Unwarranted intrusion of odontogenic cyst into the maxillary antrum.

During the early growth phase, every individual is involved in a prolonged series of developmental processes in the maxillofacial region. Formation of cysts associated with such three-dimensional growth of the maxillofacial skeleton as well as deciduous and permanent tooth development. The origin of cystic jaw lesions may be odontogenic or non-odontogenic, developmental, or inflammatory and they are epithelial-lined or non-epithelial-lined cysts in nature. These cysts are considered to be aggressive cysts when they tend to grow rapidly and can cause significant damage to the surrounding bone and tissues if left untreated. Aggressive cystic lesion of the jaw needs special attention in order to prevent recurrences or even worsen and widespread disease. The management of the maxillary sinus requires individualisation based on its clinical and histopathological characteristics. Here, we report a case of an aggressive odontogenic cyst in a 30s-aged female patient in the left maxillary sinus with the literature review.

Odontogenic Keratocyst in Maxillary Sinus with Ectopic Third Molar: A Case Report.

BACKGROUND Odontogenic keratocyst (OKC) is a common odontogenic cyst, and it occurs more frequently in the mandible, with the posterior region of the dental arch, the angle, or the ramus being the most commonly affected sites. Odontogenic keratocyst occurring within the maxillary sinus is extremely rare, accounting for only about 1% of cases. CASE REPORT A 20-year-old female patient without any clinical symptoms underwent an oral examination, during which a dense dental shadow was identified within the maxillary sinus, surrounded by a low-density shadow. Physical examination revealed absence of the left maxillary third molar, with intact mucosa. The patient reported no history of tooth extraction. X-ray and cone-beam computed tomography revealed a high-density image within the left maxillary sinus, resembling a tooth and surrounded by a soft-tissue shadow, which exhibited a greater density in comparison to conventional odontogenic cysts. The initial diagnosis was odontogenic keratocyst in the maxillary sinus with an ectopic maxillary third molar. Surgical enucleation of the cyst and extraction of the impacted tooth were carried out utilizing the Caldwell-Luc approach. Histopathological analysis confirmed the presence of OKC. No significant recurrence was noted during the 6 months of follow-up. CONCLUSIONS Odontogenic keratocysts in the maxillary sinus with ectopic third molar are rare and may not have any symptoms in the early stage. Surgery can be performed using the Caroler-Luke approach to achieve ideal treatment results. In view of the high recurrence rate of OKC, close follow-up should be conducted after surgery.

High-Resolution Ultrasound of Odontogenic Cutaneous Sinus Tract: An International Multicentric Experience and a Review of the Literature.

OBJECTIVES: To investigate the role of high-resolution ultrasound (HR-US) in the initial and differential diagnosis of the Odontogenic Cutaneous Sinus Tract (OCST) in a multicentric setting. METHODS: Skin HR-US examinations of OCSTs performed between January 2019 and June 2023 at different Institutions were retrospectively reviewed. Epidemiological and clinical data (age, gender, location of the skin lesion, causative tooth, and the clinical suspicion) as well as HR-US imaging findings (morphology and length of the sinus tract, Doppler signal, and cortical bone interruption of maxilla or mandible) were collected. US examinations were performed by expert radiologists using a high-performance US scanner, employing a high-frequency linear probe (15 MHz or higher frequencies). In only one patient the HR-US exam was integrated with strain elastography (SE). RESULTS: Sixteen patients were enrolled with a median age of 37.6 years (range 16-70 years). The most frequent clinical suspicion was epidermal cyst, while OCST was suspected in only two cases. In all cases, HR-US depicted the sinus tract as a nodular, triangular or "champignon-shaped" lesion in the subcutaneous layer, which continued with a slightly tortuous band structure, up to the focally interrupted cortical bone plate. Furthermore, color Doppler evaluation showed color signals around and/or within the lesion, expression of inflammation. On SE, the sinus tract showed a hard pattern, due to fibrous and granulomatous tissue. CONCLUSIONS: HR-US, thanks to its high spatial resolution, allows the evaluation of OCST, and play a crucial diagnostic role, mainly when the clinical suspicious is different.

Application of machine learning in the preoperative radiomic diagnosis of ameloblastoma and odontogenic keratocyst based on cone-beam CT.

OBJECTIVES: Preoperative diagnosis of oral ameloblastoma (AME) and odontogenic keratocyst (OKC) has been a challenge in dentistry. This study uses radiomics approaches and machine learning (ML) algorithms to characterize cone-beam CT (CBCT) image features for the preoperative differential diagnosis of AME and OKC and compares ML algorithms to expert radiologists to validate performance. METHODS: We retrospectively collected the data of 326 patients with AME and OKC, where all diagnoses were confirmed by histopathologic tests. A total of 348 features were selected to train six ML models for differential diagnosis by a 5-fold cross-validation. We then compared the performance of ML-based diagnoses to those of radiologists. RESULTS: Among the six ML models, XGBoost was effective in distinguishing AME and OKC in CBCT images, with its classification performance outperforming the other models. The mean precision, recall, accuracy, F1-score, and area under the curve (AUC) were 0.900, 0.807, 0.843, 0.841, and 0.872, respectively. Compared to the diagnostics by radiologists, ML-based radiomic diagnostics performed better. CONCLUSIONS: Radiomic-based ML algorithms allow CBCT images of AME and OKC to be distinguished accurately, facilitating the preoperative differential diagnosis of AME and OKC. ADVANCES IN KNOWLEDGE: ML and radiomic approaches with high-resolution CBCT images provide new insights into the differential diagnosis of AME and OKC.

Comparing the characteristics of recurrent versus primary odontogenic keratocysts - A single center retrospective cohort study.

The high recurrence rate of odontogenic keratocysts (OKC) entails a large number of follow-up interventions after primary surgery. This study aimed to compare recurrent with primary OKC in regard to recurrence rate, treatment modality, radiographic and clinical findings. A single center retrospective cohort study with surgically treated OKC between 2012 and 2021 was conducted. The primary predictor was recurrence type of the lesion: primary (P-OKC), first recurrence (R1-OKC) and second recurrence (R2-OKC). The primary outcome variables were recurrence and time to recurrence. 68 surgeries were identified. Recurrence was not significantly associated with recurrence type (p = 0.906) but with the method of surgery (p < 0.001). Marsupialized R1-OKC recurred earlier than marsupialized P-OKC. Diameter was significantly associated with recurrence type (p = 0.002). R1-OKC had a smaller median diameter than P-OKC and R2-OKC were smaller than R1-and P-OKC. P-OKC were associated with teeth in 79% of surgeries, R1-OKC in 61% and R2-OKC in 27% (p = 0.007). Postoperative numbness was present after 40% of surgeries and decreased to 15% at follow-up, independently of recurrence type. Time to recurrence may be shorter for recurrent marsupialized OKC. Recurrent OKC are smaller and less often associated with teeth. Postoperative numbness after OKC surgery has a good prognosis.

Management regulations for odontogenic keratocyst: a case report and review of the literature.

BACKGROUND: Reconstruction of the entire dentition with odontogenic keratocyst is a very challenging quandary. Most cases of odontogenic keratocyst are often reported to be benign, resulting in severe occlusal discrepancies with the maxillary and mandibular dentition. Dental radiographs occasionally reveal an uncommon, locally aggressive developing cyst termed as odontogenic keratocyst, which is typically located in the posterior jaw. When this cyst occurs in the anterior region, it is often misdiagnosed with other periapical lesions due to its lack of response to pulp vitality tests. CASE PRESENTATION: This clinical case scenario demarcates the endodontic management of a patient diagnosed with odontogenic keratocyst. A 37-year-old Indian male patient reported to the department with throbbing pain in the lower left posterior tooth requiring endodontic therapy. This patient also presented with odontogenic keratocyst in the anterior region of the jaw, for which he had undergone surgical rehabilitation. This case report highlights the clinical protocol for the endodontic therapy in patient diagnosed with ododntogenic keratocyst. Masticatory impairment was not visible after the follow-up period and the treatment outcome was successful. CONCLUSION: This case report details the presentation, characteristic radiographic findings, and endodontic management of a patient with an extremely rare condition of odontogenic keratocyst. The management involves multidisciplinary approach for the rehabilitation.

Accuracy of machine learning in the diagnosis of odontogenic cysts and tumors: a systematic review and meta-analysis.

BACKGROUND: The recent impact of artificial intelligence in diagnostic services has been enormous. Machine learning tools offer an innovative alternative to diagnose cysts and tumors radiographically that pose certain challenges due to the near similar presentation, anatomical variations, and superimposition. It is crucial that the performance of these models is evaluated for their clinical applicability in diagnosing cysts and tumors. METHODS: A comprehensive literature search was carried out on eminent databases for published studies between January 2015 and December 2022. Studies utilizing machine learning models in the diagnosis of odontogenic cysts or tumors using Orthopantomograms (OPG) or Cone Beam Computed Tomographic images (CBCT) were included. QUADAS-2 tool was used for the assessment of the risk of bias and applicability concerns. Meta-analysis was performed for studies reporting sufficient performance metrics, separately for OPG and CBCT. RESULTS: 16 studies were included for qualitative synthesis including a total of 10,872 odontogenic cysts and tumors. The sensitivity and specificity of machine learning in diagnosing cysts and tumors through OPG were 0.83 (95% CI 0.81-0.85) and 0.82 (95% CI 0.81-0.83) respectively. Studies utilizing CBCT noted a sensitivity of 0.88 (95% CI 0.87-0.88) and specificity of 0.88 (95% CI 0.87-0.89). Highest classification accuracy was 100%, noted for Support Vector Machine classifier. CONCLUSION: The results from the present review favoured machine learning models to be used as a clinical adjunct in the radiographic diagnosis of odontogenic cysts and tumors, provided they undergo robust training with a huge dataset. However, the arduous process, investment, and certain ethical concerns associated with the total dependence on technology must be taken into account. Standardized reporting of outcomes for diagnostic studies utilizing machine learning methods is recommended to ensure homogeneity in assessment criteria, facilitate comparison between different studies, and promote transparency in research findings.

Glandular odontogenic cyst: Review of literature and report of two cases.

Glandular odontogenic cyst (GOC) is a rare developmental odontogenic cyst from the cell rests of Serres. GOC is locally aggressive with a tendency toward recurrence. The most common site of occurrence is the anterior mandible with an asymptomatic presentation. Radiographically, it presents as unilocular or multilocular radiolucency. It bears histopathological resemblance to low-grade mucoepidermoid carcinoma. We report two cases of GOC occurring in a 16-year-old and a 33-year-old male patient with a review of the clinical presentation, histopathological features, and diagnostic aspects of GOC reported so far in literature.

Long-term investigation of minimally invasive alcohol-based therapy as the treatment of odontogenic keratocyst:A retrospective cohort study.

The aim of this study was to evaluate the clinical efficacy of alcohol-based therapy for patients with large odontogenic keratocysts (OKCs). The study was implemented as a retrospective, single-center study. Patients treated with ethanol-based therapy for odontogenic keratocyst were retrospectively evaluated for baseline and postoperative data. The pre- and postoperative clinical situation and the extent of radiographic shrinkage were compared. The event is defined as the achievement of >50% reduction in cyst volume. The cyst reduction rate calculated on panoramic radiographs ranged from 7.4% to 99.9% (mean [standard deviation] 55.3% [27.9%]) and was statistically significant (P < 0.05). Specifically, it has been found that, radiographically, 47.6% of patients achieved >50% reduction in cyst volume within 12 months. The continuous cortical bone was rebuilt, and the cyst cavity was filled with regenerated trabecular bone. The 22 included patients presented with nonclinical problems, had no need for further intervention, and exhibited persistent impaction of the teeth. The results of this study demonstrated that ethanol-based therapy triggered marked radiographic reductions of large OKC, indicating that using this technique is efficient.

Cysts and Benign Odontogenic Tumors of the Jaws.

This article addresses jaw lesions including cysts and benign odontogenic tumors in terms of their definition and clinical and imaging features and discusses pertinent differential diagnoses..

Digital pathology-based artificial intelligence models for differential diagnosis and prognosis of sporadic odontogenic keratocysts.

Odontogenic keratocyst (OKC) is a common jaw cyst with a high recurrence rate. OKC combined with basal cell carcinoma as well as skeletal and other developmental abnormalities is thought to be associated with Gorlin syndrome. Moreover, OKC needs to be differentiated from orthokeratinized odontogenic cyst and other jaw cysts. Because of the different prognosis, differential diagnosis of several cysts can contribute to clinical management. We collected 519 cases, comprising a total of 2 157 hematoxylin and eosin-stained images, to develop digital pathology-based artificial intelligence (AI) models for the diagnosis and prognosis of OKC. The Inception_v3 neural network was utilized to train and test models developed from patch-level images. Finally, whole slide image-level AI models were developed by integrating deep learning-generated pathology features with several machine learning algorithms. The AI models showed great performance in the diagnosis (AUC = 0.935, 95% CI: 0.898-0.973) and prognosis (AUC = 0.840, 95%CI: 0.751-0.930) of OKC. The advantages of multiple slides model for integrating of histopathological information are demonstrated through a comparison with the single slide model. Furthermore, the study investigates the correlation between AI features generated by deep learning and pathological findings, highlighting the interpretative potential of AI models in the pathology. Here, we have developed the robust diagnostic and prognostic models for OKC. The AI model that is based on digital pathology shows promise potential for applications in odontogenic diseases of the jaw.

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.

A case of odontogenic keratocyst in the buccal space: characterization by multimodality imaging including computed tomography, diffusion-weighted magnetic resonance imaging, and ultrasonography.

Odontogenic keratocyst (OKC) is a relatively common non-inflammatory jaw lesion. OKC is known to occur most often in the mandibular angle and mandibular ramus, but rarely outside the bone. In this report, we describe characteristic multimodality imaging of OKC in the buccal space, especially diffusion-weighted MR imaging (DWI) with apparent diffusion coefficient (ADC) mapping, extra-oral and intra-oral ultrasonography. On clinical examination, an approximately 20 mm in diameter mass with elastic hardness was found the left side of the buccal area. Contrast-enhanced CT showed areas of internal non-contrast lesions in the left buccal space. On T1-weighted image, the mass showed multilocular high signal intensity, and homogeneous internal. T2-weighted images revealed high signal at the marginal part and slightly median signal in the internal part. STIR images revealed a heterogeneous high signal in the interior. Furthermore, DWI and ADC map showed high signal and moderate-to-low signal intensity, respectively. ADC value of the lesion was 1.55 × 10-3 mm2 s-1. On extra-oral ultrasonography, the tumor showed clear boundary, hypoechoic, homogeneous internal architecture and vascular signals, and heterogeneous hard of the lesion. On intra-oral ultrasonography also showed clear boundary, hypoechoic, homogeneous internal architecture, heterogeneous hard of the tumor, and back echo enhance. The histopathologic diagnosis based on a full excisional specimen was odontogenic keratocyst. This case suggests that multimodality imaging, especially MR imaging with ADC and DWI, and extra and intra-oral ultrasonography with color Doppler imaging and elastography, could be effective for evaluating buccal lesions.

[Surgical removal of an atypically large extensive radicular cyst in the mandible: a case report.] / Atypisch grosse radikuläre Zyste. Operative Entfernung einer atypisch grossen ausgedehnten radikulären Zyste im Unterkiefer, ein Fallbericht.

The radicular cyst is the most common odontogenic cyst and is caused by inflammation. It can become atypically large, although the size of the radiographic osteolysis says nothing about the entity of the lesion. This case shows an unusually large multilocular radicular cyst expanding buccally from tooth 46 in a patient with severe autism who can only be treated under general anesthesia. The clinical and radiological picture as well as the intraoperative situation was more indicative of an aggressive cyst or benign tumor. The lesion was surgically completely removed and the teeth 46, 47 and 48 were extracted because of poor compliance and prognosis. Histopathology revealed a radicular cyst. There were no postoperative complications. After eight months, the lesions had almost completely reossified.

[Nasal obstruction: Odontogenic cysts in 4 brachycephalic dogs]. / Nasale Obstruktion: Odontogene Zysten bei 4 brachyzephalen Hunden.

OBJECTIVE: Odontogenic cysts may be of developmental or inflammatory origin. They are frequently observed in brachycephalic dogs. Due to their expansive growth, cysts in the maxilla may extend into the nasal cavity, obstruct the nasal airway and cause nasal discharge. Epithelial cysts may lead to a comparable clinical picture. A new endonasal endoscopic intervention for the removal of these cysts is described. MATERIAL AND METHODS: Four brachycephalic dogs (Boxer, Chihuahua, French bulldog, Pug) with unilateral cysts obstructing the nasal cavity were included in the study. The animals underwent clinical examination, computed tomography (CT) imaging and rhinoscopy examination. Histopathologic evaluation of the cyst wall was performed. In addition to dental surgery and conventional extraction of the involved tooth, the cyst wall was removed by endoscopic intervention via the physiologic nasal opening. Clinical course following treatment was assessed by rhinoscopy and CT. RESULTS: The main clinical signs were unilateral or bilateral serous to hemorrhagic nasal discharge. Nasal airflow was restricted in all patients. Removal of the cysts and involved teeth did not lead to any intra- and postoperative complications. No recurrence of the cysts was observed. Histologic diagnosis consisted of an epidermoid cyst, a follicular cyst, a radicular cyst, and a canine odontogenic parakeratinized cyst (COPC). Neoplastic transformation was excluded in all cases. CONCLUSIONS: Removal of the cyst wall may be performed by means of minimally invasive endoscopic intervention via the physiologic nasal entrance. The procedure is curative and carries the risk of only few complications. In cases in which treatment is restricted to extraction of the affected tooth, the nasal airway may remain obstructed due to a calcified cyst wall. CLINICAL RELEVANCE: In brachycephalic dogs, oronasal defects due to dental pathology are the most common reason for chronic nasal discharge, whereas in normocephalic dogs nasal neoplasia are. Odontogenic cysts carry importance as differential diagnosis of nasal discharge.

Multiple odontogenic keratocysts in a patient with Lowe syndrome: a first case report and literature review.

Lowe syndrome (LS) is a rare disease (1:500,000) with X-linked recessive inheritance involving the kidneys, eyes, and nervous system. A Mexican 25-year-old male patient presented for diagnosis of multiple radiolucent lesions observed on routine radiographic examination. General aspects revealed cognitive delay, eye alterations, and kidney involvement, which support the diagnosis of LS. Radiolucent well-delimited lesions were observed in both mandibular angle and symphysis. Under general anesthesia, incisional biopsy and decompression were performed. Histological aspects led to diagnosing odontogenic keratocyst (OKC) for all lesions. The lesions in the right and left mandibular angles were decompressed, and the symphyseal lesion was enucleated. A 2-month follow-up shows the bone healing process. There are few reports detailing oral findings in LS. Here, we reported the first case of multiple OKC in a patient with LS. In addition, we performed a literature review on odontogenic lesions in patients affected by LS.

[Cone-beam CT imaging features of common cystic lesions associated with the impacted mandibular third molar].

Objective: To analyze the imaging features of cone-beam CT (CBCT) of ameloblastoma (AB), odontogenic keratocyst (OKC) and dentigerous cysts (DC) associated with the mandibular impacted third molars,so as to provide useful information for differential diagnosis of these lesions. Methods: The patients who were with complete clinical data, pathological diagnosis and CBCT images from AB, OKC and DC around the mandibular impacted third molars were collected in Peking University Hospital of Stomatology from August 2016 to December 2021. A total of 109 patients (14 were diagnosed as AB, 23 were diagnosed as OKC and the others were diagnosed as dental cysts) were collected, including 73 males and 36 females. The age ranged from 11 to 70. The analyzed imaging features included location and internal density of the lesions, bone expansion, root resorption of adjacent teeth and types of the impacted teeth. The Chi square test was used to compare the gender of different lesions, and the Fisher's exact test was used to compare imaging features of lesions. When P<0.05, there was a significant difference among the three. Logistic regression analysis was performed to determine the imaging features that significantly contribute to correct imaging diagnosis. Corresponding P-values were calculated for all factors from multivariate models. Results: In the 23 cases of OKC, no special location was observed for the center of the lesion, heterogeneous high-density were seen in 21.7% of the cases, 56.5% of the cases had no significant bone expansion and the impacted teeth were not specially oriented. Among the 14 AB, 7 cases (7/14) were mainly located in the ramus of the mandible, and all cases (14/14) had buccal/lingual expansion of the jaw, 8 cases (8/14) presented root resorption of the adjacent teeth, and mesial impacted mandibular third molar were seen in 6 cases (6/14). Among the 72 DC, 88.9% (64/72) of the cases were mainly limited to the crown of the impacted third molar, 72.2% (52/72) of the cases had no obvious bone expansion, inverted impacted teeth were shown in 56.9% (41/72) of the cases. There was a significant difference among the three groups (χ2=7.30, P=0.026) in gender. AB and odontogenic cyst were more common in men than in women, while the incidence of OKC was roughly equal between men and women.There were significant differences in the location (P<0.001), internal density (P=0.001) of the lesions, bone expansion (P<0.001) and types of the impacted teeth (P<0.001), while no statistical difference was found for root resorption of adjacent teeth (P=0.153). Logistics regression analysis showed that the location of the lesion, internal density, bone expansion, root resorption of adjacent teeth and the types of impacted teeth had significant effects on the accurate diagnosis of the three kinds of lesions. Conclusions: Location, internal density, bone expansion and types of the impacted teeth played an important role in the correct imaging diagnosis. Further analysis indicates that when the classification of impacted teeth and the location of lesions are considered synchronously, DC can be differentiated from AB and OKC.

Volumetric reduction in large cystic jaw lesions postoperative enucleation: a longitudinal clinical study.

BACKGROUND: Enucleation, a surgical procedure, is commonly used to treat large jaw cysts, unicystic ameloblastomas and keratocysts. However, it remains unclear to what extent the jaw bone regenerates after enucleation. We aimed to evaluate the percentage and the survival analysis of jaw bone regeneration, in terms of cavity volume residual (CVR), in patients who underwent enucleation of large jaw cysts, unicystic ameloblastomas and keratocysts. METHODS: We collected data longitudinally from 75 patients who underwent jaw cystic lesions enucleation at the Stomatological Hospital of Xi'an Jiaotong University, between January 2015 and June 2021. All patients had both preoperative and postoperative cone-beam computed tomography (CBCT) imaging data. CBCT images were analyzed using Image J. Changes in the CVR were assessed at various follow-up time points, and the Kaplan-Meier method was utilized to evaluate the CVR over time. RESULTS: The patients had a mean age of 31.7 years (range: 5.5-72 years) with 58.66% of them being male. The postoperative CVR was 32.20% at three months, 21.10% at six months, 15.90% at 12 months, and 5.60% at 24 months. The percentage of CVR during follow-up periods for the initial size Quartile (Q)1 (212.54-1569.60 mm3) was substantially lower than those of Q2 and Q3 at and after seven months of follow-up and became statistically significant at the 12-month mark. CONCLUSION: This study demonstrates that spontaneous bone regeneration can occur after enucleation of large jaw cysts, unicystic ameloblastomas and keratocysts, even without the use of filler materials. The initial size of the lesion had a significant impact on the outcome of cystic lesion enucleation over time. To minimize the risks associated with radiation exposure and expenses, we recommend reducing the frequency of CT imaging follow-ups for patients with small initial cavity sizes (ranging from 212.54 to 1569.60 mm3).

Nasopalatine Duct Cyst in a 31 Year-Old Male: Imaging Findings in Computed Tomography / Quiste del Canal Nasopalatino en un Hombre de 31 años: Hallazgos en Imágenes de Tomografía Computarizada

A 31-year-old man is presented and is evaluated by panoramic radiography. As a finding, an extensive lesion with a cystic appearance was detected in the anterior part of the maxilla. Computed tomography shows a lesion corresponding to the characteristics of a cyst. In the histology the combination of two types of epithelium is observed, pseudostratified columnar and stratified squamous, confirming that this was a nasopalatine duct cyst.

Se presenta el caso de un hombre de 31 años, evaluado mediante radiografía panorámica. Como hallazgo se detecta una extensa lesión de aspecto quístico en la parte anterior del maxilar. En la tomografía computada se observa una lesión que corresponde a las carácterísticas de un quiste. La histología muestra una combinación de dos tipos de epitelio, pseudostratificado columnar y estratificado escamoso, confirmando que se trataba de un quiste del canal nasopalatino.

Prevalence of odontogenic cysts in a group of Libyan population: A retrospective study.

Background: Odontogenic cysts (OCs) are commonly encountered lesions affecting the human jaws having special clinical and radiographic features depending on cyst type. The aim of this study was to determine the prevalence of odontogenic jaw cysts in a Libyan population in Benghazi and to compare these data with previously published reports from Libyan and other geographic areas. Materials and Methods: This is a descriptive study where screening of 2189 biopsies (retrieved from the archives of The Department of Oral Pathology/University of Benghazi, Libya) was performed for the sake of recognizing the three cysts chosen for the purpose of this study. Results: : Out of the screened lesions, 276 cases (12.6%) were diagnosed as odontogenic cysts in the period from 2006 to 2019. Of those, 67.39% were inflammatory and 32.61% were developmental in nature. Radicular cysts (60.5%) were the most frequent cysts followed by dentigerous cysts (14.8%) and keratocysts (14.5%). The mean ages of the patients were 32.3, 29.7, and 33.2 years, respectively. Occurrence of the cysts was noticed more in the maxilla than in the mandible (1.3:1). The overall male-to-female ratio was 1.1:1. Conclusions: The prevalence of odontogenic cysts was similar to that reported in a previous study in Libya and other countries irrespective to WHO (2017) classification of odontogenic cysts.