Recurrence of odontogenic keratocysts and possible prognostic factors: Review of 455 patients

Development of Automated Risk Stratification for Sporadic Odontogenic Keratocyst Whole Slide Images with an Attention-Based Image Sequence Analyzer

(1) Background: The categorization of recurrent and non-recurrent odontogenic keratocyst is complex and challenging for both clinicians and pathologists. What sets this cyst apart is its aggressive nature and high likelihood of recurrence. Despite identifying various predictive clinical/radiological/histopathological parameters, clinicians still face difficulties in therapeutic management due to its inherent aggressive nature. This research aims to build a pipeline system that accurately detects recurring and non-recurring OKC. (2) Objective: To automate the risk stratification of OKCs as recurring or non-recurring based on whole slide images (WSIs) using an attention-based image sequence analyzer (ABISA). (3) Materials and methods: The presented architecture combines transformer-based self-attention mechanisms with sequential modeling using LSTM (long short-term memory) to predict the class label. This architecture leverages self-attention to capture spatial dependencies in image patches and LSTM to capture sequential dependencies across patches or frames, making it suitable for this image analysis. These two powerful combinations were integrated and applied on a custom dataset of 48 labeled WSIs (508 tiled images) generated from the highest zoom level WSI. (4) Results: The proposed ABISA algorithm attained 0.98, 1.0, and 0.98 testing accuracy, recall, and area under the curve, respectively, whereas VGG16, VGG19, and Inception V3, standard vision transformer attained testing accuracies of 0.80, 0.73, 0.82, 0.91, respectively. ABISA used 58% fewer trainable parameters than the standard vision transformer. (5) Conclusions: The proposed novel ABISA algorithm was integrated into a risk stratification pipeline to automate the detection of recurring OKC significantly faster, thus allowing the pathologist to define risk stratification faster.

Odontogenic Keratocysts: Presentation and Surgical Outcome in a Sample of Sudanese Patients

Background

Odontogenic keratocyst (OKC) is a benign intraosseous lesion relatively frequent in the oral cavity. It has a locally aggressive behavior and exhibits a high propensity to recur after treatment. The present study aimed to investigate the clinicoradiographic presentations and outcomes of surgical treatment of OKC at Khartoum Teaching Dental Hospital. Material and Methods. Fifty-five cases of OKC files at the Department of Oral and Maxillofacial Surgery in Khartoum Teaching Hospital between 2012 and 2022 were reviewed and studied using a descriptive prospective cross-sectional study. Data were analyzed using Statistical Package for the Social Sciences (SPSS) version 27.

Results

Out of 55 cases studied, the mean age at the time of diagnosis was 30 ± 17.6 years; of them, 28 (50.9%) were males and 27 (49.1%) were females. The most common clinical manifestation was swelling (34.9%), followed by pain (28.0%). Sixty-five percent of the OKCs were located in the posterior mandible, and multilocular radiolucency (73.6%) was the most prevalent radiological finding. Enucleation with Carnoy's solution (CS) (55.2%) was the most common surgical modality that was used in more than half the patients, and only six patients had a recurrence. Marsupialization and segmental resection had no recurrence, while marginal resection and curettage had the highest recurrence rate of 20%. Patients with consanguineous parents had a higher recurrence rate (15%) compared with patients who had nonconsanguineous parents (8.6%). None of the patients died or had a malignant transformation.

Conclusion

The most common location for the cyst was the mandible, and multilocular radiolucency was the most prevalent radiological finding. Enucleation with CS was the most commonly used surgical modality, used in more than half of the patients, with only six patients experiencing recurrence.

An Insight Into the Effect of Odontogenic Keratocysts on Surrounding Structures: Cone-Beam Computed Tomography-Based Analysis of Cases

Introduction  An odontogenic keratocyst (OKC) is a benign intraosseous lesion with potential to demonstrate aggressive and invasive behavior. The aim of this retrospective study was to analyze the imaging features of the OKC using cone-beam computed tomography (CBCT) and to evaluate the association between the internal structure of the lesion and the effect of the lesion on surrounding structures. Methods Overall, 32 CBCT scans of histopathologically diagnosed cases of OKC were analyzed retrospectively. The following variables were analyzed: anatomic location of the lesions (mandible body (right/left), ramus (right/left), mandible body+ramus (right/left), maxilla (right/left), and both jaws), the internal structure of the lesion (unilocular/multilocular), and the effect of the lesion on the surrounding anatomical structures (involvement of the inferior alveolar nerve canal (IANC), displacement of the IANC, cortical expansion, displacement of the tooth, resorption of the root, associated impacted tooth, associated missing tooth). We also looked for the association between the internal structure and the effect of the lesion on anatomic structures. Results Out of 32 cases, 29 (90.6%) cases involved the mandible alone. Statistically significant association (p-value 0.005) was present between the internal structure and mean age of presentation as well as between the internal structure and impacted tooth (p-value 0.027). The association between the internal structure and other variables was statistically not significant. Conclusions The radiographic features of OKCs can be variable, and these lesions have a considerable effect on the tooth, IANC, and cortical bone. Significant association was found between the internal structure, age, and impacted tooth. Since OKCs have a high recurrence rate, CBCT is advised for evaluating the extent and location of any cortical perforations.

Clinical indications for radical resection of odontogenic keratocyst: A systematic review

The aim of this study was to identify clinico pathological indications for radical resection of odontogenic keratocysts (OKCs) in the literature and formulate clinical guidelines for the management of OKCs based on these findings. A systematic review of the literature was undertaken in September 2021 in PubMed/Medline, Scopus, Web of Science, Google Scholar, and Cochrane databases. The following MeSH Keywords terms were used in the search strategies: (odontogenic keratocyst) OR (keratocystic odontogenic tumor) OR (primordial cyst) AND (treatment) OR (Radical resection) OR (Resection of OKC) OR (Treatment methods). Eligibility criteria included publications of clinical studies on histologically confirmed OKCs which underwent radical resection. Studies with less than 5 OKCs, experimental studies, epidemiological studies, studies that included orthokeratinized odontogenic cyst, and review papers were excluded. Ten studies on OKCs reporting on segmental or marginal resections were identified and analyzed qualitatively. Of the total of 221 OKCs that underwent radical resection, 67 OKCs were primary, 30 were recurrent, and the remaining were unclear whether they were primary or recurrent. Segmental mandibulectomy was performed in 131 OKCs, marginal mandibulectomy in 87 OKCs, and 3 OKCs were treated by partial maxillectomy. The main indications for radical resection were multilocular appearance, large OKCs (> 5 cm), multiple recurrent OKCs with or without cortical perforation, and malignant transformation. In conclusion, radical resection has its place in the management of OKC. It is indicated when there is an aggressive lesion with bony perforation, involvement of the pterygoid musculature or skull base, and malignant transformation. The surgeon should aim to identify these features to manage OKC appropriately and to prevent multiple recurrences. Clinical guidelines for the management of OKCs are proposed.

Evaluating histopathological factors of predicting the recurrence rate of odontogenic keratocyst

Background

Odontogenic keratocyst (OKC) is one of the most common jaw cysts with high recurrence rate. Some possible factors affecting recurrence that have not been evaluated in previous studies are examined in this study. This study aimed to predict the recurrence rate of OKC and more viable treatment of OKC.

Materials and Methods

In this descriptive, analytical, and cross-sectional study, 10 recurrent OKCs, which both slides before and after recurrence were accessible, were collected from oral and maxillofacial pathology department's archive. First, they were evaluated based on common histopathologic features. In the second phase, the frequency of these findings in 36 OKCs (24 samples with recurrence and 12 without recurrence after 5 years) was evaluated based on clinical, radiological, and histopathologic features. Data were analyzed by SPSS, Wilcoxon signed-rank test, McNamara, t-test, Chi-square, Mann-Whitney, Fisher's exact test, Cohen's kappa coefficient, and odds ratio (P < 0/05).

Results

According to this study, OKC in women, with multilocular radiolucency and mitosis in basal layer of epithelium as well as diffused inflammation, were statistically associated with probability of recurrence (P = 0.05, 0.035, 0.033, and 0.045, respectively). The corrugated surface, reverse polarity, hypercellularity in parabasal, and satellite cysts can affect the recurrence of OKC with odds ratios = 2.364, 2.364, 1.190, and 1.500, respectively).

Conclusion

Gender (women), multilocular radiolucency, diffused inflammation in stroma, and mitosis in basal layer of epithelial lining, can statically predict the possibility of recurrence rate. In addition, findings regarding the age (in younger patients), corrugated surface, reverse polarity, and sub-basal cleft can be helpful in predicting recurrence.

Ensemble Deep-Learning-Based Prognostic and Prediction for Recurrence of Sporadic Odontogenic Keratocysts on Hematoxylin and Eosin Stained Pathological Images of Incisional Biopsies

(1) Background: Odontogenic keratocysts (OKCs) are enigmatic developmental cysts that deserve special attention due to their heterogeneous appearance in histopathological characteristics and high recurrence rate. Despite several nomenclatures for classification, clinicians still confront challenges in its diagnosis and predicting its recurrence. This paper proposes an ensemble deep-learning-based prognostic and prediction algorithm, for the recurrence of sporadic odontogenic keratocysts, on hematoxylin and eosin stained pathological images of incisional biopsies before treatment. (2) Materials and Methods: In this study, we applied a deep-learning algorithm to an ensemble approach integrated with DenseNet-121, Inception-V3, and Inception-Resnet-V3 classifiers. Around 1660 hematoxylin and eosin stained pathologically annotated digital images of OKC-diagnosed (60) patients were supplied to train and predict recurrent OKCs. (3) Results: The presence of SEH (p = 0.004), an incomplete epithelial lining, (p = 0.023), and a corrugated surface (p = 0.049) were the most significant histological parameters distinguishing recurrent and non-recurrent OKCs. Amongst the classifiers, DenseNet-121 showed 93% accuracy in predicting recurrent OKCs. Furthermore, integrating and training the traditional ensemble model showed an accuracy of 95% and an AUC of 0.9872, with an execution time of 192.9 s. In comparison, our proposed model showed 97% accuracy with an execution time of 154.6 s. (4) Conclusions: Considering the outcome of our novel ensemble model, based on accuracy and execution time, the presented design could be embedded into a computer-aided design system for automation of risk stratification of odontogenic keratocysts.

Appropriate follow-up period for odontogenic keratocyst: a retrospective study

Purpose

The aim of this study was to conduct epidemiologic investigations on the pattern of the lesion and differences between treatment modalities in terms of recurrence by reviewing follow-up records to form a basis for planning patient follow-up visits.

Materials and methods

In this retrospective, single-center cohort study, 266 patients diagnosed with odontogenic keratocyst between 1993 and 2013 were included. Medical records and radiographic images were analyzed for age distribution, occurrence site and size, treatment modalities, and recurrence.

Results

The average age at first diagnosis was 33.1 years, and the male to female ratio was 1.33:1.00. The highest rate of incidence was in the third decade followed by the fourth, second, and fifth decades. The incidence in the maxilla was 34%, and 66% in the mandible. Mandibular ramus was most commonly involved. Lesions between 3 and 6 crowns were the most common, and the rate of recurrence increased with size. Enucleation after decompression had higher rate of recurrence (35.8%) than enucleation (27.1%), but there was no statistical significance.

Conclusion

The recurrence of odontogenic kerotocyst (OKC) was significantly associated with large size, multilocular form, and surgical procedure. A 10-year follow-up period is recommended to determine any recurrence of OKC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40902-021-00301-x.

Novel recurrence risk stratification of odontogenic keratocysts: A systematic review

The aim of this study was to identify all clinical, radiological, histopathological, and immunohistochemical features associated with recurrence of odontogenic keratocysts (OKCs) in the literature and formulate a recurrence risk stratification based on these findings. A search was performed in PubMed/Medline, Scopus, Web of Science, Google Scholar and Cochrane databases for clinical and laboratory studies reporting on clinico-pathological features that led to OKC recurrences for the period 2000 to 2020. Twenty-three studies were identified and analyzed qualitatively. A total of 2064 OKCs were included of which 439 OKCs were recurrent with a mean follow-up period of 46.7 months. Significantly associated parameters with OKC recurrence included age (variable age categories), large (>4 cm), multilocular lesions with cortical perforation, association with dentition, presence of daughter cysts, and epithelial budding. Immunohistochemical markers including high Ki67 index and AgNOR count were also implicated. A recurrence risk stratification was formulated based on these findings. Although the level of evidence from the included studies was low, there was considerable evidence that the clinico-pathological parameters identified were linked with higher OKC recurrence. The surgeon, radiologist, and pathologist should aim to identify these features when making a diagnosis so as to determine the appropriate management regime and prevent recurrences.

Prevalence of odontogenic cysts and its associated factors in South Indian population

Background:

Odontogenic cysts (OCs) constitute a major part of oral pathological lesions, but little is known about their distribution patterns in various populations.

Aims:

The aim was to determine the prevalence and factors associated with the cases of histopathologically diagnosed OCs that report to our institution and to analyze the factors associated with the presence of OCs and to study the biologic behavior of different types of cysts.

Materials and Methods:

A cross-sectional study was performed on 596 oral and maxillofacial specimens during 2013–2017. Out of these, the cases which were histopathologically proven as OCs were separated and data were collected and analyzed regarding the age, gender, primary symptom, site, radiographic feature, histopathologic diagnosis, treatment given, recurrences and associated conditions if any.

Results:

Of the 596 cases included in the study, 67 (11.2%) had a histopathological diagnosis of OCs. 41 cases were inflammatory cysts and 26 developmental cysts. 28 cases (41.8%) were reported as periapical cysts, 10 cases (14.9%) were odontogenic keratocysts (OKCs), 9 cases (13.4%) were dentigerous cysts, 8 cases (11.9%) were inflamed cyst wall, 5 cases (7.5%) each of residual cyst and developmental OCs and one case (1.5%) each of orthokeratinized OC and calcifying OC.

Conclusion:

This study showed that the prevalence of OCs was similar to other reported studies. Periapical cysts were the most common cysts reported, followed by OKCs showing that the latter were more frequent than dentigerous cysts.

Sub-epithelial hyalinization, incomplete cystic lining, and corrugated surface could be a predictor of recurrence in Odontogenic Keratocysts

BACKGROUND

Odontogenic Keratocysts (OKCs) are known for their rapid growth and tendency to invade the adjacent tissues. Its high recurrence rate (2.5%-62%) has attracted many kinds of research to identify new parameters to predict recurrence that would enable better treatment outcomes for such patients. The present study aims to correlate Sub-Epithelial Hyalinization (SEH) that has not been explored in an Asian population to date and other histopathologic features of OKC to its recurrence propensity.

MATERIALS & METHODS

A total of 60 OKCs were analyzed for histopathologic correlation of thickness of lining, complete/incomplete lining, corrugated surface, ortho/para keratinization, intercellular edema, reversed polarity, basilar hyperplasia, the palisading arrangement of basal cells, presence/absence of rete pegs, folding of the epithelium, epithelial/connective tissue separation, SEH, basal offshoots, daughter cysts and inflammation with recurrence to arrive at the most significant histologic feature predicting recurrence.

RESULTS

The most significant histologic parameter differentiating recurrent and non-recurrent OKCs was the presence of SEH (p = 0.004), incomplete lining epithelium (p ​= ​0.023), and a corrugated surface (p ​= ​0.049). Several other histologic parameters evaluated did not statistically correlate with recurrence, this can be attributed to the smaller sample size considered in the present study.

CONCLUSION

SEH is a reliable histologic parameter to predict recurrence in OKCs. The presence of SEH is indicative of a higher recurrence potential in OKCs. Evaluation of histological parameters and their correlation with recurrence in OKCs on a larger sample size could validate the results of the current study undertaken and potentially unravel more insights on predicting recurrence.

KEY MESSAGES

Sub-epithelial hyalinization is a significant feature for predicting recurrence in OKC.

Gorlin Syndrome: Recent Advances in Genetic Testing and Molecular and Cellular Biological Research

Gorlin syndrome is a skeletal disorder caused by a gain of function mutation in Hedgehog (Hh) signaling. The Hh family comprises of many signaling mediators, which, through complex mechanisms, play several important roles in various stages of development. The Hh information pathway is essential for bone tissue development. It is also the major driver gene in the development of basal cell carcinoma and medulloblastoma. In this review, we first present the recent advances in Gorlin syndrome research, in particular, the signaling mediators of the Hh pathway and their functions at the genetic level. Then, we discuss the phenotypes of mutant mice and Hh signaling-related molecules in humans revealed by studies using induced pluripotent stem cells.

[Clinicopathological analysis of 844 cases of odontogenic keratocysts]

OBJECTIVE

To investigate the clinicopathologic features and prognostic factors in odontogenic keratocyst (OKC), and to provide new reference for clinic treatment and management of these patients.

METHODS

Clinicopathological data of 844 cases initially diagnosed as or associated with OKC at Department of Oral Pathology, Peking University Hospital of Stomatology from 2000 to 2018 were collected. The cases were divided into 4 groups: sporadic OKCs (intraosseous, cystic lesion irrelevant to nevoid basal cell carcinoma syndrome), syndromic OKCs, solid OKCs and peripheral OKCs. The patients were follow-up for 6 to 216 months and the factors that might relate to recurrence were analyzed.

RESULTS

There were 805 cases (95.4%) of sporadic OKCs, 32 cases (3.8%) of syndromic OKCs, 3 cases of solid OKCs and 4 cases of peripheral OKCs. The main age of sporadic OKCs was 36.03 years with the peak at the second and third decades. Ratio of male and female was 1.27:1. The predilection site was the molar and ramus area of mandibular (56.2%). In the study, 428 cases (71.2%) were unilocular in radiography while 28.8% were multilocular. The recurrent rate of enucleation with the follow-up was 20.1% (118/588) while most of them occurred in 1-3 years after surgery. The recurrent rate of multilocular patients (39.0%) was significantly higher than that of the unilocular. Enucleation after marsupialization (43 cases) or enucleation only (545 cases) showed no difference in recurrence (P>0.05). The syndromic OKCs was younger (main 20.97) and preferred to be multiple compared with sporadic OKCs (30/32, 93.7%). The predilection site was also molar and ramus area of mandibular (41.7%). Age and gender distribution of multiple cases had no significant difference with those in sporadic OKCs. More daughter cysts and epithelial islands were seen (56.3% and 17.9%). Furthermore, the recurrent rate was significantly higher than that of the sporadic OKCs (13/29, 44.9%). But there was no evidence of recurrent-related factors. The age of solid and peripheral OKCs, averaged at 45.00 and 65.75 years, were older than others. Four of peripheral OKCs showed no recurrence after enucleation.

CONCLUSION

The recurrence rate of sporadic OKCs after enucleation is 20.1%. The multilocular lesions prefer to be recurrent. There is no significant difference of recurrence with enucleation only or enucleation after marsupialization. Compared with sporadic OKCs, the syndromic patients are younger and easier to be multiple. It tends to be recurrent frequently and rapidly. There are no related factors about recurrence of syndromic patients. The clinicians should considerate comprehensively and make an individual management of therapy and follow-up. Solid and peripheral OKCs are rare and older.