Diagnosing the most common odontogenic cystic and osseous lesions of the jaws for the practicing pathologist

CITED1 expression in odontogenic cysts

BACKGROUND

Originating from odontogenic tissue, Odontogenic cysts are pathological cavities lined with epithelial cells and surrounded by fibrous connective tissue. This study investigated expression of CITED1 protein in different types of odontogenic cysts.

MATERIAL AND METHOD

40 keratocysts, 40 radicular cysts, and 40 dentigerous cysts were excised and processed for routine paraffin wax embedding protocol. Macroscopic and panoramic radiographies images were used for diagnosis. Demographical properties and dental parameters were recorded. Cystic tissues were stained with hematoxylin-eosin dye and CITED1 antibody. Semi-quantitative analysis was performed for immune staining. The protein-protein interaction network, hub gene detection and KEGG analysis were conducted using Cytoscape software.

RESULT

Odontogenic keratocysts was imaged with 6-8 layered epithelial cells and fibrous cyst walls with inflammatory cells. Radicular cysts had stratified squamous epithelium with varying thickness, ciliated cells, and Rushton hyaline bodies. Dentigerous cysts presented hyperplastic non-keratinized epithelium, fibrous tissue, rete ridges, and inflammatory cells. CITED1 immunoexpression was highest in odontogenic keratocysts, followed by radicular cysts, and lowest in dentigerous cysts. Nuclear and cytoplasmic CITED1 expression was significantly elevated in odontogenic keratocysts compared to radicular and dentigerous cysts. The top five targets of CITED1 were identified, primarily showing enrichment in hormone and cancer related pathways.

CONCLUSIONS

Positive CITED1 expression in all three types of odontogenic cysts suggest a potential role for CITED1 in the pathogenesis of odontogenic cysts, particularly in keratocysts. Further investigations are needed to elucidate the exact mechanisms underlying the differential expression of CITED1 and its implications for the development and progression of odontogenic cysts.

Predictors of complications associated with unerupted maxillary canines: a cone beam computed tomography study

To detect predictive factors for the occurrence of complications associated with unerupted maxillary canines (C). A total of 83 cone beam computed tomograms (CBCT), made from November 1, 2021 to October 31, 2022, have met the inclusion criteria, whereby 110 unerupted C were detected. Independent variables were: gender, age, and C position. Outcome variables were detected complications: external root resorption (ERR) and dilaceration of adjacent tooth, ERR and dilaceration of C, dentigerous cyst, canine ankylosis, and adjacent teeth malposition. Chi-square test and logistic regression analysis were used to examine the relationship between income variables and detected complications. Vertical position of unerupted C showed as predictor for adjacent tooth dilacerations and malposition. Chance for dilaceration increases 5.5-fold with C position at the middle third of lateral incisor (LI) root, while chance of malposition increases 23.4-fold with its supra-apical position to the LI root, in comparison to the C position occlusal to the LI cemento-enamel junction. Age is a predictive factor for dentigerous cysts, with decreasing the chance of their occurrence 1.5-fold with each additional year of age. Early evaluation of the vertical position and timely treatment of C are decisive steps in preventing complications.

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.

Deep learning system for distinguishing between nasopalatine duct cysts and radicular cysts arising in the midline region of the anterior maxilla on panoramic radiographs

Purpose

The aims of this study were to create a deep learning model to distinguish between nasopalatine duct cysts (NDCs), radicular cysts, and no-lesions (normal) in the midline region of the anterior maxilla on panoramic radiographs and to compare its performance with that of dental residents.

Materials and Methods

One hundred patients with a confirmed diagnosis of NDC (53 men, 47 women; average age, 44.6±16.5 years), 100 with radicular cysts (49 men, 51 women; average age, 47.5±16.4 years), and 100 with normal groups (56 men, 44 women; average age, 34.4±14.6 years) were enrolled in this study. Cases were randomly assigned to the training datasets (80%) and the test dataset (20%). Then, 20% of the training data were randomly assigned as validation data. A learning model was created using a customized DetectNet built in Digits version 5.0 (NVIDIA, Santa Clara, USA). The performance of the deep learning system was assessed and compared with that of two dental residents.

Results

The performance of the deep learning system was superior to that of the dental residents except for the recall of radicular cysts. The areas under the curve (AUCs) for NDCs and radicular cysts in the deep learning system were significantly higher than those of the dental residents. The results for the dental residents revealed a significant difference in AUC between NDCs and normal groups.

Conclusion

This study showed superior performance in detecting NDCs and radicular cysts and in distinguishing between these lesions and normal groups.

Metamorphosis of Dentigerous cyst: A case Series with Insight into Molecular Profiling

The objective of this study was to review the clinical, radiologic, and histologic aspects of cases of dentigerous cysts metamorphosing into different entities along with comments on the molecular factors involved in the process. A series comprising 8 cases of dentigerous cysts was performed retrospectively along with a comprehensive literature review. Two cases of dentigerous cyst converting into mucous metaplasia were included, out of which one case was transformed into ameloblastoma after a year. The other two cases were reported as acanthomatous and unicystic ameloblastoma, whereas four transitioned to AOT. The complete review of cases and literature with molecular profiling concluded that the lining of dentigerous cysts has the potential for transforming into benign odontogenic tumors. Therefore, a careful clinical and histopathological examination is crucial for the correct diagnosis. Also, a thorough molecular understanding of the cystic lining is required.

Pediatric Oral Pathology: Odontogenic Cysts

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

Central Odontogenic Fibroma of the Mandible in a 9-year-old Child: A Case Report with 24-month Follow-up

Background

Central odontogenic fibroma (COF) is a rarely benign tumor with an incidence of only 0.1% among all odontogenic tumors, which commonly involve the mandible.

Case description

A 9-year-old child reported with asymptomatic bony expansion of the mandible, showing an unilocular radiolucency on an orthopantomogram. The tumor was managed surgically by enucleation, and the surgical stent was placed, which was later modified as a removable functional space maintainer. The patient was followed up for 24 months with the complete healing of periapical radiolucency and the eruption of displaced permanent tooth to the proper position.

Conclusion

This case report discusses the importance of the dentist in assessing and diagnosing COF, especially in the pediatric age group.

Differential expression of PEA3 in odontogenic cysts and tumors

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

The value of a specialized second-opinion pathological diagnosis for oral and maxillofacial lesions

OBJECTIVES

An error in the diagnosis of an oral or maxillofacial lesion could potentially be detrimental to a patient's prognosis and management. Major discrepancies between the initial and subsequent diagnoses of head and neck pathologies range from 7 to 53%. This study determined the rate of discrepancies found in the diagnoses of oral and maxillofacial lesions after a second opinion in Saudi Arabia.

METHODS

A retrospective single-center study was conducted by oral and maxillofacial pathology consultants to review all cases referred for a second opinion to the oral and maxillofacial pathology laboratory between January 2015 and December 2020. If the second-opinion diagnosis matched the original diagnosis, this was described as "agreement." If the second-opinion diagnosis did not match the original diagnosis but would not change the management or prognosis of a patient, this was classified as a "minor disagreement." If the second-opinion diagnosis resulted in the changing of a patient's management or prognosis, this was categorized as a "major disagreement." Chi-square test and Fisher's exact test were used to compare data between original and second-opinion diagnoses. A p-value of less than 0.05 was considered significant.

RESULTS

Of 138 cases, 59 (43%) had an initial diagnosis and a second-opinion diagnosis that were in major disagreement. The most common tumor for which there was a major disagreement was squamous cell carcinoma. No single factor influenced the occurrence of major disagreements.

CONCLUSIONS

Our evaluation reiterates the importance of obtaining a second opinion from a specialist in oral and maxillofacial pathology to improve the diagnostic accuracy for lesions. A formal system for this step, in addition to the obtaining of adequate clinical and radiographic information about a patient, is mandatory for the review of difficult cases.

Conservative management of dentigerous cyst in children: Report of two clinical cases

The dentigerous cyst is the second most common odontogenic. The prevalence rates ranging from 0.8% to 3.6% in the general population. It affects people especially at the second and third decade of life with a male predilection. It presents a preference for the mandibular region particularly for the second lower premolar. Surgical marsupialization or decompression are the most conservative treatment modalities as it prevents the risks of cyst removal as nerve injuries and preserves the unerupted tooth. Two clinical cases of two young patients presenting a dentigerous cyst involving impacted teeth, which were successfully treated by decompression will be reported in order to highlight the benefits and limits of cyst decompression as well as detailing its operating protocol and its instructions.

Prelacrimal Approach to Maxillary Sinus Pathology

Background

Access to the anterior, lateral, inferior, and inferomedial maxillary sinus has been a limitation of the middle meatal antrostomy. Expanded techniques such as the modified medial maxillectomy provide access to many of these areas but require remucosalization, and crusting can occur during the recovery phase. The prelacrimal approach (PLA) offers direct 0° endoscope access to these areas. Additionally, PLA can preserve the nasolacrimal duct and mucosal coverage.

Objectives

We describe the current surgical technique and outcomes of PLA patients.

Methods

Consecutive adult patients with pathology addressed by PLA to the maxillary sinus were assessed. The primary outcome was the restoration of the lateral wall, and the secondary outcomes were early (< 90 days) and late morbidity (> 90 days).

Results

Forty patients (52.8 ± 17 years, 62.5% female) were assessed. All patients had successful restoration of the lateral nasal wall (100% [95CI: 91.2%-100%]). The complications reported were primarily dysesthesia (early 10% and late 2.5%).

Conclusion

The PLA provides robust access to the anterior, lateral, inferior, and inferomedial maxilla. PLA offers rapid mucosal recovery while preserving the normal physiology and the lacrimal systems with low morbidity.

Clinical and pathomorphological aspects of odontogenic tumors

BACKGROUND

Odontogenic tumors (OTs) comprise a group of heterogeneous lesions ranging from hamartomatous or non-neoplastic tissue proliferation to benign or malignant neoplasms with metastatic potential. OTs are derived from epithelial, ectomesenchymal, and/or mesenchymal elements of tooth-forming ("odontogenic") tissues, which show variable clinical and histopathological features.

OBJECTIVE

Herein, the authors summarize the World Health Organization (WHO) 2022 classification of OTs and further highlight diagnostic tips and differential clues for the most common OTs.

CONCLUSION

OTs may not be commonly encountered in the daily practice of many pathologists. This makes their diagnosis challenging as there is little practice in understanding the features required for their classification. However, diagnosing the vast majority of these lesions is not difficult provided the following aspects are considered: 1) the general knowledge of tooth development; 2) a few key histological observations; 3) very basic knowledge of the clinical and especially the radiographic features with which they are associated.

Radiolucent Lesions of the Jaws: An Attempted Demonstration of the Use of Co-Word Analysis to List Main Similar Pathologies

(1) Background: Many radiolucent jaw lesions exist, and they often show a radiographic resemblance, rendering diagnosis a challenging act. Closely related lesions should be frequently mentioned together in the academic literature, which might be helpful for junior practitioners in determining their differential diagnosis. The usefulness of bibliometric analysis in this respect has yet to be demonstrated. (2) Methods: This study evaluated academic publications on radiolucent jaw lesions, as indexed by the Web of Science Core Collection database. The mentions of radiolucent jaw lesions were extracted from the complete bibliographic records of the publications, and co-word analyses were conducted with the aid of VOSviewer. (3) Results: Based on 1897 papers, visualization maps were synthesized to evaluate co-occurrences of the radiolucent jaw lesions. Ameloblastoma was frequently mentioned together with odontogenic keratocyst, dentigerous cyst, and radicular cyst. Osseous dysplasia was co-mentioned with osteomyelitis, ossifying fibroma, odontoma, fibrous dysplasia, and apical periodontitis. (4) Conclusions: The co-word analysis, a form of bibliometric analysis, could demonstrate a relatedness of radiolucent jaw lesions that could be considered at differential diagnosis.

Effect of deep transfer learning with a different kind of lesion on classification performance of pre-trained model: Verification with radiolucent lesions on panoramic radiographs

Purpose

The aim of this study was to clarify the influence of training with a different kind of lesion on the performance of a target model.

Materials and Methods

A total of 310 patients (211 men, 99 women; average age, 47.9±16.1 years) were selected and their panoramic images were used in this study. We created a source model using panoramic radiographs including mandibular radiolucent cyst-like lesions (radicular cyst, dentigerous cyst, odontogenic keratocyst, and ameloblastoma). The model was simulatively transferred and trained on images of Stafne's bone cavity. A learning model was created using a customized DetectNet built in the Digits version 5.0 (NVIDIA, Santa Clara, CA). Two machines (Machines A and B) with identical specifications were used to simulate transfer learning. A source model was created from the data consisting of ameloblastoma, odontogenic keratocyst, dentigerous cyst, and radicular cyst in Machine A. Thereafter, it was transferred to Machine B and trained on additional data of Stafne's bone cavity to create target models. To investigate the effect of the number of cases, we created several target models with different numbers of Stafne's bone cavity cases.

Results

When the Stafne's bone cavity data were added to the training, both the detection and classification performances for this pathology improved. Even for lesions other than Stafne's bone cavity, the detection sensitivities tended to increase with the increase in the number of Stafne's bone cavities.

Conclusion

This study showed that using different lesions for transfer learning improves the performance of the model.

Minimally Invasive Two-Staged Surgery in the Treatment of Large Cystic Lesions of the Jaw

Background: Cystic lesions of the jaw are commonly found in clinical practice. Large, expansive cysts raise challenges for the clinician from both diagnostic and surgical perspectives. The aim of our work is to present a combined, two-staged surgical approach in histologically confirmed non-aggressive cystic lesions of the jaw. Methods and Results: We report the case of an extensive mandibular cyst, associating a high risk of bone fracture, that is treated in the initial stage by cystic decompression through marsupialization with concomitant histological diagnostic confirmation, followed in the second stage by radical excision and mandibular reconstruction with titanium mesh, with the purpose of prevention for oro-cystic chronic fistula formation. Conclusions: Large odontogenic mandibular cysts imply a meticulously conducted assessment and treatment. Marsupialization should be taken into consideration for the treatment of large cystic lesions, followed by secondary enucleation, with minimal risks for the patient. The soft tissue healing process can be optimized with the use of titanium meshes, as an alternative for other reconstructive techniques, in the management of large cystic lesions.

Diagnostic Accuracy of Cystic Lesions Using a Pre-Programmed Low-Dose and Standard-Dose Dental Cone-Beam Computed Tomography Protocol: An Ex Vivo Comparison Study

Background: This study aimed to analyze the diagnostic reliability of radiographic assessment of cystic lesions using a pre-set, manufacturer-specific, low-dose mode compared to a standard-dose dental cone-beam computed tomography (CBCT) imaging protocol. Methods: Forty pig mandible models were prepared with cystic lesions and underwent both CBCT protocols on an Orthophos SL Unit (Dentsply-Sirona, Bensheim, Germany). Qualitative and quantitative analysis of CBCT data was performed by twelve investigators independently in SIDEXIS 4 (Dentsply-Sirona) using a trial-specific digital examination software tool. Thereby, the effect of the two dose types on overall detectability rate, the visibility on a scale of 1 (very low) to 10 (very high) and the difference between measured radiographic and actual lesion size was assessed. Results: Low-dose CBCT imaging showed no significant differences considering detectability (78.8% vs. 81.6%) and visibility (9.16 vs. 9.19) of cystic lesions compared to the standard protocol. Both imaging protocols performed very similarly in lesion size assessment, with an apparent underestimation of the actual size. Conclusion: Low-dose protocols providing confidential diagnostic evaluation with an improved benefit–risk ratio according to the ALADA principle could become a promising alternative as a primary diagnostic tool as well as for radiological follow-up in the treatment of cystic lesions.

Use of anterior ramus bone graft for mandibular reconstruction in elderly patients

In this study, we investigated the feasibility of using a geometrically designed anterior ramus graft to reconstruct lateral mandibular defects. This was achieved by assessing the anatomical dimensions of the mandibular ramus on computed-tomographies. The design sequence and application of the graft was also demonstrated using one of our cases. The following dimensions were measured; a and b - horizontal length from mid-ramus to the posterior and anterior ramus border respectively, c - longest length of the graft, Mp - width at the centre of the ramus, h - vertical length of the angle at its cross-section, w - horizontal length of the angle at its cross-section, x - cross-sectional area along the mandible angle. A total of 80 mandibular rami were examined. The mean length of a, b, c were 17.3 ± 1.8 mm, 15.9 ± 1.2 mm, 54.6 ± 3.8 mm, respectively. The mean width of Mp was 9.8 ± 1.1 mm. The mean cross section area of Eo-Md (x) was 326.7 ± 67.8 mm². The average length of h and w were 26.5 ± 3.2 and 15.6 ± 2.1 mm, respectively. The use of virtual surgical planning (VSP) to geometrically design the graft was also described. Together with VSP, the anterior ramus bone graft will allow for reconstruction of the mandible with greater surgical efficiency, reduced complexity and without the need for extra-oral bone harvest. This may be an useful alternative in situations where simpler reconstructive procedures are preferred.

The differences in mitochondrial function, mitochondrial dynamics, and cell death between odontogenic cysts/tumors and normal dental follicles

We aimed to compare mitochondrial function, mitochondrial dynamics, apoptosis, and necroptosis between odontogenic cysts/tumors, including radicular cysts, dentigerous cysts, ameloblastoma, vs. dental follicles as control. We demonstrated that mitochondrial dysregulation and imbalanced mitochondrial dynamics were observed in ameloblastoma. Apoptosis was increased in dentigerous cysts, and ameloblastoma, while necroptosis was suppressed in ameloblastoma. Necroptosis in radicular cysts was higher than that of control, suggesting that the inflammation-associated cell death occurred in radicular cysts. Our findings suggest ameloblastoma exhibited mitochondrial dysfunction, decreased mitochondrial fusion, and potential apoptosis. Therefore, alleviating mitochondrial dysregulation and apoptosis may be novel-targeted therapy for odontogenic cysts and tumors.

Ghost cell odontogenic carcinoma of the left maxilla

We report the case of a 25-year-old man with a maxillary ghost cell odontogenic carcinoma (GCOC). The patient presented to the maxillofacial and head and neck surgery clinic with a growing lump in the left maxilla. Initial workup with CT revealed a cystic lesion in the left upper jaw with associated bone erosion and an enhancing soft-tissue component. Enucleation showed a GCOC associated with a calcifying odontogenic cyst. After the diagnosis was obtained, the patient underwent widening of the first surgical resection. GCOCs are rare odontogenic neoplasms with unspecific clinical and imaging presentation, whose definitive characterisation is based on pathology. Current treatment approaches mainly involve surgical excision, but the prognosis is highly unpredictable due to intertumoral heterogeneity. As tumour recurrences occur in 73% of cases, radical surgery with negative margins is highly recommended. Therefore, it is essential to recognise this entity to offer patients adequate management.

Developmental Odontogenic Lesions Associated with the Crown of an Impacted Tooth: A Guide to the Distinct Histologic Features Required for Classification

Odontogenic cysts are categorized as inflammatory and developmental. Of the developmental odontogenic cysts, the dentigerous cyst is the most common and by definition is attached to the cervical region of an unerupted tooth. The cyst envelops the crown forming a sac. However, there are other developmental cysts, and rarely, odontogenic tumors, that can have a similar clinical and radiographic presentation as dentigerous cyst, including odontogenic keratocyst, orthokeratinized odontogenic cyst and ameloblastoma, unicystic type. Understanding the key histologic differences of these cysts will aid the pathologist to correctly diagnose these lesions, ensuring appropriate clinical management.

Assessment of Hounsfield unit in the differential diagnosis of odontogenic cysts

OBJECTIVES

The purpose of this study was to evaluate the usefulness of Hounsfield unit (HU) assessment with multislice-CT in the differentiation of radicular cysts (RCs), dentigerous cysts (DCs) and odontogenic keratocysts (OKCs).

METHODS

In total, 307 odontogenic cysts (RCs, DCs and OKCs) were included in this study. Cysts with lesion diameter <10 mm, cysts with artefacts affecting measurement of HU values, cysts involving infection and recurrent cysts were regarded as exclusion criteria. Images were acquired in three different types of CT scanners: Aquilion ONE, Discovery CT750 HD and SOMATOM Definition Flash. Differences in HU values among scanners and among types of odontogenic cysts were assessed using one-way analysis of variance; multiple comparisons were performed post hoc, using the Tukey-Kramer honestly significant difference test.

RESULTS

In total, 164 cysts were analysed in this study (64 RCs, 57 DCs and 43 OKCs). Regardless of the type of lesion, the Aquilion ONE scanner demonstrated a significant difference in HU value, compared with the Discovery CT750 HD scanner. Regardless of CT scanner model, HU values significantly differed between DCs and OKCs (p < 0.0001), as well as between OKCs and RCs (p < 0.0001).

CONCLUSIONS

HU values were found to vary among CT scanners and should always be associated with other lesion imaging features while interpreting and elaboration diagnostic hypothesis. Notably, the results suggested that OKCs might be able to be differentiated from DCs and RCs by using HU values.

Cell-block as ancillary tool for the diagnosis of cystic and cyst-like jaw lesions

BACKGROUND

The cell-block technique is a cytological diagnostic method that decreases cellular dispersion; however, its usefulness regarding intraosseous lesions is underexplored. Therefore, this study aimed to assess the diagnostic usefulness of cell-block for cystic and cyst-like jaw lesions.

METHODS

Individuals with cystic or cyst-like jaw lesions who underwent aspiration biopsy were considered eligible. Aspiration of luminal content was prepared and processed by the cell-block technique. Cytological evaluations were blindly performed by two trained PhD students (in a single evaluation) and one oral and maxillofacial pathologist (OMP). Cohen's kappa statistic was used to measure inter-rater agreement.

RESULTS

The sample was composed of 52 lesions, represented by 25 radicular cysts (RC), 17 odontogenic keratocysts (OKC), 5 idiopathic bone cavities (IBC), and 5 unicystic ameloblastomas (UA). The kappa coefficient of cell-block compared to histopathological diagnosis was 0.390 (95% confidence interval [95%CI], 0.195-0.585) for PhD students and 0.612 (95%CI, 0.433-0.791) for the OMP. The highest concordance rates between cell-block and histopathological diagnosis were observed for RC (PhD = 76.0%; OMP = 80.0%) and OKC (PhD = 58.8%; OMP = 76.5%). Conflicting results were found regarding IBC (PhD = 40.0%; OMP = 80.0%) and UA, that presented the overall lowest concordance rates (PhD = 20.0%; OMP = 40.0%).

CONCLUSION

The cell-block technique presented a high diagnostic usefulness for detecting RC and OKC and, if associated with clinical and radiographic characteristics, might be sufficient for final diagnosis of these diseases. Regarding IBC and UA, an analysis with a higher number of cases is recommended to determine the true usefulness of the cell-block as ancillary tool for the diagnosis of these lesions.

Periapical Cyst and Odontogenic Remnants on Osseous Mandibulectomy Margins: Two Diagnostic Pitfalls

In this article, we describe 2 high-stake diagnostic pitfalls that occurred in a single patient having undergone partial glossectomy and marginal mandibulectomy for invasive squamous cell carcinoma. Margins were grossly uninvolved. Histopathology showed a moderately differentiated squamous cell carcinoma. Microscopic evaluation of margins was challenging, as the inferior osseous margin submitted en face showed spongiotic epithelium with mixed chronic and acute inflammation, representing a periapical cyst after correlation with the gross examination. Another section of the osseous margin showed a small non-atypical epithelial nest, consistent with an odontogenic epithelial rest. We wish to raise awareness of these diagnostic pitfalls as a bone margin with such epithelial foci could be misinterpreted as positive, with serious therapeutic consequences.

Cyst volume changes measured with a 3D reconstruction after decompression of a mandibular dentigerous cyst with an impacted third molar

The aim of this article is to describe a large mandibular cyst treated with decompression followed by surgical enucleation. Furthermore, we described the utility of cyst volume measurements by using a 3D reconstruction on Cone Beam Computed Tomography (CBCT). The dentigerous cyst is the most common cyst type of epithelial origin, arising from remnants of odontogenic epithelium, asymptomatic and associated with the crown of an unerupted or partially or completely impacted tooth. However, after a long duration and extension of the cyst volume it may provoke significant bone resorption, cortical expansion, tooth displacement and the vitality of neighboring teeth may be affected. The regular treatment of this lesion is enucleation and extraction of the involved tooth. Marsupialization and decompression are proposed when the volume of the cyst is well developed to release the cystic pressure and allow the bone cavity to progressively decrease in volume with the gradual apposition of bone. This report presents a large dentigerous cyst related to impacted mandibular third molar of a 21-year-old male patient. The cyst was treated successfully by decompression and later by surgical enucleation with surgical extraction of the related molar. In conclusion, the combination of decompression and surgical approach showed on the three-dimensional CBCT investigation a significant correlation between the treatment and volume reduction of the cyst. The clinical case described allows us to observe bone formation after decompression and surgical enucleation was performed with less risk on vital anatomic elements.

Imaging of Benign Odontogenic Lesions

Numerous benign cysts or solid tumors may present in the jaws. These arise from tooth-forming tissues in the dental alveolus or from nonodontogenic tissues in the basal bone of the mandible and maxilla. Radiologists provide 2 deliverables to assist in diagnosis and management: (1) appropriately formatted images demonstrating the location and extent of the lesion and (2) interpretive reports highlighting specific radiologic findings and an impression providing a radiologic differential diagnosis. This article provides guidance on essential image protocols for planning treatments, a radiologic differential diagnostic algorithm based on location and pattern recognition, and a summary of the main features of benign odontogenic lesions.

Volumetric analysis of keratocystic odontogenic tumors and non-neoplastic jaw cysts - Comparison and its clinical relevance

The keratocystic odontogenic tumor (KCOT) is capable of causing vast osseous destruction. Histopathological examination is pivotal for diagnosis. The diagnostic process can sometimes be hindered by tissue inflammation of KCOTs with loss of defining criteria, resulting in misdiagnosis as an odontogenic jaw cyst. We discuss the possible merits of volumetric analysis when facing this particular diagnostic dilemma and for pathophysiological characterization of KCOTs. We included 114 patients, of whom 27 were histopathologically diagnosed with a KCOT and 87 with dentigerous (n = 41) and periapical cyst (n = 46). Semiautomatic segmentation and radiological analysis of preoperative cone beam computed tomography (CBCT) image data was carried out using ITK-SNAP. The mean volumetric extent of KCOTs is significantly higher compared to non-neoplastic odontogenic jaw cysts (p = 0.001). The mean volume and standard deviation for KCOTs and non-neoplastic odontogenic jaw cysts was 10381 mm³ ± 6410 and 5813 mm³ ± 4425, respectively. Volumetric analysis reveals that KCOTs significantly exceed the mean size of non-neoplastic odontogenic jaw cysts, adding an argument in favor of the neoplastic nature of KCOTs. In the case of difficult histopathological examination, lesions with a size exceeding a value of about 3000 mm³ could be considered for close clinico-radiologic follow-up.