with histologic features of an ameloblastic fibroma in conjunction with the presence of dentin and enamel. It usually appears as a well-circumscribed radiolucency with radiopaque foci and slow growth and is commonly seen in children and young adults. A 13-year-old boy presented with an asymptomatic swelling in the posterior right region of the mandible and the right ascending ramus. The clinical, imaging, and histopathologic findings confirmed the diagnosis of an AFO. After 8 months, a radiolucent lesion involving the unerupted mandibular left third molar was observed; a final diagnosis of a dentigerous cyst (DC) was established for this lesion. Although coincidental events, metachronous odontogenic lesions suggest a possible common genetic origin, since both can be caused by related cellular signaling pathways. Complete enucleation is recommended for both AFOs and DCs; rates of recurrence are low.

Endoscopic modified medial maxillectomy for odontogenic cysts and tumours

BACKGROUND

Odontogenic maxillary cysts and tumours originate from the tooth root and have traditionally been treated through an intraoral approach. Here, we report the efficacy and utility of endoscopic modified medial maxillectomy (EMMM) for the treatment of odontogenic maxillary cysts and a tumour.

METHODOLOGY

We undertook EMMM under general anaesthesia in six patients: four had radicular cysts, one had a dentigerous cyst, and one had a keratocystic odontogenic tumour.

RESULTS

The cysts and tumours were completely excised and the inferior turbinate and nasolacrimal duct were preserved in all patients. There were no peri- or postoperative complications, and no incidences of recurrence.

CONCLUSION

Endoscopic modified medial maxillectomy appears to be an effective and safe technique for treating odontogenic cysts and tumours.

Odontogenic Cysts and Neoplasms

This article reviews a myriad of common and uncommon odontogenic cysts and tumors. The clinical presentation, gross and microscopic features, differential diagnosis, prognosis, and diagnostic pitfalls are addressed for inflammatory cysts (periapical cyst, mandibular infected buccal cyst/paradental cyst), developmental cysts (dentigerous, lateral periodontal, glandular odontogenic, orthokeratinized odontogenic cyst), benign tumors (keratocystic odontogenic tumor, ameloblastoma, adenomatoid odontogenic tumor, calcifying epithelial odontogenic tumor, ameloblastic fibroma and fibroodontoma, odontoma, squamous odontogenic tumor, calcifying cystic odontogenic tumor, primordial odontogenic tumor, central odontogenic fibroma, and odontogenic myxomas), and malignant tumors (clear cell odontogenic carcinoma, ameloblastic carcinoma, ameloblastic fibrosarcoma).

Conservative management of large mandibular dentigerous cysts with a novel approach for follow up: Two case reports

BACKGROUND

Dentigerous cysts are odontogenic cysts of the jaws accounting for approximately 24% of all epithelium-lined jaw cysts. Rarely, these cysts can become extremely large causing additional symptoms, while challenging treatment. This article represents a novel approach for radiological treatment follow up of large dentigerous cysts.

MATERIAL AND METHODS

Dentigerous cysts were treated by marsupialization, using dedicated obturators and enucleation of the cyst afterwards. Teeth vitality in the lesion was regularly assessed by laser doppler flowmetry, follow-up of lesion regression was accomplished using semi-automatic radiographic analysis of bone healing quantification.

RESULTS

Cystic marsupialization by means of the obturator resulted in a number of advantages compared to a conventional approach: lower risk of spontaneous fracture of the mandible, anatomical structure preservation, mandibular canal identification and preservation of tooth vitality as measured by intraoral laser doppler flowmetry. Notwithstanding that a 1-year follow-up panoramic image could not visualize a remnant bone defect nor cystic lesion recurrence, 3D-CBCT based semi-automated bone quantification could only demonstrate an increase of 46% of mineralized bone volume one year after surgery. Bone healing typically occurred starting from the periphery of the original lesion towards the inner core.

CONCLUSIONS

The presently reported cystic marsupialization was useful as a preliminary treatment for subsequent enucleation. 3-D CBCT based objective quantification of the bone volume and healing can provide new insights in lesion healing in general and more particular in the outcome of specific diagnostic and therapeutic challenges.

Dentigerous cyst associated with ectopically impacted maxillary second premolar

Dentigerous cysts are benign odontogenic cysts that are accompanying with the crown of permanent teeth. They are typically single in incidence and are situated in the mandible. They are usually associated with impacted mandibular third molar and maxillary canines. Here we report a very rare presentation of dentigerous cyst in anterior maxilla accompanying with ectopically impacted maxillary second premolar. The cyst was enucleated along with extraction of premolar.

The evaluation of Ki67, p53, MCM3 and PCNA immunoexpressions at the level of the dental follicle of impacted teeth, dentigerous cysts and keratocystic odontogenic tumors

The aim of this study is to analyze the immunoexpression of Ki67, p53, MCM3 and PCNA markers in epithelial remnants of dental follicles of impacted teeth and to identify a possible correlation between the immunoexpression of these markers in dentigerous cysts and keratocystic odontogenic tumors in order to evaluate their evolutionary behavior.

MATERIALS AND METHODS

A total of 102 cases were included in the study and divided into three subgroups: the first subgroup consisted of 62 cases with dental follicles of impacted teeth, the second included 20 cases of dentigerous cysts and the third subgroup comprised a number of 20 cases with keratocystic odontogenic tumors. Immunomarking with the four antibodies was performed.

RESULTS

A positive marking was obtained in over 60% of the dental follicles for all markers. Statistically significant differences were also obtained in dentigerous cysts and keratocystic odontogenic tumors for Ki67, p53 and MCM3. Assessment of the four antibodies in the two layers of keratocystic odontogenic tumors shows a positive correlation between Ki67 and MCM3 both for the basal and parabasal layer, with slightly increased values in the latter.

CONCLUSIONS

In order to determine the proliferative capacity of epithelial remnants in the dental follicles, Ki67 and PCNA, Ki67 and MCM3 are the most useful markers in practice; they have similar behavior and are more likely to help in distinguishing between dentigerous cysts and keratocystic odontogenic tumors.

Kissing molars: report of three cases and new prospective on aetiopathogenetic theories

Kissing molars (KMs) is an extremely rare condition of impacted third molars, pointed in the opposite direction in a single follicular space; it consists exactly in a full impacted of permanent molars which occurs only in the lower jaw. Actually, about less than thirty cases have been reported in scientific literatures. The aetiology and pathogenesis of this pathological double dental inclusion remain unknown; above all events that lead two molars to appear, as KMs remain mysterious. The association to metabolic connective diseases such as mucopolysaccharidosis was emphasized. KMs considered as an isolated event, may be associated to an abnormal position of the tooth-bud from lower permanent molars, or fourth supernumerary tooth (distomolar). Recently, hyperplastic dental follicle (HDF), with a down regulation of matrix metal-proteinases and up regulation of several genes of collagens, has been mentioned in association with KMs. In this paper, after having analyzed three new cases of KMs that have been treated, we report a new hypothesis. This last is based on the failure in the dental follicle's ability to initiate or continue properly resorption of the overlying alveolar bone, by many exogenous factors which may act on eruptive phase that would lead to its rotation with its contents coming out a pathological situation of KMs. The therapy of choice is related to the surgical removal of KMs through a double odontectomy with transalveolar method. Other treatments can be, eventually, orthodontic therapy of the impacted teeth and a radiological follow-up without surgery.

HSP70 expression in dentigerous cyst, odontogenic keratocyst, and ameloblastoma

Heat shock proteins (HSPs) work as molecular chaperones that can assist cells to deal with stressful situations. Members of the HSP70 family can regulate cell growth and transformation and are involved in the maintenance of cellular homeostasis. In view of the distinct clinical behavior of odontogenic lesions, the objective of the present study was to investigate the immunohistochemical expression of HSP70 in these lesions. In this study, 70 formalin-fixed paraffin-embedded tissue blocks of odontogenic lesion-16 unicystic ameloblastomas (UAs), 17 solid ameloblastomas (SAs), 18 odontogenic keratocysts (OKCs), and 19 dentigerous cysts (DCs)-were reviewed by immunohistochemistry for HSP70 staining. In this study, HSP70 immunostaining was evident in all groups of the specimen. Mean percentage of HSP70 staining in SAs (84.2 ± 11.3) and OKCs (83.4 ± 6.8) were significantly higher than UAs (64.4 ± 9.8) and DCs (12.6 ± 10.2) (p = 0.00). But, there was no statistically significant difference between HSP70 expression in SAs and OKCs. The result of this study proposes that high expression rate of HSP70 has a role in the pathogenesis of ameloblastoma and OKC and is one of the reasons for the aggressive behavior of ameloblastoma and high recurrence role of OKC, reinforcing the classification of OKC as an odontogenic tumor.

Relationship between the positions of impacted third molars and the presence of dentigerous cysts

The objective of this study was to assess the association between the histopathological diagnoses of dentigerous cysts and pericoronal follicles and the positions of impacted third molars. The sample comprised 151 cases, diagnosed as dentigerous cysts and pericoronal follicles. Most patients were female (70.9%), white (90.1%), and age 20 years or older (63.6%). Ninety-eight cases (64.9%) were diagnosed as pericoronal follicles and 53 (35.1%) as dentigerous cysts. Teeth that developed dentigerous cysts were predominantly located in the mandible (84.9%), in a mesioangular position (49.1%), and in the 20- to 29-year age group (66.0%). The mandible seems to be the most frequent location of impacted teeth, probably because mandibular tooth eruption is more difficult, as well as dentigerous cysts, probably because the long duration of impaction increases the exposure to inflammatory stimuli and, thus, the potential for formation of dentigerous cysts. The findings also suggest that the incidence of dentigerous cysts tends to increase with age, especially for mandibular teeth in mesioangular positions.

Twist expression in dentigerous cyst, odontogenic keratocyst, and ameloblastoma

Epithelial-mesenchymal transition (EMT) is a process which is associated with a loss of intercellular adhesion, acquired mesenchymal shape, and increased motility by epithelial cells. Twist is one of the key regulators of EMT.In view of the distinct clinical behavior of odontogenic lesions, the objective of the present study was to investigate the immunohistochemical expression of Twist in these lesions. In this study, 70 formalin-fixed, paraffin-embedded tissue blocks of odontogenic lesion consisting of 16 unicystic ameloblastomas (UA), 17 solid ameloblastomas (SA), 18 odontogenic keratocysts (OKC), and 19 dentigerous cysts (DC) were reviewed using immunohistochemistry for Twist staining. In this study, Twist immunostaining was evident in all groups of the specimens except the dentigerous cyst group. Twist expression was seen in 58.8 % (10/17) of SA, 50 % (8/16) of UA, and 44.4 % (8/18) of OKCs. 23.5 % of SA, 18.8 % of UA, and 16.7 % of OKCs showed Twist expression in more than 50 % of cells. Statistical analysis showed that Twist expression levels were significantly higher in ameloblastomas (SA and UA) and OKCs than dentigerous cysts (P = 0.002). There were no significant differences between Twist expression in SAs, UAs, and OKCs (P > 0.05). The results of this study propose that the high expression rate of Twist plays a role in the pathogenesis of ameloblastomas and OKCs and might be one of the reasons for the aggressive behavior of ameloblastomas and high recurrence of OKCs and could reinforce the classification of OKC as an odontogenic tumor.

Oral and maxillofacial lesions in a Thai pediatric population: a retrospective review from two dental schools

OBJECTIVE

To determine the prevalence of oral and maxillofacial lesions in a Thai pediatric population.

MATERIAL AND METHOD

Oral biopsy records from pediatric patients between the ages of 0 and 15 years in the files ofFaculty of Dentistry, Mahidol University, and the files of Faculty of Dentistry, Khon Kaen University were reviewed. The patients were divided into three age groups, including 0 to 5, 6 to 10, and 11 to 15 years. Excluding the diagnosis of normal tissues, the oral and maxillofacial lesions were classified into nine categories.

RESULTS

Of 13,050 biopsied oral and maxillofacial lesions, 1,389 cases (10.6%) came from pediatric patients. The largest number of lesions was odontogenic cysts and tumors, followed by inflammatory and reactive lesions, and salivary gland pathology The top ten most prevalent lesions contributed 73% of all oral biopsies. The most common lesion was dentigerous cyst, followed by mucocele and pyogenic granuloma.

CONCLUSION

The vast majority of oral diseases in children were benign and related to either developmental or tissue reaction, while malignant lesions were found in a very small proportion of all oral biopsies.

Bilateral impacted inverted mesiodens associated with dentigerous cyst

Mesiodens, the most common type of supernumerary tooth, usually results in malocclusion, poor esthetics and cyst formation. The occurrence of a dentigerous cyst around the crown of an unerupted supernumerary tooth is infrequent. We present a case of a dentigerous cyst associated with a nonsyndromic bilateral impacted inverted supernumerary tooth in a 13-year-old boy. A thorough clinical workup, including 3-D reconstruction image and histological examination confirming the features of a dentigerous cyst is presented in this report.

Eruption of impacted permanent teeth after treatment of a dentigerous cyst: a case report

Dentigerous cysts are the most common developmental odontogenic cysts. It is a benign and asymptomatic intraosseous lesion that affects the bones of the maxillofacial complex, interfering with tooth eruption. Although enucleation is the treatment of choice, marsupialization is the better option for large cysts involving unerupted permanent teeth. The purpose of this article is to report the eruption of impacted permanent mandibular right canine and first and second premolars after marsupialization of an infected dentigerous cyst. Two years after marsupialization and orthodontic treatment, the cyst disappeared and the canine and premolars erupted uneventfully.

Immunophenotypic characterization and distribution of dendritic cells in odontogenic cystic lesions

OBJECTIVE

To analyze the expression and distribution patterns of mature dendritic cells (mDCs) and immature DCs (imDCs) in radicular cysts (RCs), dentigerous cysts (DtCs), and keratocystic odontogenic tumors (KCOTs).

MATERIALS AND METHODS

Forty-nine odontogenic cystic lesions (OCLs) (RCs, n = 20; DtCs, n = 15; KCOTs, n = 14) were assessed using the following markers: S100, CD1a and CD207 for imDCs; and CD83 for mDCs.

RESULTS

Almost all cases were S100, CD1a, and CD207 positive, whereas 63% were CD83 positive. RCs presented greater number of immunostained cells, followed by DtCs, and KCOTs. The number of S100+ cells was greater than both CD1a+ and CD207+ cells (P < 0.001), which showed approximately similar amounts, followed by lower number of CD83+ cells (P < 0.001) in each OCL type. Different from S100+ cells, both CD1a+ and CD207+ cells on the epithelium (P < 0.05) and CD83+ cells on the capsule (P < 0.05) were preferentially observed. In RCs, significant correlation was found between the thickness epithelium with S100+ and CD1a+ cells, and between the degree of inflammation with CD83+ cells.

CONCLUSIONS

Dendritic cell populations in OCLs can be phenotypically heterogeneous, and it could represent distinct lineages and/or functional stages. It is suggested that besides DC-mediated immune cell interactions, DC-mediated tissue differentiation and maintenance in OCLs should also be considered.

[Dentigerous cyst in the mixed dentition]

Dentigerous cyst is a developmental odontogenic cyst, which apparently develops by accumulation of fluid between the reduced enamel epithelium and the tooth crown of an unerupted tooth. Management of dentigerous cyst in primary dentition needs special consideration regarding the preservation of the developing permanent tooth buds. A case of dentigerous cyst is reported in primary dentition of a 7-year-old female patient and its management. By extracting the infected primary teeth, opening the cyst and ensuring continuous drainage, it is possible to achieve spontaneous eruption of the involved permanent teeth into the dental arch even if they are badly dislocated. Simultaneous with the eruption of the permanent teeth, ossification of the bony defect can take place. The reparatory process is completed in one to two years, during this time the patient has been given a space-maintainer.

Management of a deeply impacted mandibular third molar and associated large dentigerous cyst to avoid nerve injury and improve periodontal healing: case report

As dentigerous cysts increase in size, the risk of postsurgical complications increases as well. Emphasis is usually placed on the risk of neurologic damage caused by trauma during and after surgical removal and of mandibular fracture resulting from the large residual bone defect. However, influence on the periodontal status of neighbouring teeth should also be taken into account. In this article, we present an interdisciplinary, safe, minimally invasive approach to treating large dentigerous cysts associated with deeply impacted third molars. A dentigerous cyst is an epithelial-lined pathologic cavity that develops in association with the crown of an unerupted tooth and appears radiographically as a well-circumscribed pericoronal radiolucency. The cyst not only inhibits the eruption of the associated tooth (usually, a mandibular third molar), but can also carry it to unusual positions in the jaw. Dentigerous cysts may enlarge causing extensive bone resorption and even pathologic fracture. The greater the size of the cyst, the higher the risk of neurologic damage caused by trauma during and after surgical removal and of mandibular fracture resulting from the postoperative bone defect.7,8 Moreover, the removal of large cysts can lead to a severe infrabony defect at the root surface of adjacent teeth, jeopardizing their long-term periodontal health. "Orthodontic extraction" is a combined orthodontic-surgical approach that decreases the risk of neurologic complications and facilitates the surgical extraction of impacted mandibular third molars that are in close contact with the mandibular canal, even when associated with cystic lesions.13 This case report shows that the interdisciplinary approach is also effective in preventing periodontal breakdown on the distal surface of the adjacent second molar.

Large erupting complex odontoma in a dentigerous cyst removed by a piecemeal resection

Odontomas (ODs) are the most frequent odontogenic tumors in Western societies, they are often asymptomatic and discovered during routine radiography The purpose of this report was to describe the case of a 10-year-old child with an odontoma within a dentigerous cyst (DC). The patient presented with a 1-week history of painful swelling involving the right mandible and cheek. An intraoral examination revealed a defect of the oral mucosa behind the permanent mandibular first molar, which resembled an exposed alveolar bone or tooth remnants. Clinical and radiographic evaluation revealed a large erupting OD associated with a dentigerous cyst. The OD was separated into pieces and enucleated together with the dentigerous cyst to preserve the mandible's integrity and because of the patient's age. This is the first report of an erupting OD associated with a DC in a child. Surgical removal might be a challenge when large ODs are encountered.

Dentigerous cyst of the maxilla with impacted tooth displaced into orbital rim and floor

We report a case of dentigerous cyst of the maxilla and maxillary sinus that caused the ectopic displacement of an unerupted tooth into the orbital rim and floor. After an incisional biopsy, marsupialization of the lesion promoted its involution and stimulated osteogenesis. This in turn simplified the surgical enucleation of the specimen and removal of the unerupted tooth without the excessive loss of the bony contours of the maxilla.

A pigmented dentigerous cyst in a patient with multiple dentigerous cysts of the jaws: a case report

AIM

The aim of this article is to report an unusual and interesting case of non-syndromic multiple dentigerous cysts of the maxilla and mandible associated with melanin pigment and melanocytes in the epithelial lining in one of the cysts. In addition, embryologic aspect and origin of melanocytes are briefly discussed.

BACKGROUND

Dentigerous cysts are the second most common odontogenic cysts after radicular cysts. They are usually solitary with multiple cysts reported on occasion in association with syndromes. While melanocytes and melanin-pigment are widely distributed in the skin, the nervous system, certain types of mucosa, uveal tract, and other areas, they are not normally present within bone in mammals.

REPORT

A 37-year-old Iranian male was referred to an oral surgeon by his dentist for evaluation and treatment of multiple cyst-like radiolucent lesions around the crowns of some unerupted permanent teeth in both maxillary and mandibular anterior areas. The biopsy revealed numerous granules of melanin-pigment distributed throughout the epithelial lining of one of these cysts in addition to the characteristic histopathologic features of adentigerous cyst. Histochemical analysis confirmed the pigment was melanin, and many of the cells containing melanin were immunohistochemically positive for s-100 protein.

SUMMARY

Although the specific origin and pathologic significance of the melanocytes described here cannot be explained, it may be of interest for future investigations.

Clinicopathological study of dentigerous cysts in Singapore and Malaysia

This was a retrospective study of dentigerous cysts in people from the Singapore-Malaysian region. The purpose of this study was to present the clinicopathologic features of dentigerous cysts in the Oriental population and to compare these data with those from other reported studies. Biopsy records from 1981 to 1993 of 119 cases of dentigerous cysts from patients in Malaysia and Singapore showed that 36.1% of patients were female and 63.9% patients were male. Among patients with cysts, 70.5% were Chinese, 23.2% were Malays, 2.7% were Indian and 3.6% were other ethnic groups. The mean age of these patients was 30.2 +/- 17.3 years with a peak incidence occurring in the second and third decades. The location of the lesions was almost equal to the maxilla (50.9%) and the mandible (49.1%). There was a marked predilection for the posterior mandible (42.7%) followed by the anterior maxilla (38.2%). Histologically, 90.8% of the cysts were lined by a non-keratinised stratified squamous epithelium. The cyst linings were mainly thin (90.0%) with 38.7% of cases having a mixed thick and thin lining. Mucous metaplasia was observed in 9 (7.6%) cases. Rushton bodies were seen in 3.4% of cases. Cholesterol clefts in the epithelial lining and lumen were found in 16.8% cases while 12.6% of cases exhibited cholesterol clefts in the cyst wall. Other cellular structures within the cyst wall were lymphocytes (66.4%), plasma cells (52.1%), Russell bodies (16.0%) and histiocytes (4.2%). Odontogenic keratocysts were observed in 5.0% of cases. One case of adenomatoid odontogenic tumour was also observed. Epithelial atypia was seen in 9.2% of cases, islands of stratified squamous epithelial cells in 8.4% of cases while one case showed a combination of these two features. In conclusion, some clinical features seen in this study are similar to that for the Caucasian population such as prevalence in male, peak incidence in the second and third decades and the predilection for the posterior mandible and anterior maxilla. Histopathologically, odontogenic keratocyst and adenomatoid odontogenic tumour were observed in dentigerous cysts.

Adenomatoid odontogenic tumour associated with dentigerous cyst - unusual case report

The adenomatoid odontogenic tumor is a relatively uncommon lesion which mainly affects females in their second decade of life, exhibiting predilection for the anterior region of the maxilla. The lesion is usually associated with the crown of an enclosed tooth, most commonly the maxillary canine. In this paper we present a case of adenomatoid odontogenic tumor associated with a dentigerous cyst affecting the left maxillary region in a 13-year-old female. The authors also discuss clinical, radiographic, histopathologic and therapeutic features of the case.

Metastatic breast carcinoma discovered in a dentigerous cyst — a case report

This paper reports a patient with a history of breast cancer, who presented with altered sensation to the right lower lip and chin. An orthopantomogram showed a probable dentigerous cyst associated with an unerupted lower wisdom tooth, which was closely related to the inferior dental canal. The tooth and cyst were enucleated under general anaesthesia. The subsequent histopathology report concluded that the cyst contained metastatic adenocarcinoma from a primary breast tumour.

Oligonucleotide microarray analysis of ameloblastoma compared with dentigerous cyst

BACKGROUND

Ameloblastoma is a benign, but locally invasive tumor known for its high rate of recurrence. However, few comprehensive genetic studies have been conducted about its tumorigenesis. Our aim was to identify possible genes involved in the development and progression of ameloblastoma, using microarray analysis with dentigerous cyst as a control.

METHODS

Total RNA was extracted from two fresh dentigerous cysts and ameloblastoma specimens. Following microarray analysis, semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry were performed on selected genes.

RESULTS

Seventy-three genes were overexpressed and 49 were underexpressed. These genes were divided into categories according to function. The microarray results for 13 selected genes were verified with semiquantitative RT-PCR.

CONCLUSIONS

We identified important genes related to the development and progression of ameloblastoma through a large-scale gene expression analysis. This study will stimulate further investigations on genes significant for early diagnosis and prognosis of ameloblastoma.

Immunohistochemical analysis of the biological potential of odontogenic keratocysts

BACKGROUND

The aim of this study was to analyse the usefulness of detecting important apoptosis and proliferation markers in assessing the biological potential of odontogenic keratocysts (OKC) and thus selecting the optimal diagnostic algorithm for these lesions.

METHODS

Indirect immunohistochemistry and relevant statistical methods were used for analysis of formalin-fixed and paraffin-embedded samples from 98 patients.

RESULTS

Nevoid basal cell carcinoma syndrome (NBCCS) keratocysts were characterized by higher expression of Bcl-2, p27Kip1 and c-erbB-2 as well as by lower proliferative activity measured by Ki-67 in basal cell epithelium and by a lower inflammatory response in comparison with sporadic keratocysts. Dentigerous, radicular and non-specified odontogenic cysts differed from both NBCCS and sporadic keratocysts in a wide spectrum of apoptosis and/or cell cycle-related protein expressions, higher proliferation in the basal cell layer, and vice versa, lower proliferation in the suprabasal cell layer.

CONCLUSIONS

The NBCCS keratocysts have a different immunophenotype from sporadic keratocysts and both types are distinguishable from dentigerous, radicular and non-specified odontogenic cysts. These findings confirm the separate biological potential of these lesions and the results of the immunohistochemical analysis have diagnostic and prognostic implications.

Cytokeratin expression patterns for distinction of odontogenic keratocysts from dentigerous and radicular cysts

BACKGROUND

The clinical outcome of treatment of odontogenic cysts differs depending on separate entities. Particular clinical relevance must be attached to the distinction between odontogenic keratocysts, which have an evident tendency to recur, and other odontogenic cysts. The aim of this study was to evaluate cytokeratin (CK) expression patterns as an additional tool for characterization of different cysts as the histomorphologic appearance often is not decisive.

METHODS

Thirty cases of dentigerous and radicular cysts respectively as well as 15 cases of odontogenic keratocysts were considered. Expression of CK 5/6, 7, 10, 13, 17, 19 and 20 was determined in addition to Ki-67 immunohistochemically.

RESULTS

Expression of CK 17 was discernible in 93.3% of the odontogenic keratocysts, but only in 35.0% of dentigerous and radicular cysts under study (P < 0.001). CK 19 could be detected in 48.3% of dentigerous and radicular cysts, whereas odontogenic keratocysts were completely negative (P < 0.002).

CONCLUSION

Immunohistochemical detection of CK 17 and 19 seems to be a valuable additional parameter distinguishing between odontogenic keratocysts and other odontogenic--especially dentigerous--cysts which clinically are likely the most significant differential diagnoses in this context. J Oral Pathol Med (2005) 34: 558-64.

Cell proliferation, apoptosis and apoptosis-related factors in odontogenic keratocysts and in dentigerous cysts

BACKGROUND

The purpose of this study was to elucidate why odontogenic keratocysts (OKC) can form cystic lesions but not tumor masses, notwithstanding their prominent proliferative activity.

METHODS

We investigated cellular proliferation, cell death, and expression of apoptosis-related proteins in the lining cells of OKCs and of dentigerous cysts (DGCs).

RESULTS

TdT-mediated dUTP-biotin nick end labeling (TUNEL)-positive cells were observed in the surface layers of OKCs and of DGCs. However, no TUNEL-positive cells were seen in the basal or intermediate layers of both cysts. Ki67-positive ratio in the intermediate layer was the highest in OKCs. The p53-positive ratio of the intermediate layer was highest in OKCs. Bcl-2-positive cells were discernible exclusively in the basal layer of OKCs.

CONCLUSIONS

These results suggest that cellular proliferation and death is regulated in association with apoptosis-related proteins in the lining epithelia of OKCs, and subsequently those cysts are seen as cystic lesions but not as tumor masses.

The differential expression pattern of BMP-4 between the dentigerous cyst and the odontogenic keratocyst

BACKGROUND

Bone morphogenic protein-4 (BMP-4) is widely expressed in oral cavity and involved in tooth morphogenesis, cellular differentiation and proliferation. The purpose of this study was to compare the difference in expression pattern of BMP-4 in odontogenic keratocysts (OKC) and dentigerous cysts (DC).

METHODS

We evaluated 77 cysts, OKC (n = 34) or DC (n = 43). The average age of patients with OKC was 29.5 +/- 14.4 and that of patients with DC was 36.1 +/- 19.4. The male to female ratio was 20:14 for OKC and 27:16 for DC. Ten cases of OKC were recurrences. Expression of BMP-4 was determined by immunohistochemistry and in situ hybridization.

RESULTS

The intensity scales were (-) for invisible or trace staining, (+) for visible staining, and (++) for dense, strong staining. OKCs exhibited the following staining patterns: the epithelium in 15/34 specimens and the mesenchymal cells in 17/34 specimens showed (++) stain. In contrast, the staining pattern of DC was (-) for epithelium in 37/43 specimens. The mesenchymal cells showed (-) degree staining in 30/43 specimens. The difference between the groups studied was significant (P < 0.001 in epithelium and mesenchymal cells). When recurrent and non-recurrent OKC were compared BMP-4 was expressed more intensely in the recurrent cases (P = 0.036 in epithelium). The difference in BMP-4 expression in mesenchymal cells was not significant. In situ hybridization demonstrated positive mRNA probes to BMP-4 were localized in epithelium and mesenchymal cells of OKCs and DCs.

CONCLUSIONS

BMP-4 was expressed more intensely in OKC when compared with DC, and was more intensely expressed in recurrent cases.

[Odontogenic keratocyst in dentigerous position. A clinical case]

Cysts that may develop in the maxillo-mandibular region and adjacent tissues may be of odontogenic origin, non-odontogenic origin, pseudocysts, cysts associated with the maxillary sinus and those developed from the soft tissues. These may vary as to their histogenesis, frequency, behavior and treatment. This article presents the clinical case of an 18-year-old female patient with an initial radiographic diagnosis of dentigerous cyst, which after exploratory punction and surgical removal under general anesthesia yielded a final diagnosis of odontogenic keratocyst. The patient's evolution was satisfactory with a 2-year radiographic control, without evidence of recurrence.