Application of machine learning in the preoperative radiomic diagnosis of ameloblastoma and odontogenic keratocyst based on cone-beam CT.

OBJECTIVES: Preoperative diagnosis of oral ameloblastoma (AME) and odontogenic keratocyst (OKC) has been a challenge in dentistry. This study uses radiomics approaches and machine learning (ML) algorithms to characterize cone-beam CT (CBCT) image features for the preoperative differential diagnosis of AME and OKC and compares ML algorithms to expert radiologists to validate performance. METHODS: We retrospectively collected the data of 326 patients with AME and OKC, where all diagnoses were confirmed by histopathologic tests. A total of 348 features were selected to train six ML models for differential diagnosis by a 5-fold cross-validation. We then compared the performance of ML-based diagnoses to those of radiologists. RESULTS: Among the six ML models, XGBoost was effective in distinguishing AME and OKC in CBCT images, with its classification performance outperforming the other models. The mean precision, recall, accuracy, F1-score, and area under the curve (AUC) were 0.900, 0.807, 0.843, 0.841, and 0.872, respectively. Compared to the diagnostics by radiologists, ML-based radiomic diagnostics performed better. CONCLUSIONS: Radiomic-based ML algorithms allow CBCT images of AME and OKC to be distinguished accurately, facilitating the preoperative differential diagnosis of AME and OKC. ADVANCES IN KNOWLEDGE: ML and radiomic approaches with high-resolution CBCT images provide new insights into the differential diagnosis of AME and OKC.

What Is the 5-year Incidence of Recurrent Disease of Odontogenic Keratocysts?

PURPOSE: There is no consensus on the ideal treatment of odontogenic keratocysts (OKCs). Certain risk factors may modify the disease recurrence rate. The purpose of this study was: 1) to estimate the incidence of OKC recurrence in a statistically rigorous manner; and 2) to identify risk factors associated with OKC recurrence. METHODS: The investigators designed and implemented a retrospective cohort study and enrolled a sample derived from the population of patients presenting to the Department of Oral and Maxillofacial Surgery outpatient clinics at the University of Washington School of Dentistry and Harborview Medical Center for evaluation and management of OKCs between January 1, 2010, and December 31, 2020. Predictor variables included demographics (age, gender), radiographic characteristics (location of lesion, locularity, size, and cortical perforation), and type of operation performed (decompression + cystectomy, enucleation ± adjuvant therapy, or resection). The primary outcome variable was time to recurrent disease, defined as the time from treatment to radiographic or clinical evidence of a new lesion (recorded in months). Kaplan-Meier analysis was used to estimate median time to recurrence, and Cox proportional hazards models were used to identify covariates statistically associated with recurrent disease (P ≤ .05). RESULTS: The sample was composed of 60 subjects with 63 previously untreated lesions. Eight subjects (13%) developed a recurrent lesion during the study interval with a median time to recurrence of 31 (interquartile range, 24 to 48) months. One of the 8 recurrences occurred within 12 months of treatment and 7 of the 8 recurrences occurred more than 21 months after treatment. Based on using Kaplan-Meier analysis, the 5-year incidence of disease recurrence was estimated to be 34%. Lesions with cortical perforation were 8.3 times more likely to recur (95% confidence interval [1.7, 41.3]; P-value = .01), and multilocular lesions were 10.6 times more likely to recur (95% confidence interval [1.3, 86.9]; P-value = .03). The sample size was the limiting factor to performing regression analyses. CONCLUSIONS: Virtually every publication on OKCs to date reports frequencies of disease recurrence rather than applying appropriate survival analyses commonly used to estimate outcomes in cancer research. Failure to use the appropriate statistical analyses underestimates the risk of disease recurrence. Our study is no exception. The estimated frequency of disease recurrence during the study interval was 13% (8/60). When survival analyses are applied that account for varying months of follow-up, the incidence of disease recurrence is 34 per 100 per 5 years. We recommend the application of time-to-event analyses in the study of disease entities with the potential for recurrence.

Refined Topical 5-Fluorouracil Technique for the Targeted Treatment of Odontogenic Keratocysts.

PURPOSE: An innovation in the treatment of odontogenic keratocysts (OKCs) is the adjunctive application of 5-fluorouracil (5-FU). Although the original approach remains effective, it may often be a challenge for the patient to return postoperatively and/or tolerate non-resorbable packing removal. The purpose of the present study is to determine whether our refined approach, where we directly apply 5-FU-coated absorbable gelatin sponge to the surgical cavity, would be an effective treatment for OKCs with similar efficacy as with our original approach. MATERIALS AND METHODS: A retrospective case series studying the treatment efficacy of our refined topical 5-FU approach on OKCs was reviewed. The study population was composed of all patients presenting for evaluation and management of OKCs with our refined technique between September 1, 2017 and July 1, 2022 at Stony Brook University Hospital. The primary outcomes included 1) time to OKC recurrence, and 2) incidence of trigeminal nerve injury following OKC treatment with the refined topical 5% 5-FU technique. Other study variables included age, gender, tumor location, and tumor size. Data analyses included descriptive statistics reported as median [interquartile range], and Kaplan-Meier survival analysis for time to OKC recurrence. RESULTS: Thirteen patients with 15 OKCs were reviewed (6 women and 7 men). There were no OKC recurrences with a median follow-up time of 28.5 (24) months. Normal bony healing was observed in all cases and there were no adverse local or systemic events, no alterations in sinus function, and no incidences of infraorbital or inferior alveolar nerve paresthesia. CONCLUSIONS: Our case series demonstrates that this refinement further increases technical ease, decreases operating time, and precludes the need for packing removal, with similar efficacy as the original approach.

Squamous Cell Carcinoma Arising From Odontogenic Cyst Epithelium or Oral Mucosa Epithelium After Marsupialization of Odontogenic Radicular Cyst in Posterior Mandible?

Squamous cell carcinomas (SCCs) are common malignant tumors in the oral and maxillofacial region. However, SCCs secondary to marsupialization of odontogenic radicular cysts are extremely rare. The authors report an unusual case of a 43-year-old male presented with dull pain in the right molar region of the mandible without numbness of lower lips, who had a long history of smoking, alcohol consumption, and betel nut chewing. Computerized tomography revealed a round well-defined unilocular radiolucent at the apex of lower right premolars, 2 nonvital teeth. The clinical diagnosis was the radicular cyst of the right mandible. The patient was initially treated with root canal therapy of the teeth followed by marsupialization with a mandibular vestibular groove incision. While the patient did not follow the instruction of irrigation of the cyst and had no regular follow-up. The reexamination of computerized tomography indicated a round well-defined unilocular radiolucent at the apex of lower right premolars and filled with a soft tissue without clear boundary with buccal muscles at 31 months follow-up. There were no masses or ulcer around the mandibular vestibular groove incision and the patient had no sign of numbness of lower lips. The clinical diagnosis was the radicular cyst of right mandible with infection. A curettage was performed. However, the pathologic diagnosis was well-differentiated SCC. An extended radical surgical resection including segmental resection of the right mandible was performed. The histopathology was well-differentiated SCC without the cyst epithelium and invasion of bone, which can be distinguished from primary intraosseous SCC. The case indicates that marsupialization performed in patients with a history of smoking, alcohol consumption, and betel nut chewing, has a risk of suffering from oral SCC.

Intraosseous Mucoepidermoid Carcinoma of the Mandible Detected as an Asymptomatic Swelling.

Intraosseous mucoepidermoid carcinoma (IMEC) is a rare neoplasm of the jawbones. Although hypotheses focused on the malignant transformation of the epithelial mucosa of odontogenic cysts or ectopic salivary gland tissue have been suggested, the etiology of the disease is still unclear. It is more frequent in middle-aged individuals, has a slight female predilection, and is more common in the mandible than in the maxilla. Cortical enlargement is the most common symptom, while some lesions are detected by coincidence on radiography. This paper reports an IMEC of the mandible of a 35-year-old female, possibly arising from the remains of an odontogenic cyst associated with an unerupted mandibular molar, which was operated in an external center 5 years ago before IMEC diagnosis.

Idiopathic bone cavity mimicking a botryoid odontogenic cyst: A rare radiographic presentation in an older adult.

OBJECTIVES: This report describes an unusual case of a multilocular idiopathic bone cavity (IBC) that presented as a botryoid odontogenic cyst situated between the mandibular lateral incisor and canine in an older adult. BACKGROUND: The IBC represents an intraosseous concavity that appears radiographically as a unilocular or multilocular radiolucent lesion found in various skeletal sites, including the jaw. Atypical cases of gnathic IBC have not been appreciated in the gerodontologic literature. MATERIALS AND METHODS: The teeth adjacent to the bony lesion had normal pulpal responses to cold. A full-thickness flap was elevated and provided a direct entry into a bony concavity, which was devoid of an epithelial lining and fluid. RESULTS: The lack of a cystic lining within the empty osseous lesion following surgical entry, concomitant with the vital pulpal status of the proximal teeth, led to a diagnosis of an IBC. The bony walls underwent curettage and copious irrigation prior to primary closure. A 10-month follow-up revealed partial evidence of osseous repair. The patient will continue to be monitored. CONCLUSION: Timely surgical intervention of central lesions of the jaws may improve clinical outcomes. Variants of the IBC should be included in the differential diagnosis of multilocular lesions, particularly in the geriatric population.

Volumetric reduction in large cystic jaw lesions postoperative enucleation: a longitudinal clinical study.

BACKGROUND: Enucleation, a surgical procedure, is commonly used to treat large jaw cysts, unicystic ameloblastomas and keratocysts. However, it remains unclear to what extent the jaw bone regenerates after enucleation. We aimed to evaluate the percentage and the survival analysis of jaw bone regeneration, in terms of cavity volume residual (CVR), in patients who underwent enucleation of large jaw cysts, unicystic ameloblastomas and keratocysts. METHODS: We collected data longitudinally from 75 patients who underwent jaw cystic lesions enucleation at the Stomatological Hospital of Xi'an Jiaotong University, between January 2015 and June 2021. All patients had both preoperative and postoperative cone-beam computed tomography (CBCT) imaging data. CBCT images were analyzed using Image J. Changes in the CVR were assessed at various follow-up time points, and the Kaplan-Meier method was utilized to evaluate the CVR over time. RESULTS: The patients had a mean age of 31.7 years (range: 5.5-72 years) with 58.66% of them being male. The postoperative CVR was 32.20% at three months, 21.10% at six months, 15.90% at 12 months, and 5.60% at 24 months. The percentage of CVR during follow-up periods for the initial size Quartile (Q)1 (212.54-1569.60 mm3) was substantially lower than those of Q2 and Q3 at and after seven months of follow-up and became statistically significant at the 12-month mark. CONCLUSION: This study demonstrates that spontaneous bone regeneration can occur after enucleation of large jaw cysts, unicystic ameloblastomas and keratocysts, even without the use of filler materials. The initial size of the lesion had a significant impact on the outcome of cystic lesion enucleation over time. To minimize the risks associated with radiation exposure and expenses, we recommend reducing the frequency of CT imaging follow-ups for patients with small initial cavity sizes (ranging from 212.54 to 1569.60 mm3).

[Treatment tactics for patients with retention cysts, odontogenic cysts, mucocele and other pathologies of the maxillary sinuses as preparation for a sinus lift]. / Lechebnaya taktika v otnoshenii retentsionnykh kist, odontogennykh kist, mukotsele i drugikh zabolevanii verkhnechelyustnoi pazukhi pri podgotovke k sinus-liftingu.

OBJECTIVE: The aim the studi. Differential diagnosis of retention cysts of the maxillary sinus with odontogenic cysts, acute and chronic sinusitis, aspergillosis, and mucocele in preparation for sinus-lifting surgery. MATERIAL AND METHODS: The analysis of the case histories of 265 patients aged 18-65 years of both sexes who were treated at the dental clinic «Rudenta Family¼ from 2016 to 2021 was carried out. On the basis of clinical symptoms and data of cone-beam computed tomography (CBCT), a description of the pathologies of HPV is given for the purpose of differential diagnosis and correct interdisciplinary interaction with ENT doctors for the purpose of dental implantation in the lateral parts of the upper jaw. RESULTS: In 90 (out of 265) patients (34%), a change in the condition of the maxillary sinus mucosa was detected. 18 patients (7%) for preoperative preparation were sent to the ENT department of the FSBI «CCB with polyclinic¼ of the UDP of the Russian Federation with diagnoses: chronic maxillary sinusitis of various etiologies and mucocele. In this group of patients, sinus lifting followed by dental implantation was performed 6 months after endoscopic maxillofacial surgery under the control of CBCT. Retention cyst Retention cysts of the maxillary sinus were of different sizes in 62 (23.4%) patients and, depending on the size and localization of the sinus-lifting was performed with simultaneous removal of the cyst, or without removal of the cyst. CONCLUSION: Retention cysts do not need to be removed as a preoperative preparation for sinus lifting. In the case of large sizes and difficulty in peeling the Schneider membrane, retention cysts are removed by a dental surgeon during antral augmentation as one of the stages of the operation. In such pathologies as odontogenic cyst, acute and chronic sinusitis, aspergillosis, mucocele, interdisciplinary interaction of ENT doctor and dentist is necessary. Differential diagnosis of maxillary snus pathology is carried out on the basis of clinical data and a picture of cone-beam computed tomography.

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.

Consequences of Decompression Treatment With a Special-Made Appliance of Nonsyndromic Odontogenic Cysts in Children.

PURPOSE: Odontogenic cysts can cause changes in bone structure. The purpose of this study is to evaluate the change in bone healing before and after decompression of nonsyndromic odontogenic cysts in children. METHODS: A retrospective cohort study was performed including children diagnosed with nonsyndromic odontogenic cysts between January 2016 and December 2020. Study variables included the measurement times (baseline: T0, 1-month postoperative: T1, and end treatment: T2), measurement regions (middle cyst and control area), maxilla, and mandible. The primary and secondary outcome variables were fractal dimension (FD), treatment time, and cyst volume, respectively. Bone healing was evaluated using the fractal analysis method, the results of which are expressed as the FD. Data were analyzed by Friedman repeated measures analysis of variance by ranks, the Wilcoxon rank, Mann-Whitney U, and Kruskal-Wallis tests, Spearman correlation analysis, and linear regression model. RESULTS: Twenty-three children (9 girls,14 boys) with a mean age of 9.57 ± 2.02 years were included into the study. A comparison of the measurement regions showed that the middle cyst area (1.279 ± 0.090) had significantly lower FD values than control area before decompression (T0; P < .001). Statistically significant differences were observed in FD values at T0, T1, and T2 (1.279 ± 0.090, 1.311 ± 0.090, and 1.384 ± 0.075) in the middle cyst area (P <. 001). After decompression, no significant difference was found in FD values between the middle cyst (1.384 ± 0.075) and the control area (1.401 ± 0.050). CONCLUSIONS: Decompression resulted in successful bone healing in children with odontogenic cysts. Conservative treatment methods should be preferred due to the continuation of growth and development in pediatric patients.

Decompression of Odontogenic Keratocysts Before Enucleation Reduces the Rate of Recurrence.

BACKGROUND: The purpose of this study was to determine if 2-stage conservative treatment (decompression followed by enucleation) of odontogenic keratocysts reduced the rate of recurrence compared to single-stage conservative treatment. METHODS: This was a pooled cohort study composed of both patients identified at our institution and cases reported in the literature. The primary predictor variable was treatment modality (single versus 2-staged conservative treatment). The outcome variable was the overall recurrence rate. RESULTS: A total of 684 patient cases were included in the final pooled sample. The mean age was 39.80years (range: 7-80 years). The mandible (76.8%) was the most common site, with the rest of the lesions manifesting in the maxilla (23.0%). A total of 58.1% of the lesions were unilocular, whereas the remaining 41.9% were multilocular. Two-stage conservative treatment demonstrated a lower recurrence rate (14.5% versus 22.1%; P = 0.029). CONCLUSIONS: Decompression is known to reduce lesion size and optimize the favorability of conservative treatment. Furthermore, we propose that 2-staged treatment may also be associated with a lower recurrence rate.

A Volumetric and Morphological Analysis of Recurrent Odontogenic Keratocysts by Semiautomatic Segmentation.

PURPOSE: The authors conducted this study to provide morphological and volumetric data of recurrent odontogenic keratocysts of the upper and lower jaw to emphasize risk factors in accordance with their radiological appearance and guide clinical decisions for jeopardized patients. METHODS: By applying the open-source software "ITK-Snap" on cone-beam computed tomography images, volumetric measurements of histopathologically diagnosed recurrent odontogenic keratocysts could be performed. For statistical investigations, descriptive statistics and independent Student t test were performed. The intraclass correlation coefficient was used to assess intra- and inter-rater reliabilities. P values P  < 0.05 were considered significant. RESULTS: Forty patients (24 male and 16 female) were included in this study. Recurrent odontogenic keratocysts had a mean maximum diameter of 28.91 mm ± 12.00 mm and a mean volume of 4.48 cm3 ±â€Š4.29 cm3. According to morphology, irregular shape (P = 0.001; P = 0.005), unclear margin (P = 0.001; P = 0.001), multilocular morphology (P = 0.001; P = 0.001), and cortical bone exceedance (P = 0.001; P = 0.007) are statistically significantly associated with a larger cyst diameter and volume. Furthermore, significant differences by diameter and volume could be shown between patients with and without iliac crest graft reconstruction (P = 0.001; P = 0.001). CONCLUSIONS: Volumetric analysis reveals that recurrent odontogenic keratocysts show large diametric and volumetric extension that leads to complex reconstruction by iliac crest grafts, adding an argument that special attention should be paid to this entity and its recurrence. in case of difficult histopathological examination, lesions with irregular shape and margin, multilocular morphology, cortical bone exceedance, and clinically visible symptoms should be considered for close morphological and volumetric clinico- radiological follow-up.

Odontogenic Keratocyst in the Masseter Muscle.

ABSTRACT: Odontogenic keratocyst (OKC) arising from purely soft tissue other than the mucosa covering the jawbone is rare. A 57- year-old Korean female patient presented with a lump on her right cheek, which had been suspected as a fibrotic mass on the buccinator muscle by the local clinic. Magnetic resonance imaging showed an ovoid mass in the buccal space just before the right ramus with an enhancing component in the marginal area, and the interior of the mass revealed a fluid signal. Histopathologically, the lesion showed the typical features of OKC and the cyst wall contained some daughter cysts and the minor salivary gland, muscle, and fat tissues. The authors report a very unique case of OKC arising in the masseter muscle.

Mandibular Buccal Bifurcation Cyst: Report of Two Cases.

Mandibular buccal bifurcation cyst is a rare inflammatory odontogenic cyst. We reported two cases who complained of painful swelling of extraoral soft tissue. Intraoral examination revealed the partially erupted mandibular first molar. Cone beam computed tomography showed a well-defined cystic lesion surrounding the first molar. Histopathologic images showed the cyst wall was infiltrated by a large number of plasma cells, neutrophils and eosinophils, and lined with a thin layer of non-keratinized stratified squamous epithelium. Finally, the two patients were diagnosed as mandibular buccal bifurcation cyst and treated with cyst enucleation and curettage.

Recurrent odontogenic keratocyst with orbital invasion.

Odontogenic keratocysts (OKCs) are aggressive lesions that have been variously classified as neoplasms or cysts according to the World Health Organisation (WHO). They can be challenging to surgically remove and the cysts can exhibit locally aggressive behaviour if incompletely excised. We describe a case of recurrent OKC invading the orbit requiring multidisciplinary approach for extended surgical excision, and review the current literature regarding this condition.

Management of radicular cyst associated with primary teeth using decompression: a retrospective study.

BACKGROUND: Radicular cysts arising from primary teeth are rare. Enucleation and marsupialization or decompression are treatment approach to odontogenic cysts. Decompression known to achieve good results in various cysts is widely used in clinic. This study aims to evaluate the efficiency of decompression in reducing radicular cysts associated with primary teeth in children. METHODS: Cases of radicular cysts associated with primary teeth treated by decompression were reviewed in the present study. Clinical information and radiologic data of pre and post decompression were measured and analyzed. RESULTS: Twenty-three patients treated for 25 cysts were included. All lesions with mean initial area 3.66 ± 2.00 cm2 were reduced after decompression time ranging 2 to 10 months. Mean rate of reduction was 0.77 ± 0.44 cm2/mo and large lesions (> 3.5 cm2) had a significantly higher reduction rate compared to smaller ones (< 3.5 cm2) (P < 0.00). All effected succedaneous teeth erupted after treatment at follow-up while 12 (46%) of them had root development problems. CONCLUSIONS: Decompression represents superiority as an effective and less invasive treatment in radicular cysts associated with primary teeth. TRIAL REGISTRATION: This study was retrospectively registered in the Ethics Committee of Ninth People's Hospital Affiliated with Shanghai JiaoTong University School of Medicine (No.SH9H-2022-T158-1).

Investigation of the effects of marsupialization on histomorphological and immunohistochemical markers of odontogenic keratocysts.

Background: Despite its extensive bone resorption and high recurrence rate, marsupialization is the preferred option in the treatment of odontogenic keratocysts (OKCs). Aim: We aimed to assess the effect of marsupialization on histomorphological and biochemical markers of OKCs. Materials and Methods: The study is conducted on 48 paraffin blocks of 24 OKC cases between the years 2012 to 2018. The main clinical, radiographic, and histomorphometric measurements were recorded. Immunohistochemical staining with E-cadherin, Ki67, IL1α, TNFα, Slug, and Snail were performed and compared for pre-marsupialization and post-marsupialization values. Results: OKCs mostly located in the mandibular posterior region. The mean marsupialization period was 8.8 ± 6.5 (3-25) months. The mean radiographic size of OKC (57.1 ± 53.5 mm) was significantly reduced after marsupialization (22.6 ± 19.9 mm, P = 0.002). Histologically, significantly increased thickness of the OKC epithelium (p = 0.002) and collagen production (p = 0.034) was detected after marsupialization. The post-marsupialization group showed positive correlation of inflammation score to both TNFα (r: 0.69, P < 0.001) and IL-1α (r: 0.58, P = 0.008) expressions in connective tissue. Among immunohistochemical parameters, only Slug expression was significantly higher after marsupialization (p = 0.019). Conclusion: Our study suggests that increased Slug expression may enable the second surgery by increasing fibrosis in the cyst wall.

Traumatic bone cyst in the mandibular ramus - A diagnostic dilemma.

Traumatic bone cysts (TBCs) are uncommon, nonneoplastic lesions occurring more commonly in the metaphysis of the long bones and contribute to only 1% of the cysts occurring in the jaws. Seen more commonly in the mandible between the canine and third molar, their occurrence in the ramus-condyle region is very rare. The radiographic appearance of this lesion is like odontogenic keratocyst (OKC) or ameloblastoma and, therefore, extremely challenging to diagnose. Misdiagnosis often results in aggressive treatment for an otherwise innocuous entity. The purpose of this article is to encourage the surgeon to consider the possibility of a TBC when encountering asymptomatic large lytic lesions in the ramus of the mandible especially in younger individuals to avert an extensive radical surgery.

Glandular Odontogenic Cyst-A Case Series.

The glandular odontogenic cyst (GOC) is an uncommon jawbone cyst with a challenging diagnosis because of the presence of several clinical and histopathologic overlaps with other odontogenic lesions and central mucoepidermoid carcinoma. To date, less than 200 cases of GOC have been published in the literature with reliable clinical and histopathologic information. Furthermore, the lack of a well-documented GOC case series impairs a more detailed understanding about the biological behavior and appropriate management of the lesion. Therefore, in this study, we report 3 well-documented cases of GOC in the literature. In one of the cases, the incisional biopsy was misdiagnosed as a dentigerous cyst, and the lesion recurred. Therefore, we also discuss key points regarding the diagnosis and treatment of GOC.

Modified Carnoy's Compared to Carnoy's Solution Is Equally Effective in Preventing Recurrence of Odontogenic Keratocysts.

PURPOSE: Carnoy's solution (CS), the gold standard for adjunctive chemical cautery in treatment of odontogenic keratocysts (OKCs), has been banned for 7 years, leading to substitution with the non-chloroform containing modified Carnoy's solution (MC) without data to support its effectiveness. We performed this study to compare the earlier data with CS to the more current outcomes with MC. METHODS: A retrospective cohort study was conducted on patients diagnosed with OKC and treated by a single surgeon (GHB) with enucleation and curettage (EC), peripheral ostectomy, and application of CS or MC. The primary predictor variables were use of CS or MC. The primary outcome variables were recurrence (yes vs. no) and time to recurrence. Secondary variables included demographics, anatomic location, and whether teeth adjacent to the lesion were extracted. Statistical analyses included chi-squared test/Fisher's exact test, Wilcoxon rank sum test, and Kaplan-Meier curves. RESULTS: 77 patients, 36 patients in the CS group and 41 in the MC group, met inclusion criteria, including at least 1 year of follow-up time. Characteristics of the groups were similar: median age 41.5 and 46, 61% and 71% male gender, 81% and 90% posterior, and 64% and 50% mandibular lesions, respectively. Overall recurrence was similar, 14.29%, with 5 (13.9%) recurrences in the CS group and 6 (14.6%) in the MC group (P = 0.92). Median time to recurrence was 24 months for both groups. Preserving adjacent teeth was associated with a significant increase in recurrence (P = 0.0036). CONCLUSION: Based on this comparison of retrospective outcome data, we found no significant difference in recurrence rate or distribution of time to recurrence between OKCs treated with CS or MC. Aggressiveness of surgical technique is likely a predictive factor in recurrence rate. Future studies should focus on prospective studies and continuing follow-up of the MC group.