Can clinical and radiological features predict recurrence in solitary keratocystic odontogenic tumors?

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.

Odontogenic Keratocyst Presented as Multi-Locular Radiolucency in Mandibular Canine and Premolar Region: A Case Report

An odontogenic keratocyst (OKC) was first described by Philipsen in 1956. They are benign cysts of odontogenic origin that behave aggressively and have a high recurrence rate. The present case report describes an unusual presentation of OKC as a multi-locular lesion in the anterior mandible. A 14-year-old male patient was referred to the oral maxillofacial surgery clinic in Tabuk Specialist Dental Centre by his orthodontist to evaluate a radiolucent lesion that had been identified in his lower anterior teeth during an OPG examination. The patient was medically fit and had multiple previous dental restorations. An intraoral examination revealed a small bony expansion in the cystic lesion on the buccal side. The panoramic radiograph showed well-defined multi-locular radiolucencies in the lower left canine area, despite there being no tooth resorption; however, there was a slight divergence noted between the teeth. An excisional biopsy was performed, and the subsequent histopathological examination revealed a cystic lesion diagnosed as an odontogenic keratocyst. The six-month follow-up OPG showed that the site had completely healed without any lesions recurring. OKCs can present at any age, irrespective of gender. The differential diagnosis included a lateral periodontal cyst or a radicular cyst when the tooth was not vital. In this case, the six-month follow-up OPG following surgery revealed no recurrence, although a close follow-up is recommended because of the high recurrence rate.

[Techniques for the treatment of keratocyst, review of the literature and case report]

The odontogenic keratocystic tumor (OKT) or also currently known as odontogenic keratocyst (OK) is a benign pathology derived from the remains of the dental lamina characteristic for possessing variable amounts of desquamated keratin. It usually rises as solitary or with the presence of satellite cysts, the appearance of these satellite cysts is frequently related to the possible recurrence of OK, according to the literature, this recurrence can vary between 0 - 50%. As for the treatment stage of (OKT), it can be mentioned that at present there is a well-defined histological and clinical criterion, which facilitates its recognition and therefore its treatment. According to the literature, there are several treatment procedures that can be classified into non-conservative or radical treatments and conservative treatments accompanied by adjuvant methods. Within the non-conservative or radical treatments, we find en bloc resection, which is the most aggressive way to treat a keratocyst; however, it is the most effective way to avoid recurrence. Within the conservative treatments, marsupialization, decompression, and enucleation with or without adjuvant therapy are described. It is paramount to know how to recognize the different types of treatment for (OKT) since this will be conditioned by multiple factors, such as the location of nearby bone structures and the size of the lesion considering the possible involvement of dental structures. The objective is to seek the lowest-risk treatment possible, which avoids recurrence and finally puts an end to this pathology.

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).

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.

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.

Autologous bone marrow aspirate concentrate (BMAC) for treatment of keratocystic odontogenic tumour (KCOT)-a case report

Management of keratocystic odontogenic tumor (KCOT) has always remained a conundrum due to its aggressive behavior, indicating wide resection. Achieving an esthetically and functionally acceptable reconstruction remains a challenge. Herein, we present a novel and less invasive technique for the treatment of KCOT. A 55-year-old female presenting with pain in the lower jaw for the past 3 months was diagnosed with a large KCOT extending from 35 to 47 region. CT images revealed buccal and lingual cortical bone erosion. Management was done in two stages: cyst curettage and chemical cauterization, followed by application of Bone Marrow Aspirate Concentrate (BMAC) with a delay of two months, to increase the thickness of eroded cortical bone. On follow-up at one year, ossification of the defect was observed. BMAC is a cocktail of mesenchymal stromal cells, hematopoietic stem cells, fibroblasts, mononuclear cells, macrophages, endothelial cells, progenitor cells, growth factors and cytokines. BMAC cocktail provide an anti-inflammatory, anti-fibrotic, anti-apoptotic, and immunomodulatory environment. Autologous platelet rich plasma provides various growth factors (TGF-β, PDGF, EGF, HGF, NGF, IGF-1) and cytokines. Addition of PRP in BMAC cocktail enhance the regeneration of tissues, where PRP act as a functional regenerative scaffold for cell integration, proliferation, and differentiation that can expedite macroscale musculoskeletal tissue healing. Autologous BMAC with corticocancellous bone acts as an osteoconductive scaffold capable of regenerating the large bone defect created by the curettage of KCOT.

Imaging Characteristic of 11 Lesions of Odontogenic Keratocyst in the Indian Subpopulation: A Cone-Beam Computed Tomography Experience

Background:

The clinical feature and radiographic appearance of orthokeratinized odontogenic keratocyst (OKC) are not characteristic, which may lead to the misdiagnosis. The radiographic appearance of OKC may range from a small unilocular radiolucency to a large multilocular radiolucency, resembling other odontogenic cysts and tumors.

Aim:

The aim was to illustrate the characteristic feature of OKC presented on the digital panoramic radiograph and cone-beam computed tomography (CBCT), which may provide great value for the differential diagnosis and the treatment planning and also to compare the various radiographic features of OKC in CBCT and digital panoramic radiograph.

Materials and Methods:

Digital panoramic and CBCT records of seven cases, with 11 lesions of OKC were analyzed retrospectively from the patients' database from our institute (2014 to 2016), which was histopathologically diagnosed as OKC.

Results:

The mean age of the patients was 24.1 years, and the female-to-male ratio was 3: 4. Six of 11 lesions were localized within the mandible, and five lesions were in the maxilla.

Conclusion:

The presurgical assessment with radiological information is extremely important for treatment planning, and CBCT provides us with an accurate and faster three-dimensional representation of a lesion at a lower dose and cost, but the role of panoramic radiograph cannot be refuted.

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.

Odontogenic keratocyst: imaging features of a benign lesion with an aggressive behaviour

Abstract

The latest (4th) edition of the World Health Organization (WHO) Classification of Head and Neck Tumours, published in January 2017, has reclassified keratocystic odontogenic tumour as odontogenic keratocyst. Therefore, odontogenic keratocysts (OKCs) are now considered benign cysts of odontogenic origin that account for about 10% of all odontogenic cysts. OKCs arise from the dental lamina and are characterised by a cystic space containing desquamated keratin with a uniform lining of parakeratinised squamous epithelium. The reported age distribution of OKCs is considerably wide, with a peak of incidence in the third decade of life and a slight male predominance. OKCs originate in tooth-bearing regions and the mandible is more often affected than the maxilla. In the mandible, the most common location is the posterior sextant, the angle or the ramus. Conversely, the anterior sextant and the third molar region are the most common sites of origin in the maxilla. OKCs are characterised by an aggressive behaviour with a relatively high recurrence rate, particularly when OKCs are associated with syndromes. Multiple OKCs are typically associated with the nevoid basal cell carcinoma syndrome (NBCCS), an autosomal dominant multisystemic disease. Radiological imaging, mainly computed tomography (CT) and, in selected cases, magnetic resonance imaging (MRI), plays an important role in the diagnosis and management of OKCs. Therefore, the main purpose of this pictorial review is to present the imaging appearance of OKCs underlining the specific findings of different imaging modalities and to provide key radiologic features helping the differential diagnoses from other cystic and neoplastic lesions of odontogenic origin.

Key Points

• Panoramic radiography is helpful in the preliminary assessment of OKCs.

• CT is considered the tool of choice in the evaluation of OKCs.

• MRI with DWI or DKI can help differentiate OKCs from other odontogenic lesions.

• Ameloblastoma, dentigerous and radicular cysts should be considered in the differential diagnosis.

• The presence of multiple OKCs is one of the major criteria for the diagnosis of NBCCS.

Recurrence rate of odontogenic keratocyst treated by enucleation and peripheral ostectomy: Retrospective case series with up to 12 years of follow-up

Background

Odontogenic keratocysts have been reported with high recurrence rates in the literature so various treatment modalities from simple enucleation to resection have been performed to achieve the cure. The purpose of this retrospective study was to investigate the recurrence rate of odontogenic keratocysts (OKCs) treated by enucleation and peripheral ostectomy.

Material and Methods

An electronic search of the database of the Hacettepe University, Faculty of Medicine, Department of Pathology, was undertaken to identify patients histologically diagnosed with OKCs treated at Department of Oral and Maxillofacial Surgery between 2001 and 2015.

Results

In total, 81 patients were studied. The mean age at the time of diagnosis was 42 years, and the male:female ratio was 1:0.7. OKCs were located primarily in the posterior mandibular region (41%). Twenty-seven patients were re-examined to determine the recurrence rate. The mean follow-up period was 5 years (range, 1–12 years). The recurrence rate was 14.8%. The relationship between location of the lesion and recurrence was not statistically significant (p = 0.559). There was also no statistically significant relation between the recurrence rate and treatment option of teeth involved in the lesion (p = 0.579).

Conclusions

The authors conclude that treatment of OKCs by enucleation with peripheral ostectomy is associated with minimal morbidity and is preferred over other aggressive treatment modalities. Meticulous radiographic examination and careful surgical resection may decrease the recurrence rate of OKCs.

Key words:Odontogenic keratocyst, recurrence rate, enucleation, enucleation plus peripheral ostectomy.

Ability of Oral and Maxillofacial Surgery Residents in Diagnosing Jaw Cysts: A Retrospective 20 Years Study

INTRODUCTION

Diagnosis of odontogenic cysts despite of their benign nature is a critical and challenging problem especially among undergraduate and postgraduate students.

AIM

This study aimed to evaluate the capability of oral and maxillofacial surgery residents in diagnosing odontogenic cysts.

MATERIALS AND METHODS

This cross-sectional study was executed on 312 patient records over the past 20 years since October 1995 till December 2014 in Taleghani Hospital, Tehran, Iran. All recorded data was based on 2005 World Health Organization (WHO) classifications. The differential diagnosis was made by 65 residents based on clinical and paraclinical evaluations established in the charts. Differential diagnoses made by the residents were compared to the histopathological examination as the gold standard for identifying the nature of the cysts. Weighted kappa test was used to show the degree of agreement.

RESULTS

Data extracted from 312 records were analyzed. The mean age of examined patients was 27.6 years. The accuracy of diagnosis among the residents was moderate (k_w=0.5). The diagnosis made by the residents was significantly related to the radiographic view of the cysts (p<0.05). The residents were able to identify odontogenic keratocysts and dentigerous cysts in most cases.

CONCLUSION

There are several factors associated with the occurrence of pathologic odontogenic cysts which could help either the clinician or the pathologist in diagnosing the odontogenic cysts of the jaws. The surgeons should consider these related factors before the final diagnosis and choosing the appropriate treatment plan.

Surgical removal of keratocystic odontogenic tumours via a Le Fort I osteotomy approach: a retrospective study of the recurrence rate

The keratocystic odontogenic tumour (KCOT) is one of the most aggressive odontogenic cysts and has a high recurrence rate. The treatment of these tumours is the subject of debate. A KCOT in the posterior maxilla with sinus involvement is rare. Few reports have been published in the literature. The purpose of this study was to evaluate the recurrence rate after surgical removal of maxillary KCOTs via a Le Fort I osteotomy. A search was performed to identify patients with a follow-up time of at least 5 years. Nine patients were included in the study. The following clinical variables were analyzed: age at surgery, sex, symptoms, site and size of the tumour, surgical approach, and recurrence rate. The surgical approaches were curettage (n=6) and enucleation (n=3). Recurrence was seen in three patients (33%); all had multilocular tumours. No recurrence was seen in patients with unilocular tumours. The Le Fort I osteotomy approach allows direct visualization and ensures wide excision, minimizing the risk of recurrence. In this series, cases with a multilocular KCOT showed a higher risk of recurrence due to the difficulty of removing the tumour in total. All recurrences took place within 2 years of the intervention; a 5-year follow-up is recommended.

A systematic review of the literature of nevoid basal cell carcinoma syndrome affecting East Asians and North Europeans

OBJECTIVE

To compare, by systematic review, North European and East Asian consecutive case series of nevoid basal cell carcinoma syndrome (NBCCS).

STUDY DESIGN

A systematic review of the literature was performed for all consecutive case series of NBCCS, which included keratocystic odontgenic tumors (KCOTs) arising in North European and East Asian communities. The clinical and radiologically apparent features were identified and synthesized, and a meta-analysis was performed.

RESULTS

East Asian reports were significantly more "proband only" compared with North European reports. Significant differences between these 2 communities were observed for 5 of the 6 major features and 11 of the 27 minor features. With regard to the major NBCCS features, the North Europeans displayed significantly more frequent basal cell carcinomas, calcified falx cerebri, palmar and plantar pits, and a family history, whereas the East Asians displayed KCOTs significantly more frequently. With regard to minor features, East Asians displayed significantly more frequent cleft lips and palates and hypertelorism.

CONCLUSIONS

East Asians displayed multiple KCOTs and cleft lips and palates more frequently compared with North Europeans.