A Rare Odontogenic Cyst in an Uncommon Area: Case Report and Review of the Literature / Um cisto odontogênico raro em uma área incomum: Relato de caso e revisão da literatura

Abstract Objective Orthokeratinized odontogenic cyst is a rare developmental odontogenic cyst of the jaws. It is a less aggressive intraosseous cyst identified by an orthokeratinized epithelium. Case Report A 50-year-old male patient with the chief complaint of swelling in the anterior part of his face, and, intraorally, there was diffuse swelling in the palatal cortex. On panoramic radiography, there was a well-defined unilocular radiolucency on the right side of the maxilla and palatal cortical expansion, and thinning of the buccal and palatal cortexes was observed. The histopathological examination revealed a pathologic cyst that was lined by a thick orthokeratinized epithelium. Therefore, the diagnosis was orthokeratinized odontogenic cyst. Conclusion The orthokeratinized odontogenic cyst displays characteristic clinical, histopathological, and biological features that differ significantly from those of keratocystic odontogenic tumor (KCOT), but it has a better prognosis and lower recurrence rate. Thus, other radiolucent lesions of the jaws, including keratocystic odontogenic tumor (KCOT), must be considered in the differential diagnosis.

Resumo Objetivo O cisto odontogênico ortoceratinizado é um raro cisto odontogênico maxilar. É um cisto intraósseo menos agressivo, identificado por um epitélio ortoceratinizado. Relato de caso Um paciente do sexo masculino, de 50 anos de idade, com queixa principal de edema na parte anterior da face, e, intraoralmente, havia edema difuso no córtex palatal. Na radiografia panorâmica, havia uma radioluminescência unilocular bem definida no lado direito da maxila e expansão cortical palatina, e desbastamento dos córtex vestibular e palatino. O exame histopatológico revelou cisto patológico revestido por espesso epitélio ortoceratinizado. Logo, o dignóstico foi de cisto odontogênico ortoceratinizado. Conclusão O cisto odontogênico ortoceratinizado apresenta características clínicas, histopatológicas e biológicas que diferem significativamente das do tumor odontogênico ceratocístico (TOC), mas tem melhor prognóstico e menor taxa de recorrência. Portanto, outras lesões radiolúcidas dos maxilares, incluindo TOC, devem ser consideradas no diagnóstico diferencial.

Effect of the sonic hedgehog inhibitor GDC-0449 on an in vitro isogenic cellular model simulating odontogenic keratocysts.

Odontogenic keratocysts (OKCs) are common cystic lesions of odontogenic epithelial origin that can occur sporadically or in association with naevoid basal cell carcinoma syndrome (NBCCS). OKCs are locally aggressive, cause marked destruction of the jaw bones and have a propensity to recur. PTCH1 mutations (at ∼80%) are frequently detected in the epithelia of both NBCCS-related and sporadic OKCs, suggesting that PTCH1 inactivation might constitutively activate sonic hedgehog (SHH) signalling and play a major role in disease pathogenesis. Thus, small molecule inhibitors of SHH signalling might represent a new treatment strategy for OKCs. However, studies on the molecular mechanisms associated with OKCs have been hampered by limited epithelial cell yields during OKC explant culture. Here, we constructed an isogenic PTCH1R135X/+ cellular model of PTCH1 inactivation by introducing a heterozygous mutation, namely, c.403C>T (p.R135X), which has been identified in OKC patients, into a human embryonic stem cell line using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9) system. This was followed by the induction of epithelial differentiation. Using this in vitro isogenic cellular model, we verified that the PTCH1R135X/+ heterozygous mutation causes ligand-independent activation of SHH signalling due to PTCH1 haploinsufficiency. This activation was found to be downregulated in a dose-dependent manner by the SHH pathway inhibitor GDC-0449. In addition, through inhibition of activated SHH signalling, the enhanced proliferation observed in these induced cells was suppressed, suggesting that GDC-0449 might represent an effective inhibitor of the SHH pathway for use during OKC treatment.

Glandular Odontogenic Cyst in Maxilla: A Case Series.

Glandular odontogenic cyst is rare phenomenon with 0.012% to 0.03% frequency of all jaw cysts and worldwide prevalence of 0.17%. Diagnosis of Glandular odontogenic cyst, well known for its aggressive growth potential and high rate of recurrence, is very crucial. This report presents cases of two 50-year old individuals with Glandular odontogenic cyst presenting as a radiolucent lesion of maxilla. Final diagnosis was made on the basis of histopathological features and further confirmed by immunohistochemical analysis. Keywords: histology; immunohistochemistry; odontogenic cyst.

Active Intracystic Negative Pressure Could Induce Osteogenesis.

Based on previous findings, the author introduces the term "sugosteogenesis," a biological phenomenon that occurs by using the Evocyst, a device that exerts active intracystic negative pressure. The term "sugosteogenesis" comes from the Latin word "sugo-," meaning "suck," and Greek words "osteo-," meaning "bone," and genesis, "origin."

Retrospective study of spontaneous bone regeneration after decompression of large odontogenic cystic lesions in children.

BACKGROUND/AIM: Surgical treatment of odontogenic cysts in childhood could be accompanied by injury of important anatomical structures. Even though enucleation is considered to be preferable treatment of odontogenic cysts, the specificities of pediatric age favor more conservative surgical approach. The aim of this study was to assess the effectiveness of decompression as the uttermost treatment of odontogenic cysts in the pediatric age. METHODS: This retrospective study included 22 patients, 7-16 years old, with a single jaw cystic lesion. The majority of these lesions were dentigerous cyst (14), and the rest belonged to keratocystic odontogenic tumor (KCOT) (8). All lesions were primarily treated with decompression; it was a final treatment (one-stage procedure) in 13 dentigerous cysts, and it was followed by enucleation (two-stage procedure) in one dentigerous cyst and all the KCOT. RESULTS: A total of 13 (59.1%) dentigerous cysts were treated successfully only with decompression as one stage procedure, while the other 9 (40.9%) cysts required enucleation (1 dentigerous and 8 KCOT), after decompression (p ≤ 0.001). CONCLUSION: Related to non-aggressive lesions, more conservative treatment approach, such as decompression as one-stage procedure, should be considered. On the other hand, KCOTs in children require a two-stage procedure for a successful treatment outcome.

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.

Imuno-expressão da metalotioneída em cistos e tumores odontogênicos / Metallothionein immunoexpression in odontogenic cysts and in odontogenic tumours

Cistos e tumores odontogênicos são lesões originadas dos tecidos que formam os dentes e apresentam diferentes comportamentos biológicos. A metalotioneíra (MT) é relacionada à homeostase de metais, regulação da diferenciação e proliferação celular e inibição da apoptose. Com relação aos cistos e tumores odontogênicos, a MT poderia ter um papel na regulação da diferenciação e proliferação celuar e na inibição da apoptose, refletindo no comportamento biológico. Os objetivos são avaliar e comparar a expressão da MT entre: 1) cistos odontogêncios e tumor odontogênico ceratocístico (TOC); 2) TOC associados à Síndrome do Carcinoma Basocelular Nevóide (SCBN) e não associados; 3) tumores odontogênicos benignos. Objetivou-se também correlacionar a imuno-expressão da MT com a proliferação celular e com a inflamação. A amostra incluiu cisto radicular (CR), cisto dentígero (CD), TOC (primário associado ou não à (SCBN), cisto odontogênico ortoceratinizado (COO), ameloblastoma sólido (ABS), tumor odontogênico escamoso (TOE), tumor odontogênico adenomatóide (TOA), tumor odontogênico cístico calcificante (TOCC) e tumor odontogênico epitelial calcificante (TOEC). Foi realizada imunoistoquímica para MT, Ki-67 e PCNA...

Inhibition of SHH signaling pathway: molecular treatment strategy of odontogenic keratocyst.

Odontogenic keratocyst (OKC) is a relatively common cystic lesion occurred in the tooth-bearing areas of the jaws. This entity is thought to arise from the dental lamina or its remnant with significant growth capacity and recurrence potential. The Sonic hedgehog (SHH) signaling pathway plays a critical role in tooth development. Patched (PTCH) combines with Smoothened (SMO) to form a receptor complex for SHH ligand. Mutations in the PTCH resulting in aberrant activation of SHH signaling pathway were identified as the underlying genetic event of both sporadic and syndrome-related OKCs. We postulate that any strategy to develop antagonists of active receptor, transcriptional factors of SHH signaling pathway will be an effective treatment for OKC. These strategies include reintroducing a wild-type form of PTCH, inhibition of the SMO molecule by synthetic small antagonists and suppression of the downstream transcription factors of the SHH signaling pathway. It seems that inhibition of SMO by intracystic injection of antagonist protein of SMO is the most potential treatment choice.

[In vitro study on bone resorption of odontogenic cysts and ameloblastomas].

OBJECTIVE: To investigate the effect of bone resorption by odontogenic cysts and ameloblastomas in vitro. METHODS: Fragments of odontogenic cysts (14 odontogenic keratocysts, 6 inflamed odontogenic keratocysts, 5 dentigerous cysts) and ameloblastomas (n = 7) were incubated in vitro for 24 h. The supernatant was then removed into the culture system of SD rat calvaria. After incubation (48 h), the calcium contents of the media were measured by atom spectrophotometer. The supernatant of odontogenic cysts and ameloblastomas was measured for the bone resorption related factors such as IL-6, TNF-alpha, PGE(2), bone Gla-containing protein (BGP) and calcitonin (CT) by a radioimmunoassay system. RESULTS: The calcium released in the calvaria culture media by all the odontogenic lesions was significantly higher than that in the blank controls (P < 0.01). The inflamed odontogenic keratocyst group had a significantly higher calcium concentration than odontogenic keratocyst and ameloblastoma groups (P < 0.05). In addition, the concentration of IL-6, TNF-alpha, PGE(2) and CT in the culture media of all odontogenic lesions were significantly higher than that of the blank controls (P < 0.05). IL-6 concentration in the inflamed and non-inflamed odontogenic keratocyst groups were significantly higher than that of ameloblastoma group (P < 0.05). CT concentration in the inflamed odontogenic keratocyst was significantly higher than those of odontogenic keratocyst and dentigerous cyst groups (P < 0.05). Correlation and regression analysis showed that IL-6 was significantly correlated with the calcium content (P < 0.01). CONCLUSIONS: The odontogenic lesions could promote bone resorption in vitro and it is likely to be related to some of the cytokines secreted by the lesions.

The multifocal nature of odontogenic keratocysts.

The odontogenic keratocyst, OKC, is a very aggressive intraosseos lesion with a recurrence rate of approximately 25 percent to 60 percent.' The tendency for this lesion to "return" after surgical treatment has prompted studies to obtain more information concerning the inherent nature of the lesion. The OKC lesions are usually treated with enucleation of the soft tissue lining, curettage and ostectomy of the bony margins, or with more aggressive block resection. The purpose of this study was to characterize the multifocal aspect of the OKC and to demonstrate the presence of cystic lesions remote from the margins of the primarily diagnosed cyst itself. A retrospective chart review was conducted of seven patients who had sustained a long history of recurrent OKCs. Three types of documentation were reviewed for each patient: Orthopantomograms, cephalograms, and CT scans, which had been taken over the long-term course of the disease, Detailed operation reports of surgical procedures to treat the OKC lesions, and; Large histologic specimens from the six patients who received total resection of the involved mandibular bodies. These hemimandibulectomy slides offered a unique opportunity to observe OKC activity throughout a wide osseous area. All patients hod been operated multiple times over a period of 10 to 21 years, coming eventually to mandibular resection. The operating surgeon in all of the cases was one of the authors, Philip J. Boyne, DMD, MS, DSc. All patients exhibited the multifocal nature of OKCs with demonstrable cyst formation at distant sites in the mandible. Two patients had local recurrences at the margins of the primary lesion in addition to cyst formation at distant sites. The authors concluded that clinicians should respect the multifocal nature of OKCs. The "recurrences" observed in OKCs may not necessarily be due to the degree of skill of the surgeon or the technique used to eradicate the primary cyst, but instead are probably a reflection of the multifocal nature of the pathologic lesion itself. The OKC is a very aggressive intraosseos lesion of the jaws, which not infrequently clinicians detect in the process of routine oral examination.

Relation between size of odontogenic jaw cysts and the pressure of fluid within.

Intracystic fluid pressure may have a crucial role in the growth of odontogenic jaw cysts. In this study, we investigated the relation between the size of the cyst and the pressure of the fluid within odontogenic keratocysts, dentigerous cysts, and radicular cysts. The radiolucent area of the cyst on a panoramic radiograph was linearly related to the volume in the cavity, and the correlation coefficient (gamma) was 0.70 (n = 25, P < 0.001). Intracystic fluid pressure correlated negatively with the radiolucent area in odontogenic keratocysts (gamma = -0.76, n = 9, P = 0.02), dentigerous cysts (gamma = -0.54, n = 16, P = 0.03), and radicular cysts (gamma = -0.69, n = 10, P = 0.03). The values of [(intracystic fluid pressure (mmHg)) x (radiolucent area (cm(2)))] did not differ significantly among the three types of cyst. Intracystic fluid pressure may therefore be negatively related to the size of all three types of cyst.

Cisto odontogênico glandular: uma lesão rara / Glandular odontogenic cisty: a rare lesion

Esta revisão da literatura sobre o cisto odontogêncio glandular justifica-se pela raridade dessa lesão. Os aspectos clínicos, radiográfico e histopatológicos da entidade patológica em questão são cuidadosamente abordados e ênfase especial é dada às considerações conflitantes dos diversos autores

Marsupialization for odontogenic keratocysts: long-term follow-up analysis of the effects and changes in growth characteristics.

OBJECTIVE: This study evaluated the effects of marsupialization on odontogenic keratocysts (OKCs) and its role in conjunction with enucleation and curettage. STUDY DESIGN: Twenty-eight primary OKCs, treated by marsupialization before enucleation and curettage, were examined in this study. The effect of marsupialization and recurrence data after a follow-up period of at least 3 years were evaluated. The changes of growth characteristics during marsupialization were analyzed by means of histopathologic and immunohistochemical studies with monoclonal anti-Ki-67 antibody. RESULTS: The effect of marsupialization was evaluated as extremely effective (64.3%), moderately effective (32.1%), and poorly effective (3.6%). In 5 lesions, the cysts disappeared macroscopically and further surgery was not done. Recurrence was observed in 6 lesions (21.4%), and there was no significant difference in recurrence rates between the lesions treated with or without marsupialization. There appeared to be a predilection for recurrence in the lesions in the mandibular ramus region and also for radiographically multilocular lesions. Microscopic examination showed substantial changes from a parakeratinized or orthokeratinized epithelium into a hyperplastic, stratified, nonkeratinizing squamous epithelium after marsupialization in many cases. There was no significant difference in labeling index between premarsupialization (20.2% +/- 12.0%) and postmarsupialization (15.3% +/- 10.3%). CONCLUSION: Marsupialization was found to be effective as a preliminary treatment for large OKCs. This procedure does not appear to affect the recurrence tendency of OKCs, and the probable changes in growth characteristics become rather less aggressive.

Nuevas consideraciones en el diagnóstico del queratoquiste odontogénico / New considerations about the diagnosis of odontogenic keratocyst

El queratoquiste odontogénico (QO) es una forma clínica e histológicamente bien diferenciada de otros quistes odontogénicos. Es conocido por su agresividad, elevada tasa de recurrencia y puede estar asociado al síndrome del carcinoma basocelular nevoide (SCBN). Recientemente se ha propuesto en la literatura que la pérdida del gen supresor de tumor patched humano (ptch) es el posible origen molecular del QO. En este trabajo se revisan las características clínicas, histopatológicas y moleculares de los QOs, discutiéndose también el tratamiento y la recurrencia (AU)

A radiologic analysis of dentigerous cysts and odontogenic keratocysts associated with a mandibular third molar.

OBJECTIVE: The purpose of this study was to discriminate radiographically between dentigerous cysts (DCs) and odontogenic keratocysts (OKCs) associated with a mandibular third molar. STUDY DESIGN: The material consisted of panoramic radiographs of dentigerous cysts (44 patients, 45 cysts) and odontogenic keratocysts (15 patients, 16 cysts), all of which were related to a mandibular third molar. The radiographic images were analyzed with reference to the patients' ages and symptoms. RESULTS: The mean age of patients in the OKC group was less than that of patients in the DC group. The mean area of the cysts in the OKC group was larger than that of those in the DC group. The mean distance from the second to the third molar in the DC group was greater than that in the OKC group. Although there was a significant correlation between the area and distance in the DC and OKC groups, the patients' ages did not significantly correlate to the area and distance of either cyst. CONCLUSIONS: The OKCs had a tendency toward rapid growth in the patient's youth but short movement of a third molar compared with the DCs. The DCs and OKCs do not appear to develop gradually from the period when follicles or dental lamina were formed but arise at various periods randomly.

Clinico-pathologic study of odontogenic cysts in a Mexican sample population.

BACKGROUND: Odontogenic cysts are uncommon lesions that frequently behave agressively and attain a large size. Unfortunately, information on the relative incidence of these cysts from different populations is not abundant. In Mexico, for example, only a few examples have been reported. The aim of this study was to ascertain the frequency of odontogenic cysts in a Mexican sample and to compare these data with previously reported studies from other countries. METHODS: The files of the Oral and Maxillofacial Pathology Diagnosis Service at the School of Dentistry at the Universidad Nacional Autónoma de México (UNAM) were reviewed and all accessions of odontogenic cysts were listed. Clinical and radiographic data were recorded and microscopic slides evaluated according to the most recent World Health Organization (WHO) classification (1992). RESULTS: Three hundred and four cases of odontogenic cysts (55.9% male predominance) were found. The most frequent odontogenic cysts were the following: periapical cyst (38. 8%); dentigerous cyst (35.5%), and odontogenic keratocyst (18.8%). Periapical cyst was more frequent in females, and maxillary anterior teeth were most commonly involved. Dentigerous cysts appeared in males at a rate of 64.8%, this cyst found more frequently between the 1st and 2nd decades of life and in the molar zone. Odontogenic keratocyst was more frequent in males (59.6%), between the 2nd and 4th decades of life and more common in the molar zone. CONCLUSIONS: More than 50% of the sample were aggressive cysts (dentigerous and keratocyst). Our results suggest that Mexican patients develop aggressive odontogenic cysts more commonly than other populations. Our figures point to the need for a precise diagnosis in order to institute the correct surgical procedure, prevent recurrence, and forestall more extensive tissue destruction.

The polymorphous odontogenic cyst.

Over the years there have been sporadic reports of unusual cystic lesions of the jaws, not readily classified under conventional headings but which have been variously diagnosed as median-mandibular, glandular, sialo-odontogenic or botryoid odontogenic cyst. We present five cases which do not fit into other categories of odontogenic cyst, two of which have recurred within a few years of conservative treatment. This paper aims to alert clinicians to the propensity for regrowth of these cysts, proposes the term polymorphous odontogenic cyst for these lesions, to encompass their varied histological appearances and discusses their distinction from other cyst types with mucous and papillary formations in epithelium.