Decompression of keratocystic odontogenic tumors leading to increased fibrosis, but without any change in epithelial proliferation

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).

Does active decompression of odontogenic keratocyst change the histologic diagnosis?

AIM

The purpose of this study was to compare the histopathologic findings of pre- and post-active decompression of odontogenic keratocyst and to establish if such findings were consistent.

MATERIALS AND METHODS

A retrospective case series from a group of patients diagnosed with odontogenic keratocyst who underwent active decompression and distraction sugosteogenesis followed by final enucleation was designed and implemented. The dependent variable was changed in histologic diagnosis, as evaluated by an oral and maxillofacial pathologist. Other variables included age, gender, anatomic location of the lesion, and time elapsed from initial biopsy to final enucleation.

RESULTS

Six patients diagnosed with odontogenic keratocyst who underwent active decompression followed by enucleation and curettage were studied. The mean age was 45.6 years (range, 16 to 74) 83.33% were males, 16.66 females. Lesions were located in the mandible in 83.33% of cases and in the maxilla in 16.66% of cases. Post-active decompression histologic examination at the time of definitive enucleation was consistent with the initial diagnosis in 83.33% of cases.

CONCLUSIONS

The histopathological diagnosis at the time of definitive treatment by enucleation and curettage is consistent with the pre-active decompression diagnosis.

Unveiling metabolic changes in marsupialized odontogenic keratocyst: A pilot study

OBJECTIVE

We aimed to assess which metabolic pathways would be implicated in the phenotypic changes of the epithelial lining of odontogenic keratocyst after marsupialization, comparing pre- and post-marsupialized lesions with adjacent oral mucosa.

MATERIALS AND METHODS

Eighteen formalin-fixed and paraffin-embedded tissues from six subjects were divided into three paired groups: odontogenic keratocyst pre- (n = 6) and post-marsupialization (n = 6), and adjacent oral mucosa (n = 6). The metabolic pathways found in these groups were obtained by high-performance liquid chromatography-mass spectrometry-based untargeted metabolomics performed.

RESULTS

Through putative metabolite annotation followed by pathway enrichment and predictive analysis with automated algorithms (Mummichog and Gene Set Enrichment Analysis), we found differences in many cellular processes that may be involved in inflammation, oxidative stress response, keratinocyte-basal membrane attachment, differentiation, and proliferation functions, all relevant to odontogenic keratocyst pathobiology and the phenotype acquired after marsupialization.

CONCLUSION

Our study was able to identify several metabolic pathways potentially involved in the metaplastic changes induced by marsupialization of odontogenic keratocysts. An improved comprehension of this process could pave the way for the development of targeted therapies.

The immunohistochemical profile of basal cell nevus syndrome-associated and sporadic odontogenic keratocysts: a systematic review and meta-analysis

OBJECTIVES

To provide a systematic review of the literature on studies comparing the immunoprofile of nevoid basal cell carcinoma syndrome (BCNS)-associated and sporadic odontogenic keratocysts (OKCs), in order to identify markers that could accurately distinguish the two OKC subtypes.

MATERIALS AND METHODS

We searched MEDLINE/Pubmed, Web of Science, EMBASE via OVID, and grey literature for publications until December 28th, 2019, that compared the immunohistochemical expression of the two OKC subtypes. The studies were qualitatively assessed using the Critical Appraisal Tool for Case Series (Joana Briggs Institute). Sensitivity and specificity, positive and negative likelihood ratio, diagnostic odds ratio and area under the curve, and pooled estimates were calculated, using a random-effects model.

RESULTS

Seventy-one studies were qualitatively analyzed; 61 markers were evaluated in one study and 32 in ≥ 2 studies. Twenty-five studies reported differential expression of 29 markers in the form of higher number of positive cells or greater staining intensity usually in BCNS-associated OKCs. Meta-analysis for bcl-2, Cyclin D1, CD56, CK18, p53, and PCNA showed that none of those markers is distinguishable between BCNS-associated and sporadic OKCs, in a 95% confidence interval. The risk of bias was high in 34 studies, moderate in 22, and low in 15.

CONCLUSIONS

The present systematic review and meta-analysis uncovered that, although several immunohistochemical markers might characterize the OKC phenotype, they cannot discriminate between the BCNS-associated and sporadic OKCs.

CLINICAL RELEVANCE

This study highlighted the requirement for additional screening for markers by immunohistochemistry, preferentially coupled to alternative diagnostic applications such as genomics technologies.

C, Agustín MF, André Xavier Padilha F, Neimar S, Rogério Belle DO. Multimodal Protocol for the Treatment of Odontogenic Keratocysts

Purpose:

The aim of this study is to evaluate longitudinally the effectiveness of a multimodal protocol based on decompression followed by enucleation combined with the use of liquid nitrogen under local anesthesia for the treatment of odontogenic keratocysts.

Methods:

Seven patients with a diagnosis of odontogenic keratocyst were evaluated longitudinally to clinical and histological features, and pre- and postoperative radiographs were analyzed. Data were collected on the epidemiological profile of patients and on cysts, including the presence of recurrence, duration of drainage device use, lesion site, and presence of postoperative complications.

Results:

No recurrence was observed during follow-up. Mean follow-up was 59.57 months (range, 18-96 months). No pathological fracture was observed. None of the patients had persistent paresthesia of the inferior alveolar nerve. Substantial reduction in cyst size and epithelial differentiation were observed in all patients after multimodal treatment.

Conclusion:

Based on these results, the multimodal protocol proposed here was effective in the treatment of odontogenic keratocysts by reducing lesion size, avoiding possible damage to adjacent anatomical structures, and allowing a surgical procedure with less morbidity. The longitudinal follow-up of patients showed that this treatment modality is associated with a low recurrence rate compared with alternative therapies.

Changes in Cellular Regulatory Factors before and after Decompression of Odontogenic Keratocysts

Decompression followed by enucleation, which is one of the treatments used for odontogenic keratocysts (OKCs), is frequently used in OKC lesions of large sizes. This method offers the advantage of minimizing the possibility of sensory impairment without creating a wide-range bone defect; moreover, the recurrence rate can be significantly lower than following simple enucleation. This study aimed to assess the changes in histology and expression of proliferation markers in OKCs before and after decompression treatment. A total of 38 OKC tissue samples from 19 patients who had undergone decompression therapy were examined morphologically and immunohistochemically to observe changes in proliferative activity before and after decompression. The markers used for immunohistochemistry (IHC) staining were Bcl-2, epidermal growth factor receptor (EGFR), Ki-67, P53, PCNA, and SMO. The immunohistochemistry positivity of the 6 markers was scored by using software ImageJ, version 1.49, by quantifying the intensity and internal density of IHC-stained epithelium. The values of Bcl-2, Ki-67, P53, proliferating cell nuclear antigen (PCNA), and SMO in OKCs before and after decompression showed no significant change. No correlation between clinical shrinkage and morphologic changes or expression of proliferation and growth markers could be found. There was no statistical evidence that decompression treatment reduces potentially aggressive behavior of OKC within the epithelial cyst lining itself. This might indicate that decompression does not change the biological behavior of the epithelial cyst lining or the recurrence rate.

Histological changes in odontogenic parakeratinized keratocysts treated with marsupialization followed by enucleation

Background

The purpose of this study was to evaluate whether marsupialization treatment induces changes in the histology of odontogenic keratocyst epithelium and to compare our experience with the literature.

Material and Methods

A retrospective revision of histological samples was performed. 5 patients with odontogenic keratocyst treated with marsupialization follow by enucleation were selected. Histologic evaluation analyzed the changes in the keratocyst epithelium after marsupialization in terms of type of keratinization, thickness of the epithelium and connective tissue, the presence of acanthosis, the presence and grade of fibrosis, the type and grade of inflammation and the presence and number of mitotic figures and daughter cysts.

Results

In our case series, a variation of para-keratinized into ortho-keratinized keratocyst was found in one case, and no significant increases were observed in the epithelium and capsule thickness, or even in the level of inflammation. However, we observed an increase in fibrosis and qualitative changes in inflammation type.

Conclusions

Minor and major histological changes were associated with reduction in cyst volume, which resulted in a simpler and less invasive cystic enucleation after marsupialization.

Key words:Keratocyst, marsupialization, enucleation, histology, histological changes.

Computerized Evaluation of the Immunoexpression of Ki-67 Protein in Odontogenic Keratocyst and Dentigerous Cyst

Evaluation and comparison of odontogenic keratocysts and detigerous cysts immunoexpression and immunostaining intensities of Ki-67 antigen by assessing the whole extent of the epithelium (all epithelium layers in combination) and each layer individually. Ki-67 immunoexpression was evaluated in 15 odontogenic keratocysts and 6 dentigerous cysts using automated methods and the Aperio Technologies Inc. computer system. No statistically significant differences were observed in immunoexpression nor in immunostaining intensities between both lesions. Also, no statistically significant differences were found between odontogenic keratocysts from maxilla versus mandible nor primary versus recurrent. However, odontogenic keratocyst showed a significantly higher cellular proliferation index in the suprabasal layers compared to the basal layer. Assessment of the cellular proliferation index through a computerized system enabled the evaluation of all epithelial tissue without field selection. The increased Ki-67 immunoexpression in suprabasal layers of odontogenic keratocyst suggests a different biological behavior and more aggressive proliferation potential when compared to dentigerous cyst. The same result was found in recurrent odontogenic keratocysts when compared with primary ones. The odontogenic keratocysts of the maxilla and mandible have similar Ki-67 immunoexpression. The evaluation of cellular proliferation only by immunohistochemical analysis with Ki-67 antigen does not provide enough data to elucidate the biological behavior of odontogenic keratocyst.

Therapeutic management of the odontogenic keratocyst. An energetic approach with a conservative perspective and review of the current therapeutic options

Background

Odontogenic keratocysts (OKC) are cystic lesions appearing in the jaws, usually asymptomatic with a progressive growth into the bone. Many of them are diagnosed by a routine radiological examination.

Material and Methods

This study reports a 12-year-old girl that presented an asymptomatic large radiolucent unilocular lesion associated to the crown of 3.8 that caused displacement of the molar and the inferior alveolar canal. Differential diagnosis included OKC, unicystic ameloblastoma, ameloblastic fibroma, dentigerous cyst and orthokeratinized odontogenic cyst. Two surgical interventions were performed; first, a marsupialization, and 10 months after, the third molar extraction plus cyst enucleation, mucosa excision and the application of Carnoy’s solution.

Results

The anatomopathological exam confirmed diagnosis of OKC. There was no evidence of recurrence after 2 years of follow-up.

Conclusions

Marsupialization followed by surgical enucleation with mucosa excision and Carnoy’s solution can help manage treatment of OKC, a lesion characterized by an aggressive behavior.

Key words:Odontogenic keratocyst, mucosa excision, carnoy solution, third molar, tooth extraction.

Self-Retained Voice Prosthesis in the Decompression of the Odontogenic Keratocyst: A Technical Note

Decompression of the odontogenic keratocyst has been a long-standing treatment modality in the armamentarium of oral-maxillofacial surgeons. Many different types of effective decompression tubes have been described in the literature. They reduce the size of the cystic lesion by decreasing the intraluminal pressure, induce histologic structural changes in the epithelial lining of the cyst, and allow for bone deposition to occur from the periphery of the cystic cavity. However, many of these have pitfalls including tube dislodgement, traumatization of the oral mucosa, and mucosal overgrowth. We describe a novel technique using an indwelling voice prosthesis (Inhealth Technologies, Carpinteria, CA) to decompress odontogenic keratocysts. We found that our method provides effective decompression using appropriate-length prostheses fit to the cyst dimensions. It provides improved comfort in patients, with less mucosal irritation or overgrowth, improved ease of irrigation, and improved retention that often does not require sutures.

Comparison of wall removal type versus wall retaining type of decompression for treating large mandibular odontogenic cysts

OBJECTIVE

To evaluate the differences between two types of decompression for treating large mandibular odontogenic cysts.

MATERIALS AND METHODS

This retrospective, cohort study included patients who were diagnosed for large mandibular odontogenic cysts from January 2015 to April 2018 and underwent two different types of decompression based on removal or retention of the cyst wall. The primary outcome was the percentage of the residual cyst area within 1 year after surgery. We used the propensity score matching (PSM) to balance the covariates of the two groups, and the primary outcome was analyzed by the non-inferiority test.

RESULTS

A total of 93 cases were included in our study. After 1 year, the wall removal group was non-inferior to the wall retaining group in terms of cyst area, cyst volume, and the difference between the HU values of the original cyst region and the normal mandible. In subgroup analysis, we found there were no differences between two groups in the percentage of patients in whom the cystic area was reduced by 90% after 1 year.

CONCLUSION

Our findings suggest that the wall removal group showed better results than the cyst wall retaining group in large mandibular odontogenic cysts.

Decompression and Enucleation of a Mandibular Radicular Cyst, Followed by Bone Regeneration and Implant-Supported Dental Restoration

Odontogenic cysts are usually treated by enucleation (cystectomy). Limited cysts (less than 5 cm) are usually managed by primary excision (total cystectomy), whereas larger ones (exceeding 5 cm) are often decompressed or marsupialized. Because it consists only of opening a much smaller surgical window, decompression is regarded as a more conservative method of treatment: this method associates the creation of an opening (window) into the cystic cavity with the suturing of a decompressing device (plastic tube or stent) at the periphery of the cyst. Apart from releasing intraluminal pressure in the pathological cavity, this procedure helps the lesion to progressively decrease in volume “with a gradual increase in bone apposition” and preserves pulp vitality and periodontal integrity of the adjacent teeth. We are reporting a case of a mandibular radicular cyst that was treated by decompression, followed by enucleation, bone reconstruction, and restoration with two osseointegrated dental implants. The cystic cavity progressively decreased in volume and increased in bone density.

Recurrence of nonsyndromic odontogenic keratocyst after marsupialization and delayed enucleation vs. enucleation alone: a systematic review and meta-analysis

PURPOSE

This study was conducted in order to determine whether marsupialization before definitive enucleation of nonsyndromic odontogenic keratocysts (OKCs) is capable of decreasing the recurrence rate more effectively than just enucleation.

METHODS

We searched MEDLINE, Web of Science, Scopus, and Cochrane Library, until August 5th of 2017 for original studies reporting on the treatment of OKCs with and without previous marsupialization and the related recurrence rate. All records and data were independently assessed, meta-analysis was performed, and the odds ratio of recurrence was the effect measure; P value for the summary effect of < 0.05 was considered statistically significant.

RESULTS

The 748 records retrieved were reduced to 6 studies to be qualitatively assessed and 5 studies were included in the meta-analysis. The overall odds ratio of 0.57 [0.25-1.28] of the pooled values pointed that marsupialization reduced the recurrence rate in comparison to just enucleation; however, the P value showed that there is no strong evidence to support this statement.

CONCLUSIONS

Marsupialization followed by enucleation after 12 to 18 months reduces the recurrence rate, but more studies are necessary to support this statement.

Odontogenic Keratocysts as First Manifestation of Nevoid Basal Cell Carcinoma Syndrome: Surgical Management and Immunohistochemical Analysis

Nevoid Basal Cell Carcinoma Syndrome (NBCCS), also known as Gorlin syndrome, is a rare autosomal dominant disorder, with no gender predilection. Individuals with NBCCS are commonly diagnosed between 17 and 35 years old and can present multiple basal cell carcinomas scattered throughout the body, presence of recurrent and early-onset odontogenic keratocysts (OKCs) and skeletal abnormalities. This article describes a case of a 13-year-old white boy who referred complaining of facial asymmetry. Extraoral examination revealed volumetric increase displacing the nasal ala from the right side and extended to the zygomatic bone. The intraoral evaluation showed mixed dentition with moderate degree of malocclusion. In addition, bilateral vestibular fornix swelling was observed in the upper canine region. An increase in volume was also detected on the hard palate on the right side. Computed tomography revealed multiple hypodense lesions with cystic appearance. The aspiration was positive, with a yellowish aspirate of serous consistency of all lesions. Given the numerous lesions, it was decided to decompress them for posterior enucleation procedures. In addition to other manifestations, the patient was diagnosed with NBCCS. Although common, the occurrence of OKCs in pediatric patients, especially in multiple lesions, is highly indicative of NBCCS, and its investigation should be considered, even in the absence of other signs of this syndrome. Synchronous decompression was satisfactory and can be used in similar cases of multiple cystic lesions.

Influence of surgical decompression on the expression of inflammatory and tissue repair biomarkers in periapical cysts

OBJECTIVE

The biologic effects of surgical decompression on the epithelium and connective tissues of periapical cysts are not fully understood. The aim of this study was to evaluate the expression of tissue repair and inflammatory biomarkers in periapical cysts before and after surgical decompression.

STUDY DESIGN

Nine specimens of periapical cysts treated with decompression before undergoing complete enucleation were immunohistochemically analyzed to investigate the expression of interleukin-1β, tumor necrosis factor-α, transforming growth factor-β1, matrix metalloproteinase-9, Ki-67, and epidermal growth factor receptor. Expression of the biomarkers was classified as positive, focal, or negative. Ki-67 immunoexpression was calculated as a cell proliferation index. The expression of the biomarkers was compared in the specimens from decompression and from the final surgical procedure.

RESULTS

Computed tomography demonstrated that volume was reduced in all cysts after decompression. There were no differences in the immunoexpression of the proinflammatory and tissue repair biomarkers when comparing the specimens obtained before and after the decompression.

CONCLUSIONS

Surgical decompression was efficient in reducing the volume of periapical cysts before complete enucleation. When comparing the specimens obtained from surgical decompression and from complete surgical removal, the immunohistochemical analysis did not show a decrease in proinflammatory biomarkers; neither did it show an increase in tissue repair biomarkers.