Diagnóstico y tratamiento conservador del queratoquiste odontogénico

Resumen El queratoquiste odontogénico es una entidad potencialmente agresiva y de alta recurrencia, con características clínicas y radiográficas no definidas claramente. Se presenta en cualquier etapa de la vida. El 70 a 80% se ubican en la mandíbula, comúnmente en la región de tercer molar y ángulo mandibular desde donde progresan hacia la rama y cuerpo. Son lesiones en general asintomáticas que pueden alcanzar dimensiones notables. A menudo se encuentran en el examen radiográfico de rutina. El objetivo del presente artículo es reportar el caso de una mujer de 40 años de edad, con un queratoquiste odontogénico paraqueratinizado, evaluando sus características clínicas, radiográficas e histopatológicas que llevaron a un manejo y tratamiento conservador oportuno y adecuado con resultados satisfactorios. Concluyendo que la minuciosa elaboración de la historia clínica basado en hallazgos clínicos, radiográficos e histopatológicos conduce a un diagnóstico correcto, que permite la elaboración de un plan de tratamiento adecuado.

Resumo O Queratocisto odontogênico potencialmente agressivo e de alta recorrência, com características clínicas e radiográficas não claramente definidas. Ocorre em qualquer estágio da vida. 70 a 80% estão localizados na mandíbula, geralmente na região do terceiro molar e no ângulo mandibular de onde progridem para o ramo e o corpo. São lesões geralmente assintomáticas que podem atingir dimensões notáveis. Eles são freqüentemente encontrados no exame radiográfico de rotina. O objetivo deste artigo é relatar o caso de uma mulher de 40 anos com um queratocisto odontogênico paraqueratinizado, avaliando suas características clínicas, radiográficas e histopatológicas que conducem ao manejo e tratamento conservador oportuno e adequado, com resultados satisfatórios. Concluindo que o cuidadoso preparo da história médica com base em achados clínicos, radiográficos e histopatológicos leva a um diagnóstico correto, o que permite o desenvolvimento de um plano de tratamento adequado.

Abstract Odontogenic keratocysts are potentially aggressive and have high recurrence rates. Their clinical and radiographic features are not clearly defined. They can occur at any stage of life. Seventy to 80% are located in the mandible, commonly in the area between the third molar and the mandibular angle, from where they grow towards the ramus and body. They are generally asymptomatic lesions that can grow considerably. They are often found on routine radiographs. This paper reports the case of a 40-year-old woman with a parakeratinized odontogenic keratocyst. After assessing the cyst's clinical, radiographic and histopathological features, we managed and treated the condition timely, conservatively, and with satisfactory results. We concluded that preparing the patient's dental history carefully and based on clinical, radiographic, and histopathological findings allowed us to make the correct diagnosis and develop the necessary treatment plan.

Gorlin-Goltz Syndrome: The importance of Clinical Investigation and a Multidisciplinary Approach

ABSTRACT: Gorlin-Goltz Syndrome is a genetic disorder characterized by a series of clinical changes, including the presence of multiple odontogenic keratocysts and nevus basal cell carcinomas. As these lesions involve the maxillofacial region and can evolve to severe sequelae, it is essential that the dental surgeon recognize this pathology, in order to promote a correct investigation and early multidisciplinary diagnosis and treatment. The treatment for the cysts varies according to the lesion's characteristics and location, and therefore, the request for complementary exams is essential. According to literature, the approach varies from conservative to more invasive, and several supporting therapies are mentioned. Thus, this article aims to report a case of a young patient diagnosed with Gorlin-Goltz Syndrome by a dental surgeon, who treated conservatively and interdisciplinarly, and obtained a satisfactory result. In addition, it makes a bibliographic review on this genetic condition, elucidating its therapeutic forms.

RESUMEN: El síndrome de Gorlin-Goltz es un trastorno genético caracterizado por una serie de cambios clínicos, que incluyen la presencia de múltiples queratoquistes odontogénicos y nevus carcinomas basocelulares. Como estas lesiones involucran la región maxilofacial y pueden evolucionar a secuelas severas, es esencial que el cirujano oral conozca esta patología para realizar una investigación correcta y un diagnóstico y tratamiento multidisciplinario temprano. El plan de tratamiento para los quistes varía de acuerdo con las características y la ubicación de la lesión y, por lo tanto, la solicitud de exámenes complementarios es esencial. Según la literatura, el enfoque varía de conservador a más invasivo, y se mencionan varias terapias de apoyo. Por lo tanto, este artículo tiene como objetivo informar un caso de un paciente joven diagnosticado con el síndrome de Gorlin-Goltz por un cirujano dentista, que trató de forma conservadora e interdisciplinaria, y obtuvo un resultado satis- factorio. Además, realiza una revisión bibliográfica sobre esta condición genética, aclarando sus formas terapéuticas.

Odontogenic keratocyst

@#A 37-year-old woman consulted for a slow-growing mass of one-year duration on the left side of the mandible with associated tooth mobility. Clinical examination showed buccal expansion along the left hemi-mandible from the mid-body to the molar-ramus region with associated mobility and displacement of the pre-molar and molar teeth. Radiographs showed a well-defined unilocular radiolucency with root resorption of the overlying teeth. Decompression and unroofing of the cystic lesion was performed. Received in the surgical pathology laboratory were several gray-white rubbery to focally gritty tissue fragments with an aggregate diameter of 1 cm. Histopathologic examination shows a fibrocollagenous cyst wall lined by a fairly thin and flat stratified squamous epithelium without rete ridges. (Figure 1) The epithelium is parakeratinized with a wavy, corrugated surface while the basal layer is cuboidal and quite distinct with hyperchromatic nuclei. (Figure 2) Based on these features, we signed the case out as odontogenic keratocyst (OKC). Odontogenic keratocysts are the third most common cysts of the gnathic bones, comprising up to 11% of all odontogenic cysts, and most frequently occurring in the second to third decades of life.1,2 The vast majority of cases occur in the mandible particularly in the posterior segments of the body and the ramus. They typically present as fairly large unilocular radiolucencies with displacement of adjacent or overlying teeth.1 If associated with an impacted tooth the radiograph may mimic that of a dentigerous cyst.2 Microscopically, the parakeratinized epithelium without rete ridges, and with a corrugated luminal surface and a prominent cuboidal basal layer are distinctive features that enable recognition and diagnosis.1,2,3 Occasionally, smaller “satellite” or “daughter” cysts may be seen within the underlying supporting stroma, sometimes budding off from the basal layer. Most are unilocular although multilocular examples are encountered occasionally.1 Secondary inflammation may render these diagnostic features unrecognizable and non-specific.2 Morphologic differential diagnoses include other odontogenic cysts and unicystic ameloblastoma. The corrugated and parakeratinized epithelial surface is sufficiently consistent to allow recognition of an OKC over other odontogenic cysts, while the absence of a stellate reticulum and reverse nuclear polarization will not favor the latter diagnosis.2,3 Odontogenic keratocysts are developmental in origin arising from remnants of the dental lamina. Mutations in the PTCH1 gene have been identified in cases associated with the naevoid basal cell carcinoma syndrome as well as in non-syndromic or sporadic cases.1,3 These genetic alterations were once the basis for proposing a neoplastic nature for OKCs and thus the nomenclature “keratocystic odontogenic tumor” was for a time adopted as the preferred name for the lesion.3,4 Presently, it is felt there is not yet enough evidence to support a neoplastic origin and hence the latest WHO classification reverts back to OKC as the appropriate term.1 Sekhar et al. gives a good review of the evolution of the nomenclature for this lesion.3 Treatments range from conservative enucleation to surgical resection via peripheral osteotomy.5 Reported recurrences vary in the literature ranging from less than 2% of resected cases up to 28% for conservatively managed cases.1,5 These are either ascribed to incomplete removal or to the previously mentioned satellite cysts - the latter being a feature associated with OKCs that are in the setting of the naevoid basal cell carcinoma syndrome.1,2,3 Thus, long term follow-up is recommended.5 Malignant transformation, though reported, is distinctly rare.

Analysis of collagen fibers in keratocystic odontogenic tumor and ameloblastoma: A polarizing microscopic study

Introduction: Collagen forms an integral part of connective tissue and maintains its structural integrity. It has natural birefringence which is attributed to the arrangement of its fibers and is enhanced by special stains such as picrosirius red through polarizing microscopy. The polarization colors differ according to the fiber thickness and pattern of arrangement which in turn related to aggressiveness. Hence, the present study was conducted to evaluate collagen fibers in keratocystic odontogenic tumor (KCOT) and ameloblastoma using polarizing microscopy. Aim: This study aims to compare and correlate different types and patterns of collagen fibers in KCOT and ameloblastoma using picrosirius red stain under polarizing microscopy to delineate their aggressiveness. Materials and Methods: The color, thickness, and orientation of collagen fibers in the KCOTs (n = 15) and ameloblastomas (n = 15) were studied histochemically by staining the sections with picrosirius red and examined under polarizing microscope using image analyzer software. Results: When collagen fiber bundles in KCOT and ameloblastoma were compared, significant difference was noted between yellowish-orange collagen fiber bundles, but no significant difference was observed between greenish-yellow and orange-red collagen bundles. With respect to orientation and organization, the results are statistically significant (P < 0.05). Conclusion: The connective tissue stroma of KCOT could be regarded not just as a structural support but as a functional part of the lesion. In KCOT, the thin, parallel, and loosely arranged greenish-yellow collagen fibers may be attributed to its high recurrence rate and biological aggressiveness.

Expression of Interleukin-1 Alpha and Interleukin-6 Expression in Keratocystic Odontogenic Tumors and Ameloblastomas

Both Ameloblastomas and odontogenic keratocysts share many clinical features in common such as local aggressiveness, high recurrence rates and radical management options. Understanding the pathogenesis and biological behavior of these would improve our success at diagnosis and treatment. Despite efforts focused on understanding the pathogenesis of these lesions still little is known about them. AIM: To evaluate the expression of IL-1α and IL-6 by immunohistochemistry in ameloblastomas and KCOTs and correlate their expression with with their increase in size and extent of bone destruction. Methods: A total of 25 cases of ameloblastomas and 25 cases of keratocystic odontogenic tumors were included in the study. All histological slides were stained immunohistochemically to show the expression of IL-1α and IL-6. Results: Immunohistochemical expressions of IL-1α and IL-6 in ameloblastoma was observed in only stellate reticulum-like cells While in KCOT the immonohistochemical expression of both the antibodies in comparision to ameloblastoma was observed only in the lining epithelial cells. The higher expression rates of IL-1α and IL-6 were associated with increases in tumor size in ameloblastomas and connective tissue cyst wall thickness in keratocystic odontogenic tumors. Conclusion: The higher expression rates of IL-1α and IL-6 were associated with increased tumor size in ameloblastomas and with connective tissue cyst wall thickness in KCOT. Thus we can suggest that the cytokines play a role on aggressive behaviour of ameloblastomas and keratocystic odontogenic tumors by facilitating increased bone resorption.

Volume change pattern of decompression of mandibular odontogenic keratocyst / 대한악안면성형재건외과학회지

OBJECTIVES: This study was aimed to analyze the reducing pattern of decompression on mandibular odontogenic keratocyst and to determine the proper time for secondary enucleation. MATERIALS AND METHODS: Seventeen patients with OKC of the mandible were treated by decompression. Forty-five series of CT data were taken during decompression and measured by using InVivo software (Anatomage, San Jose, Calif) and were analyzed. RESULTS: The expected relative volume during decompression is calculated using the following formula: V(t) = V initial × exp.(at + 1/2bt 2) (t = duration after decompression (day)). There was no significant directional indicator in the rate of reduction between buccolingual and mesiodistal widths. CONCLUSION: The volume reduction rate gradually decreased, and 270 days were required for 50% volume reduction following decompression of OKC. The surgeon should be aware of this pattern to determine the timing for definitive enucleation. CLINICAL RELEVANCE: The volume reduction rate and pattern of decompression of the OKC can be predicted and clinicians should be considered when treating OKC via decompression.

Retrospective clinical study of multiple keratocystic odontogenic tumors in non-syndromic patients

OBJECTIVES: A keratocystic odontogenic tumor (KOT) is a type of odontogenic tumor that mainly occurs in the posterior mandible. Most KOTs appear as solitary lesions; however, they sometimes occur as multiple cysts. This study analyzed the clinical features of multiple KOTs. MATERIALS AND METHODS: The participants were diagnosed with KOT by biopsy with multiple surgical sites, and were patients at the Pusan National University Hospital and the Pusan National University Dental Hospital from January 1, 2005 to March 31, 2016. Charts, records, images and other findings were reviewed. RESULTS: A total of 31 operations were conducted in 17 patients. The mean patient age was 28.4±20.1 years. Multiple KOTs were found to occur at a young age (P<0.01). The predominant sites were in the posterior mandible (28.6%). Most cases of multiple lesions appeared in both the upper and lower jaw, and 40.3% of lesions were associated with unerupted and impacted teeth. The overall recurrence rate measured by operation site was 10.4% (8/77 sites). No patients were associated with nevoid basal cell carcinoma syndrome. CONCLUSION: The pure recurrence rate was lower than estimated, but there was a higher possibility of secondary lesions regardless of the previous operation site; therefore, long-term follow-up is necessary.

Diffusion-Weighted MR Imaging of Unicystic Odontogenic Tumors for Differentiation of Unicystic Ameloblastomas from Keratocystic Odontogenic Tumors

OBJECTIVE: Differentiating unicystic ameloblastomas from keratocystic odontogenic tumors (KCOT) is necessary for the planning of different treatment strategies; however, it is difficult based on conventional CT and MR sequences alone. The purpose of this study was to investigate the utility of diffusion-weighted imaging (DWI) and apparent diffusion coefficients (ADCs) in the differentiation of the two tumors. MATERIALS AND METHODS: We prospectively studied 40 patients with odontogenic cysts and tumors of the maxillomandibular region using conventional MR imaging and DWI. ADCs were measured using 2 b factors (500 and 1000). RESULTS: Unicystic ameloblastomas (n = 11) showed free diffusion on DWI and a mean ADC value of 2.309 ± 0.17 × 10-3 mm2/s. KCOT (n = 15) showed restricted diffusion on DWI with a mean ADC value of 0.923 ± 0.20 × 10-3 mm2/s. The ADC values of unicystic ameloblastomas were significantly higher than those of KCOT (p < 0.001, Mann-Whitney U-test). An ADC cut-off value of 2.0 × 10-3 mm2/s to differentiate KCOT and unicystic ameloblastomas resulted in a 100% sensitivity and 100% specificity. Dentigerous cysts (n = 3) showed restricted diffusion on DWI and similar ADC values (1.257 ± 0.05 × 10-3 mm2/s) to those of KCOT. CONCLUSION: Diffusion-weighted imaging and ADC determination can be used as an adjuvant tool to differentiate between unicystic ameloblastomas and KCOT, although the ADC values of dentigerous cysts overlap with those of KCOT.

Tumor odontogénico queratoquístico en seno maxilar: reporte de un caso clínico / Keratocystic odontogenic tumor in the maxillary sinus: report of a clinical case

El tumor odontogénico queratoquístico, es una patología que se encuentra asociada a la retención de un órgano dentario, en especial al tercer molar, es reconocido por su potencial destructivo y extenso, erosionando placas corticales que envuelven mucosa y tejidos blandos, la etiología del tumor odontogénico queratoquístico está probablemente relacionada con el desarrollo de la lámina dental (o restos de Serres) y con una mayor recidiva dentro de los tumores odontogénicos, siendo motivo de su reclasificación en el 2005 por la OMS. Se presenta casoclínico de un tumor odontogénico queratoquístico en el seno maxilarderecho, se exponen los métodos utilizados para la exploración clínica,radiológica y el tratamiento quirúrgico elegido.

The keratocystic odontogenic tumor is a condition associated withtooth retention, particularly of the third molar. It is recognized as beingpotentially highly destructive, by eroding cortical plates overlying theoral mucosa and soft tissues. The etiology of keratocystic odontogenictumor is probably related to the development of the dental lamina (orremains of Serres) and the recurrence rate is high compared to that ofother odontogenic tumors, the reason for their reclassifi cation by theWHO in 2005. We present a clinical case of a keratocystic odontogenictumor in the right maxillary sinus, including an explanation of themethods used for clinical and radiological examination, and the chosensurgical treatment.

Keratocystic odontogenic tumor with ossification and calcification: A case report with unusual histological findings.

The keratocystic odontogenic tumor (KCOT), formerly known as odontogenic keratocyst, is a benign developmental odontogenic tumor with many distinguishing clinical and histologic features. Hard tissue deposits, which usually take the form of dystrophic calcifications, cartilaginous tissue, or dentinoid, are uncommon findings in the connective tissue capsule of the KCOT. We report a case of a 33‑year‑old female with KCOT showing osseous tissue and calcified deposits close to its epithelial lining, which is an extremely rare occurrence. A brief review on the reported prevalence of hard tissue deposits in KCOTs and possible mechanisms that has been implicated in mineralization and bone formation has been discussed.

Keratocystic Odontogenic Tumour Admixed With Giant Cells: Case Report and Review on the Role of RANK/RANKL in its Pathogenesis

‘Odontogenic keratocyst’ (OKC) was the term coined by Philipsen in the year 1956, while Pindborg and Hansen in the year 1963 described the details of this cyst[1,2]. OKC is renamed as keratocystic odontogenic tumour (KCOT) by WHO[3] taking into view its aggressive and recurrent nature. OKC arises from the rests of dental lamina[1]. It can occur anywhere in the oral cavity wherever the osseous structures are present, but most commonly in the posterior regions of the mandible[2,4]. Since the clinical and radiological profile of OKC mimics other lesions it may affect the appropriate diagnosis. Here we report a case of aggressive OKC which affected an entire quadrant of the mandible along with the ramus.

Primary Intraosseous Squamous Cell Carcinoma Arising from Parakeratinized Kerato - Cystic Odontogenic Tumor Associated with Impacted Mandibular Canine: A Rare Entity.

Primary intraosseous carcinoma (PIOC) that arises from the epithelial lining of odontogenic cyst is a rare entity that represents about 1-2% of all oral and maxillofacial carcinoma. In particular, PIOC arising from keratocystic odontogenic tumor (KCOT) is rare when compared with such occurrence in other odontogenic cysts such as radicular cyst, residual cyst, and dentigerous cyst. Th e following case report discusses a case of squamous cell carcinoma arising from parakeratinized KCOT associated with impacted mandibular canine in a 43-year-old male patient with a complaint of painful swelling in the mandible. A review of reported cases from 1981 of PIOC arising from KCOT alone is also included.

Keratocystic Odontogenic Tumor of the Mandible – A Case Report

Odontogenic keratocyst has been renamed as KCOT (Keratocysticodontogenic tumour) by the World Health Organization in 2005. It is a benign intraosseous neoplasm of the jaw. They develop from the dental lamina remenants in the mandible and maxilla. KCOT is of particular interest because of its recurrence rate and aggressive behaviour. We are here presenting a case of KCOT in middle aged male patient.

Enucleation of large keratocystic odontogenic tumor at mandible via unilateral sagittal split osteotomy: a report of three cases

Keratocystic odontogenic tumor (KCOT) is a common benign tumor of osseous lesions in dental and maxillofacial practice. We describe three cases of large KCOT located in the posterior part of the mandible extending to the angle and ramus region, which were enucleated via sagittal split osteotomy (SSO) of the mandible. There are cases in which a conventional enucleation procedure does not ensure complete excision of the entire lesion without damage to vital structures like the inferior alveolar nerve. In such cases, a SSO approach could be a better choice than conventional methods. The purpose of this article is to describe our experience using unilateral mandibular SSO for removal of a KCOT from the mandible.

Imaging diagnosis of keratocystic odontogenic tumour in mandible / 实用放射学杂志

Objective To discuss the X-ray and CT manifestations of keratocystic odontogenic tumour(KCOT)in mandible,to im-prove the diagnostic accuracy of the disease.Methods The X-ray and CT features of KCOT(n=25)in mandible,which were proved by surgery and pathology,were retrospectively analyzed.Results The KCOT,including solitary tumor(n=23)and multiple tumor (n=2),mainly displayed unilocular or multilocular in shape with distinct sclerosing margin.Disruption of the adjacent cortex was de-tected in 7 cases,growth along the long axis of mandible in 18 cases,compression and displacement of the adjacent teeth in 21 cases, resorption of bevel of roots in 2 cases.Conclusion Most lesions of KCOT in mandible have characteristic manifestation in X-ray and CT findings,which is helpful for diagnosis and differential diagnosis.

Keratocystic odontogenic tumor: clinicopathological aspects and treatment / Tumor odontogénico queratoquístico: aspectos clínico-patológicos y tratamiento

The keratocystic odontogenic tumor is a benign intraosseous neoplasm derived from remnants of the dental lamina and it occurs with high frequency. Regarding histological characteristics, it has a high recurrence rate which is one of the main therapeutic problems. Also, it presents high local aggressiveness, expressed in cortical expansion, delayed eruption and displacement of teeth, blood vessels and nerves. At present, there are various treatments, being ideal the one which presents the lowest risk of recurrence with low morbidity for the patient. In this review, the main histopathological, clinical and therapeutic aspects of this oral pathology are discussed.

El tumor odontogénico queratoquístico es una neoplasia intraósea benigna que deriva de restos de la lámina dental, y que se presenta con alta frecuencia. Sus características histológicas le confieren una elevada tasa de recidiva, siendo este uno de sus principales problemas terapéuticos. Presenta además una considerable agresividad local, la cual se expresa con la expansión de corticales óseas, retardo en la erupción y desplazamiento de dientes, vasos sanguíneos y nervios. En la actualidad existen diversos tratamientos, siendo el ideal aquel que presente el menor riesgo de recidiva con una baja morbilidad para el paciente. En la presente revisión se discuten los principales aspectos histopatológicos, clínicos y terapéuticos de esta patología oral.

Odontogenic Keratocyst- The Controversies in Nomenclature and Treatment Modalities.

Summary: Odontogenic keratocysts (OKC) now officially known as Keratocystic odontogenic tumor (KCOT) is a benign odontogenic intraosseous tumor which is potentially agrressive having distinguished clinical and histopathological features. Based on a literature review, more aggressive treatment — either resection or enucleation supplemented with Carnoy’s solution with or without peripheral ostectomy — results in a lower recurrence rate than enucleation alone or marsupialization. WHO’s reclassification of this lesion from cyst to tumour underscores its aggressive nature and should motivate clinicians to manage the disease in a correspondingly aggressive manner. The purpose of this paper is to review and discuss the redesignation of KCOT and the implications for treatment.

Treatment of Keratocystic Odontogenic Tumors in Nevoid Basal Cell Carcinoma Syndrome

Tumor odontogénico queratoquístico: revisión de la literatura a propósito de un caso clínico / Keratocystic odontogenic tumor: a review of the literature in reference to a clinical case

El Tumor odontogénico queratoquístico es una entidad benigna de prevalencia relativamente alta que surge desde los remanentes de la lámina dental, el cual tiene un potencial comportamiento agresivo y alta recurrencia. Este tiende a crecer lentamente dentro del canal medular en sentido anteroposterior transformándose en una gran lesión sin causar una expansión obvia. Esta revisión describe la clínica, imagenología y tratamientos actuales del Tumor Odontogénico Queratoquístico a propósito de un paciente de sexo masculino 30 años diagnosticado con esta entidad.

Keratocystic Odontogenic tumor is a benign entity with relatively high prevalence that arises from remains of dental lamina. It has a potentially aggressive behaviour, high recurrence and anteroposterior slow growth in the medullar canal, which can become large lesion without obvious expansion. This review describes clinical, imagenological and current treatments of Keratocystic Odontogenic Tumor in 30- year-old male patient diagnosed with this entity.

Immunohistochemical expression of protein 53, murine double minute 2, B-cell lymphoma 2, and proliferating cell nuclear antigen in odontogenic cysts and keratocystic odontogenic tumor.

Introduction: Even though odontogenic cysts share a similar histogenesis, they show different growth and differentiation profile due to differences in the proliferative cellular activity. Aims: We perform an immunohistochemical assessment of protein 53 (p53), proliferating cell nuclear antigen (PCNA), B-cell lymphoma 2 (bcl-2), and murine double minute 2 (MDM2) expression in odontogenic cysts and keratocystic odontogenic tumor analyzing their correlation with the biological behavior of these lesions. Materials and Methods: By the streptavidin-biotin-peroxidase method with antibodies against p53, PCNA, bcl-2, and MDM2 proteins, 11 radicular cysts, 11 dentigerous cysts, and 11 keratocystic odontogenic tumor were analyzed. The non-parametric Mann-Whitney U-test and Kruskall-Wallis test (P ≤ 0.05) were used to analyze the data. Results: Immunopositivity for PCNA was observed in all cases appraised, predominantly in the suprabasal layer of keratocystic odontogenic tumor epithelial lining (SD ± 19.44), but no significant differences were found among the groups of lesions. Bcl-2 immunoexpression was observed especially in the basal layer of keratocystic odontogenic tumor. PCNA LI was significantly higher than bcl-2 LI in keratocystic odontogenic tumor. MDM2 and p53 immunoexpression were not detected in the lesions studied. Among the evaluated lesions, the keratocystic odontogenic tumor showed different immunoexpression of the proliferation and apoptosis markers. Conclusion: The results of this study suggest that the keratocystic odontogenic tumor presents distinct biological behavior of the odontogenic cysts, as for the processes of proliferation, apoptosis, and differentiation, reinforcing the information in favor of the neoplastic nature of this lesion.