Prevalence profile of odontogenic cysts and tumors on Brazilian sample after the reclassification of odontogenic keratocyst

Cysts of the jaws: A multicentre study

OBJECTIVES

To determine the relative frequency, demographic and pathologic profiles of patients diagnosed with cysts of the jaws.

MATERIALS AND METHODS

Biopsy records of the participating institutions from 2000 to 2020 were reviewed for lesions diagnosed in the cyst category. Demographic data, the location of the cysts and pathologic diagnoses were collected. Data were analyzed by appropriate statistics using IBM SPSS software version 28.0.

RESULTS

From 148,353 accessioned cases, 25,628 cases (17.28%) were diagnosed in the cyst category. Mean age of the patients ± SD = 42.62 ± 19.36 years. Paediatric patients (aged ≤ 16 years) accounted for 9.63%, while geriatric patients (aged ≥ 65) comprised 14.22% of all the patients. The male-to-female ratio was 1.27:1. The majority of the lesions were encountered in the mandible. The most prevalent cyst was radicular cyst followed by dentigerous cyst and odontogenic keratocyst. In the paediatric group, dentigerous cyst was the most prevalent, whereas in the geriatric group, radicular cyst was the most common.

CONCLUSIONS

In general, the results of this study are in accordance with previous studies. This study provides an invaluable database for clinicians when formulating clinical differential diagnoses as well as for pathologists in rendering the final diagnosis.

Frequency and Demographic Analysis of Odontogenic Tumors in Three Tertiary Institutions: An 11-Year Retrospective Study

Odontogenic tumors (OTs) are distinct conditions that develop in the jawbones, exhibiting diverse histopathological features and variable clinical behaviors. Unfortunately, the literature on this subject in Saudi Arabia remains sparse, indicating a pressing need for more comprehensive data concerning the frequency, demographics, treatment modalities, and outcomes of OTs.

OBJECTIVES

The study aims to evaluate the frequency, demographic features, treatment, and outcomes of OTs across three tertiary medical centers.

METHODS AND MATERIAL

OT cases were identified in King Abdulaziz Medical City (KAMC), King Fahad Medical City (KFMC), and Prince Sultan Military Medical City (PSMMC) from January 2010 to December 2021.

RESULTS

Ninety-two OT cases were identified from the anatomical pathology laboratories of three tertiary hospitals. KFMC contributed the highest number of cases (43.5%), followed by KAMC (30.4%) and PSMMC (26.1%). The median age of OT patients was 29 years (range: 5-83), with males representing more than half of the patients (56.5%). The mandible was the most frequent site of OT occurrence (72.5%), with ameloblastoma being the predominant OT (63.0%), followed by odontoma (19.5%). Among the treatment modalities, bone resection was employed the most (51.0%), followed by enucleation (25.6%). Notably, 11.5% of OT cases with available follow-up data exhibited recurrence, with ameloblastoma accounting for eight recurrent cases.

CONCLUSIONS

Although OTs are relatively common in the jaws, they are rare in anatomical pathology laboratories and the general population. This study contributes valuable insights into the epidemiology characteristics, treatment trends, and recurrence rates of OTs in Saudi Arabia.

Jaw Cysts: A Retrospective Study in a Turkish Subpopulation

Objectives: Cysts seen in the jaws may be odontogenic or non-odontogenic, depending on the tissue of origin. Although there are different methods to diagnose these lesions, histopathological examination of tissue biopsy of the lesion is accepted as the 'gold standard' in cases where the diagnosis is insufficient. Although there are different methods to diagnose these lesions, histopathological examination of tissue biopsy of the lesion is accepted as the 'gold standard' in cases where the diagnosis is insufficient. Materials and Methods: Pathology results of 436 patients who applied to Zonguldak Bülent Ecevit University Faculty of Dentistry, Oral and Maxillofacial Radiology Clinic between 2016-2021 for any reason and underwent biopsy were retrospectively scanned using digital archives. While classifying the cyst, the criteria published by the World Health Organization (WHO) in 2017 were taken into account. Obtained results were recorded for statistical analysis. SPSS 22.0 Software Package Program (SPSS 22.0 Software Package Program, Inc. Chicago, IL, USA) was used as statistical software in the study. Results: Of the 436 patients included in the study, 250 (57.3%) were male and 186 (42.7%) were female. The ages of the patients ranged between 7 and 82 years, and the mean age of the patients was 35.5±15.8. As a result of the findings, it was determined that the most common cysts were radicular cysts (53.7%). Radicular cysts were most commonly located in the posterior mandible and anterior maxilla anatomically. Conclusions: In addition to clinical and radiological examination, histopathological examination of biopsy samples taken from tissues is of great importance in the correct diagnosis and treatment planning of jaw cysts.

Effectiveness of different treatments for odontogenic keratocyst: a network meta-analysis

Odontogenic keratocysts (OKC) are benign but aggressive lesions. As there is a lack of well randomized clinical studies assessing the effectiveness of the different treatment options for OKC, a network meta-analysis (NMA) was performed to identify the best treatment option with the lowest recurrence rate. An electronic search was performed following the PRISMA guidelines to identify all clinical studies comparing treatment options against enucleation alone. The outcome variable was recurrence. The predictor variables were treatments. The eight included treatments were: enucleation with peripheral ostectomy/curettage (E + PO/curettage); enucleation with cryotherapy (E + CRYO); enucleation with/without PO followed by modified Carnoy's solution (E ± PO+MCS); enucleation with PO and with topical 5-fluorouracil (E + PO+5FU); enucleation with/without PO followed by original Carnoy's solution (E ± PO+CS); marsupialization alone (MARS); marsupialization followed by secondary enucleation with/without PO (MARS+2°E ± PO); and resection. The odds ratio was used to estimate the recurrence rate. A frequentist NMA was performed using Stata software. A total of 2989 patients in 40 studies were included. Both direct pairwise meta-analysis and NMA showed that E + 5FU+PO was significantly superior to E ± PO+MCS. However, no statistically significant difference was found between E ± PO+CS vs E + 5FU+PO, E ± PO+MCS, and resection, respectively (all very low quality evidence). The three most effective treatments in reducing the recurrence rate were E + PO+ 5FU (98.1%; very low quality evidence), resection (83.5%; very low quality evidence), and E ± PO+CS (63.8%; moderate quality evidence). The findings from this study suggest that CS remains the most effective fixative agent after enucleation and PO until proven otherwise. Additionally, 5FU appears to be an effective method with promising results that needs further research. Finally, the efficacy of MCS remains controversial; further in vivo and in vitro studies are required to determine new protocols. As this NMA included retrospective studies, the results should be interpreted with great caution (level of evidence: type III).

Expression of a Tumor Stem Cell Marker (Aldehyde Dehydrogenase 1-ALDH1) in Benign Epithelial Odontogenic Lesions

The morphological diversity and different biological behaviors of human lesions has been attributed to the presence of cells with stem cell (SC) characteristics. Among SC markers, ALDH1 has been used in studies investigating different neoplasms and high expression of this marker was associated with clinicopathological features and prognosis in some groups. The aim of this study was to analyze the presence and distribution of SCs based on the expression of ALDH1 in epithelial odontogenic cysts and tumors. The sample consisted of 80 cases (20 dentigerous cysts (DCs), 20 odontogenic keratocysts (OKCs), 20 ameloblastomas (AMs), and 20 adenomatoid odontogenic tumors (AOTs). An immunoreactivity score was obtained from the percentage of positive cells and intensity of immunostaining. A level of 5% (p < 0.05) was adopted for the statistical tests. Immunoexpression of ALDH1 was observed in cytoplasm and nucleus-cytoplasm. The median scores indicated significantly higher expression in OKCs and DCs compared to AMs (p < 0.0001) and AOTs (p < 0.0001). In the tumor stroma and cystic capsule, immunoreactivity was detected in all odontogenic cysts studied and in 85% and 90% of AMs and AOTs, respectively. The expression of ALDH1 suggests the presence of SCs in the odontogenic lesions studied. Epithelial immunoexpression was higher in odontogenic cysts than in odontogenic tumors.

Artificial intelligence in dentomaxillofacial radiology

Artificial intelligence (AI) has the potential to revolutionize healthcare and dentistry. Recently, there has been much interest in the development of AI applications. Dentomaxillofacial radiology (DMFR) is within the scope of these applications due to its compatibility with image processing methods. Classification and segmentation of teeth, automatic marking of anatomical structures and cephalometric analysis, determination of early dental diseases, gingival, periodontal diseases and evaluation of risk groups, diagnosis of certain diseases, such as; osteoporosis that can be detected in jaw radiographs are among studies conducted by using radiological images. Further research in the field of AI will make great contributions to DMFR. We aim to discuss most recent AI-based studies in the field of DMFR.

Epidemiological evaluation of jaw cysts according to the new WHO classification: a 30-year retrospective analysis

The aim of the present study was to analyze the epidemiology of maxillofacial odontogenic and non-odontogenic cysts diagnosed for 30 years in a Brazilian population. A retrospective descriptive cross-sectional study was performed. Biopsy records were obtained from the archives of a Brazilian referral center between 1989 and 2019. Data regarding age, gender, anatomical location, and histopathological diagnosis were collected and categorized. Further, a literature search for similar studies was performed. A total of 6.994 biopsy records were evaluated, but only 367 (5.24%) cases were classified as odontogenic cysts (OC) or non-odontogenic cysts (NOC). Among all cystic lesions, 341 cases (92.9%) were OC and 26 cases (7.1%) were NOC. These lesions were more common in females (n = 208 / 56.67%) and located mostly in the mandible (n = 195 / 53.1%). In patients with OC, the radicular cyst was the most frequent (n = 134 / 36.5%), followed by the dentigerous cyst (n = 101 / 27.5%) and the odontogenic keratocyst (n = 52 / 14.2%). Patients with NOC had a higher frequency of epidermoid cyst (n = 12 / 3.3%), oral lymphoepithelial cyst (n = 7 / 1.9%), and nasopalatine duct cyst (n = 4 / 1.1%). The OCs were more prevalent than NOCs, and inflammatory cysts were the most common among all the OCs.

Imaging of odontogenic keratocysts: a pictorial review

INTRODUCTION

The aim of the present article was to review and depict the main radiological features of odontogenic keratocysts, thus helping the differential diagnoses from other odontogenic cysts and neoplasms.

METHODS

A review of articles published between January 2000 and October 2020 using Medline and the MeSH Term "odontogenic keratocyst" in combination with the following terms 'imaging,' 'radiology,' 'panoramic radiograph,' and 'computed tomography,' was performed.

RESULTS

Radiographically, OKCs are well-defined unilocular or multilocular radiolucencies bounded by corticated margins. Most lesions are unilocular; instead, multilocular OKCs represent about the 30% of cases, mainly involving the posterior mandible. When, particularly in large lesions, OKCs display a multilocular presentation with adjacent satellite cysts (daughter cysts) a "soap-bubble appearance" can be recognized.

CONCLUSIONS

Panoramic radiograph and CT still play an important role in the diagnosis and treatment planning of OKCs. Unfortunately, it may not be easy to differentiate OKCs from other odontogenic lesions, especially when they are small and unilocular. Histopathological findings are still necessary to obtain a definitive diagnosis.

The epidemiology and management of odontogenic keratocysts (OKCs): A European multicenter study

The objective of the present study was to assess the epidemiology including demographic variables, diagnostic features, and the management of odontogenic keratocyst (OKCs) at several European departments of maxillofacial and oral surgery. This study is based on a systematic computer-assisted database that allowed the recording of data from treated OKCs. The following data were recorded for each patient: gender, age, voluptuary habits, comorbidities, site, size, radiographic features, treatment of OKCs, length of hospital stay, complications, recurrence, management and complications of eventual recurrence. A total of 405 patients, 249 male and 156 female, with 415 OKCs (407 sporadic and 8 syndromic lesions) were included in the study: 320 lesions were found in the mandible, whereas 95 were found in the maxilla. In the mandible, the most frequently involved subsite was the angle, whereas in the maxilla it was the molar region. The most frequently performed treatment option was enucleation plus curettage/peripheral ostectomy in 204 OKCs (recurrence rate, 9%). Decompression without residual cystectomy (recurrence rate, 66%), marsupialization with residual enucleation with the use of Carnoy's solution (recurrence rate, 50%), decompression with residual cystectomy (recurrence rate, 43%), and simple enucleation (recurrence rate, 24%) were the treatment options with the highest recurrence rates. An appropriate management of odontogenic keratocysts should be individualized, taking into consideration clinical and radiological findings, as well as patients' age and comorbidities.

A Retrospective Study to Evaluate Biopsies of Oral and Maxillofacial Lesions

Background:

The clinical manifestations of these lesions comprises pain, paresthesia, swelling, drainage, tooth loss, root resorption, and facial deformity. Alteration in oral and maxillofacial (OMF) tissues of the lesions may cause esthetically and functionally unfavourable effects in patients.

Aims and Objectives:

To determine the frequency of odontogenic cysts, tumors, and other lesions.

Materials and Methods:

Patient's records of histopathological reports from the archives of the Department of Oral and Maxillofacial Pathology were obtained and reviewed over a period of 2 years, and therefore, the lesions were classified into four groups. In cases of recurrent lesions, only the primary diagnosis was considered. The research protocol was approved by the ethical committee of the institution.

Results:

About 56.4% of males had ameloblastoma, 54.9% of females had cementoma. 59.4% females had giant cell granuloma, 87.5% females had pyogenic granuloma, 77.2% females had osteoma, 65.1% of the female population were belongs to the benign fibro-osseous lesions and 50.2% of females were from fibrous dysplasia in group 3. About 58.8% females had squamous cell carcinoma in group 4.

Conclusion:

To adequately determine the prevalence and incidence rate of OMF lesions, biopsies performed by other specialists such as otolaryngologists and plastic surgeons in OMF regions should also be evaluated.

An observational retrospective study of odontogenic cyst´s and tumours over an 18-year period in a Portuguese population according to the new WHO Head and Neck Tumour classification

Background

Odontogenic cysts and tumours of the jaws represent one of the most prevalent groups of oral-maxillofacial lesions. We aimed to evaluate the clinical and pathological characteristics of a cohort of odontogenic cysts (OC) and odontogenic tumours (OT) of the jaws in a Portuguese population.

Material and Methods

This observational retrospective study analysed patients diagnosed with either an OC or OT of the jaws at a central hospital of Oporto, Portugal, between 1988 and 2006. Data collected from patients’ files included demographic, clinical, radiological and histopathological information. Recurrence was evaluated using univariate and multivariate analysis.

Results

The sample consisted of 397 patients, 231 males (58.2%) and 166 females (41.8%), with a mean-age of 36.7±17 years. Twenty-seven patients (6.8%) presented with more than one lesion providing a total of 433 lesions. There were 396 (91.5%) OC, mostly represented by radicular cysts (n=257;59.4%), dentigerous cysts (n=79;18.2%), or odontogenic keratocysts (n=50;11.5%). There were 37 (8.5%) OT, mostly represented by ameloblastomas (n=16;3.7%), and odontomas (n=9;2.1%). The most common initial clinical manifestation was swelling (n=224;51.7%). Recurrence was observed in 30 cases (6.9%), mostly in ameloblastomas (n=6;37.5%) and odontogenic keratocysts (n=12;24%). In the multivariate analysis the diagnosis classification of the lesion was the only independent and significant variable related with the recurrence (P=0.04).

Conclusions

Radicular cysts were the most commonly occurring type of OC and ameloblastomas the most commonly occurring OT. Amelobastomas and odontogenic keratocysts were the lesions with the highest rates of recurrence. This large sample provides useful information about the frequency profile and characteristics of OC and OT over a period of 18 years, allowing valuable comparison with data from other countries.

Key words:Odontogenic cysts and tumours, radicular cyst, dentigerous cyst, odontogenic keratocyst, ameloblastoma, recurrence.

Ghost cell odontogenic carcinoma: A case report

Ghost cell odontogenic carcinoma (GCOC) is a rare malignant neoplasm characterized by the presence of ghostcells. It is considered to originate from either a calcifying odontogenic cyst (COC) or a dentinogenic ghost cell tumor(DGCT). Its clinical and radiographic characteristics are non-specific, including slow growth, locally aggressivebehavior, and eventual metastasis. This case report describes a 43-year-old Thai man with plain radiographs and cone-beam computed tomographic images revealing a unilocular radiolucency with non-corticated borders surrounding an impacted left canine associated with radiopaque foci around the cusp tip. Based on the microscopic findings, the lesion was diagnosed as GCOC. Partial maxillectomy of the right maxilla was performed, and radiotherapy was administered. An obturator was made to support masticatory functions Three years later, the lesion showed complete boneremodeling and no signs of recurrence, and long-term follow-up was done regularly.

Impact of changing classification systems on prevalence and frequency distribution of odontogenic tumors in tertiary care center of Nagpur

INTRODUCTION

The classification of odontogenic tumors has been revised from time to time in order to provide unified terminology. This reclassification had considerable impact on their prevalence and frequency distribution.

OBJECTIVES

This study was aimed to emphasize impact of changing classification systems on prevalence and relative frequency of odontogenic tumors. The secondary objective was to analyze demographics of various histological types of odontogenic tumors in comparison to published literature. Review of Indian studies (1992-2020) elaborating frequency of odontogenic tumors is summarized in the end.

METHODS

This was a hospital-based retrospective study wherein case files of odontogenic tumors diagnosed from 1990 to 2019 period were retrieved. The classification system used originally at the time of diagnosis was retained and prevalence of odontogenic tumors in three different periods (1990-2004, 2005-2016 and 2017-2019) was compared. Further, prevalence, frequency distribution and demographics of all these tumors (1990-2019) were analyzed using latest World Health Organization 2017 classification.

RESULTS

A total of 345 odontogenic tumors was diagnosed as per World Health Organization 2017 system of classification from 1990 to 2019. 96.81% tumors were benign and 3.81% constituted malignant odontogenic tumors. However, there was marked increase in prevalence of odontogenic tumors in 2005-2016 (6.2%) period as compared to 1990-2004 (3.87%) and 2017-2019 (3.47%). Ameloblastoma remained the most common tumor in three different periods, whereas keratocystic odontogenic tumor became second commonest tumor in 2005-2016 as compared to odontoma in 1990-2004 and adenomatoid odontogenic tumor in 2017-2019.

CONCLUSIONS

The continuous evolving systems of classification may partly be responsible for inconsistency in odontogenic tumors, with inclusion of keratocystic odontogenic tumor,and has marked impact on prevalence and frequency distribution of odontogenic tumors. The geographical variations in demographics of odontogenic tumors might reflect genetic and environment influence; however it requires elucidation by further studies.

New World Health Organization classification of odontogenic tumours: impact on the prevalence of odontogenic tumours and analysis of 1231 cases from Turkey

The aims of this study were to describe the frequency of odontogenic tumours (OT) based on the World Health Organization (WHO) 4^th edition of Head and Neck Tumours in Turkey, to compare the results with other regions and to assess the frequency changes of OT worldwide after the new WHO classification. OT were selected from the pathology department's files between 1971-2018. In a total of 1231 OT, 1215 (98.7%) were benign, whereas malignant OT were only 16 cases (1.3%). The three most common tumours were ameloblastoma (n=366, 29.7%), odontoma (n=335, 27.2% both complex and compound types), and odontogenic myxoma (n=190, 15.4%), respectively. After the 2017 classification, the decrease of OT frequency was found among 20%-42% in the selected epidemiological series because of re-classification of some lesions. The pattern of incidence in the Turkish population is similar to that in other populations. However, there are some differences in the frequency of the tumour types. It is obvious that the relative frequency of odontogenic tumours worldwide will change based on the new classification. It should be kept in mind that this is not a real decrease of OT cases. These marked changes in the frequency and prevalence of OT is just related to reclassification of some entities.

Evaluation of biopsies of oral and maxillofacial lesions: a retrospective study

Objectives

This study aimed to determine the prevalence of odontogenic cysts, tumors, and other lesions among reports in the archives of the Department of Oral and Maxillofacial Surgery at the Faculty of Dentistry affiliated with Kocaeli University collected over a four-year period.

Materials and Methods

In this retrospective study, patient records from the archive of the Department of Oral and Maxillofacial Surgery from 2014 to 2018 were reviewed. Patient demographic information (age and sex) and lesion location were recorded and analyzed.

Results

From a total of 475 files reviewed, odontogenic cyst was confirmed in 340 cases (71.6%), and odontogenic tumor was confirmed in 52 cases (10.9%). Regarding odontogenic cyst type, the most common was radicular cyst (216 cases), followed by dentigerous cyst (77 cases) and odontogenic keratocyst (23 cases). Among odontogenic tumors, the most frequent was odontoma (19 cases), followed by ossifying fibroma (18 cases) and ameloblastoma (9 cases). Giant cell granuloma was also reported in 35 cases.

Conclusion

The distribution pattern of odontogenic cysts and tumors in our retrospective study is relatively similar to that reported in the literature. Complete clinical reports for final diagnosis of these lesions and routine follow-up examinations are very important for treatment.

New WHO odontogenic tumor classification: impact on prevalence in a population

Objectives:

This study approaches the history of reclassifications and redefinitions around the odontogenic keratocyst (OK), as proposed by the World Health Organization (WHO), and aims to understand the impact of those changes on the prevalence and epidemiology of odontogenic tumors (OTs).

Methodology:

Cases of OTs diagnosed in an Oral Pathology service between January 1996 and December 2016 were reviewed. Demographic data of patients such as age, gender and site of lesions were retrieved from their respective records.

Results:

Within the studied period, 7,805 microscopic reports were elaborated and 200 (2.56%) of these were diagnosed as OTs. Out of these 200, between 1996 and 2005, prior to the 2005 WHO classification, there were 41 (20.5%) OTs cases, being odontoma the most frequent (23; 56.09%), followed by ameloblastoma (8; 19.51%) and myxoma (03; 7.31%). Between 2006 and 2016, after the previous 2005 WHO classification there were 159 (79.5%) OTs, being odontogenic keratocystic tumor (KCOT) the most frequent (68; 42.76%), followed by odontoma (39; 24.52%) and ameloblastoma (21; 13.20%).

Conclusions:

As of today, the most recent WHO classification to be followed brings KCOT back to the cyst category, which will impact on the prevalence and epidemiology of OTs; thus, this study was able to identify a considerable increase (287.80%) in the prevalence of OTs when the 2005 WHO classification was utilized. Despite being an important academic exercise, classifying odontogenic lesions and determining whether to place the odontogenic keratocyst in a cyst or tumor category is crucial to establish the correct diagnosis and treatment to follow, whether by oral medicine or oral surgery specialist, or by the general practitioner.

The presentation of odontogenic keratocysts in the jaws with an emphasis on the tooth-bearing area: a systematic review and meta-analysis

PURPOSE

This study was conducted in order to gain insight in the actual ratio of odontogenic keratocysts occurring in the tooth-bearing area as compared to the posterior region of the jaws in order to come up with reliable data to base upon a rational treatment policy.

METHODS

We searched MEDLINE, Web of Science, Scopus, and Cochrane databases for studies reporting on the location of mandibular and maxillary odontogenic keratocysts. All records were independently assessed and a meta-analysis was performed. Risk difference with a confidence interval of 95% of having the lesion in the posterior region versus the tooth-bearing area was the effect measure. P value for the summary effect of < 0.05 was considered statistically significant.

RESULTS

The 2615 records retrieved were reduced to 34 studies to be qualitatively/quantitatively assessed. The pooled values showed that the difference in the clinical risk of having keratocysts in the posterior region of the mandible and in the tooth-bearing area of the maxilla is 21 and 43%, respectively (P < 0.02 and P < 0.00001).

CONCLUSIONS

A substantial amount of keratocysts occur in the tooth-bearing area of the jaws, requiring attention.

Demographic and Clinical Characteristics of 5294 Jaw Cysts: A Retrospective Study of 38 Years

The aim of the present study is to report the demographic and clinical characteristics of all jaw cysts diagnosed in a single Oral Pathology Department. 5294 cases of jaw cysts diagnosed during a 38-year period were retrospectively collected and classified according to the latest classification of Head and Neck Tumors of the World Health Organization. The patients' gender and age, as well as the main clinical features of the cysts were retrieved from biopsy report forms. Jaw cysts were more common in male patients, with a male to female ratio of 1.6:1. Most patients were in the 4th-6th decade of life, with a mean age of 42.3 ± 16.1 years. There was no jaw predilection and the majority of lesions were more commonly encountered in the anterior region of the maxilla, followed by the molar region of the mandible. The most common jaw cyst was radicular cyst followed by dentigerous cyst, residual cyst and odontogenic keratocyst. The majority of jaw cysts are of inflammatory origin and represent a sequale of pulp necrosis. However, other type of jaw cysts may also be found.

Clinicopathological analysis of odontogenic tumors over 22 years period: Experience of a single center in northeastern Brazil

Background

Odontogenic tumors (OTs) are uncommon neoplastic lesions of the maxilla and mandible, which present difficult diagnosis and therapeutics. This paper aims to determine the frequency and distribution of OTs, over a period of 22 years, at a public university in Northeastern Brazil.

Material and Methods

We reviewed all cases of OTs from oral pathology laboratory of Federal University of Rio Grande do Norte (UFRN), from 1996 to 2017. The tumors were classified according to the latest (2017) World Health Organization Classification of Tumors. Data on age, gender, anatomic site, symptomatology, radiographic findings and tumor size were analyzed.

Results

In the analyzed period, 247 cases of OTs were diagnosed. Epithelial tumors were more common with 127 cases (51.8%). The most common tumors were ameloblastoma (n = 112 / 45.4%), odontoma (n = 89 / 36.1%) and odontogenic myxoma (n = 17 / 6.9%). Malignant odontogenic tumors were extremely rare in the studied population with only 2 cases (0.8%) of diagnosed carcinomas. These tumors were diagnosed in a wide age range, from 5 to 81 years, being more common in the second and third decades of life. In general, the mandible was the most affected anatomic site (n = 162/66%) and the mandible:maxilla ratio was of 2:1. Ameloblastoma was the tumor with the highest number of symptomatic cases (n = 26) and with the highest mean size (cm) with 4.5cm.

Conclusions

Odontogenic tumors were rare in the sample studied (2.2%), with ameloblastoma and odontoma being the most common tumors. Continuous studies that show the characteristics of these lesions are fundamental, especially after modifications in the international classification.

Key words:Odontogenic tumors, jaw neoplasms, epidemiology, oral pathology.

Application of Convolutional Neural Network in the Diagnosis of Jaw Tumors

Objectives

Ameloblastomas and keratocystic odontogenic tumors (KCOTs) are important odontogenic tumors of the jaw. While their radiological findings are similar, the behaviors of these two types of tumors are different. Precise preoperative diagnosis of these tumors can help oral and maxillofacial surgeons plan appropriate treatment. In this study, we created a convolutional neural network (CNN) for the detection of ameloblastomas and KCOTs.

Methods

Five hundred digital panoramic images of ameloblastomas and KCOTs were retrospectively collected from a hospital information system, whose patient information could not be identified, and preprocessed by inverse logarithm and histogram equalization. To overcome the imbalance of data entry, we focused our study on 2 tumors with equal distributions of input data. We implemented a transfer learning strategy to overcome the problem of limited patient data. Transfer learning used a 16-layer CNN (VGG-16) of the large sample dataset and was refined with our secondary training dataset comprising 400 images. A separate test dataset comprising 100 images was evaluated to compare the performance of CNN with diagnosis results produced by oral and maxillofacial specialists.

Results

The sensitivity, specificity, accuracy, and diagnostic time were 81.8%, 83.3%, 83.0%, and 38 seconds, respectively, for the CNN. These values for the oral and maxillofacial specialist were 81.1%, 83.2%, 82.9%, and 23.1 minutes, respectively.

Conclusions

Ameloblastomas and KCOTs could be detected based on digital panoramic radiographic images using CNN with accuracy comparable to that of manual diagnosis by oral maxillofacial specialists. These results demonstrate that CNN may aid in screening for ameloblastomas and KCOTs in a substantially shorter time.

Calcifying odontogenic cyst, dentinogenic ghost cell tumor, and ghost cell odontogenic carcinoma: A systematic review

BACKGROUND

The aim of this study was to integrate the available data published on calcifying odontogenic cyst (COC), dentinogenic ghost cell tumor (DGCT), and ghost cell odontogenic carcinomas (GCOCs) into a comprehensive analysis of their clinicoradiological features, treatment, and recurrence.

MATERIALS AND METHODS

An electronic search with no publication date restriction was undertaken in October 2017 in the following databases: PubMed, Medline Ovid, Web of Science, and Scopus. Eligibility criteria included publications containing enough clinical, radiological, and histopathological information to confirm a definite diagnosis of these lesions. Data were evaluated descriptively.

RESULTS

The literature review indicated a total of 234 publications reporting 367 COCs, 55 DGCTs and 44 GCOCs. These lesions have a predilection for Asian males. COCs mainly affect the mandible and patients in the second decade of life, DGCTs mostly affect the mandible and patients in the fourth decade of life, and GCOCs mostly affect the maxilla and patients in the fifth decade of life.

CONCLUSION

Conservative surgery was the most common therapy for COCs and DGCTs, while radical surgery was most common for GCOCs. This study provides important and interesting data that could help clinicians and surgeons as well as oral and maxillofacial pathologists with the diagnosis and management of these lesions.